Evaluation of Brown and red seaweeds-extracts as a novel larvicidal agent against the deadly human diseases-vectors, Anopheles stephensi, Aedes aegypti and Culex quinquefasciatus.

Infectious diseases such as malaria, dengue, and yellow fever are predominantly transmitted by insect vectors like Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus in tropical regions like India and Africa. In this study, we assessed the larvicidal activity of commonly found seaweeds, including Padina gymnospora, P. pavonica, Gracilaria crassa, Amphiroa fragilissima, and Spatoglossum marginatum, against these mosquito vectors. Our findings indicate that extracts from P. gymnospora Ethyl Acetate (PgEA), P. pavonica Hexane (PpH), and A. fragilissima Ethyl Acetate (AfEA) displayed the highest larval mortality rates for A. stephensi, with LC50 values of 10.51, 12.43, and 6.43 µg/mL, respectively. Additionally, the PgEA extract from P. gymnospora exhibited the highest mortality rate for A. aegypti, with an LC50 of 27.0 µg/mL, while the PgH extract from the same seaweed showed the highest mortality rate for C. quinquefasciatus, with an LC50 of 9.26 µg/mL. Phytochemical analysis of the seaweed extracts revealed the presence of 71 compounds in the solvent extracts. Fourier-transform infrared spectra of the selected seaweeds indicated the presence of functional groups such as alkanes, alcohols, and phenols. Gas chromatography-mass spectrometry analysis of the seaweeds identified major compounds, including hexadecanoic acid in PgEA, tetradecene (e)- in PpEA, octadecanoic acid in GcEA, and 7-hexadecene, (z)-, and trans-7-pentadecene in SmEA.

Biodegradation efficacy of selected marine microalgae against Low-Density Polyethylene (LDPE): An environment friendly green approach.

The present study dealt with the five marine microalgae strains viz., Chloroidium saccharophilum, Picochlorum maculatum, Amphora sp., Hymenomonas globosa and Limnospira indica and their effective degradation ability of Low-Density Polyethylene for the period of 45 days. The incubation of LDPE in microalgae culture has resulted in the maximum weight loss (20.16 ± 0.14 %), higher reduction rate (0.005/day) and lower half-life (138.4 days) in the LDPE treated with P. maculatum. The SEM images of all treated LDPE revealed surface erosion and the ATR-FTIR spectra showed functional group peaks along with new peaks at 1369.35 cm-1, 2332.96 cm-1 and 500-726 cm-1. Carbonyl (Keto, Ester), Vinyl and Internal double bond indices increased significantly in all the treated groups. The crystallinity was decreased (64.13 %) in P. maculatum treated LDPE than the control (71.37 %). Thermogravimetric analysis showed the reduction in thermal stability after biodegradation. This efficient microalgal degradation as a bioremediation technique will reduce the plastic pollution.

Phytochemical profiling and biological activity of Plectranthus amboinicus (Lour.) mediated by various solvent extracts against Aedes aegypti larvae and toxicity evaluation

Objective: To analyze the phytochemical compounds and to investigate the bio-toxic efficacy of various solvent extracts of Plectranthus amboinicus against mosquito larvae activity and lethality on non-targeting organisms. Methods: The methanol, ethyl acetate, hexane, and aqueous extracts of Plectranthus amboinicus were subjected to analyze the mosquitocidal activity against the dengue vector, Aedes aegypti and toxicity assays on zebra fish and brine shrimp. Three replications were performed, and negative control was also maintained. Amongst, ethyl acetate extract of Plectranthus amboinicus was chosen for the determination of bio-active compounds. Results: The mosquitocidal assays of methanol and ethyl acetate extracts of Plectranthus amboinicus showed the maximal activity with minimal concentration against the 4th instar mosquito-larvae of Aedes aegypti through the following lethal concentration (LC50 and LC90) values: 53.36 & 92.51 μg/mL and 13.64 & 86.09 μg/mL, respectively. In addition, the plant extracts showed no toxicity on zebra fish embryo and brine shrimp assays. The gas-chromatography analysis of the ethyl acetate extract of Plectranthus amboinicus revealed the presence of seven different compounds. Among them, PAEA-fraction 60 contained a major active bioactive compound, hexadecanoic acid, methyl ester (270.0). Conclusions: Plectranthus amboinicus possesses mosquitocidal properties and could be used as a potential alternative source for preparing the mosquitocidal agents.

Larvicidal, Histopathological, Antibacterial Activity of Indigenous Fungus Penicillium sp. Against Aedes aegypti L and Culex quinquefasciatus (Say) (Diptera: Culicidae) and Its Acetylcholinesterase Inhibition and Toxicity Assessment of Zebrafish (Danio rerio).

Fungal metabolites are considered to be most efficient tools to overcome the issues related to insecticide resistance and environmental pollution. The present study focus on the evaluation of the mosquito larvicidal efficacy of metabolites of seven indigenous fungal isolates (Penicillium sp. Aspergillus niger, A. flavus, A. parasiticus, Rhizopus sp. Mucor sp. and Aspergillus sp.) on the larvae of Aedes aegypti and Culex quinquefasciatus under the laboratory condition. The preliminary screening of the isolate, Penicillium sp. showed better larvicidal effect when compared to other fungi. The fungus was grown on Potato Dextrose Broth (PDB) in the laboratory (at 25°C) and maintained in the relative humidity (at 76 ± 4% for 15 days). Larvicidal potency of mycelial ethyl acetate extract (MEAE) of Penicillium sp. was performed against 1st to 4th instars larvae of Ae. aegypti and Cx. quinquefasciatus using four different concentrations (100, 200, 300, and 500 µg/ml) that showed better larval mortality values (µg/ml) of LC50 = 6.554, 5.487, 6.874, 6.892, and the LC90 = 11.486, 10.366, 12.879, 13.865 for Ae. aegypti and LC50 = 7.000, 13.943, 18.129, 25.212 and the LC90 = 12.541, 23.761, 30.923, 41.696 for Cx. quinquefasciatus. Exposure of metabolite to larvae resulted in behavior changes i.e., excitation, up and down with aggressive movement, anal papillae biting behavior. Further, the larvae treated with Penicillium sp. metabolite exhibited significant reduction in the levels of acetylcholinesterase. The 4th instar mosquito larvae treated with the 500 µg/ml mycelia extract showed severe histological damages. During the antibacterial analysis of Penicillium sp.- mycelium the maximum growth inhibition zone was recorded in Shigella dysenteriae (31.2 mm) and Klebsiella pneumoniae (31.1 mm) followed by others. In addition, to check the toxicity of Penicillium sp. MEAE against embryos of Zebrafish, a model system, using different concentrations of metabolites (1.0, 0.5, 0.125 mg/ml, 30, 3.0, and 0.5 µg/ml) and life-stage parameters were observed at 124 hpf. Furthermore, the Fourier Transformed Infrared and GCMS spectrum analysis of mycelium reflected several chemical compounds. The outcome of the study clearly shows that Penicillium sp. metabolites could serve as an ideal eco-friendly, single-step and inexpensive source for the control of Ae. aegypti and Cx. quinquefasciatus larvae.

Target and non-target toxicity of fern extracts against mosquito vectors and beneficial aquatic organisms.

Dengue and malaria are significant mosquito-borne diseases that are rapidly spread worldwide, mainly in temperate countries. Pteridophytes were identified to be a significant source of novel mosquitocidal agents. The present research was to explore the eco-friendly larvicides from methanol extracts of ferns, viz., Actiniopteris radiata, Adiantum caudatum, Cheilanthes swartzii, Hemionitis arifolia and Lycopodium clavatum. The larvicidal potential of the extracts screened using larvae of dengue vector Aedes aegypti (III and IV instar) and malarial vector Anopheles stephensi (III and IV instar), showed 10-100% mortality rates. Biosafety assessment was made on embryos of Danio rerio and Artemia nauplii. The phyto-constituents of the methanol extract of A. radiata leaves were identified through gas chromatography-mass spectrometry (GC-MS). Methanolic leaf extracts of A. radiata, A. caudatum and C. swartzii exhibited larvicidal activity against III and IV instar larvae of Ae. aegypti (LC50: 37.47, 74.51 and 152.38 and 67.58, 95.89 and 271.46 ppm) and An. stephensi (LC50: 70.35, 112.12 and 301.05 and 113.83, 175.30 and 315.19 ppm), respectively. The GC-MS of the methanol extract of A. radiata leaves revealed the presence of 7 phyto-components among which, Carbamic acid, phenyl-, (2-Nitrophenyl) methyl ester (1), Benzoic acid, 3- methylbenzoate (2) and 4-(benzylimino)- 1,4-dihydro-1-(p-toluoylmethyl) pyridine (3) were dominant. Biosafety assessment of methanol extract of A. radiata leaves on embryos of Danio rerio (Zebra fish) and Artemia nauplii (micro crustacean) revealed that there were no destructive or teratogenic effects. To conclude, the larvicidal activity and insignificant toxicity to non-target aquatic organisms of A. radiata leaves makes it a potential and environment safe biocontrol agent against dengue and malarial vectors.

Isolation, structural elucidation and antiplasmodial activity of fucosterol compound from brown seaweed, Sargassum linearifolium against malarial parasite Plasmodium falciparum.

The brown seaweed, Sargassum linearifolium (Turner) C. Agardh, 1820 is commonly available along the south-east coast of India. Its compound fucosterol was isolated and confirmed through spectral characterisation and chemical transformation methods. The antiplasmodial effect of the isolated fucosterol was investigated against the 3D7 chloroquine sensitive Plasmodium falciparum strain, parasitaemia percentage was determined at 48 h and morphological change was studied through microscopic examination after Giemsa staining. A perceptible antiplasmodial effect was produced by fucosterol compound against the P. falciparum and positive control, chloroquine with the IC50 values (µg/mL) of 7.48 and 12.81, respectively. Fucosterol showed higher antiplasmodial activity as compared to chloroquine. It is inferred that both the fucosterol and chloroquine could have inhibited the schizont stage of the parasite during the intra-erythrocyte asexual development. The findings underline the usefulness of the seaweed-based fucosterol and further studies are warranted.

Antibacterial efficacy of silver nanoparticles and ethyl acetate's metabolites of the potent halophilic (marine) bacterium, Bacillus cereus A30 on multidrug resistant bacteria.

Bacteria are generally responsible for the prevalence of several diseases and pathogenic bacteria are showing increasing resistance to different antibacterials. During the present study an extremophilic bacterium-A30 isolated from the marine waters was characterized and evaluated against four multi-drug resistant (MDR) pathogens, viz; Methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The sensitivity pattern of the selected pathogens was tested with 31 antibiotics. Among the 47 marine microbial extracts tested on 4-MDR pathogens viz: Methicillin-resistant Staphylococcus aureus (MRSA), E. coli, K. pneumoniae and P. aeruginosa, only our strain A30 strain exhibited highest efficacy. This strain was subsequently subjected to 16S rDNA sequencing which confirmed its allocation as Bacillus cereus. Silver nanoparticle (AgNPs) synthesis and ethyl acetate extraction were performed using the supernatant of B. cereus. The synthesized AgNPs were characterized by UV-Visible, Fourier-transform infra-red (FT-IR), X-ray diffraction (XRD), Field emission-scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX), and Zeta potential analyses. The presence of functional groups and 13 bioactive components in the ethyl acetate extract were analyzed using FT-IR and gas chromatography-mass spectrometry (GC-MS). The synthesized of AgNPs and the ethyl acetate extract showed preponderant activity against P. aeruginosa and MRSA, respectively. The effects of AgNPs were significant when compared to ethyl acetate extract. Therefore, the halophilic bacterium, B. cereus mediated AgNPs could provide antibacterial applications in the biomedical industries.

Lantana camara Linn root extract-mediated gold nanoparticles and their in vitro antioxidant and cytotoxic potentials.

The Lantana camara Linn root extract derived gold nanoparticles (Au NPs) were characterized by Ultraviolet-Visible spectroscopy, X-ray diffraction, fourier transform-infrared, high resolution transmission electron microscopy, selected area electron diffraction pattern and energy dispersive X-ray analyses. In DPPH assay, the inhibitory concentration (IC50) of Au NPs and gallic acid was 24.17 and 5.39 µg/ml, whereas, for cytotoxicity assay, the IC50 of Au NPs was 17.72 and 32.98 µg/ml on MBA-MB-231 and Vero cells, respectively. Thus, the Au NPs possess significant in vitro antioxidant and cytotoxic properties which could be considered as potential alternate for the development of anticancer drug in future.

Structural characterization and evaluation of mosquito-larvicidal property of silver nanoparticles synthesized from the seaweed, Turbinaria ornata (Turner) J. Agardh 1848.

The silver nanoparticles synthesized from Turbinaria ornata (To-AgNPs) showed spherical with crystalline nature (20-32 nm) was evaluated against fourth instar larvae of three mosquitoes. The maximum activity of To-AgNPs was recorded on Aedes aegypti followed by Anopheles stephensi and Culex quinquefasciatus with the following lethal concentration values (µg/ml): LC50 of 0.738, 1.134, and 1.494; and LC90 of 3.342, 17.982, and 22.475, respectively. The obtained respective values (µg/ml) vis-a-vis aqueous extract (To-AE) were: 2.767 and 40.577; 4.347 and 158.399, and 7.351 and 278.994. The findings revealed that To-AgNPs could form a base for the development of an eco-friendly, low-cost pesticide.

Phytochemical profiling of Turbinaria ornata and its antioxidant and anti-proliferative effects.

OBJECTIVES: To analyse the phytochemicals and evaluate the antioxidant and anti-proliferative ability of Turbinaria ornata (Turner) J. Agardh, 1848. METHODS: A phytochemical analysis of the T. ornata-hexane extract (To-HE) and T. ornata-aqueous extract (To-AE) was performed. T. ornata extracts were analysed by gas chromatography-mass spectrometry (GC-MS), Fourier transform infrared spectroscopy (FTIR) and high-performance liquid chromatography (HPLC). The antioxidant properties of To-HE and To-AE were determined by 2,2-diphenyl-1-picrylhydrazyl radical scavenging (DPPH) and ferric ion reducing power (FRAP) assays. In addition, the in vitro anti-proliferative properties of To-HE and To-AE were assessed in kidney epithelial cells from the African green monkey (Vero) and in adenocarcinomic human alveolar basal epithelial cells (A549) using the MTT (3-(4,5-dimethylthiazol- 2yl)-2,5-diphenyltetrazolium bromide, a yellow tetrazole) assay. RESULTS: The phytochemical screening of T. ornata revealed the presence of saponin, alkaloids, amino acids, fixed oil and fat and phenolic compounds (tannins, flavonoids and total phenol). A higher antioxidant ability was found in To-HE than in To-AE. The anti-proliferative efficacy values (µg/mL) of To-HE and To-AE for A549 and Vero cells were 62.91 and 93.00 and 72.64 and 106.6, respectively. The FTIR analysis revealed the presence of functional groups such as alcohols, amides, aromatics, amines, alkyl halides, alkynes, alkanes and carboxylic acids. The GC-MS analysis of To-HE revealed the presence of 13 active compounds. CONCLUSION: Owing to its recorded anti-proliferative effect, further pharmaceutical studies on the development of this anticancer drug are merited.

Response of three cyprinid fish species to the Scavenger Deterrent Factor produced by the mutualistic bacteria associated with entomopathogenic nematodes.

The symbiotic bacteria, Photorhabdus and Xenorhabdus associated with entomopathogenic nematodes (EPNs) in the genera Heterorhabditis and Steinernema, respectively, produce a compound(s) called the Scavenging Deterrent Factor (SDF). SDF deters a number of terrestrial insect scavengers and predators and one bird species from feeding on host insects killed by the nematode-bacterium complex but has not been tested against aquatic vertebrates. Moreover, the Heterorhabditis-Photorhabdus association is believed to have evolved in an aquatic environment. Accordingly, we hypothesized that SDF will deter fish from feeding on nematode-killed insects and tested the responses of three omnivorous fresh water fish species, Devario aequipinnatus, Alburnoides bipunctatus, and Squalius pursakensis, to SDF in the laboratory. When the fish were exposed to Galleria mellonella larvae killed by the Heterorhabditis- or Steinernema-bacterium complex at 2 or 4days post-infection, all three fish species made several attempts to consume the cadavers but subsequently rejected them. However, all fish species consumed freeze-killed control larvae. In a choice test, when D. aequipinnatus or A. bipunctatus were offered a pair of nematode-killed larvae, both fish species rejected these cadavers; when offered a nematode-killed larva and a freeze-killed larva, both fish species consumed the freeze-killed larva but not the nematode-killed one. In further tests with D. aequipinnatus, there was no significant difference in the number of 2-day-old Bacillus thuringiensis subsp. kurstaki-killed (Btk) larvae consumed compared to freeze-killed larvae, but significantly fewer 4-day-old Btk-killed larvae were consumed compared to freeze-killed larvae. When D. aequipinnatus was fed G. mellonella larvae killed by the symbiotic bacteria, the fish rejected the cadavers. When given freeze-killed or nematode-killed mosquito (Aedes aegypti) larvae, the fish consumed significantly more of the former larvae (99%) compared to the latter (55%). When D. aequipinnatus was placed in a symbiotic cell-free supernatant for 18h, a significant reduction in consumption of freeze-killed larvae compared to cell-free Btk or control broth supernatant was observed. We showed that SDF protects the nematode-killed insects from being consumed by omnivorous fishes and suggests that they will have minimal effects on recycling of EPNs in the aquatic environment.

Idaein chloride induced p53 dependent apoptosis in cervical cancer cells through inhibition of viral oncoproteins.

Host dependent expression of early HPV oncoproteins, E6 and E7 play central role in the formation of cervical carcinoma. Presently, we have shown that the cyanidin analog, idaein chloride treatment induced dose dependent apoptosis (IC50 = 2.579 µg/ml) in HPV positive - HeLa cells. Flow cytometric analysis showed arrest of cell cycle at G1 phase with an increased sub G1 cell population on 12th h of exposure. The recorded reduced expression levels of cell cycle proteins - cyclin D, cdk 4 and cdk 6 confirmed the occurrence of cell cycle arrest at G1 phase. In addition, the idaein chloride significantly inhibited the expression of E6 and E7 proteins, resulting in p53 re-expression and hence triggering of p53 dependent apoptosis. This has been further supported by the recorded variations in the expression patterns of p21/WAF, pRb and E2F regulatory proteins. In case of mitochondrial apoptotic markers, the expression of Bax was restored and Bcl-2 level got decreased at 12th h. Cleaved caspases 3 & 9 and PARP were also observed after 3 h of treatment. Interestingly, the epigenetic regulatory enzymes (DNMTs) were inhibited by idaein chloride. Thus, idaein chloride could be a potent source for developing a drug against cervical carcinoma.

Structural characterization, antioxidant and in vitro cytotoxic properties of seagrass, Cymodocea serrulata (R.Br.) Asch. & Magnus mediated silver nanoparticles.

The present study pertains to the synthesis, structural elucidation, antioxidant and in vitro cytotoxic properties of silver nanoparticles (AgNPs) from marine angiosperm, Cymodocea serrulata aqueous extract (CSAE). The characterization was made through UV-Visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), zeta potential and dynamic light scanning (DLS) analyses. The UV-Vis spectrum resulted in a strong surface plasmon resonance (SPR) at 430 nm. The average crystalline size of the AgNPs was predicted through XRD peaks that indicated the 2 theta values of 37.84°, 44.06°, 64.42° and 77.74° for Bragg's refraction index. The functional groups responsible for the bio-reduction of Ag(+) into Ag(0) were focused through FTIR spectrum. The FESEM images showed that the C. serrulata mediated AgNPs (CS-AgNPs) were spherical in shape. DPPH assay revealed the higher free radical scavenging activity in CS-AgNPs, when compared to CSAE. The cytotoxicity assay on the cervical cancer (HeLa) and African green monkey kidney (Vero) cells upon treatment with CSAE: 107.7 & 124.3 µgml(-1) and CS-AgNPs: 34.5 & 61.24 µgml(-1), respectively showed good inhibition rate. These findings highlight the fact that C. serrulata could be a potential source for developing potent drugs and further studies are needed.

Ethyl acetate extract from marine sponge Hyattella cribriformis exhibit potent anticancer activity by promoting tubulin polymerization as evidenced mitotic arrest and induction of apoptosis.

BACKGROUND: Marine sponges are important sources of bioactive compounds. OBJECTIVE: This study investigated the anticancer properties of Hyattella cribriformis ethyl acetate (EA) fraction in various cancer and normal cell lines. MATERIALS AND METHODS: anticancer assay was carried out in 15 cell lines to evaluate the anticancer potential of the EA fraction. Impact on cell cycle distribution was determined using flow cytometry. The fraction was investigated for interfering microtubules assembly in both in vitro and cellular assay. Further studies were conducted to determine the fraction induced cell death (apoptosis) using calcein/propidium iodide dual staining, activated caspase-3 and phosphorylation of Bcl-2 protein at Ser70. DNA fragmentation assay was performed to confirm the apoptosis. RESULTS: EA fraction exhibited potent inhibition of cancer cell growth and resulted in 50% growth inhibition (GI50) of 0.27 µg/mL in A673 cell line. Sarcoma (MG-63, Saos-2) and ovarian (SK-OV-3 and OVCAR-3) cancer cell lines also showed superior anticancer activity GI50 of 1.0 µg/mL. Colon and breast cancer cell lines exhibited moderate GI compare other cancer cell lines and normal human lung fibroblast showed GI50 of 15.6 µg/mL. EA fraction showed potent G2/M phase arrest in A673 cell line and induced apoptosis at 48 h exposure. EA fraction promoted microtubule polymerization in tubulin polymerization assay and increased level of polymerized tubulin in the HeLa cells. Fraction induced the activation of caspase-3 and phosphorylation of Bcl-2 anti-apoptotic protein. Fraction induced DNA fragmentation in HeLa cells as evidence of apoptosis. CONCLUSION: Marine sponge H. cribriformis EA fraction exhibited potent anticancer activity through tubulin polymerization and induction of apoptosis.

GC-MS analysis of bioactive components and synthesis of gold nanoparticle using Chloroxylon swietenia DC leaf extract and its larvicidal activity.

A rapid bio-reduction of chloroauric acid (HAuCl4) was achieved by Chloroxylon swietenia DC leaf extract (CSLE), which resulted in the formation of well dispersed C. swietenia gold nanoparticles (CSGNPs). The formation of GNPs was confirmed by color changes from yellowish green to purple and their characteristic peak at 545 nm. The characterization of synthesized CSGNPs was made through X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), high resolution transmission electron microscopy (HRTEM) equipped with energy dispersive X-ray spectroscopy (EDX) followed by size and zeta potential analyses. The GC-MS profile of C. swietenia methanolic leaf extract (CSMLE) resulted 20 phytocomponents, among those heptacosanoic acid, 25-methyl-, methyl ester (C29H58O2) attributes highest peak area. The efficiency of the synthesized CSMLE, CSGNPs and CSLE were tested against fourth instar larvae of malarial and dengue vector, which resulted more substantial upshot than with leaf extract treated. The Lethal concentration (LC50) values of CSMLE, CSGNPs and CSLE were found to be 0.509, 0.340, 0.423 ppm and 0.602, 0.188, 0.646 ppm on Aedes aegypti and Anopheles stephensi, respectively. The findings form an important baseline information proceeding biologically innocuous biopesticide for controlling the malarial and dengue vectors.

Mukia maderaspatana (Cucurbitaceae) extract-mediated synthesis of silver nanoparticles to control Culex quinquefasciatus and Aedes aegypti (Diptera: Culicidae).

Mosquitoes and mosquito-borne diseases are prone to raise health and economic impacts. Synthetic insecticide-based interventions are indeed in situations of epidemic outbreak and sudden increases of adult mosquitoes. Nanoparticles are being used in many commercial applications and were found that aqueous silver ions can be reduced by an aqueous extract of plant parts to generate extremely stable silver nanoparticles in water. Based on this, silver nanoparticles (SNPs) were synthesized using leaf aqueous extract (LAE) of Mukia maderaspatana. Further, the synthesized SNPs were characterized by UV-visible spectrum, which indicated a strong plasmon resonance at 427 nm. X-ray diffraction (XRD) analysis revealed the average crystalline size of the synthesized SNPs was approximately 64 nm by Debye-Scherrer formulae. Fourier transform infrared (FTIR) spectroscopy analysis revealed the presence of different functional groups like amines, halides, alkanes, alkynes, amides, and esters with respective stretches, which are responsible for the bio-reduction of silver ions. Field emission scanning electron microscopy (FESEM) depicted the spherical morphology of SNPs with size range of 13-34 nm. The larvicidal activity of LAE and SNPs exhibited an effective mortality to Aedes aegypti and Culex quinquefasciatus. The lethal concentration (LC50; LC90) of LAE and SNPs were found to be 0.506; 1.082, 0.392; 0.870 ppm and 0.211; 0.703, 0.094; 0.482 ppm, respectively on A. aegypti and C. quinquefasciatus. Thus, the synthesized SNPs have shown preponderant larvicidal activity, but further studies are needed to formulate the potential larvicidal agents.

Antigonon leptopus: a potent biological source for extermination of fish bacterial pathogens Providencia and Aeromonas.

This study pertains to the phytochemical components and the biological properties of the weed, Antigonon leptopus Hook. & Arn. (AUT/PUS/064). Phytochemical screening of methanolic leaf extract of A. leptopus revealed the presence of saponin, phenolic compounds, tannins, flavonoids, alkaloids, fixed oils and amino acids. Accordingly, 12 phytochemical components were analysed and characterised by GC-MS. Antibacterial activity was evaluated against fish and clinical pathogens. Fish pathogens, Providencia vermicola (MTCC 5578) and Aeromonas hydrophila (MTCC 646) were more sensitive to the methanolic leaf extract than clinical pathogens. A useful information was obtained from the phytochemistry of A. leptopus leaves, which would pave way to further applications to treat fish diseases and for utility in the pharmaceutical field.

Structural characterization, antioxidant and anticancer properties of gold nanoparticles synthesized from leaf extract(decoction)of Antigonon leptopus Hook. &Arn.

Tea is an aromatic beverage prepared by pouring boiling water over alleviated leaves of the tea plant. Tea prepared from the aerial parts of Antigonon leptopus has been traditionally used as remedy for cold, diabetes and pain in many countries. The gold nanoparticles (Au NPs) synthesized from powdered leaf extract (decoction) of A. leptopus were characterized by UV­visible spectroscopy (UV­vis), X-ray diffraction (XRD), Fourier transform-infrared (FT-IR), high resolution transmission electron microscopy (HR-TEM), selected area electron diffraction (SAED) pattern and energy dispersive X-ray (EDX) analyses to define the formation of Au NPs. Further, the synthesized Au NPs were well characterized based on their strong surface plasmon resonance (SPR), crystalline nature, functional groups, size and dispersed shapes, purity and Bragg's reflections of face centered cubic (fcc) structure of metallic gold. The Au NPs showed higher free radical scavenging property when compared to the effect of leaf extract. Cytotoxicity study of synthesized Au NPs exhibited the growth inhibitory property at the concentration (GI50) of 257.8 µg/mL in human adenocarcinoma breast cancer (MCF-7) cells after 48 h. Thus, the Au NPs synthesized from the Mexican creeper, A. leptopus revealed the important biological properties: as a free radical as well as anticancer agent. We conclude that the A. leptopus derived biological materials have promising potential as a source for the development of anticancer drug in future.

Effect of sub-acute exposure to nickel nanoparticles on oxidative stress and histopathological changes in Mozambique tilapia, Oreochromis mossambicus.

The aim of the present study was to assess the oxidative stress, antioxidant response and histopathological changes of nickel nanoparticles (Ni NPs) exposure (14 days) in Mozambique tilapia, Oreochromis mossambicus. Ni NPs were synthesized by metal salt reduction method and characterized by X-ray diffraction (XRD) and Transmission electron microscopy (TEM). The XRD peaks at 44°, 51° and 76° were indexed to the (111), (200) and (220) Bragg's reflections of cubic structure of Nickel, respectively. The crystallite sizes were calculated using Scherrer's formula applied to the major intense peaks and found to be the size of 56nm. TEM images showed that the synthesized Ni NPs are spherical in shape. Biochemical analysis indicated that the superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activity was significantly affected by Ni NPs treated O. mossambicus. Reduced antioxidant enzymes and the contents of antioxidants were lowered in the liver and gills of fishes treated with Ni NPs. After 14 days of exposure, a significant accumulation of Ni in the Ni NPs in experimental group was observed in the gill and skin tissues, with the highest levels found in the liver. Ni NPs exposed fish showed nuclear hypertrophy (NH), nuclear degeneration (ND), necrosis (NC) and irregular-shaped nuclei were observed in liver tissue. The hyperplasia of the gill epithelium (GE), lamellar fusion of secondary lamellae (LF), dilated marginal channel (MC), epithelial lifting (EL) and epithelial rupture were observed in gill tissue. Degeneration in muscle bundles (DM), focal area of necrosis (NC) vacuolar degeneration in muscle bundles (VD), edema between muscle bundles (ED) and splitting of muscle fibers were noticed in skin tissue. Further ecotoxicological evaluation will be made concerning the risk of Ni NPs on aquatic environment.

Overexpression of circulating miRNA-21 and miRNA-146a in plasma samples of breast cancer patients.

Breast cancer is the second most common malignant disease affecting Indian women and is the leading cause of cancer-related mortality. MicroRNAs (miRNAs) are remarkably stable in blood, which makes them novel and promising biomarkers for cancer detection and diagnosis. In this study, we investigated whether expression levels of circulating specific miRNAs, such as microRNA-21 (miR-21) and microRNA-146a (miR-146a) could be used as potential biomarkers in plasma of breast cancer patients and healthy individuals. We compared the expression levels of breast cancer associated specific miRNA--miR-21 and miR-146a in plasma samples of histopathologically reported 14 patients (aged 35-61 yrs) with breast cancer and an additional 8 healthy volunteers (aged 35-54 yrs). The miRNA expression level was determined by TaqMan quantitative PCR (qPCR) assay. The miRNA expression level of each sample was normalized to that of miR-16 as reference and expressed as relative expression (2(deltaCt)). Our results showed that the circulating level of miR-21 and miR-146a were significantly higher in plasma samples of breast cancer patients, when compared to those of healthy controls (p < 0.0004 and p < 0.005, respectively). Thus, analyzing expression of miR-21 and miR-146a from plasma samples of breast cancer patients might be useful in the diagnosis of breast cancer. However, further studies with larger number of patients and control individuals are needed to confirm the results.