Search

The aim of the present study was to synthesize silver (Ag) and titanium dioxide (TiO 2 ) nanoparticles (NPs) using green synthesis from aqueous leaf extract of Euphorbia prostrata as antileishmanial agents and to explore the underlying molecular mechanism of induced cell death. In vitro antileishmanial activity of synthesized NPs was tested against promastigotes of Leishmania donovani by alamarBlue and propidium iodide uptake assays. Antileishmanial activity of synthesized NPs on intracellular amastigotes was assessed by Giemsa staining. The leishmanicidal effect of synthesized Ag NPs was further confirmed by DNA fragmentation assay and by cell cycle progression and transmission electron microscopy (TEM) of the treated parasites. TEM analysis of the synthesized Ag NPs showed a spherical shape with an average size of 12.82 ± 2.50 nm, and in comparison to synthesized TiO 2 NPs, synthesized Ag NPs were found to be most active against Leishmania parasites after 24 h exposure, with 50% inhibitory concentrations (IC 50 ) of 14.94 μg/ml and 3.89 μg/ml in promastigotes and intracellular amastigotes, respectively. A significant increase in G 0 /G 1 phase of the cell cycle with a subsequent decrease in S (synthesis) and G 2 /M phases compared to controls was observed. The growth-inhibitory effect of synthesized Ag NPs was attributed to increased length of S phase. A decreased reactive oxygen species level was also observed, which could be responsible for the caspase-independent shift from apoptosis (G 0 /G 1 arrest) to massive necrosis. High-molecular-weight DNA fragmentation as a positive consequence of necrotic cell death was also visualized. We also report that the unique trypanothione/trypanothione reductase (TR) system of Leishmania cells was significantly inhibited by synthesized Ag NPs. The green-synthesized Ag NPs may provide promising leads for the development of cost-effective and safer alternative treatment against visceral leishmaniasis.

Titanium dioxide nanoparticles (TiO2 NPs) are widely used in paints, printing ink, rubber, paper, cosmetics, sunscreens, car materials, cleaning air products, industrial photocatalytic processes, and decomposing organic matters in wastewater due to their unique physical, chemical, and biological properties. The present study was conducted to assess the antiparasitic efficacies of synthesized TiO2 NPs utilizing leaf aqueous extract of Solanum trilobatum against the adult head louse, Pediculus humanus capitis De Geer (Phthiraptera: Pediculidae); larvae of cattle tick Hyalomma anatolicum (a.) anatolicum Koch (Acari: Ixodidae), and fourth instar larvae of malaria vector Anopheles subpictus Grassi (Diptera: Culicidae). The green synthesized TiO2 NPs were analyzed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy analysis (EDX), and Atomic force microscopy (AFM). XRD analysis of synthesized TiO2 NPs revealed that the particles were in the form of nanocrystals as evidenced by the major peaks at 2? values of 27.52, 36.21, and 54.43 identified as 110, 101, and 211 reflections, respectively. FTIR spectra exhibited a prominent peak at 3,466 cm-1 and showed OH stretching due to the alcoholic group, and the OH group may act as a capping agent. SEM images displayed NPs that were spherical, oval in shape, individual, and some in aggregates with an average size of 70 nm. Characterization of the synthesized TiO2 NPs using AFM offered a three-dimensional visualization and uneven surface morphology. The pediculocidal and acaricidal activities of synthesized TiO2 NPs showed the percent mortality of 31, 42, 63, 82, 100; 36, 44, 67, 89, and 100 at 2, 4, 6, 8, and 10 mg/L, respectively, against P. h. capitis and H. a. anatolicum. The average larval percent mortality of synthesized TiO2 NPs was 38, 47, 66, 79, and 100 at 1, 2, 3, 4, and 5 mg/L, respectively, against A. subpictus. The maximum activity was observed in the aqueous leaf extract of S. trilobatum, TiO(OH)2 solutions (bulk), and synthesized TiO2 NPs with LC50 values of 35.14, 25.85, and 4.34 mg/L; 47.15, 29.78, and 4.11 mg/L; and 28.80, 24.01, and 1.94 mg/L, and r 2 values of 0.982, 0.991, and 0.992; 0.947, 0.987, and 0.997; and 0.965, 0.998 and 0.985, respectively, against P. h. capitis, H. a. anatolicum, and A. subpictus. This study provides the first report on the pediculocidal, acaricidal, and larvicidal activity of synthesized TiO2 NPs. This is an ideal eco-friendly, novel, low-cost, and simple approach to satisfy the requirement of large-scale industrial production bearing the advantage for the control of P. h. capitis, H. a. anatolicum, and A. subpictus. � 2013 Springer-Verlag Berlin Heidelberg.

Malaria caused by the protozoan parasite Plasmodium falciparum , is a major health problem of the developing world. In the present study medicinal plants from Eastern Ghats of South India have been extracted with ethyl acetate and assayed for growth inhibition of asexual erythrocytic stages of chloroquine (CQ)-sensitive (3D7) and (CQ)-resistant (INDO) strains of P . falciparum in culture using the fluorescence-based SYBR Green I assay. Studied extracts showed a spectrum of antiplasmodial activities ranging from (a) very good (IC 50 Cyperus rotundus and Zingiber officinale ); (b) good (IC 50 , >10–15 μg/mL: Ficus religiosa and Murraya koenigii ); (c) moderate (IC 50 > 15–25 μg/mL: Ficus benghalensis ); (d) poor activity (IC 50 > 25–60 μg/mL) and (e) inactive (IC 50 > 60 μg/mL). Resistance indices ranging from 0.78 to 1.28 suggest that some of these extracts had equal promise against the CQ resistant INDO strain of P . falciparum . Cytotoxicity assessment of the extracts against HeLa cell line using MTT assay revealed that the selectivity indices in the range of 3–15 suggesting a good margin of safety.

The present study was on assessment of the anti-parasitic activities of nickel nanoparticles (Ni NPs) against the larvae of cattle ticks Rhipicephalus (Boophilus) microplus and Hyalomma anatolicum (a.) anatolicum (Acari: Ixodidae), fourth instar larvae of Anopheles subpictus, Culex quinquefasciatus and Culex gelidus (Diptera: Culicidae). The metallic Ni NPs were synthesized by polyol process from Ni-hydrazine as precursor and Tween 80 as both the medium and the stabilizing reagent. The synthesized Ni NPs were characterized by Fourier transform infrared (FTIR) spectroscopy analysis which indicated the presence of Ni NPs. Synthesized Ni NPs showed the X-ray diffraction (XRD) peaks at 42.76°, 53.40°, and 76.44°, identified as 1 1 1, 2 2 0, and 2 0 0 reflections, respectively. Scanning electron microscopy (SEM) analysis of the synthesized Ni NPs clearly showed that the Ni NPs were spherical in shape with an average size of 150 nm. The Ni NPs showed maximum activity against the larvae of R. (B.) microplus, H. a. anatolicum, A. subpictus, C. quinquefasciatus and C. gelidus with LC50 values of 10.17, 10.81, 4.93, 5.56 and 4.94 mg/L; r2 values of 0.990, 0.993, 0.992, 0.950 and 0.988 and the efficacy of Ni-hydrazine complexes showed the LC50 values of 20.35, 22.72, 8.29, 9.69 and 7.83 mg/L; r2 values of 0.988, 0.986, 0.989, 0.944 and 0.978, respectively. The findings revealed that synthesized Ni NPs possess excellent larvicidal parasitic activity. To the best of our knowledge, this is the first report on larvicidal activity of blood feeding parasites using synthesized Ni NPs.

The present study was to determine the efficacies of anti-parasitic activities of synthesized silver nanoparticles (Ag NPs) using stem aqueous extract of Cissus quadrangularis against the adult of hematophagous fly, Hippobosca maculata (Diptera: Hippoboscidae), and the larvae of cattle tick, Rhipicephalus (Boophilus) microplus (Acari: Ixodidae). Contact toxicity method was followed to determine the potential of parasitic activity. Twelve milliliters of stem aqueous extract of C. quadrangularis was treated with 88 ml of 1mM silver nitrate (AgNO(3)) solution at room temperature for 30 min and the resulting solution was yellow-brown color indicating the formation extracellular synthesis of Ag NPs. The synthesized Ag NPs were characterized with UV-visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Field emission scanning electron microscope (FESEM) and energy dispersive X-ray (EDX) spectroscopy. The synthesized Ag NPs were recorded by UV-visible spectrum at 420 nm and XRD patterns showed the nanoparticles crystalline in nature. FTIR analysis confirmed that the bioreduction of Ag((+)) ions to Ag NPs were due to the reduction by capping material of plant extract. FESEM image of Ag NPs showed spherical and oval in shape. By using the Bragg's Law and Scherrer's constant, the average mean size of synthesized Ag NPs was 42.46 nm. The spot EDX analysis showed the complete chemical composition of the synthesized Ag NPs. The mortality obtained by the synthesized Ag NPs from the C. quadrangularis was more effective than the aqueous extract of C. quadrangularis and AgNO(3) solution (1 mM). The adulticidal activity was observed in the aqueous extract, AgNO(3) solution and synthesized Ag NPs against the adult of H. maculata with LC(50) values of 37.08, 40.35 and 6.30 mg/L; LC(90) values of 175.46, 192.17 and 18.14 mg/L and r(2) values of 0.970, 0.992 and 0.969, respectively. The maximum efficacy showed in the aqueous extract, AgNO(3) solution and synthesized Ag NPs against the larvae of R. (B.) microplus with LC(50) values of 50.00, 21.72 and 7.61 mg/L; LC(90) values of 205.12, 82.99 and 22.68 mg/L and r(2) values of 0.968, 0.945 and 0.994, respectively. The present study is the first report on antiparasitic activity of the experimental plant extract and synthesized Ag NPs. This is an ideal eco-friendly and inexpensive approach for the control of H. maculata and R. (B.) microplus.

Ethnopharmacological relevance An ethnopharmacological investigation of medicinal plants traditionally used to treat diseases associated with fevers in Dharmapuri region of South India was undertaken. Twenty four plants were identified and evaluated for their in vitro activity against Plasmodium falciparum and assessed for cytotoxicity against HeLa cell line. Aim of the study This antimalarial in vitro study was planned to correlate and validate the traditional usage of medicinal plants against malaria. Materials and methods An ethnobotanical survey was made in Dharmapuri region, Tamil Nadu, India to identify plants used in traditional medicine against fevers. Selected plants were extracted with ethyl acetate and methanol and evaluated for antimalarial activity against erythrocytic stages of chloroquine (CQ)-sensitive 3D7 and CQ-resistant INDO strains of Plasmodium falciparum in culture using the fluorescence-based SYBR Green I assay. Cytotoxicity was determined against HeLa cells using MTT assay. Results Promising antiplasmodial activity was found in Aegle marmelos [leaf methanol extract (ME) (IC50 = 7 μg/mL] and good activities were found in Lantana camara [leaf ethyl acetate extract (EAE) IC50 = 19 μg/mL], Leucas aspera (flower EAE IC50 = 12.5 μg/mL), Momordica charantia (leaf EAE IC50 = 17.5 μg/mL), Phyllanthus amarus (leaf ME IC50 = 15 μg/mL) and Piper nigrum (seed EAE IC50 = 12.5 μg/mL). The leaf ME of Aegle marmelos which showed the highest activity against Plasmodium falciparum elicited low cytotoxicity (therapeutic index > 13). Conclusion These results provide validation for the traditional usage of some medicinal plants against malaria in Dharmapuri region, Tamil Nadu, India.

The purpose of the present study was based on assessments of the antiparasitic activities of synthesized titanium dioxide nanoparticles (TiO2 NPs) utilizing leaf aqueous extract of Catharanthus roseus against the adults of hematophagous fly, Hippobosca maculata Leach (Diptera: Hippoboscidae), and sheep-biting louse, Bovicola ovis Schrank (Phthiraptera: Trichodectidae). The synthesized TiO2 NPs were analyzed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The formation of the TiO2 NPs synthesized from the XRD spectrum compared with the standard confirmed spectrum of titanium particles formed in the present experiments were in the form of nanocrystals, as evidenced by the peaks at 2θ values of 27.43°, 36.03°, and 54.32°. The FTIR spectra of TiO2 NPs exhibited prominent peaks at 714 (Ti–O–O bond), 1,076 (C–N stretch aliphatic amines), 1,172 (C–O stretching vibrations in alcoholic groups), 1,642 (N–H bend bond), and 3,426 (O–H stretching due to alcoholic group). SEM analysis of the synthesized TiO2 NPs clearly showed the clustered and irregular shapes, mostly aggregated and having the size of 25–110 nm. By Bragg’s law and Scherrer’s constant, it is proved that the mean size of synthesized TiO2 NPs was 65 nm. The AFM obviously depicts the formation of the rutile and anatase forms in the TiO2 NPs and also, the surface morphology of the particles is uneven due to the presence of some of the aggregates and individual particles. Adulticidal parasitic activity was observed in varying concentrations of aqueous leaf extract of C. roseus, TiO2 solution, and synthesized TiO2 NPs for 24 h. The maximum parasitic activity was observed in aqueous crude leaf extracts of C. roseus against the adults of H. maculata and B. ovis with LD50 values of 36.17 and 30.35 mg/L, and r 2 values of 0.948 and 0.908, respectively. The highest efficacy was reported in 5 mM TiO2 solution against H. maculata and B. ovis (LD50 = 33.40 and 34.74 mg/L; r 2 = 0.786 and 0.873), respectively, and the maximum activity was observed in the synthesized TiO2 NPs against H. maculata and B. ovis with LD50 values of LD50 = 7.09 and 6.56 mg/L, and r 2 values of 0.880 and 0.913, respectively. This method is considered as an innovative alternative approach to control the hematophagous fly and sheep-biting louse.

The aim of the present study was to investigate the adulticidal and larvicidal activity of dried leaf hexane, ethyl acetate, acetone, and methanol extracts of Nelumbo nucifera, Manilkara zapota, Ipomoea staphylina, and Acalypha indica against the adults of Haemaphysalis bispinosa (Acarina: Ixodidae), hematophagous fly Hippobosca maculata (Diptera: Hippoboscidae), and fourth instar larvae of malaria vector Anopheles subpictus (Diptera: Culicidae). Parasites were exposed to varying concentrations of plant extracts for 24 h. All extracts showed moderate parasitic effects; however, the percent parasitic mortality observed in the crude leaf hexane, ethyl acetate, acetone, and methanol extracts of N. nucifera and M. zapota against H. bispinosa were 80, 74, 72, and 100 and 100, 83, 74, and 91, respectively, and the activity for I. staphylina and A. indica against Hip. maculata were 100, 93, 87, and 66 and 78, 90, 87, and 100 at 2,000 ppm, respectively; the larvicidal activity for the same extracts of I. staphylina against A. subpictus were 76, 82, 84, and 100 at 100 ppm, respectively. The maximum efficacy was observed in the leaf methanol extract of N. nucifera, hexane extract of M. zapota and leaf hexane extract of I. staphylina, and methanol extract of A. indica against the adults of H. bispinosa and Hip. maculata with LC(50) and LC(90) values of 437.14 and 200.81, and 415.14 and 280.72 ppm, 1,927.57 and 703.52 ppm, and 1,647.70 and 829.39 ppm, respectively. The effective larvicidal activity was observed in leaf methanol extract of I. staphylina against A. subpictus with LC(50) and LC(90) values of 10.39 and 37.71 ppm, respectively. Therefore, this study provides the first report on the adulticidal and larvicidal activity of crude solvent extracts. This is an ideal eco-friendly approach for the control of H. bispinosa, Hip. maculata, and the medically important vector A. subpictus.

The purpose of this study is to determine the efficacies of hexane, chloroform, ethyl acetate, acetone, and methanol leaf extracts of Euphorbia hirta L., Psidium guajava L., Ricinus communis L., Solanum trilobatum L., and Tridax procumbens L. against sheep fluke Paramphistomum cervi (Digenea: Paramphistomatidae). All plant extracts showed moderate effects after 24 h of exposure; however, the highest parasite mortality was found in the methanol extract of R. communis. In the present study, bioassay-guided fractionation of methanol extract of R. communis led to the separation and identification of epicatechin as a potential new compound (LC(50) = 31.2; LC(90) = 105.0 ppm) against P. cervi. The structures were established from infrared, ultraviolet, (1)H-nuclear magnetic resonance (NMR), (13)C-NMR, and mass spectral data which confirmed the identification of the compound epicatechin from R. communis. Results of this study showed that the methanol extract of R. communis may be considered as a potent source and epicatechin as a new natural parasitic agent.

The purpose of the present study was to investigate the acaricidal and larvicidal activity against the larvae of Haemaphysalis bispinosa Neumann (Acarina: Ixodidae) and larvae of hematophagous fly Hippobosca maculata Leach (Diptera: Hippoboscidae) and against the fourth-instar larvae of malaria vector, Anopheles stephensi Liston, Japanese encephalitis vector, Culex tritaeniorhynchus Giles (Diptera: Culicidae) of synthesized silver nanoparticles (AgNPs) utilizing aqueous leaf extract from Musa paradisiaca L. (Musaceae). The color of the extract changed to light brown within an hour, and later it changed to dark brown during the 30-min incubation period. AgNPs results were recorded from UV–vis spectrum at 426 nm; Fourier transform infrared (FTIR) analysis confirmed that the bioreduction of Ag+ ions to silver nanoparticles are due to the reduction by capping material of plant extract, X-ray diffraction (XRD) patterns clearly illustrates that the nanoparticles formed in the present synthesis are crystalline in nature and scanning electron microscopy (SEM) support the biosynthesis and characterization of AgNPs with rod in shape and size of 60–150 nm. After reaction, the XRD pattern of AgNPs showed diffraction peaks at 2θ = 34.37°, 38.01°, 44.17°, 66.34° and 77.29° assigned to the (100), (111), (102), (110) and (120) planes, respectively, of a faced centre cubic (fcc) lattice of silver were obtained. For electron microscopic studies, a 25 μl sample was sputter-coated on copper stub, and the images of nanoparticles were studied using scanning electron microscopy. The spot EDX analysis showed the complete chemical composition of the synthesized AgNPs. The parasite larvae were exposed to varying concentrations of aqueous extract of M. paradisiaca and synthesized AgNPs for 24 h. In the present study, the percent mortality of aqueous extract of M. paradisiaca were 82, 71, 46, 29, 11 and 78, 66, 38, 31and 16 observed in the concentrations of 50, 40, 30, 20, 10 mg/l for 24 h against the larvae of H. bispinosa and Hip. maculata, respectively. The maximum efficacy was observed in the aqueous extract of M. paradisiaca against the H. bispinosa, Hip. maculata, and the larvae of A. stephensi, C. tritaeniorhynchus with LC50 values of 28.96, 31.02, 26.32, and 20.10 mg/lm, respectively (r 2 = 0.990, 0.968, 0.974, and 0.979, respectively). The synthesized AgNPs of M. paradisiaca showed the LC50 and r 2 values against H. bispinosa, (1.87 mg/l; 0.963), Hip. maculata (2.02 mg/l; 0.976), and larvae of A. stephensi (1.39; 0.900 mg/l), against C. tritaeniorhynchus (1.63 mg/l; 0.951), respectively. The χ 2 values were significant at p

The emergence and spread of Plasmodium falciparum with resistance to chloroquine (CQ), the safest and cheapest anti-malarial drug, coupled with the increasing cost of alternative drugs especially in developing countries have necessitated the urgent need to tap the potential of plants for novel anti-malarials. The present study investigates the anti-malarial activity of the methanolic extracts of 13 medicinal plants from the Malaiyur and Javadhu hills of South India against blood stage CQ-sensitive (3D7) and CQ-resistant (INDO) strains of P. falciparum in culture using the fluorescence-based SYBR Green I assay. Sorbitol-synchronized parasites were incubated under normal culture conditions at 2% hematocrit and 1% parasitemia in the absence or presence of increasing concentrations of plant extracts. CQ and artemisinin were used as positive controls, while 0.4% DMSO was used as the negative control. The cytotoxic effects of extracts on host cells were assessed by functional assay using HeLa cells cultured in RPMI containing 10% fetal bovine serum, 0.21% sodium bicarbonate and 50 μg/mL gentamycin (complete medium). Plant extracts (bark methanol extracts of Annona squamosa (IC(50), 30 μg/mL), leaf extracts of Ocimum gratissimum (IC(50), 32 μg/mL), Ocimum tenuiflorum (IC(50), 31 μg/mL), Solanum torvum (IC(50), 31 μg/mL) and Justicia procumbens (IC(50), 63 μg/mL), showed moderate activity. The leaf extracts of Aristolochia indica (IC(50), 10 μg/mL), Cassia auriculata (IC(50), 14 μg/mL), Chrysanthemum indicum (IC(50), 20 μg/mL) and Dolichos biflorus (IC(50), 20 μg/mL) showed promising activity and low activity was observed in the flower methanol extracts of A. indica , leaf methanol extract of Catharanthus roseus, and Gymnema sylvestre (IC(50),100 μg/mL). These four extracts exhibited promising IC(50) (μg/mL) of 17, 24, 19 and 24 respectively also against the CQ resistant INDO strain of P. falciparum. The high TC(50) in mammalian cell cytotoxicity assay and the low IC(50) in anti-malarial P. falciparum assay indicates selectivity and good resistance indices in the range of 0.9-1.7 for leaf extracts of A. indica, C. auriculata, C. indicum and D. biflorus suggests that these may serve as anti-malarial agents even in their crude form. These results indicate a possible explanation of the traditional use of some of these medicinal plants against malaria or malaria-like conditions.

The head lice, Pediculus humanus capitis De Geer is an obligate ectoparasite of humans that causes pediculosis capitis, a nuisance for millions of people worldwide, with high prevalence in children. P. humanus capitis has been treated by methods that include the physical remotion of lice, various domestic treatments, and conventional insecticides. None of these methods render complete protection, and there is clear evidence for the evolution of resistance and cross-resistance to conventional insecticides. Non-toxic alternative options are hence needed for head lice treatment and/or prevention, and natural products from plants are good candidates for safer control agents that may provide good anti-lice activity. The plant extracts are good and safe alternatives due to their low toxicity to mammals and easy biodegradability. The present study carried out the pediculocidal activity using the hexane flower bud extract of Syzygium aromaticum (Myrtaceae) against P. humanus capitis examined by direct contact and fumigant toxicity (closed- and open-container methods) bioassay. The chemical composition of S. aromaticum flower bud hexane extract was analyzed by gas chromatography-mass spectrometry. The major chemical constituent (58.79%) of flower bud hexane extract S. aromaticum was identified as chavibetol (5-allyl-2-methoxyphenol) by comparison of mass spectral data and retention times. The hexane extract of S. aromaticum was subjected to gas chromatography analysis, and totally 47 compounds were detected, of which chavibetol was predominantly present. The other major constituents present in the hexane extract were eugenol acetate (phenol,2-methoxy-4-(2-propenyl)-,acetate (15.09%), caryophyllene-(I1) (2,6,10,10-tetramethyl bicyclo [7.2.0] undeca-1,6-diene (13.75%), caryophyllene oxide (3.04%), 2,6,6,9-tetramethyl-1,4,8-cycloundecatriene (1.67%), and copaene (1.33%). The filter paper contact bioassay study showed pronounced pediculicidal activity in the flower bud hexane extract of S. aromaticum. The toxic effect was determined for every five in an 80-min treatment. The result showed percent mortality of 40, 82, and 100 at 5, 10, and 20 min, and the median lethal time (LT(50)) value was 5.83 (0.5 mg/cm(2)); 28, 82, and 100 at 5, 10, and 30 min. (LT(50) = 6.54; 0.25 mg/cm(2)); and 13, 22, 42, 80, and 100 at 5, 10, 20, 40, and 80 min (LT(50) = 18.68; 0.125 mg/cm(2)), respectively. The vapor phase toxicity was tested at 0.25 mg/cm(2). There was a significant difference in pediculicidal activity of S. aromaticum extract against P. humanus capitis between closed- and open-container methods. Adult mortalities were determined for every five in 60 min (closed method) and for every ten in 180 min (open method). The closed method showed the percent mortality was 45, 88, and 100 at 5, 10, and 15 min (LT(50) = 5.39), respectively. In the open-container method, the percent mortality was observed 5, 20, 47, 84, and 100 at 10, 20, 60, 120, and 180 min (LT(50) = 47.91), respectively. The mortality was more effective in the closed containers than in open ones, indicating that the effect of hexane extract was largely a result of action in the vapor phase exhibited fumigant toxicity. Studies of anti-lice activity of extract provide the basis for preliminary conclusions of structure activity relationships; although no clear patterns can yet be drawn. We here attempt to provide a concise compilation of the available information on anti-lice activity of plant extracts and plant-derived compounds.

This no-choice, laboratory study focuses on the feeding of homogeneous powdered, dried, yeast with different plant extracts on mosquito fourth-instar larvae to determine the effects on their mortality. Screening for antifeedant activity of plant extracts with some known medicinal attributes could lead to the discovery of new agents for vector control. The aim of this study was to investigate the antifeedant activity of crude leaf hexane, ethyl acetate, acetone, and methanol extracts of Andrographis lineata Wallich ex Nees. (Acanthaceae), Anisomeles malabarica (L.) Sims. (Lamiaceae), Argemone mexicana L. (Papaveraceae), Aristolochia bracteolata Lam. (Aristolochiaceae), Chrysanthemum indium L. (Asteraceae), Datura metal L. (Solanaceae), Eclipta prostrata L. (Asteraceae), and Sesbania grandiflora (L.) Pers. (Fibaceae) against the fourth-instar larvae of Anopheles subpictus Grassi (Diptera:Culicidae). All the crude extracts showed antifeedant activity in a dose-dependent manner. The plant extracts exhibited a significant antifeedant activity after 24 and 48 h of exposure; however, the highest larval mortality was found in leaf ethyl acetate extract of A. malabarica, acetone extract E. prostrata, methanol extract of A. lineata, C. indium, and S. grandiflora after 24 h (LC(50) = 2.53, 2.82, 2.31, 2.56, and 2.08 mg/mL; LC(90) = 6.40, 8.06, 7.45, 6.98, and 6.20 mg/mL), respectively. The hexane extract of A. lineata, D. metal, methanol extract of A. bracteolata and E. prostrata showed larval mortality after 48 h (LC(50) = 3.05, 2.11, 3.00, and 2.18 mg/mL; LC(90) = 9.06, 6.22, 8.23, and 5.77 mg/mL), respectively. One hundred percent larval mortality was observed in methanol extract of A. lineata, and C. indium after 24 h and the hexane extract of A. lineata and D. metal after 48 h at 10 mg/100 mL. The methanol extracts of A. lineata and C. indium significantly increased larval mortality in comparison to larvae fed with untreated diet. Bacillus thuringiensis subsp. israelensis is widely accepted as a biological pesticide because of its highly specific activity against dipteran insects without adverse effects on other organisms. The feeding deterrent activity of different herbal extracts against the larvae of malaria vector A. subpictus exhibited significantly lower toxicity compare with the bio larvicides, B. thuringiensis. These results suggest that the methanol extract of A. lineata, C. indium, the hexane extract of A. lineata and D. metal have the potential to be used as an ideal eco-friendly approach for the control of the medically important vector A. subpictus. These findings corroborate traditional insecticidal application of selected plants and the results can be extended for the control of mosquitoes.

Objective: To determine the adult emergence inhibition (EI) and adulticidal activities of hexane, chloroform, ethyl acetate, and acetone leaves extracts of Anisomeles malabarica (A. malabarica), Euphorbia hirta (E. hirta), Ocimum basilkum (O. basilicum), Ricinus communis (R. communis), Solanum trilobatum (S. trilobatum), Tridax procumbens (T. procumbens) and seeds of Gloriosa superba (G. superba) against Anopheles stephensi (An. stephensi). Methods: The EI and adulticidal trials were carried out according to World Health Organization (WHO) procedures with slight modifications. The extracts were diluted in dimethyl sulphoxide in order to prepare a serial dilution of test dosages (15.625, 31.25. 62.5, 125, 250, 500 and 1000 μg/mL). Five duplicate trials were carried out for every sample concentration, and for each trial a negative control was included and the mortality was determined after 24 h of exposure. Results: The highest El activity was found in ethyl acetate extracts of A. malabarica, chloroform extracts of O. basilicum, S. trilobatum, acetone of extract of R. communis, T. procumbens, and seed extract of C. superba with EI50 values 143.12, 119.82, 157.87, 139.39, 111.19, and 134.85 μg/mL, and the effective adulticidal activity was observed in chloroform, acetone extracts of C. superba, T. procumbens, R. communis, S. trilobatum and ethyl acetate extract of O. basilicum with LD50 values 120.17, 108.77, 127.22, 163.11, 118.27, and 93.02 μg/mL, respectively. Chi-square value was significant at P＜0.05 level. Conclusions: These results should encourage further efforts to investigate the compounds that might possess good EI and adulticidal properties when isolated in pure form.

The aim of this study was to investigate the larvicidal potential of the hexane, chloroform, ethyl acetate, acetone, methanol, and aqueous leaf extracts of Nelumbo nucifera Gaertn. (Nymphaeaceae) and synthesized silver nanoparticles using aqueous leaf extract against fourth instar larvae of Anopheles subpictus Grassi and Culex quinquefasciatus Say (Diptera: Culicidae). Nanoparticles are being used in many commercial applications. It was found that aqueous silver ions can be reduced by aqueous extract of plant parts to generate extremely stable silver nanoparticles in water. The results recorded from UV-vis spectrum, scanning electron microscopy, X-ray diffraction, and Fourier transform infrared support the biosynthesis and characterization of silver nanoparticles. Larvae were exposed to varying concentrations of plant extracts and synthesized silver nanoparticles for 24 h. All extracts showed moderate larvicidal effects; however, the maximum efficacy was observed in crude methanol, aqueous, and synthesized silver nanoparticles against the larvae of A. subpictus (LC(50) = 8.89, 11.82, and 0.69 ppm; LC(90) = 28.65, 36.06, and 2.15 ppm) and against the larvae of C. quinquefasciatus (LC(50) = 9.51, 13.65, and 1.10 ppm; LC(90) = 28.13, 35.83, and 3.59 ppm), respectively. These results suggest that the leaf methanol, aqueous extracts of N. nucifera, and green synthesis of silver nanoparticles have the potential to be used as an ideal eco-friendly approach for the control of the A. subpictus and C. quinquefasciatus. This is the first report on the mosquito larvicidal activity of the plant extracts and synthesized nanoparticles.

Malaria is a major global public health problem, and the alarming spread of drug resistance and limited number of effective drugs now available underline how important it is to discover new antimalarial compounds. In the present study, ten plants were extracted with ethyl acetate and methanol and tested for their antimalarial activity against chloroquine (CQ)-sensitive (3D7) and CQ-resistant (Dd2 and INDO) strains of Plasmodium falciparum in culture using the fluorescence-based SYBR Green assay. Plant extracts showed moderate to good antiparasitic effects. Promising antiplasmodial activity was found in the extracts from two plants, Phyllanthus emblica leaf 50% inhibitory concentration (IC₅₀) 3D7: 7.25 μg/mL (ethyl acetate extract), 3.125 μg/mL (methanol extract), and Syzygium aromaticum flower bud, IC₅₀ 3D7:13 μg/mL, (ethyl acetate extract) and 6.25 μg/mL (methanol extract). Moderate activity (30-75 μg/mL) was found in the ethyl acetate and methanol extracts of Abrus precatorius (seed) and Gloriosa superba (leaf); leaf ethyl acetate extracts of Annona squamosa and flower of Musa paradisiaca. The above mentioned plant extracts were also found to be active against CQ-resistant strains (Dd2 and INDO). Cytotoxicity study with P. emblica leaf and S. aromaticum flower bud, extracts showed good therapeutic indices. These results demonstrate that leaf ethyl acetate and methanol extracts of P. emblica and flower bud extract of S. aromaticum may serve as antimalarial agents even in their crude form. The isolation of compounds from P. emblica and S. aromaticum seems to be of special interest for further antimalarial studies.

In recent times, there were considerable efforts made to promote the use of environmentally friendly and biodegradable natural insecticides and repellents, particularly from botanical sources. The present study explored the effects of crude leaf ethyl acetate, acetone, and methanol extracts of Aegle marmelos (L.) Correa ex Roxb, Andrographis lineata Wallich ex Nees., Andrographis paniculata (Burm.f.) Wallich ex Nees., Cocculus hirsutus (L.) Diels, Eclipta prostrata L., and Tagetes erecta L. on repellent activity against Culex tritaeniorhynchus Giles. The maximum repellent activity was observed at 500 ppm in methanol extracts of A. marmelos, ethyl acetate extracts of A. lineata, C. hirsutus, and E. prostrata and the mean complete protection time ranged from 120 to 150 min with the different extracts tested. The ethyl acetate extract of A. lineata showed 100% repellency in 120 min; acetone extracts of A. marmelos and C. hirsutus and methanol extract of T. erecta showed complete protection in 90 min at 250 ppm, respectively. These results suggest that the leaf extracts of A. marmelos, A. lineata, and C. hirsutus have the potential to be used as an ideal eco-friendly approach for the control of the C. tritaeniorhynchus. Therefore, this study provides first report on the repellent activity against Japanese encephalitis, C. tritaeniorhynchus of plant extracts from Southern India.

In the current study, in vitro evaluation of crude hexane, chloroform, ethyl acetate, acetone, and methanol extracts of Anisomeles malabarica (L.) R. Br., Gloriosa superba L., Psidium guajava L., Ricinus communis L., and Solanum trilobatum L. exhibited acaricidal and insecticidal activities against the adult of Haemaphysalis bispinosa Neumann (Acarina: Ixodidae) and hematophagous fly Hippobosca maculata Leach (Diptera: Hippoboscidae). All plant extracts showed moderate toxic effect on parasites after 24 h of exposure; the complete inhibition (100%) at the maximum concentration tested (3,000 ppm) was obtained in acetone, methanol, hexane, and chloroform extracts of A. malabarica; methanol, chloroform, and ethyl acetate extracts of G. superba; acetone extract of P. guajava; methanol extract of R. communis; and leaf hexane extract of S. trilobatum; and the lowest inhibition (38%) was recorded for the seed hexane extract of S. trilobatum. The highest parasite dead was found in leaf acetone and methanol extracts of A. malabarica, seed methanol of G. superba, leaf methanol of R. communis against H. bispinosa (LC(50) = 466.15, 719.78, 476.06, and 243.87 ppm; LC(90) = 1,837.96, 2,014.47, 1,904.36, and 2,692.15 ppm), leaf hexane and chloroform extracts of A. malabarica, seed chloroform and ethyl acetate of G. superba, leaf acetone of P. guajava, leaf methanol of R. communis, and leaf hexane extract of S. trilobatum against H. maculata (LC(50) = 495.61, 414.81, 360.02, 479.37, 646.30, 506.13, and 432.77 ppm; LC(90) = 1,914.84, 1,956.59, 1,598.54, 1,636.41, 2,192.73, 1,982.66, and 1,872.33 ppm), respectively. These results suggest that the leaf methanol of R. communis, chloroform extracts of A. malabarica, and chloroform extract of G. superba have the potential to be used as an ideal eco-friendly approach for the control of the H. bispinosa and H. maculata. Therefore, this study provides first report on the parasitic activities of plant extracts from Southern India.

Insecticides of botanical origin may serve as suitable alternative biocontrol techniques in the future. The leaf acetone, ethyl acetate, and methanol extracts of Aegle marmelos (Linn.) Correa ex Roxb, Andrographis lineata Wallich ex Nees, and Cocculus hirsutus (L.) Diels were tested for oviposition-deterrent, ovicidal, and repellent activities against Anopheles subpictus Grassi (Diptera: Culicidae). The percentage of effective oviposition repellency of 92.60 , 93.04, 95.20, 88.26, 92.80, 94.01, 95.77, 96.93, and 92.54 at 500 ppm and the lowest repellency of 47.14, 58.00, 56.52, 64.93, 71.09, 66.42, 50.62, 57.62, and 65.73 at 31.25 ppm in acetone, ethyl acetate, and methanol extracts of Aegle marmelos, Andrographis lineata, and Cocculus hirsutus, respectively. The oviposition activity index (OAI) value of acetone, ethyl acetate, and methanol extracts of Aegle marmelos, Andrographis lineata, and Cocculus hirsutus at 500 ppm were -0.86, -0.87, -0.90, -0.78, -0.87, -0.86, -0.91, -0.94, and -0.86 respectively. The OAI values revealed that the solvent plant extracts have deterrent effect, and they caused a remarkable negative response resulting in oviposition of very few eggs. Mean percent hatchability of the ovicidal activity was observed 24 h after treatment. The percent hatchability was inversely proportional to the concentration of extract and directly proportional to the eggs. Mortality of 100% with ethyl acetate extract of Aegle marmelos, methanol extracts Aegle marmelos, Andrographis lineata, and Cocculus hirsutus were exerted at 1,000 ppm. The maximum repellent activity was observed at 500 ppm in methanol extracts of Aegle marmelos, Andrographis lineata, and ethyl acetate extract of Cocculus hirsutus, and the mean complete protection time ranged from 90 to 120 min with the different extracts tested. These results suggest that the leaf extracts of Aegle marmelos, Andrographis lineata, and Cocculus hirsutus have the potential to be used as an ideal ecofriendly approach for the control of the Anopheles subpictus. Therefore, this study provides first report on the oviposition, ovicidal, and repellent activities against malaria vector, Anopheles subpictus of plant extracts from Southern India.

The present study was based on assessments of the antiparasitic activities to determine the efficacies of acetone, chloroform, ethyl acetate, hexane, and methanol dried leaf, flower, and seed extracts of Achyranthes aspera L., Anisomeles malabarica (L.) R. Br., Gloriosa superba L., Psidium guajava L., Ricinus communis L., and Solanum trilobatum L. tested against the larvae of cattle tick Rhipicephalus (Boophilus) microplus (Canestrini 1887) (Acari: Ixodidae), sheep internal parasite Paramphistomum cervi (Zeder 1790) (Digenea: Paramphistomatidae) at 2,000 ppm and fourth instar larvae of Anopheles subpictus Grassi and Culex tritaeniorhynchus Giles (Diptera: Culicidae) at 1,000 ppm. All plant extracts showed moderate effects after 24 h of exposure; however, the highest parasite mortality was found in the leaf ethyl acetate extract of A. aspera, leaf methanol extract of A. malabarica, flower methanol extract of G. superba, and leaf methanol extract of R. communis against the larvae of R. microplus (LC(50) = 265.33, 95.97, 153.73, and 181.49 ppm; LC(90) = 1,130.18, 393.88, 1,794.25, and 1,829.94 ppm); leaf acetone and chloroform of A. malabarica, flower acetone extract of G. superba, and leaf chloroform and methanol of R. communis against the adult of P. cervi (LC(50) = 108.07, 106.69, 157.61, 69.44, and 168.24 ppm; LC(90) = 521.77, 463.94, 747.02, 256.52, and 809.45 ppm); leaf ethyl acetate extract of A. aspera, leaf chloroform extract of A. malabarica, flower methanol of G. superba, and leaf methanol extract of R. communis against the larvae of A. subpictus (LC(50) = 48.83, 135.36, 106.77, and 102.71 ppm; LC(90) = 225.36, 527.24, 471.90, and 483.04 ppm); and leaf ethyl acetate extract of A. aspera, leaf chloroform extract of A. malabarica, flower methanol extract of G. superba, and leaf methanol extract of R. communis against the larvae of C. tritaeniorhynchus (LC(50) = 68.27, 95.98, 59.51, and 93.94 ppm; LC(90) = 306.88, 393.83, 278.99, and 413.27 ppm), respectively. These results suggest that the leaf ethyl acetate extract of A. aspera, leaf acetone and chloroform extract of A. malabarica, flower methanol extract of G. superba, and leaf methanol extract of R. communis have the potential to be used as an ideal eco-friendly approach for the control of the R. microplus, P. cervi, A. subpictus, and C. tritaeniorhynchus. Therefore, this study provides the first report on the larvae and adult parasitic activity of crude solvent extracts, indigenous plants consumed by the natives in southern India.

The present study explored the effects of crude leaf acetone, chloroform, hot water, methanol, petroleum ether (60-80 degrees C), and water extracts of Calotropis procera (Ait) R. Br., Canna indica L., Hibiscus rosa-sinensis Linn., Ipomoea carnea Jacq. spp. fistulosa Choisy, and Sarcostemma brevistigma Wight that were selected for investigating larvicidal potential against second and fourth instar larvae of the laboratory-reared mosquito species, Culex quinquefasciatus Say, in which the major lymphatic filariasis was used. All plant extracts showed moderate larvicidal effects after 24 h of exposure at 1,000 ppm; however, the highest larval mortality was found in leaf acetone, chloroform, methanol, and petroleum ether of C. indica (LC(50) = 29.62, 59.18, 40.77, and 44.38 ppm; LC(90) = 148.55, 267.87, 165.00, and 171.91 ppm) against second instar larvae (LC(50) = 121.88, 118.25, 69.76, and 56.31 ppm; LC(90) = 624.35, 573.93, 304.27, and 248.24 ppm) and against fourth instar larvae and acetone, hot water, methanol, and petroleum ether extracts of I. carnea (LC(50) = 61.17, 41.07, 41.82, and 39.32 ppm; LC(90) = 252.91, 142.67, 423.76, and 176.39 ppm) against second instar larvae (LC(50) = 145.37, 58.00, 163.81, and 41.75 ppm; LC(90) = 573.30, 181.10, 627.38, and 162.63 ppm) and against fourth instar larvae of C. quinquefasciatus, respectively. These results suggest that the acetone, methanol extracts of C. indica and hot water, petroleum ether extracts of I. carnea have the potential to be used as an ideal eco-friendly approach for the control of the major lymphatic filariasis vector, C. quinquefasciatus.

Mosquito control is facing a threat due to the emergence of resistance to synthetic insecticides. Insecticides of botanical origin may serve as suitable alternative biocontrol techniques in the future. The acetone, chloroform, ethyl acetate, hexane, methanol and petroleum ether extracts of leaf, flower and seed of Cassia auriculata L., Leucas aspera (Willd.), Rhinacanthus nasutus KURZ., Solanum torvum Swartz and Vitex negundo Linn. were tested against fourth instar larvae of malaria vector, Anopheles subpictus Grassi and Japanese encephalitis vector, Culex tritaeniorhynchus Giles (Diptera: Culicidae). The larval mortality was observed after 24 h of exposure. All extracts showed moderate larvicidal effects; however, the highest mortality was found in leaf petroleum ether, flower methanol extracts of C. auriculata, flower methanol extracts of L. aspera and R. nasutus, leaf and seed methanol extracts of S. torvum and leaf hexane extract of V. negundo against the larvae of A. subpictus (LC(50) = 44.21, 44.69, 53.16, 41.07, 35.32, 28.90 and 44.40 ppm; LC(90) = 187.31, 188.29, 233.18, 142.66, 151.60, 121.05 and 192.11 ppm, respectively) and against the larvae of C. tritaeniorhynchus (LC(50) = 69.83, 51.29, 81.24, 71.79, 44.42, 84.47 and 65.35 ppm; LC(90) = 335.26, 245.63, 300.45, 361.83, 185.09, 351.41 and 302.42 ppm, respectively). These results suggest that the leaf petroleum ether, flower methanol extracts of C. auriculata, leaf and seed methanol extracts of S. torvum and leaf hexane extract of V. negundo have the potential to be used as an ideal eco-friendly approach for the control of the A. subpictus and C. tritaeniorhynchus. This is the first report on the mosquito larvicidal activity of the medicinal plant extracts.

Plant extracts, especially botanical insecticides, are currently studied more and more because of the possibility of their use in plant protection. Biological activity of five solvent plant extracts were studied using fourth instar larvae of gram pod borer Helicoverpa armigera (Lepidoptera: Noctuidae), cotton leaf roller Sylepta derogata (Lepidoptera: Pyralidae) and malaria vector Anopheles stephensi (Diptera: Culicidae). Antifeedant and larvicidal activity of acetone, chloroform, ethyl acetate, hexane and methanol peel, leaf and flower extracts of Citrus sinensis, Ocimum canum, Ocimum sanctum and Rhinacanthus nasutus were used in this study. During preliminary screening, the extracts were tested at 1,000 ppm concentration. The larval mortality was observed after 24 h of exposure. All extracts showed moderate larvicidal effects; however, the highest larval mortality was found in peel chloroform extract of C. sinensis, flower methanol extract of O. canum against the larvae of H. armigera (LC50 = 65.10,51.78, LC90 = 277.39 and 218.18 ppm), peel methanol extract of C. sinensis, flower ethyl acetate extract of O. canum and leaf acetone extract of O. sanctum against the larvae of S. derogata (LC50 = 20.27,58.21,36.66, LC90 =113.15,285.70 and 668.02 ppm), peel methanol extract of C. sinensis, leaf and flower ethyl acetate extracts of O. canum against the larvae of A. stephensi (LC50 = 95.74,101.53,28.96, LC90 = 303.20,492.43 and 168.05 ppm), respectively. These results suggest that the chloroform and methanol extract of C. sinensis, ethyl acetate flower extracts of O. canum and acetone extract of O. sanctum have the potential to be used as an ideal eco-friendly approach for the control of the agricultural pests H. armigera, S. derogata and medically important vector A. stephensi.

A screening for larvicidal activity of plant extracts with some known medicinal attributes could lead to the discovery of new agents for pest and vector control. In the backdrop of recent revival of interest in developing plant-based insecticides, the present study was carried out to evaluate the larvicidal properties in three medicinal plants growing abundantly in the region of Chitheri Hills, Dharmapuri District, India. Antifeedant and larvicidal activity of the acetone, chloroform, ethyl acetate, hexane and methanol leaf extracts of Ocimum canum, Ocimum sanctum and Rhinacanthus nasutus were studied against fourth instar larvae of Spodoptera litura (Lepidoptera: Noctuidae), Aedes aegypti and Culex quinquefasciatus (Diptera: Culicidae). The larval mortality was observed after 24 h of exposure. All extracts showed moderate larvicidal effects; however, the highest larval mortality was found in methanol extract of O. canum, R. nasutus and acetone extract of O. sanctum against the larvae of S. litura (LC(50) = 36.46, 68.08 and 68.84 ppm), against A. aegypti (LC(50) = 99.42, 94.43 and 81.56 ppm) and against C. quinquefasciatus (LC(50) = 44.54, 73.40 and 38.30 ppm), respectively. This is an ideal eco-friendly approach for the control of the agricultural pest, S. litura, and medically important vectors, A. aegypti and C. quinquefasciatus.

The acetone, chloroform, ethyl acetate, hexane and methanol leaf extracts of Acalypha indica, Achyranthes aspera, Leucas aspera, Morinda tinctoria and Ocimum sanctum were studied against the early fourth-instar larvae of Aedes aegypti L and Culex quinquefasciatus Say. The larval mortality was observed after 24 h exposure. All extracts showed moderate larvicidal effects; however, the highest larval mortality was found in the ethyl acetate extract of A. aspera. In the present study, bioassay-guided fractionation of A. aspera led to the separation and identification ofa saponin as a potential mosquito larvicidal compound, with LC50 value of 18.20 and 27.24 ppm against A. aegypti and C. quinquefasciatus, respectively. 1H NMR, 13C NMR and mass spectral data confirmed the identification of the active compound. This is the first report on the mosquito larvicidal activity of the saponin from the ethyl acetate extract of A. aspera. This study investigates the potential of crude extracts from commonly used medical herbs in India as an environmentally safe measure to control the vector of dengue and lymphatic filariasis.

Background Development of resistance against the frontline anti-malarial drugs has created an alarming situation, which requires intensive drug discovery to develop new, more effective, affordable and accessible anti-malarial agents. Methods Inspired by their ethnobotanical reputation for being effective against febrile diseases, antiplasmodial potential of ethyl acetate extracts (EAE) and methanol extracts (ME) of 17 medicinal plants collected from the Eastern Ghats of South India and Buchpora, North India were explored against Plasmodium falciparum in vitro using the SYBR Green assay. The results were validated both by confirmation that the fall in fluorescence signal was not due to quenching effects mediated by phytochemical extracts and by Giemsa-stained microscopy. Results Using EAE or ME, promising antiplasmodial activity (IC50Pf3D7 ≤ 20 μg/ml), was seen in Aerva lanata (Whole aerial parts-EAE), Anisomeles malabarica (Leaf-EAE), Anogeissus latifolia (bark-EAE), Cassia alata (leaves-EAE), Glycyrrhiza glabra (root-EAE), Juglans regia (seed-ME), Psidium guajava (leaf-ME and EAE) and Solanum xanthocarpum (Whole aerial parts-EAE). EAEs from leaves of Couroupita guianensis, Euphorbia hirta, Pergularia daemia, Tinospora cordifolia and Tridax procumbens as also ME from Ricinus communis (leaf and seed) showed good antiplasmodial activity (Pf 3D7 IC50 21 - 40 μg/ml). Moderate activity (Pf 3D7 IC50: 40–60 μg/mL) was shown by the leaf EAEs of Cardiospermum halicacabum, Indigofera tinctoria and Ricinus communis while the remaining extracts showed marginal (Pf 3D7 IC50 60 to >100 μg/ml) activities. The promising extracts showed good resistance indices (0.41 – 1.4) against the chloroquine resistant INDO strain of P. falciparum and good selectivity indices (3 to > 22.2) when tested against the HeLa cell line. Conclusion These results provide validity to the traditional medicinal usage of some of these plants and further make a case for activity-guided purification of new pharmacophores against malaria. Electronic supplementary material The online version of this article (doi:10.1186/s12936-015-0564-z) contains supplementary material, which is available to authorized users.

The present study reports a low-cost, new material, eco-friendly and reproducible microbes Bacillus subtilis mediated biosynthesis of TiO2 nanoparticles. Titanium dioxide nanoparticles synthesized from titanium as a precursor, using the bacterium, B. subtilis. The synthesized nanoparticles were characterized and confirmed as TiO2 nanoparticles by using the UV spectroscopy, XRD, FTIR, AFM and SEM analysis. The morphological characteristics were found to be spherical, oval in shape, individual nanoparticles as well as a few aggregates having the size of 66–77 nm. The XRD shows the crystallographic plane of anatase of TiO2 nanoparticles, indicating that nanoparticles structure dominantly correspond to anatase crystalline titanium dioxide.

Applications based on silver nanoparticles (AgNPs) are limited by low temperatures, which cause aggregation of the nanoparticle fraction, leading to reduced efficacy of their products. We aimed at studying AgNP synthesis by psychrotolerant bacteria, its stability under long-term storage, and larvicidal activity under low-temperature conditions. Electron and atomic force microscopy studies revealed that 6 among 22 psychrotolerant isolates synthesized AgNPs with an average diameter of 1.9–14.1 nm. Pseudomonas mandelii SR1 synthesized the least-sized AgNPs with an average diameter of 1.9–10 nm, at temperatures as low as 12 °C without aggregate formation, and the synthesized nanoparticles were stable for up to 19 months of storage period. On studying their larvicidal activity, LC90 (lethal concentration) values against Anopheles subpictus and Culex tritaeniorhynchus larvae were at 31.7 and 35.6 mg/L, respectively. Stable non-aggregate AgNPs at low-temperature conditions from P. mandelii SR1, coupled with their larvicidal property, can be applied to control larval populations in water bodies located in seasonal or permanently cold environments.

The aim of the present investigation was to synthesize silver (Ag) and titanium dioxide (TiO2) nanoparticles (NPs) using the aqueous leaves extract of Euphorbia prostrata as antileishmanial agents and to explore the mechanism of induced cell death. In vitro antileishmanial activity of synthesized NPs was tested against promastigotes of Leishmania donovani by alamar Blue® cell viability reagent and propidium iodide uptake assay. The effective leishmanicidal activity of synthesized Ag NPs was further confirmed by cell cycle progression, externalized phosphatidylserine, DNA fragmentation assay, reactive oxygen species (ROS) level, intracellular non-protein thiols and transmission electron microscopy (TEM) of the treated parasites. TEM analysis of the synthesized Ag NPs and TiO2 NPs showed spherical shape with an average size of 12.82 ± 2.50 and 83.22 ± 1.50 nm, respectively. Ag NPs was found to be the most active agent against Leishmania parasites after 24 h exposure with IC50 value of 14.94 μg/mL. A significant increase in G0/ G1 phase of the cell cycle with subsequent decrease in S and G2/M phases was observed when compared to control and thus confirming the growth inhibitory effect of synthesized Ag NPs. Decreased ROS level was also observed which could be responsible for caspase independent shift from apoptosis (G0/G1 arrest) to massive necrosis. High molecular weight DNA fragmentation as a positive consequence of necrotic cell death was also visualized. In the present study, the unique trypanothione/trypanothione reductase (TR) system of Leishmania cells was significantly inhibited by synthesized Ag NPs was reported. The green synthesized Ag NPs may provide promising leads for the development of cost effective and safer alternative treatment against visceral leishmaniasis.

Malaria is an overwhelming impact in the poorest countries in the world due to their prevalence, virulence and drug resistance ability. Currently, there is inadequate armoury of drugs for the treatment of malaria. This underscores the continuing need for the discovery and development of new effective and safe antimalarial drugs. To evaluate the in vitro and in vivo antimalarial activity of the leaf ethyl acetate extract of Murraya koenigii, bioassay-guided chromatographic fractionation was employed for the isolation and purification of antimalarial compounds. The in vitro antimalarial activity was assayed by the erythrocytic stages of chloroquine-sensitive strain of Plasmodium falciparum (3D7) in culture using the fluorescence-based SYBR Green I assay. The in vivo assay was done by administering mice infected with Plasmodium berghei (NK65) four consecutive daily doses of the extracts through oral route following Peter's 4-day curative standard test. The percentage suppression of parasitaemia was calculated for each dose level by comparing the parasitaemia in untreated control with those of treated mice. Cytotoxicity was determined against HeLa cells using MTT assay. Histopathology was studied in kidney, liver and spleen of isolated compound-treated Swiss albino mice. The leaf crude ethyl acetate extract of M. koenigii showed good in vitro antiplasmodial activity against P. falciparum. The in vivo test of the leaf crude ethyl acetate extract (600 mg/kg) showed reduced malaria parasitaemia by 86.6% against P. berghei in mice. Bioassay-guided fractionation of the leaf ethyl acetate extract of M. koenigii led to the isolation of two purified fractions C3B2 (2.84 g) and C3B4 (1.97 g). The purified fractions C3B2 and C3B4 were found to be active with IC50 values of 10.5 ± 0.8 and 8.25 ± 0.2 μg/mL against P. falciparum, and in vivo activity significantly reduced parasitaemia by 82.6 and 88.2% at 100 mg/kg/body weight on day 4 against P. berghei, respectively. The isolated fractions C3B2 and C3B4 were monitored by thin-layer chromatography until a single spot was obtained with R f values of 0.36 and 0.52, respectively. The pure compounds obtained in the present investigation were subjected to UV-visible spectroscopy, Fourier transformer infrared spectroscopy, 1D and 2D (1)H-Nuclear magnetic resonance (NMR), (13)C NMR, DEPT, COSY and Mass spectral analysis. Based on the spectral analysis, it is concluded that the isolated compounds were myristic acid (C3B2) and β-caryophyllene (C3B4). The cytotoxic effect of myristic acid and β-caryophyllene showed the TC50 values of100 and 80.5 μg/mL, respectively against HeLa cell line. The histopathology study showed that protection against nephrotoxicity of kidney, hepatic damage of liver and splenocytes protection in spleen was achieved with the highest dose tested at 100 mg/kg/body weight. The present study provides evidence of antiplasmodial compounds from M. koenigii and is reported for the first time.

Infections due to protozoa of the genus Leishmania are a major worldwide health problem, with high endemicity in developing countries. The aim of this study was to evaluate the in vitro antileishmanial activity of the acetone and methanol leaf extracts of Anisomeles malabarica , flower of Gloriosa superba , leaf of Ocimum basilicum , leaf and seed of Ricinus communis against promastigotes form of Leishmania donovani . Antiparasitic evaluations of different plant crude extracts were performed on 96 well plates at 37 °C for 24–48 h. Out of the 10 experimental plant extracts tested, the leaf methanol extracts of A . malabarica , and R . communis showed good antileishmanial activity (IC 50 = 126 ± 19.70 and 184 ± 39.33 μg/mL), respectively against promastigotes. Effective antileishmanial activity was observed making these plants as good candidates for isolation of antiprotozoal compounds which could serve as new lead structures for drug development.

In the present work, we describe a low-cost, unreported and simple procedure for biosynthesis of zinc oxide nanoparticles (ZnO NPs) using reproducible bacteria, Aeromonas hydrophila as eco-friendly reducing and capping agent. UV-vis spectroscopy, XRD, FTIR, AFM, NC-AFM and FESEM with EDX analyses were performed to ascertain the formation and characterization of ZnO NPs. The synthesized ZnO NPs were characterized by a peak at 374 nm in the UV-vis spectrum. XRD confirmed the crystalline nature of the nanoparticles and AFM showed the morphology of the nanoparticle to be spherical, oval with an average size of 57.72 nm. Synthesized ZnO NPs showed the XRD peaks at 31.75°, 34.37°, 47.60°, 56.52°, 66.02° and 75.16° were identified as (100), (002), (101), (102), (110), (112) and (202) reflections, respectively. Rietveld analysis to the X-ray data indicated that ZnO NPs have hexagonal unit cell at crystalline level. The size and topological structure of the ZnO NPs was measured by NC-AFM. The morphological characterization of synthesized nanoparticles was analyzed by FESEM and chemical composition by EDX. The antibacterial and antifungal activity was ended with corresponding well diffusion and minimum inhibitory concentration. The maximum zone of inhibition was observed in the ZnO NPs (25 μg/mL) against Pseudomonas aeruginosa (22±1.8 mm) and Aspergillus flavus (19±1.0 mm). Bacteria-mediated ZnO NPs were synthesized and proved to be a good novel antimicrobial material for the first time in this study.

With a greater awareness of the hazards associated with the use of synthetic organic insecticides, there has been an urgent need to explore suitable alternative products for pest control. Musca domestica is ubiquitous insect that has the potential to spread a variety of pathogens to humans and livestock. They are mechanical carriers of more than hundred human and animal intestinal diseases and are responsible for protozoan, bacterial, helminthic, and viral infections. The present work aimed to investigate the feeding deterrent activity of synthesized silver nanoparticles (Ag NPs) using leaf aqueous extract of Manilkara zapota against M. domestica. The synthesized Ag NPs were recorded from UV-vis spectrum at 421 nm and scanning electron microscopy confirm the biosynthesis and characterization of Ag NPs with spherical and oval in shape and size of 70-140 nm. The FTIR analysis of the purified nanoparticles showed the presence of bands 1,079, 1,383, 1,627, 2,353, and 2,648 cm(-1), which were complete synthesis of AgNPs; the XRD pattern of AgNPs showed diffraction peaks at 2θ values of 38.06°, 44.37°, 64.51°, and 77.31° sets of lattice planes were observed (111), (200), (220), and (311) facts of silver, respectively. Adult flies were exposed to different concentrations of the aqueous extract of synthesized Ag NPs, 1 mM silver nitrate (AgNO(3)) solution and aqueous extract of M. zapota for 1, 2, and 3 h; however, AgNPs showed 72% mortality in 1 h, 89% mortality was found in 2 h, and 100% mortality was found in 3 h exposure at the concentration of 10 mg/mL and the leaf aqueous extract showed 32% mortality in 1 h, 48% mortality was found in 2 h, and 83% mortality was found in 3 h exposure at concentration of 50 mg/mL. The most efficient activity was observed in synthesized Ag NPs against M. domestica (LD(50) = 3.64 mg/mL; LD(90) = 7.74 mg/mL), the moderate activity reported in the aqueous extract of M. zapota (LD(50) = 28.35 mg/mL; LD(90) = 89.19 mg/mL) and nil activity were observed in AgNO(3) solution at 3 h exposure time at 10 mg/mL. Dimethyl 2, 2-dichlorovinyl phosphate (DDVP) was used as a positive control and showed the LD(50) value of 3.38 mL/L. These results suggest that the synthesized Ag NPs have the potential to be used as an ideal eco-friendly approach for the control of the adult of M. domestica. This method is considered as a new approach to control sanitary pest. Therefore, this study provides first report on the feeding deterrent activity of synthesized Ag NPs against housefly.

Green nanoparticle synthesis has been achieved using environmentally acceptable plant extract and eco-friendly reducing and capping agents. The present study was based on assessments of the antiparasitic activities to determine the efficacies of synthesized silver nanoparticles (AgNPs) using aqueous leaf extract of Mimosa pudica Gaertn (Mimosaceae) against the larvae of malaria vector, Anopheles subpictus Grassi, filariasis vector Culex quinquefasciatus Say (Diptera: Culicidae), and Rhipicephalus (Boophilus) microplus Canestrini (Acari: Ixodidae). Parasite larvae were exposed to varying concentrations of aqueous extract of M. pudica and synthesized AgNPs for 24 h. AgNPs were rapidly synthesized using the leaf extract of M. pudica and the formation of nanoparticles was observed within 6 h. The results recorded from UV-vis spectrum, Fourier transform infrared, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy support the biosynthesis and characterization of AgNPs. The maximum efficacy was observed in synthesized AgNPs against the larvae of A. subpictus, C. quinquefasciatus, and R. microplus (LC(50) = 13.90, 11.73, and 8.98 mg/L, r (2) = 0.411, 0.286, and 0.479), respectively. This is the first report on antiparasitic activity of the plant extract and synthesized AgNPs.

The source of chemical anthelmintics (levamisole, flubendazole, and thiabendazole) had limited the success of gastrointestinal nematodiasis control in sheep and goats and thus awakened interest in the study of medicinal plant extracts as alternative sources of anthelmintics. The egg hatching and larvicidal effect of indigenous plant extracts were investigated against the sheep parasite, Haemonchus contortus. The purpose of the present study was to assess the efficacy of leaf, bark, and seed ethyl acetate, acetone and methanol extracts of Andrographis paniculata (Burm.f.) Wall. ex Nees., Anisomeles malabarica (L.) R. Br., Annona squamosa L., Datura metel L., and Solanum torvum Swartz were tested against the parasitic nematode of small ruminants H. contortus using egg hatch assay (EHA) and larval development assay (LDA). The assays were run in 24-well cell culture plates at room temperature with five replicates. All plant extracts showed moderate parasitic effects after 48 and exposure for egg hatching and LDA, respectively; however, 100% egg hatching and larvicidal inhibition were found in the methanol extracts of A. paniculata, A. squamosa, D. metel, and S. torvum at 25 mg/ml and the effect was similar to positive control of Albendazole (0.075 mg/ml) and Ivermectin (0.025mg/ml) against H. contortus, respectively. The EHA result showed the ED(50) of methanol extracts of A. paniculata and D. metel, which were 2.90 and 3.08 mg/ml, and in larval development assay, the ED(50) was 4.26 and 3.86 mg/ml, respectively. These effects remain to be confirmed through in vivo studies.

The absence of a vaccine and the rampant resistance to almost all antimalarial drugs have accentuated the urgent need for new antimalarial drugs and drug targets for both prophylaxis and chemotherapy. The aim of the study was to discover effective plant extracts against Plasmodium falciparum. In the present study, the hexane, chloroform, ethyl acetate, acetone, and methanol extracts of Citrus sinensis (peel), Leucas aspera, Ocimum sanctum, Phyllanthus acidus (leaf), Terminalia chebula (seed) were tested for their antimalarial activity against chloroquine (CQ)-sensitive (3D7) strain of P. falciparum which was cultured following the candle-jar method. Antimalarial evaluations of daily replacement of culture medium containing CQ and different plant crude extracts were performed on 96-well plates at 37°C for 24 and 48 h. Parasitemia was determined microscopically on thin-film Giemsa-stained preparations. Plant extracts were tested for their cytotoxicity using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay on human laryngeal cancer cell line (HEp-2) and normal cell line (Vero). Out of the 25 extracts tested, six showed good (IC(50) 4.76-22.76 μg/mL), 15 exhibited moderate (IC(50) 31.42-88.03 μg/mL), while four displayed mild (IC(50) > 100 μg/mL) antiplasmodial activity. The leaf ethyl acetate and methanol extracts of L. aspera; ethyl acetate, acetone, and methanol extracts of P. acidus; and seed acetone extract of T. chebula had good antiplasmodial activity (IC(50) = 7.81, 22.76, 9.37, 14.65, 12.68, and 4.76 μg/mL) with selectivity indices 5.43, 2.04, 4.88, 3.35, 3.42, and 9.97 for HEp-2 and >5.79, >2.20, >11.75, >3.41, >3.94, and >7.38 for Vero cells, respectively. These analyses have revealed for the first time that the components present in the solvent extracts of L. aspera, P. acidus, and T. chebula have antiplasmodial activity. The high antiplasmodial activity observed make these plants good candidates for isolation of anti-protozoal compounds which could serve as new lead structures for drug development.

In recent years, use of environment friendly and biodegradable natural insecticides of plant origin have received renewed attention as agents for vector control because they are rich in bioactive chemicals, active against a limited number of species including specific target insects, and biodegradable. The present study was carried out to evaluate the adulticidal, repellent, and larvicidal activity of crude hexane, ethyl acetate, and methanol extracts of eight plants, viz. Aristolochia indica L., Cassia angustifolia Vahl, Diospyros melanoxylon Roxb., Dolichos biflorus L., Gymnema sylvestre (Retz) Schult, Justicia procumbens L., Mimosa pudica L., and Zingiber zerumbet L., were tested against adult and early fourth instar larvae of Culex gelidus Theobald and Culex quinquefasciatus Say (Diptera: Culicidae). The effective adult mortality was observed in methanol extract of A. indica, ethyl acetate extract of D. biflorus, and ethyl acetate and hexane extract of Z. zerumbet against C. gelidus and C. quinquefasciatus (LD(50) =37.75, 78.56, 129.44, 86.13, 80.06, 112.42, 53.83, and 46.61; LD(90) =166.83, 379.14, 521.50, 289.83, 328.18, 455.72, 181.15, and 354.50 ppm, respectively). Complete protections for 150 min were found in hexane and methanol extract of A. indica and Z. zerumbet at 1,000 ppm against mosquito bites. The highest larval mortality was found in the hexane extract of Z. zerumbet, ethyl acetate extract of D. biflorus, and methanol extracts of A. indica against C. gelidus (LC(50) =26.48, 33.02, and 12.47 ppm; LC(90) =127.73, 128.79, and 62.33 ppm) and against C. quinquefasciatus (LC(50) =69.18, 34.76, and 25.60 ppm; LC(90) =324.40, 172.78, and 105.52 ppm), respectively, after 24 h. The plant extracts are potential to be used as an ideal eco-friendly approach for the control of the Japanese encephalitis vector, C. gelidus, and lymphatic filariasis vector, C. quinquefasciatus.

Mosquito control is facing a threat because of the emergence of resistance to synthetic insecticides. Insecticides of botanical origin may serve as suitable alternative biocontrol techniques in the future. The purpose of the present study was to assess the effect of leaf ethyl acetate, acetone and methanol extracts of Aegle marmelos (L.) Correa ex Roxb (Rutaceae), Andrographis lineata Wallich ex Nees. (Acanthaceae), Andrographis paniculata (Burm.f.) Wall. ex Nees. (Acanthaceae), Cocculus hirsutus (L.) Diels (Menispermaceae), Eclipta prostrata L. (Asteraceae) and Tagetes erecta L. (Compositae) on ovicidal and oviposition-deterrent activities against Culex tritaeniorhynchus Giles (Diptera: Culicidae). The percentage of egg hatching in methanol extracts of Andrographis lineata, Cocculus hirsutus and T. erecta were 16, 12 and 16 exerted at 500 ppm, respectively. The percentage of effective oviposition repellency was 97.77 at 500 ppm and the lowest repellency was 42.06 at 31.25 ppm in methanol and acetone extracts of Andrographis lineata and Andrographis paniculata, respectively. The oviposition activity index values revealed that the solvent plant extracts have deterrent effect, and they caused a remarkable negative response resulting in oviposition of very few eggs. These results suggest that the leaf solvent plant extracts have the potential to be used as an ideal ecofriendly approach for the control of the Culex tritaeniorhynchus.

The rapid development of anthelmintic resistance, associated with the high cost of the available anthelmintic drugs, has limited the success of gastrointestinal nematodiosis control in sheep and goats and thus created interest in studying medicinal plants as an alternative source of anthelmintics. The aim of this study was carried out to evaluate the anthelmintic activity of the leaves and seed aqueous and hydro-alcoholic extracts of Melia azedarach L. (Meliaceae) were tested for in vitro ovicidal and larvicidal activity against Haemonchus contortus (Strongylida). Both extracts were evaluated at five concentrations: 12.5, 6.2, 3.12, 1.56, and 0.78 mg/ml. The leaves aqueous and hydro-alcoholic extracts inhibited 99.4% and 100% of the egg hatching and 100% of larval development at 12.5 mg/ml, respectively. In a similar way, the leaves hydro-alcoholic extract was the most active on egg inhibition (ED (50) = 1.97 and ED ( 90 ) = 5.05 mg/ml), leaves and seed aqueous and hydro-alcoholic extracts showed the best inhibition of larval development (ED ( 50 ) = 3.01, 2.43, 3.17, 2.40, and ED ( 90 ) = 10.53, 8.14, 11.94, and 8.19 mg/ml), respectively. These results suggest that utilization of M. azedarach extracts is useful in the control of H. contortus.

The purpose of the present study was to assess the effect of leaf hexane and chloroform extracts of Aegle marmelos, Andrographis lineata, Andrographis paniculata, Cocculus hirsutus, Eclipta prostrata, and Tagetes erecta on repellent, ovicidal, and oviposition-deterrent activities against Culex tritaeniorhynchus Giles (Diptera: Culicidae). The repellent action of the plant extracts tested varied depending on the plant species, part, solvent used in extraction, and the extract dose. The hexane extract of A. paniculata was more effective in exhibiting the repellent action against the mosquito as compared with A. lineata extract. Complete protections for 150 min were found in hexane extract of A. paniculata at 500 ppm against mosquito bites. Mean percent hatchability of the ovicidal activity was observed 24 h after treatment. The percent hatchability was inversely proportional to the concentration of extract and directly proportional to the eggs. No hatchability was observed with hexane, and chloroform extracts of A. lineata, A. paniculata, and hexane extract of T. erecta were exerted at 1,000 ppm. The percentage of effective oviposition repellency were 95.90, 94.75, 95.04, 90.58, 87.93, 87.14, 94.82, 95.71, 92.26, 90.58, 83.35, and 78.16 at 500 ppm, and the lowest repellency was 69.93, 53.06, 64.81, 70.06, 51.82, 54.54, 48.31, 66.71, 68.82, 61.85, 34.84, and 39.53 at 31.25 ppm in hexane and chloroform extracts of A. marmelos, A. lineata, A. paniculata, C. hirsutus, E. prostrata, and T. erecta, respectively. The oviposition activity index values revealed that the solvent plant extracts have deterrent effect, and they caused a remarkable negative response resulting in oviposition of very few eggs. These results clearly reveal that the hexane extracts of A. marmelos and A. paniculata served as a potential repellent, ovicidal, and oviposition deterrent against Japanese encephalitis vector, C. tritaeniorhynchus.

The adulticidal and larvicidal effect of indigenous plant extracts were investigated against the adult cattle tick Haemaphysalis bispinosa Neumann, 1897 (Acarina: Ixodidae), sheep fluke Paramphistomum cervi Zeder, 1790 (Digenea: Paramphistomatidae), fourth instar larvae of malaria vector, Anopheles subpictus Grassi and Japanese encephalitis vector, Culex tritaeniorhynchus Giles (Diptera: Culicidae). The aim of this study was to evaluate the toxic effect of leaf hexane, chloroform, ethyl acetate, acetone and methanol extracts of Annona squamosa L., Centella asiatica (L.) Urban, Gloriosa superba L., Mukia maderaspatensis (L.) M.Roem, Pergularia daemia (Forsk.) Chiov. and Phyllanthus emblica L. were exposed to different concentrations. All plant extracts showed moderate toxic effect on parasites after 24h of exposure; however, the highest mortality was found in leaf hexane extract of A. squamosa, methanol extracts of G. superba and P. emblica against H. bispinosa (LC(50)=145.39, 225.57 and 256.08ppm); methanol extracts of C. asiatica, G. superba, P. daemia and P. emblica against P. cervi (LC(50)=77.61, 60.16, 59.61, and 60.60ppm); acetone, ethyl acetate extracts of A. squamosa, methanol extract of C. asiatica, acetone extracts of G. superba, ethyl acetate, hexane and methanol extracts of P. daemia against A. subpictus (LC(50)=17.48, 18.60, 26.62, 18.43, 34.06, 13.63, and 50.39ppm); and chloroform, ethyl acetate extracts of A. squamosa, ethyl acetate extract of P. daemia, ethyl acetate and methanol extracts of P. emblica against C. tritaeniorhynchus (LC(50)=63.81, 60.01, 31.94, 69.09, and 54.82ppm), respectively. These results demonstrate that methanol extracts of C. asiatica, G. superba, P. daemia and P. emblica extracts may serve as parasites control even in their crude form.

Anopheles subpictus and Culex tritaeniorhynchus have developed resistance to various synthetic insecticides, making its control increasingly difficult. Insecticides of botanical origin may serve as suitable alternative biocontrol techniques in the future. The leaf acetone, chloroform, ethyl acetate, hexane, and methanol extracts of Aegle marmelos (Linn.) Correa ex Roxb, Andrographis lineata Wallich ex Nees., Andrographis paniculata (Burm.f.) Wall. ex Nees., Cocculus hirsutus (L.) Diels, Eclipta prostrata L., and Tagetes erecta L. were tested against fourth-instar larvae of malaria vector, A. subpictus Grassi and Japanese encephalitis vector, C. tritaeniorhynchus Giles (Diptera: Culicidae). All plant extracts showed moderate larvicidal effects after 24 h of exposure at 1,000 ppm; however, the highest larval mortality was found in leaf ethyl acetate of A. marmelos, E. prostrata, hexane, methanol of A. paniculata and C. hirsutus against the larvae of A. subpictus (LC(50) = 167.00, 78.28, 67.24, 142.83 ppm; LC(90) = 588.31, 360.75, 371.91, and 830.01 ppm) and against the larvae of C. tritaeniorhynchus (LC(50) = 99.03, 119.89, 88.50, 105.19 ppm; LC(90) = 479.23, 564.85, 416.39, and 507.86 ppm), respectively. These results suggest that the leaf hexane extract of A. paniculata and ethyl acetate extract of E. prostrata have the potential to be used as an ideal eco-friendly approach for the control of the A. subpictus and C. tritaeniorhynchus. Therefore, this study provides first report on the mosquito larvicidal activity of plant extracts against vectors from Southern India.

The acetone, chloroform, ethyl acetate, hexane and methanol extracts of peel and leaf extracts of Citrus sinensis, Ocimum canum, Ocimum sanctum and Rhinacanthus nasutus were tested against fourth instar larvae of malaria vector, Anopheles subpictus Grassi, Japanese encephalitis vector, Culex tritaeniorhynchus Giles (Diptera: Culicidae) and feeding deterrence to nymphs of cotton pest, Aphis gossypii Glover (Homoptera: Aphididae). The larval and nymph mortality were observed after 24 h of exposure. All extracts showed moderate larvicidal and nymphicidal effects; however, the highest mortality was found in peel chloroform extract of C. sinensis, leaf ethyl acetate extracts of O. canum and O. sanctum and leaf chloroform extract of R. nasutus against the larvae of A. subpictus (LC(50) = 58.25, 88.15, 21.67 and 40.46 ppm; LC(90) = 298.31, 528.70, 98.34 and 267.20 ppm), peel methanol extract of C. sinensis, leaf methanol extract of O. canum, ethyl acetate extracts of O. sanctum and R. nasutus against the larvae of C. tritaeniorhynchus (LC(50) = 38.15, 72.40, 109.12 and 39.32 ppm; LC(90) = 184.67, 268.93, 646.62 and 176.39 ppm), peel hexane extract of C. sinensis, leaf methanol extracts of O. canum and R. nasutus and leaf ethyl acetate extract of O. sanctum against the nymph of A. gossypii (LC(50) = 162.89, 80.99, 73.27 and 130.19 ppm; LC(90) = 595.40, 293.33, 338.74 and 450.90 ppm), respectively. These results suggest that the peel methanol extracts of C. sinensis and O. canum, ethyl acetate leaf extract of O. sanctum and leaf chloroform and ethyl acetate extract of R. nasutus have the potential to be used as an ideal eco-friendly approach for the control of the A. subpictus, C. tritaeniorhynchus and A. gossypii.

This study investigates the larvicidal potential of indigenous plant extracts from commonly used medicinal herbs as an environmentally safe measure to control the filarial vector, Culex quinquefasciatus Say (Diptera: Culicidae). The early fourth-instar larvae of C. quinquefasciatus, reared in the laboratory, were used for larvicidal assay with water, hot water, acetone, chloroform, and methanol leaf, stem-bark, and flower extracts of Acacia arabica Willd. Sans, Cedrus deodara Roxb, Hibiscus rosa-sinensis L., Mangifera indica L., Nerium indicum Mill., Nicotiana tabacum Linn., Pongamia pinnata (L.) Pierre, and Solanum nigrum Linn. All plant extracts showed moderate larvicidal effects after 24 h of exposure at 1,000 ppm; however, the highest larval mortality was found in stem-bark hot water, acetone, and methanol extracts of C. deodara (LC50 = 133.85, 141.60, and 95.19 ppm, LC90 = 583.14, 624.19, and 639.99 ppm) and leaf hot water, acetone, methanol, and chloroform extracts of N. tabacum (LC50 = 76.27, 163.81, 83.38, and 105.85 ppm, LC90 = 334.72, 627.38, 709.51, and 524.39 ppm) against the larvae of C. quinquefasciatus, respectively. This is an ideal ecofriendly approach for the control of lymphatic filariasis vector, C. quinquefasciatus.

The larvicidal activity of a petroleum ether extract of Zingiber officinale Roscoe (Zingiberaceae) was evaluated against Aedes aegypti L. and Culex quinquefasciatus Say (Diptera). Bioassay-guided fractionation led to the isolation of 4-gingerol (1), (6)-dehydrogingerdione (2) and (6)-dihydrogingerdione (3); the latter has not previously been reported from Z. officinale. The structures were established from infrared (IR), ultraviolet (UV), (1)H-nuclear magnetic resonance (NMR), (13)C-NMR and mass spectral data. Following a 24 h exposure, compounds 1-3 exhibited larvicidal activities against fourth instar larvae of A. aegypti (LC(50) 4.25, 9.80, 18.20 ppm) and C. quinquefasciatus (LC50 5.52, 7.66, 27.24 ppm), respectively. The results show that the most effective compound was 4-gingerol.

The larvicidal activity of crude hexane, ethyl acetate, petroleum ether, acetone, and methanol extracts of the leaf and bark of Ficus racemosa (Moraceae) was assayed for their toxicity against the early fourth-instar larvae of Culex quinquefasciatus (Diptera: Culicidae). The larval mortality was observed after 24-h exposure. All extracts showed moderate larvicidal effects; however, the highest larval mortality was found in bark acetone extract of F. racemosa. In the present study, bioassay-guided fractionation of acetone extract led to the separation and identification of a tetracyclic triterpenes derivative; gluanol acetate was isolated and identified as new mosquito larvicidal compound. Gluanol acetate was quite potent against fourth-instar larvae of Aedes aegypti L. (LC(50) 14.55 and LC(90) 64.99 ppm), Anopheles stephensi Liston (LC(50) 28.50 and LC(90) 106.50 ppm) and C. quinquefasciatus Say (LC(50) 41.42 and LC(90) 192.77 ppm). The structure was elucidated from infrared, ultraviolet, (1)H-nuclear magnetic resonance (NMR), (13)C-NMR, and mass spectral data. This is the first report on the mosquito larvicidal activity of the reported compound from F. racemosa.

Mosquitoes have developed resistance to various synthetic insecticides, making its control increasingly difficult. Insecticides of botanical origin may serve as suitable alternative biocontrol techniques in the future. The aim of this study was to evaluate the adult emergence inhibition (EI) and adulticidal activity of the leaf hexane, chloroform, ethyl acetate, acetone, and methanol extracts of Aegle marmelos (Linn.) Correa ex Roxb, Andrographis lineata Wallich ex Nees., Andrographis paniculata (Burm.f.) Wall. ex Nees., Cocculus hirsutus L. Diels, Eclipta prostrata L. and Tagetes erecta L. were tested against japanese encephalitis vector, Culex tritaeniorhynchus Giles (Diptera: Culicidae). All plant extracts showed moderate EI and adulticidal activity effects after 24 h of exposure at 1,000 ppm; however, the highest EI activity was found in leaf methanol extracts of A. marmelos , A. paniculata, T. erecta , and chloroform extract of E. prostrata ( EI50 = 141.94, 214.17, 166.43, and 184.58 ppm; EI90 = 590.26, 882.34, 532.00 and 571.81 ppm); and the effective adulticidal activity was observed in acetone extract of A.marmelos , hexane of A.lineata , ethlyl acetate of A.paniculata , methanol extracts of C.hirsutus , E.prostrata , and T.erecta ( LD50 = 139.05, 251.24, 205.06, 222.10, 166.73, and 232.74 ppm; LD90 = 426.19, 837.09, 813.59, 794.42, 579.43 and 807.41 ppm), respectively against C. tritaeniorhynchus . These results suggest that the leaf methanol extract of C. hirsutus , E . prostrata , and T. erecta have the potential to be used as an ideal eco-friendly approach for the control of the C. tritaeniorhynchus . Therefore, this study provides first report on the mosquito EI and adulticidal activity of plant extracts against a vector.

Objective To assess the acaricidal activity of titanium dioxide nanoparticles (TiO 2 NPs) synthesized from flower aqueous extract of Calotropis gigantea ( C. gigantea ) against the larvae of Rhipicephalus ( Boophilus ) microplus [ R. (B.) microplus ] and the adult of Haemaphysalis bispinosa ( H. bispinosa ). Methods The lyophilized C. gigantea flower aqueous extract of 50 mg was added with 100 mL of TiO(OH) 2 (10 mM) and magnetically stirred for 6 h. Synthesized TiO 2 NPs were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), and Energy dispersive X-ray spectroscopy (EDX). The synthesised TiO 2 NPs were tested against the larvae of R. (B.) microplus and adult of H. bispinosa were exposed to filter paper impregnated method. Results XRD confirmed the crystalline nature of the nanoparticles with the mean size of 10.52 nm. The functional groups for synthesized TiO 2 NPs were 1 405.19, and 1 053.45 cm −1 for -NH 2 bending, primary amines and amides and 1 053.84 and 1 078.45 cm −1 for C-O. SEM micrographs of the synthesized TiO 2 NPs showed the aggregated and spherical in shape. The maximum efficacy was observed in the aqueous flower extract of C. gigantea and synthesized TiO 2 NPs against R. (B.) microplus (LC 50 =24.63 and 5.43 mg/L and r 2 =0.960 and 0.988) and against H. bispinosa (LC 50 = 35.22 and 9.15 mg/L and r 2 = 0.969 and 0.969), respectively. Conclusions The synthesized TiO 2 NPs were highly stable and had significant acaricidal activity against the larvae of R. (B.) microplus and adult of H. bispinosa . This study provides the first report of synthesized TiO 2 NPs and possessed excellent anti-parasitic activity.