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In this study, the phytochemical, phenolic, flavonoid and bioactive compounds were successfully screened from crude extract of Sargassum wightii by LC-MS analysis after NIST interpretation. Bacterial growth inhibition study result was shown with 24 mm zone inhibition at 200 µg/mL concentration against P. aeruginosa. The increased phenolic content was much closed to gallic acid and the range was observed at 250 μg/mL concentration. In addition, flavonoid contents of the algae extract was indicated more significant with rutin at 200 μg/mL. In result, both the phenolic and flavonoid contents of the extract were more correlated with gallic acid and rutin. Further, the total anti-oxidant and DPPH radical scavenging activities were shown increased activity at 200 μg/mL concentrations. Furthermore, the excellent anti-bacterial alteration result was observed at 200 μg/mL concentration by minimum inhibition concentration. Therefore, the result was revealed that the marine algae Sargassum wightii has excellent phytochemical and anti-oxidant activities, and it has improved anti-bacterial activity against P. aeruginosa.

The multi-drug resistant effect of the Gram negative bacteria K. pneumoniae was identified by disc diffusion method using specific UTI panel discs of Kleb 1 HX077 and Kleb 2 HX090 HEXA. Among the multi-drug resistant bacteria, the carbapenem resistant (CR) effect of the K. pneumoniae was screened by specific carbapenem detection antibiotics of HEXA HX066 and HX0103 HEXA by disc diffusion method. In addition, the effective antibiotics were further performed against K. pneumoniae by minimum inhibition concentration method. Further, the carbapenemase genes of VIM 1 and IMP 1 were detected from the isolated strains by multiplex PCR method. Furthermore, the biofilm forming ability of selected carbapenem resistant K. pneumoniae was initially identified by tissue culture plate method and confirmed by exopolysaccharide arrest ability of congo red agar assay. Finally, our result was proved that the identified K. pneumoniae is carbapenemase producing strain, and its virulence was extended with strong biofilm formation.

Urinary tract infections are second most important diseases worldwide due to the increased amount of antibiotic resistant microbes. Among the Gram negative bacteria, P. mirabilis is the dominant biofilm producer in urinary tract infections next to E. coli. Biofilm is a process that produced self-matrix of more virulence pathogens on colloidal surfaces. Based on the above fact, this study was concentrated to inhibit the P. mirabilis biofilm formation by various in-vitro experiments. In the current study, the anti-biofilm effect of essential oils was recovered from the medicinal plant of Solanum nigrum, and confirmed the available essential oils by liquid chromatography-mass spectroscopy analysis. The excellent anti-microbial activity and minimum biofilm inhibition concentration of the essential oils against P. mirabilis was indicated at 200 µg/mL. The absence of viability and altered exopolysaccharide structure of treated cells were showed by biofilm metabolic assay and phenol–sulphuric acid method. The fluorescence differentiation of P. mirabilis treated cells was showed with more damages by confocal laser scanning electron microscope. Further, more morphological changes of essential oils treated cells were differentiated from normal cells by scanning electron microscope. Altogether, the results were reported that the S. nigrum essential oils have anti-biofilm ability.

In this study, the 16S rRNA of the marine endophytic actinomycete was characterized and identified as Nocardiopsis sp. strain DMS 2 (MH900226). Partial purification and spectroscopies data were interpreted and confirmed as 1, 4-diaza-2, 5-dioxo-3-isobutyl bicyclo[4.3.0]nonane. Anti-bacterial activity of the crude extract and partially purified compound were shown highest inhibition activity against biofilm forming K. pneumoniae. Minimum biofilm inhibition concentration of identified compound against K. pneumoniae was exhibited at the concentration of 300 µg/mL. Decreased metabolic activity and modified exopolysaccharide production of biofilm forming cells were observed at 350 µg/mL and 300 µg/mL concentration. At the same biofilm inhibition concentration, the intracellular architecture of the biofilm cells and extracellular shape modifications were clearly viewed by confocal laser scanning electron microscope and scanning electron microscope respectively. All the in-vitro inhibition results and microscopic images were strongly suggested that the identified compound was a potential anti-biofilm agent against tested K. pneumoniae.

The current study was concentrated to detection of anti-cancer compound from marine Streptomyces akiyoshiensis GRG 6 (KY457710) against MCF-7 breast cancer cells. The partial purification of TLC was moved three different active spots. Among the spots, the third spot of the extract was shown excellent anti-cancer properties against MCF-7 human breast cancer cells. The available anti-cancer compounds present in the partially purified extract was confirmed by GC–MS data interpretation. Three fractions of the compounds were purified by preparative HPLC and their respective spectrum was confirmed by analytical HPLC. Active anti-cancer fraction was separately purified by preparative HPLC and the cytotoxicity result was shown with 100 µg/mL concentration. The anti-cancer compound of pyrrolo [1,2-a]pyrazine-1,4-dione, hexahydro-3 was detected by LC-MS analysis after interpretation with GC–MS data. Further, the morphological damages and increased proliferation with more death cells of pyrrolo[1,2-a]pyrazine-1,4-dione, hexahydro-3 treated MCF-7 were observed by phase contrast and fluorescence microscope techniques. Finally, the nuclear condensation and increased necrotic cells of the pyrrolo[1,2-a]pyrazine-1,4-dione, hexahydro-3 treated MCF-7 cells was clearly identified by fluorescence microscope techniques using Hoechst 33,342 stain. Therefore, our result was prove, the pyrrolo[1,2-a]pyrazine-1,4-dione, hexahydro-3 rich Streptomyces akiyoshiensis GRG 6 (KY457710) as a potential anti-cancer agent against MCF-7 breast cancer cells.

The development of antibiotic resistant in K. pneumoniae is an emerging thread worldwide due to the poor antimicrobial drugs. To overcome this issue, researchers are focused on plant material and their essential oils to fight against multi drug resistant bacteria. In this context, the current study was concentrated in medicinal plant of guva leaves and their essential oils to combat multi drug resistant bacterial infections. The essential oils were successfully screened and confirmed by HRLC-MS analysis. The anti-bacterial ability of the compounds were loaded into the chitosan nanoparticles and proved by FT-IR analysis. In addition, the chitosan loaded essential oils morphology was compared with chitosan alone in SEM analysis and suggested that the material was loaded successfully. Further, the anti-bacterial ability of the chitosan loaded essential oils were primarily confirmed by agar well diffusion method. At the 100 µg/mL of lowest concentration of chitosan loaded essential oils, the multi-drug resistant K. pneumoniae was inhibited with 96% and confirmed by minimum inhibition concentration experiment. Hence, all the experiments were proved that the essential oils were successfully loaded into the chitosan nanoparticles, and it has more anti-bacterial activity against multi-drug resistant K. pneumoniae.

In this study, the anti-oxidant and anti-bacterial activity of marine brown algae Turbinaria ornata (T. ornate) extract was purified by soxhlet apparatus method. The invitro studies of total anti-oxidant activity and DPPH hydroxyl scavenging activity assays were suggested that the T. ornata extract has more anti-oxidant activity. Agar well diffusion and minimum inhibition concentration results were exhibited excellent inhibition effect of T. ornata extract against P. aeruginosa at 300 µg/mL concentration. The time-dependent bacterial inhibition assay was also confirmed the 300 µg/mL concentration at 24 h. Further, the increased death cells and extracellular shape alteration results were observed by confocal laser scanning electron microscope and scanning electron microscope. Therefore, our result was suggested that the T. ornata extract as a promising anti-bacterial agent for multi-drug resistant P. aeruginosa.

The Caulerpa taxifolia is excellent marine green algae, which produced enormous bioactive compounds with more biological activities. Also, it is an excellent source for synthesis of Ag NPs with increased bioactivity against various infections. In our study, the marine algae marine algae Caulerpa taxifolia mediated Ag NPs was synthesized effectively. The synthesized Ag NPs was characterized well using UV-spectrometer and X-ray powder diffraction (XRD) and confirmed as synthesized particle was Ag NPs. The available structure of the Ag NPs was morphologically identified by scanning electron microscope (SEM), and exact minimum size, polydispersive spherical shape of the entire Ag NPs structure was confirmed by Transmission electron microscope (TEM). Further, the anti-cancer efficiency of biosynthesized Ag NPs against A549 lung cancer cells was found at 40 µg/mL concentration by cytotoxicity experiment. In addition, the phase contrast images of the result were supported the Ag NPs, which damaged the A549 morphologically clearly. Finally, florescence microscopic images were effectively proved the anti-cancerous effect against A549 lung cancer cells due to the condensed morphology of increased death cells. All the confirmed in-vitro results were clearly stated that the Caulerpa taxifolia mediated Ag NPs has superior anti-cancer agent against A549 lung cancer cells.

Recent years Klebsiella pneumoniae (K. pneumoniae) biofilm formation (BF) is emerging thread worldwide. For tackling this problem, we have chosen Hibiscus rosa-. pneumoniae. The HPLC purified essential oils (EOs sinensis (H. rosa-sinensis) (HRS) to inhibit the BF K) of H. rosa-sinensis was performed against BF K. pneumoniae and showed concentration dependent biofilm inhibition. At the MBIC of EOs (90 µg/ml), the biofilm inhibition was showed at 92% against selected BF K. Pneumoniae. The biofilm metabolic assay, exopolysaccharide quantification and hydrophobicity index variation results exhibited with 88%, 92% and 89% reduction at 90 μg/mL was observed respectively. In addition, the morphological modification of MBIC treated K. pneumoniae was clearly viewed by scanning electron microscope (SEM). Overall, all the invitro experiments result were confirmed that the MBIC of H. rosa-sinensis EOs was very effective against BF K. pneumonia.

Marine sponge alkaloid aaptamine is a promising anti-bacterial and anti-cancer drug against ESBL producing Gram negative bacteria and HepG 2 human liver carcinoma cell line. The antibacterial activity of aaptamine against selected ESBL producing Gram negative bacteria was inhibited at the concentration of 55 µg/mL. At the minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) of 50 µg/mL, the aaptamine was significantly effective against all the ESBL positive uropathogens. Importantly, the inhibition was much high compared to other marine compounds through intracellular damage and morphological modification by confocal laser scanning electron microscope (CLSM) and scanning electron microscope (SEM). Further, the cytotoxic efficacy of aaptamine against HepG 2 cells was showed at 75 µg/mL very effectively and this concentration was indicated as IC50 dose. The morphological and intracellular nuclear damage of aaptamine treated HepG 2 cell was detected by florescence microscope using acridine orange/ethidium bromide (AO/EB) combination and Hoechst 33342 staining assays. The nuclear fragmentation of aaptamine treated HepG 2 cells were confirmed by expression of Caspase-9, Caspase-8, Caspase-3 cleavage, which provide the suggestion for the induction of intrinsic and extrinsic apoptosis pathways. In addition, the western blot analysis of appatamine treated HepG 2 cells also confirmed that the expression genes were damaged and the aaptamine showed dose and time dependent relationship. Hence, our findings suggest, the marine natural compounds aaptamine might be a potential alternative agents for ESBL producing uropathogens and human liver cancer therapy.

The aim of this study is to identify potential antibacterial compounds of endophytic actinomycetes (EA) from marine algae Caulerpa racemosa for inhibit the multi drug resistant (MDR) Gram negative bacteria (GNB) including Eschericia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), Proteus mirabilis (P. mirabilis), Klebsiella pnumonia (K. pnumoniae) and Enterobacter sp., which were confirmed by UTI panel antibiotic discs. Among the 100 EA, five strains were showed better antogonistic activity against all the selected uropathogens. In the ethyl acetate extract, the NMS 5 strains of EA showed excellent anti-bacterial activity against all the MDR uropathogen. Further, the NMS 5 extract was partially purified from thin layar chramatogaraphy (TLC) and spot 3 of TLC crude compound showed 14, 12 mm zone of inhibition against both the uropathogens. In addition, the minimum inhibition concentration (MIC) of crude exhibited the inhibition percentage was 87 and 84 at 120 µg/mL concentration. The MIC was confirmed by minimum bactericidal concentration (MBC) and it was indicated same as MIC. The treated NMS 5 crude compound of P. aeruginosa and K. pneumonia cells were showed more dead cells, intracellular damage and morphological damage with disaggregated cells by confocal laser scanning electron microscope (CLSM) and scanning electron microscope (SEM). Hence, the present study was revealed that the algae derived EA have the potential anti-bacterial metabolites for inhibition of MDR bacteria and it can be applied for various other infections after further purification.

Based on the untreated biofilm formation in urinary tract infections (UTIs), current study was focused on the inhibition of Pseudomonas aeruginosa (P. aeruginosa) biofilm formation using Nerium oleander (N. oleander) essential oils. Initially, the LC-MS analysis of antibacterial potential of hydro distillated N. oleander essential oils was detected by LC-MS analysis. Initially, the antibacterial nature of essential oils was detected by agar well diffusion method against biofilm forming P. aeruginosa. Then, the possible anti-bacterial fractions of the essential oils were purified by preparative HPLC, and confirmed by analytical HPLC peaks. Possible anti-bacterial components of the fractions were merged together and confirmed by agar well diffusion method. Consecutively, the and minimum biofilm inhibition concentration experiment was proved that the concentration of 200 µg/mL of purified essential oils was very effective against P. aeruginosa biofilm formation. The decrease survival rate of the MTT assay result was also supported the minimum biofilm inhibition concentration result. Finally, all the results were more evident; the HPLC purified N. oleander essential oils as a promising anti-biofilm factor against P. aeruginosa biofilm formation.

Recently, marine sponge drug fascaplysin has been found to have the potential to overcome cancer, particularly those of hepatocellular carcinoma. In this study, the decreased cell viability of HepG2 cells treated by fascaplysin was identified by MTT assay at very low IC50 concentration (1 µmolL−1). The morphological evidence of both acridine orange/ethidium bromide (AO/EB) and Hoechst 33342 staining assays confirmed the increased cell death of the treated HepG2 cells and the red nucleus of the cells noticed that the chromatin condensation of apoptosis also occurred at IC50 concentration of fascaflycin. Consequently, the HepG2 cell apoptosis induced by fascaplysin was proved by the translocation of phosphatidylserine exhaustion of DNA fragmentation, the activation of caspase-3, caspase-8 and caspase-9, and poly (ADP-ribose) polymerase cleavage. The results of western blot and quantitative PCR methods suggested that fascaplysin down-regulated the expression of BCL-2, up-regulated expression of p53, increased cleavage of caspase-3, caspase-8 and caspase-9 to activate caspase dependent apoptosis in HCC cells and cleared the induction of G0/G1 cell cycle arrest. Furthermore, fascaplysin inhibited migration and invasion of HepG2 cells by suppressing expression of MMP-2 and MMP-9 were clearly stated, the selected drug was potent anticancer activity against HepG2 cells. Hence, it is concluded in this study that marine sponge derived fascaplysin has the excellent inhibitory ability against HepG2 cancer cells. Keywords: Hepatocellular carcinoma, Fascaplysin, Cytotoxicity IC50 concentration, Western blot

India’s relations with its neighbours in the maritime domain have received less scholarly attention. Those studies that deal with India’s relations with its South Asian neighbours generally touch on political security, socio-cultural and economic issues. The maritime aspect is either ignored or tucked in as a part of other dimensions. The present study attempts to fill the gap in the literature by taking up the case of Sri Lanka. Sri Lanka is chosen as a case, not only because the island state is India’s closest maritime neighbour but also due to the existence of deep interactions between the two countries in diverse fields both at governmental and non-governmental levels. In the maritime domain, in the present context, technically speaking, there is no problem between the two countries. However, the fishermen issue remains one of the issues principally because of the Tamil Nadu factor. Analysing the issue in five phases, the study argues for a ‘comprehensive approach’ for its settlement.1

The ability of a natural stabilizing and reducing agent on the synthesis of silver nanoparticles (Ag NPs) was explored using a rapid and single-pot biological reduction method using Nocardiopsis sp. GRG1 (KT235640) biomass. The UV–visible spectral analysis of Ag NPs was found to show a maximum absorption peak located at a wavelength position of ∼422 nm for initial conformation. The major peaks in the XRD pattern were found to be in excellent agreement with the standard values of metallic Ag NPs. No other peaks of impurity phases were observed. The morphology of Ag NPs was confirmed through TEM observation, demonstrating that the particle size distribution of Ag NPs entrenched in spherical particles is in a range between 20 and 50 nm. AFM analysis further supported the nanosized morphology of the synthesized Ag NPs and allowed quantifying the Ag NPs surface roughness. The synthesized Ag NPs showed significant antibacterial and antibiofilm activity against biofilm positive methicillin-resistant coagulase negative Staphylococci (MR-CoNS), which were isolated from urinary tract infection as determined by spectroscopic methods in the concentration range of 5–60 µg/ml. The inhibition of biofilm formation with coloring stain was morphologically imaged by confocal laser scanning microscopy (CLSM). Morphological alteration of treated bacteria was observed by SEM analysis. The results clearly indicate that these biologically synthesized Ag NPs could provide a safer alternative to conventional antibiofilm agents against uropathogen of MR-CoNS.

The Aegle marmelos essential oils (AMEOs) were loaded on surface of the chitosan nanoparticles (CHs NPs), and it performed against carbapenemase producing K. pneumoniae. The physiochemical characterizations of CHs, CHs NPs and AMEOs-CHs NPs were confirmed by FTIR and powder XRD. The morphological observation, size, shape of the SEM and TEM results confirmed that the AMEOs was successfully coated onto the chitosan surface. Further, the excellent minimum inhibitory activity of AMEOs-CHs NPs against CR K. pneumoniae was observed at 40 μg/mL. The increased death cells, morphological damages, and shape modification were confirmed by confocal laser scanning electron microscope, scanning electron microscope and transmission electron microscope respectively. In addition, the invitro anti-carbapenemase activity, and changed color intensity of AMEOs-CHs treated result confirmed that the AMEOs-CHs has carbapenenemase enzyme degradation ability. Importantly, the fragmented DNA and suppressed VIM 1 and IMP 1 genes expression results were clearly indicated that the AMEOs-CHs was very excellent anti-bacterial material. Finally, the molecular docking results were more supported to the invitro evidences, and proved that the AMEOs-CHs as valuable biomaterials owing to their ability to fight against multi drug resistance bacteria.

In this study, the anti-cancer compound was extracted from Chrysanthemum morifolium (C. morifolium) by soxhlet apparatus method. The available anti-cancer compounds of Chrysanthemum morifolium extract were clearly detected by LC-MS analysis based on the retention time, percentages of height and occupied area. The anti-cancer compounds were separately screened from mixed compounds by NIST Wiley library interpretation. Further, the silver nanoparticle (Ag NPs) was synthesized from C. morifolium extract, and their surface plasmon resonance effect of the extract was scanned by UV–vis spectroscopy at 410 nm. Morphological identification of size and shape of the Ag NPs was confirmed by scanning electron microscope and transmission electron microscope images. Further, the anti-cancer effect of synthesized Ag NPs was exhibited more cytotoxicity effect at the concentration of 200 µg/mL. Furthermore, the morphological damages of A549 cells were clearly confirmed by fluorescence microscope using AO/EB fluorescence stain. Finally, the results were suggested that the biosynthesized Ag NPs has potential anti-cancer agent against A549 lung cancer cells.

Silver nanoparticles (Ag NPs) with anti-bacterial effects against the biofilm-producing bacteria Klebsiella pneumoniae (K. pneumoniae) were synthesized using the marine seaweed Gracilaria corticata (G. corticata). Physiochemical characterization using UV-spectrometer, fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) confirmed that the synthesized material consisted of Ag NPs. Morphological analysis using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) with energy-dispersive X-ray (EDX) analysis confirmed the shape, size, surface morphology, and available chemical composition of the Ag NPs. Furthermore, the rich phenolic and flavonoid content of G. corticata has excellent antioxidant activity, which was confirmed through gas chromatography-mass spectrometry (GC–MS) analysis. The highest antibacterial activity and biofilm reduction (88 %) of Ag NPs treated K. pneumoniae was observed at 50 μg/mL and 100 μg/mL concentrations respectively. The bacterial viability and exopolysaccharide production of K. pneumoniae significantly decreased after treatment with Ag NPs. Morphological alterations and intracellular damage were confirmed by SEM and confocal laser scanning microscopy (CLSM). Finally, the toxicity results showed a 90 % inhibitory effect against Artemiafranciscana (A.franciscana) at 100 μg/mL after 24 h of incubation. Based on our results, we propose that the Ag NPs biosynthesized using seaweed are an eco-friendly and effective bio-medical material, unlike those produced via chemical methods.