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Ayapana triplinervisis a plant species used in traditional medicine and in mystical-religious rituals by traditional communities in the Amazon. The aim of this study are to develop a nano-emulsion containing essential oil fromA.triplinervismorphotypes, to evaluate larvicidal activity againstAedes aegyptiand acute oral toxicity in Swiss albino mice (Mus musculus). The essential oils were extracted by steam dragging, identified by gas chromatography coupled to mass spectrometry, and nano-emulsions were prepared using the low energy method. Phytochemical analyses indicated the major compounds, expressed as area percentage, β-Caryophyllene (45.93%) and Thymohydroquinone Dimethyl Ether (32.93%) in morphotype A; and Thymohydroquinone Dimethyl Ether (84.53%) was found in morphotype B. Morphotype A essential oil nano-emulsion showed a particle size of 101.400 ± 0.971 nm (polydispersity index = 0.124 ± 0.009 and zeta potential = -19.300 ± 0.787 mV). Morphotype B essential oil nano-emulsion had a particle size of 104.567 ± 0.416 nm (polydispersity index = 0.168 ± 0.016 and zeta potential = -27.700 ± 1.307 mV). Histomorphological analyses showed the presence of inflammatory cells in the liver of animals treated with morphotype A essential oil nano-emulsion (MAEON) and morphotype B essential oil nano-emulsion (MBEON). Congestion and the presence of transudate with leukocyte infiltration in the lung of animals treated with MAEON were observed. The nano-emulsions containing essential oils ofA.triplinervismorphotypes showed an effective nanobiotechnological product in the chemical control ofA.aegyptilarvae with minimal toxicological action for non-target mammals.

The present study evaluated the antioxidant, cytotoxic, and larvicidal potential of the essential oil of Tridax procumbens leaves, as well as identified the compounds present in the essential oil. The antioxidant activity was evaluated by the sequestration method of 2,2-diphenyl-1-picrylhydrazyl radical, the cytotoxic activity was evaluated using Artemia salina, the larvicidal bioassay was performed with larvae in the third stage of development of the Aedes aegypti mosquito, and the identification of the metabolites was performed by gas chromatography coupled to the mass spectrometer (GC-MS). The phytochemical oil analysis showed the presence of 20 compounds, with thymol and γ-terpinene being the main ones. It presented antioxidant activity with an IC50 of 194.51 μg mL−1, demonstrating antioxidant activity in the highest concentrations tested. It presented low cytotoxic activity against A. salina, with an LC50 of 1238.67 μg mL−1, demonstrating atoxicity in the concentrations tested. The essential oil presented good larvicidal activity when compared to the literature, with an LC50 = 79.0 μg mL−1 in 24 hours and LC50 of 69.15 μg mL−1 in 48 hours. In this way, it was possible to identify that the essential oil of the leaves of T. procumbens presented potential for the development of a natural larvicide, as well as antioxidant activity satisfactory to the radical DPPH and low toxicity to A. salina.

Ayapana triplinervisis a plant species used in traditional medicine and in mystical-religious rituals by traditional communities in the Amazon. The aim of this study is to evaluate the larvicidal activity againstA. aegyptiof nano-emulsions containing essential oils fromA. triplinervismorphotypes, and acute oral toxicity in non-target organism. Essential oils were identified and nano-emulsions were prepared using the low energy method. The mortality test ofA. aegyptilarvae was performed according to the protocol recommended by the World Health Organization, and toxicity in non-target mammals was performed according to the OECD. Phytochemical analyses indicated the major compounds (E)-Caryophyllene (45.93%) and Thymohydroquinone Dimethyl Ether (32.93%) in morphotype A, and in morphotype B, Thymohydroquinone Dimethyl Ether (84.53%) was found. Morphotype A essential oil nano-emulsion showed a particle size of 101.400 ± 0.971 nm (PdI = 0.124 ± 0.009 and ZP = −19,300 ± 0.787 mV). Morphotype B essential oil nano-emulsion had a particle size of 104.567 ± 0.416 nm (PdI = 0.168 ± 0.016 and ZP = −27,700 ± 1,307 mV). Histomorphological analyses showed the presence of inflammatory cells in the liver of animals treated with morphotype A essential oil nano-emulsion (MAEON) and morphotype B essential oil nano-emulsion (MBEON). Congestion and the presence of transudate with leukocyte infiltration in the lung of animals treated with MAEON were observed. The nano-emulsions containing essential oils ofA. triplinervismorphotypes showed an effective nanobiotechnological product in the chemical control ofA. aegyptilarvae and safe for non-target mammals.

This study evaluated the larvicidal activity of Origanum majorana Linnaeus essential oil, identified the chemical composition, evaluated the antimicrobial, cytotoxic and antioxidant potential. The larvicidal activity was evaluated against larvae of the third stage of Aedes aegypti Linaeus, whereas the chemical composition was identified by gas chromatography coupled to mass spectrometer, the antimicrobial activity was carried out against the bacteria Pseudomonas aeruginosa, Escherichia coli and Staphylococcus auereus, the antioxidant activity was evaluated from of 2.2-diphenyl-1-picryl-hydrazila sequestration and Artemia salina Leach cytotoxicity. Regarding to the results, the larvicidal activity showed that O. majorana L. essential oil caused high mortality in A. aegypti L. larvae. In the chromatographic analysis, the main component found in O. majorana L. essential oil was pulegone (57.05%), followed by the other components verbenone (16.92%), trans-p-menthan-2-one (8.57%), iso-menthone (5.58%), piperitone (2.83%), 3-octanol (2.35%) and isopulegol (1.47%). The antimicrobial activity showed that E. coli and P. aeruginosa bacteria were more sensitive to oil than S. aureus, which was resistant at all concentrations. Essential oil did not present antioxidant activity, but it has high cytotoxic activity against A. salina L.

This study evaluated the larvicidal activity of O. majorana essential oil, identified the chemical composition, evaluated the antimicrobial, cytotoxic and antioxidant potential. The larvicidal activity was evaluated against larvae of the third stage of Aedes aegypti, whereas the chemical composition was identified by gas chromatography coupled to mass spectrometer, the antimicrobial activity was carried out against the bacteria Pseudomonas aeruginosa, Escherichia coli and Staphylococcus auereus, the antioxidant activity was evaluated from of 2.2-diphenyl-1-picryl-hydrazila sequestration and Artemia salina cytotoxicity. Regarding to the results, the larvicidal activity showed that O. majorana essential oil caused high mortality in A. aegypti larvae. In the chromatographic analysis, the main component found in O. majorana essential oil was pulegone (57.05%), followed by the other components verbenone (16.92%), trans-p-menthan-2-one (8.57%), iso-menthone (5.58%), piperitone (2.83%), 3-octanol (2.35%) and isopulegol (1.47%). The antimicrobial activity showed that E. coli and P. aeruginosa bacteria were more sensitive to oil than S. aureus, which was resistant at all concentrations. Essential oil did not present antioxidant activity, but it has high cytotoxic activity against A. salina.

The objective of this work was to collect information on the chemical constituents that demonstrate the larvicidal activity against Aedes aegypti, as well as the antioxidant, microbiological, and cytotoxicity potential of the essential oil of Pogostemon cablin leaves. The chemical characterization was performed by gas chromatography coupled to mass spectrometer (GC-MS). The larvicidal activity was performed according to the protocol of the World Health Organization. The antioxidant activity was evaluated through the sequestering capacity of 2,2-diphenyl-1-picryl-hydrazine (DPPH). As for the microbiological evaluation, the microdilution technique was used, according to the protocol of the Clinical and Laboratory Standards Institute. The cytotoxic activity was evaluated against the larvae of Artemia salina. The species P. cablin presented the following compounds: Patchouli alcohol (33.25%), Seyshellene (6.12%), α-bulnesene (4.11%), Pogostol (6.33%), and Norpatchoulenol (5.72%), which was in synergy with the other substances may significantly potentiate the larvicidal action of the species with the LC50 of 28.43 μg·mL−1. There was no antioxidant activity, however, it presented antimicrobial activity against all bacteria tested with Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of 62.5 μg·mL−1. The species demonstrated significant toxic action with LC50 of 24.25 μg·mL−1. Therefore, the P. cablin species showed significant larvicidal potential, antimicrobial activity, the absence of antioxidant action, and high toxicity.

The present study aimed to evaluate the chemical composition, antioxidant potential, and the cytotoxic and antimicrobial activity of the essential oil of the plant species Tithonia diversifolia (Hemsl) A. Gray. The essential oil obtained was used to identify the chemical compounds present through the techniques of GC-MS and NMR. The antioxidant potential was calculated by the sequestration method of 2,2-diphenyl-1-picrylhydrazyl. For cytotoxic activity, the larval mortality of Artemia salina was evaluated. The main chemical constituents identified are &alpha, pinene (9.9%), Limonene (5.40%), (Z)-&beta, ocimene (4.02%), p-cymen-8-ol (3.0%), Piperitone (11.72%), (E)-nerolidol (3.78%) and Spathulenol (10.8%). In the evaluation of the antimicrobial activity, bacterial strains of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa were used. The results showed that the bacterium E. coli were more susceptible to the presence of the essential oil, presenting minimal inhibitory concentration at the concentrations that were exposed. The essential oil presented antioxidant activity of 54.6% at the concentration of 5 mg&middot, mL&minus, 1 and provided a CI50 of 4.30. It was observed that the essential oil of this species was highly toxic against A. salina lavas, as its cytotoxic activity showed an LC50 of 3.11. Thus, it is concluded that T. diversifolia oils are effective in inhibiting bacterial growth and reducing oxidative stress.

The widespread use of synthetic insecticides to control diseases such as those transmitted by the vector Aedes aegypti (Linnaeus, 1762) has caused widespread resistance to mosquitoes and adverse effects on non-target organisms, such as humans and animals. In this sense, nanotechnology emerges as a strategy for developing new promising insecticidal agents against this vector. Therefore, this research developed a nanoemulsion containing A. suaveolens essential oil, as well as to evaluate the larvicidal activity of the nanoemulsion against A. aegypti and toxicity in non-target mammals. The essential oil was identified by gas chromatography coupled to a mass spectrometer, and the nanoemulsions were prepared using a low-energy method and characterized by photon correlation spectroscopy. The larvicidal activity was evaluated against A. aegypti larvae at the third stage of development, and acute oral toxicity was assessed on mice. The results showed that the main compounds found were Massoialactone (64.79%), Linalool (7.83%), and (E)-β-Farnesene (6.17%). The most stable nanoemulsion was produced in HLB 15 with a particle size of 126.73 ± 0.20 nm, polydispersity index of 0.125 ± 0.01, and zeta potential of −16.25 ± 1.48 mV after 21 days. The LC50 and LC90 values in A. aegypti larvae after 24 h were 54.23 µg.mL−1 and 96.96 µg.mL−1, respectively. After 48 h, the values were LC50 of 46.06 µg.mL−1 and LC90 of 75.31 µg.mL−1. Regarding the acute oral toxicological evaluation, the results showed that despite A. suaveolens essential oil nanoemulsion (NEOAS) having a lethal dose (LD50) greater than 2000 mg.kg−1, histological changes were observed in the kidneys and liver of treated animals. In this sense, this study allowed the development of an ecological and low-cost larvicidal nanoformulation for the control of A. aegypti.

Aeollanthus suaveolens species popularly known as catinga de mulata belongs to the Lamiaceae family. In the Amazon region, it is used in folk medicine for the treatment of gastritis, convulsions of epileptic origin, stomach pain and diarrhea in the form of tea and juice. Essential oils have analgesic, anti-inflammatory, and antimicrobial activity. This study evaluated the chemical composition of the A. suaveolens essential oil, and its cytotoxic, antimicrobial and antioxidant activity on Artemia salina Leach. The plant species was collected in Fazendinha district in the city of Macapa-AP. The essential oil obtained from the process was performed by hydrodistillation and identification of components by gas chromatography coupled with mass spectrometer. The antioxidant activity was evaluated by the kidnapping method of 2,2- diphenyl -1-picrilhidrazil radical, while the cytotoxic activity was assessed using saline A. and the microbiological activity was carried out by microdilution method with Escherichia coli, Salmonella sp. and Staphylococcus aureus bacteria. In a chromatographic analysis, the major constituents found in the essential oil of A. suaveolens were (E) -β-farnesene (37.615%), Linalool (33.375%), α-Santalene (3.255%) and linalyl acetate (3.222%). The results showed that the Escherichia coli and Salmonella sp. bacteria were more susceptible to MIC 50 mg.mL-1 when compared with the Staphylococcus aureus bacterium MIC 100 mg.mL-1. With respect to MBC concentration of 100 mg.mL-1 it was sufficient to inhibit the growth of E. coli. The essential oil did not show antioxidant activity, however, has a high cytotoxic activity against the A. salina, LC50 8.90 μg.mL-1.