Showing papers by "Annamalai University published in 2017"

Breast Cancer: Current Molecular Therapeutic Targets and New Players

Abstract: Breast cancer is the most common cancer and the most frequent cause of cancer death among women worldwide. Breast cancer is a complex, heterogeneous disease classified into hormone-receptor-positive, human epidermal growth factor receptor-2 overexpressing (HER2+) and triple-negative breast cancer (TNBC) based on histological features. Endocrine therapy, the mainstay of treatment for hormone-responsive breast cancer involves use of selective estrogen receptor modulators (SERMs), selective estrogen receptor downregulators (SERDs) and aromatase inhibitors (AIs). Agents that target estrogen receptor (ER) and HER2 such as tamoxifen and trastuzumab have been the most extensively used therapeutics for breast cancer. Crosstalk between ER and other signalling networks as well as epigenetic mechanisms have been envisaged to contribute to endocrine therapy resistance. TNBC, a complex, heterogeneous, aggressive form of breast cancer in which the cells do not express ER, progesterone receptor or HER2 is refractory to therapy. Several molecular targets are being explored to target TNBC including androgen receptor, epidermal growth factor receptor (EGFR), poly(ADP-ribose) polymerase (PARP), and vascular endothelial growth factor (VEGF). Receptors, protein tyrosine kinases, phosphatases, proteases, PI3K/Akt signalling pathway, microRNAs (miRs) and long noncoding RNAs (lncRNAs) are potential therapeutic targets. miR-based therapeutic approaches include inhibition of oncomiRs by antisense oligonucleotides, restoration of tumour suppressors using miR mimics, and chemical modification of miRs. The lnRNAs HOTAIR, SPRY4-IT1, GAS5, and PANDAR, new players in tumour development and prognosis may have theranostic applications in breast cancer. Several novel classes of mechanism-based drugs have been designed and synthesised for treatment of breast cancer. Integration of nucleic acid sequencing studies with mass spectrometry-based peptide sequencing and posttranslational modifications as well as rational drug design will provide a more comprehensive understanding of the pathophysiology of breast cancer and help in evolving therapeutic strategies.

Nimbolide upregulates RECK by targeting miR-21 and HIF-1α in cell lines and in a hamster oral carcinogenesis model.

Abstract: Reversion-inducing cysteine-rich protein with Kazal motifs (RECK), a potent inhibitor of matrix metalloproteinases (MMPs) is a common negative target of oncogenic signals and a potential therapeutic target for novel drug development. Here, we show that sequential RECKlessness stimulates angiogenesis and Notch signalling in the 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis model, a paradigm for oral oncogenesis and chemointervention. We also report the chemotherapeutic effect of nimbolide, a limonoid from the neem tree (Azadirachta indica) based on the upregulation of RECK as well as modulation of the expression of key molecules involved in invasion and angiogenesis. We demonstrate that nimbolide upregulates RECK by targeting miR-21, and HIF-1α resulting in reduced MMP activity and blockade of VEGF and Notch signalling. Nimbolide reduced microvascular density, confirming its anti-angiogenic potential. Molecular docking analysis revealed interaction of nimbolide with HIF-1α. Additionally, we demonstrate that nimbolide upregulates RECK expression via downregulation of HIF-1α and miR-21 by overexpression and knockdown experiments in SCC4 and EAhy926 cell lines. Taken together, these findings provide compelling evidence that targeting RECK, a keystone protein that regulates mediators of invasion and angiogenesis with phytochemicals such as nimbolide may be a robust therapeutic approach to prevent oral cancer progression.

Pharmacognosy, Phytochemistry and Pharmacological Properties of Achillea millefolium L.: A Review.

Abstract: Achillea millefoilum L. (Yarrow) is an important species of Asteraceae family with common utilization in traditional medicine of several cultures from Europe to Asia for the treatment of spasmodic gastrointestinal disorders, hepatobiliary, gynecological disorders, against inflammation and for wound healing. An extensive review of literature was made on A. millefoilum L. using ethno botanical text books, published articles in peer-reviewed journals, unpublished materials and scientific databases. The Plant List, International Plant Name Index and Kew Botanical Garden databases were used to authenticate the scientific names. Monoterpenes are the most representative metabolites constituting 90% of the essential oils in relation to the sesquiterpenes, and a wide range of chemical compounds have also been reported. Different pharmacological experiments in many in-vitro and in-vivo models have proved the potential of A. millefoilum with antiinflammatory, antiulcer, anticancer activities etc. lending support to the rationale behind numerous of its traditional uses. Due to the noteworthy pharmacological activities, A. millefoilum will be a better option for new drug discovery. The present review will comprehensively summarize the pharmacognosy, phytochemistry and ethnopharmacology of A. millefoilum reported to date, with emphasis on more in vitro, clinical and pathological studies needed to investigate the unexploited potential of this plant. Copyright © 2017 John Wiley & Sons, Ltd.

Hesperidin ameliorates cognitive dysfunction, oxidative stress and apoptosis against aluminium chloride induced rat model of Alzheimer's disease.

Abstract: Background/aims: Deregulation of metal ion homeostasis has been assumed as one of the key factors in the progression of neurodegenerative diseases. Aluminium (Al) has been believed as a major risk factor for the cause and progression of Alzheimer's disease (AD). In our lab, we have previously reported that hesperidin, a citrus bioflavonoid reversed memory loss caused by aluminium intoxication through attenuating acetylcholine esterase activity and the expression of Amyloid β biosynthesis related markers. Al has been reported to cause oxidative stress associated apoptotic neuronal loss in the brain. So in the present study, protective effect of hesperidin against aluminium chloride (AlCl3) induced cognitive impairment, oxidative stress and apoptosis was studied.Methods: Male Wistar rats were divided into control, AlCl3 treated (100 mg/kg., b.w.), AlCl3 and hesperidin (100 mg/kg., b.w.) co-treated and hesperidin alone treated groups. In control and experimental rats, learning and memory impairment were meas...

Guazuma ulmifolia bark-synthesized Ag, Au and Ag/Au alloy nanoparticles: Photocatalytic potential, DNA/protein interactions, anticancer activity and toxicity against 14 species of microbial pathogens.

Abstract: In the present study, we focused on a quick and green method to fabricate Ag, Au and Ag/Au alloy nanoparticles (NPs) using the bark extract of Guazuma ulmifolia L. Green synthesized metal NPs were characterized using different techniques, including UV-Vis spectroscopy, FT-IR, XRD, AFM and HR-TEM analyses. The production of Ag, Au and Ag/Au alloy NPs was observed monitoring color change from colorless to brown, followed by pink and dark brown, as confirmed by UV-Vis spectroscopy characteristic peaks at 436, 522 and 510nm, respectively. TEM shed light on the spherical shapes of NPs with size ranges of 10-15, 20-25 and 10-20nm. Biosynthesized NPs showed good catalytic activity reducing two organic dyes, 4-nitrophenol (4-NP) and Congo red (CR). UV-vis spectroscopy, fluorescence, circular dichroism spectroscopy and viscosity analyses were used to investigate the NP binding with calf thymus DNA. The binding constant of NPs with DNA calculated in UV-Vis absorption studies were 1.18×104, 1.83×104 and 2.91×104M-1, respectively, indicating that NPs were able to bind DNA with variable binding affinity: Ag/Au alloy NPs>Ag NPs>Au NPs. Ag/Au alloy NPs also showed binding activity to bovine serum albumin (BSA) over the other NPs. Ag and Ag/Au alloy NPs exhibited good antimicrobial activity on 14 species of microbial pathogens. In addition, the cytotoxic effects of Ag/Au alloy NPs were studied on human cervical cancer cells (HeLa) using MTT assay. Overall, our work showed the promising potential of bark-synthesized Ag and Ag/Au alloy NPs as cheap sources to develop novel and safer photocatalytic, antimicrobial and anticancer agents.

Green synthesis of gold nanoparticles using a cheap Sphaeranthus indicus extract: Impact on plant cells and the aquatic crustacean Artemia nauplii.

Abstract: The impact of green-fabricated gold nanoparticles on plant cells and non-target aquatic species is scarcely studied. In this research, we reported an environment friendly technique for the synthesis of gold nanoparticles (Au NPs) using the Sphaeranthus indicus leaf extract. The formation of the metal NPs was characterized by UV-Visible and FT-IR spectroscopy, XRD, SEM and TEM analyses. The UV-Visible spectra of Au NPs showed a surface plasmon resonance peak at 531nm. FT-IR analysis indicated functional bio-molecules associated with Au NPs formation. The crystalline nature of Au nanoparticles was confirmed by their XRD diffraction pattern. TEM revealed the spherical shape with a mean particle size of 25nm. Au NPs was tested at 0, 1, 3, 5, 7 and 10% doses in mitotic cell division assays, pollen germination experiments, and in vivo toxicity trials against the aquatic crustacean Artemia nauplii. Au NPs did not show any toxic effects on plant cells and aquatic invertebrates. Notably, Au NPs promoted mitotic cell division in Allium cepa root tip cells and germination of Gloriosa superba pollen grains. Au NPs showed no mortality on A. nauplii, all the tested animals showed 100% survivability. Therefore, these Au NPs have potential applications in the development of pollen germination media and plant tissue culture.

Production of Enzymes From Agricultural Wastes and Their Potential Industrial Applications.

Abstract: Enzymatic hydrolysis is the significant technique for the conversion of agricultural wastes into valuable products. Agroindustrial wastes such as rice bran, wheat bran, wheat straw, sugarcane bagasse, and corncob are cheapest and plentifully available natural carbon sources for the production of industrially important enzymes. Innumerable enzymes that have numerous applications in industrial processes for food, drug, textile, and dye use have been produced from different types of microorganisms from agricultural wastes. Utilization of agricultural wastes offers great potential for reducing the production cost and increasing the use of enzymes for industrial purposes. This chapter focuses on economic production of actinobacterial enzymes from agricultural wastes to make a better alternative for utilization of biomass generated in million tons as waste annually.

Direct solvothermal synthesis of zinc oxide nanoparticle decorated graphene oxide nanocomposite for efficient photodegradation of azo-dyes

Abstract: Zinc oxide nanoparticles decorated graphene oxide (ZnO@GO) nanocomposite was successfully prepared using graphene oxide (GO) and zinc oxide nanoparticles (ZnO NPs) as raw materials by simple solvothermal method. The X-ray diffraction pattern, X-ray photoelectron spectroscopic, Fourier transform infrared spectroscopic, and Raman spectroscopic techniques revealed the formation, elemental composition and the purity of ZnO NPs and ZnO@GO nanocomposite. The ZnO NPs were synthesized via simple thermal oxidation, the synthesized ZnO NPs exhibits an excellent near spherical shape with narrow size distribution and mean size of around 20 ± 5 nm which is vividly observed from field emission scanning electron microscopic images. The elemental compositions of ZnO@GO nanocomposite which carbon, oxygen and zinc were revealed by XPS and EDX elemental mapping. The ZnO NPs decorated on GO layers were clearly seen in the high resolution transmission electron microscopic images. The photocatalytic activities of the synthesized pure ZnO NPs and ZnO@GO nanocomposite were investigated by photodegradation of azo-dyes includes neutral red (NR), crystal violet (CV), congo red (CR) and methyl orange (MO) under UV-light irradiation. The results revealed that the ZnO@GO nanocomposite exhibited a remarkably higher photocatalytic efficiency compared to pure ZnO NPs. The enhancement of photocatalytic performance was ascribed to the synergistic effect between ZnO NPs and GO layers. Hence, the synthesized ZnO@GO nanocomposite crucial for efficient degradation of dyes such as NR, CV, CR and MO. The synthesized ZnO@GO nanocomposite exhibits a good photocatalytic activity along with good reproducibility of photodegradation, which is applicable for practical applications.

The essential oil from Zanthoxylum monophyllum a potential mosquito larvicide with low toxicity to the non-target fish Gambusia affinis.

Abstract: The mosquito larvicidal activity of Zanthoxylum monophyllum leaf essential oil (EO) and its major chemical constituents was tested against the three mosquito vectors Anopheles subpictus, Aedes albopictus and Culex tritaeniorhynchus. In the EO of Z. monophyllum, it contains 36 compounds with the two major compounds being Germacrene D-4-ol (19.40 %) and α-Cadinol (12.30). The larvicidal activity of the essential oil against An. subpictus, Ae. albopictus and Cx. tritaeniorhynchus was determined and LC50 values were estimated at 41.50, 45.35 and 49.01 µg/mL, respectively. The two major compounds Germacrene D-4-ol and α-Cadinol were tested for acute toxicity against larvae of the three mosquito vectors. Germacrene D-4-ol showed a significantly higher efficacy compared to α-Cadinol. While LC50 for Germacrene D-4-ol ranged from 6.12 to 7.26 µg/mL, LC50 values for α-Cadinol were estimated in the range from 10.27 to 12.28 µg/mL. The EO, Germacrene D-4-ol and α-Cadinol were found safer to the non-target organism Gambusia affinis (LC50 = 4234.07, 414.05 and 635.12 µg/mL, respectively), which was manifested in the high suitability of the index/predator safety factor value, ranging from 86.36 for the least sensitive larvae of Cx. tritaeniorhynchus to 102.02 for the most sensitive larvae of An. subpictus.

Biopolymer zein-coated gold nanoparticles: Synthesis, antibacterial potential, toxicity and histopathological effects against the Zika virus vector Aedes aegypti

Abstract: The control of multidrug-resistant bacteria as well as insect pests and vectors is timely and important now a days. The present study was designed to evaluate the in vitro antibacterial, antibiofilm and mosquito larvicidal effects of gold nanoparticles synthesized using the zein biopolymer (Ze-AuNPs) against Gram positive (Bacillus pumilus and Bacillus subtilis), Gram negative (Shigella sonnei and Pseudomonas aeruginosa) bacteria and third instar larvae of the dengue and Zika virus vector Aedes aegypti. The synthesized Ze-AuNPs were characterized by UV-vis spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The antibacterial assays testing Ze-AuNPs at 100μg/ml showed that the zones of inhibition against Gram positive species B. pumilus and B. subtilis were 13.9 and 14.2mm, respectively, while for Gram negative S. sonnei and P. aeruginosa they were 18.1 and 18.4mm, respectively. Light and confocal laser scanning microscopy (CLSM) confirmed the interruption and disintegration of bacterial biofilm post-treatment with Ze-AuNPs at 100μg/ml. In larvicidal assays on A. aegypti, HAuCl4 and Ze-AuNPs treated third instar larvae of A. aegypti showed LC50 of 26.6 and 6.81mg/L, respectively, and LC90 of 81.1 and 13.6mg/L respectively. The histopathological analysis of A. aegypti treated with Ze-AuNPs showed complete disintegration of abdominal region, particularly the midgut and caeca, with loss of lateral and caudal hairs. The stereomicroscopic visualization of A. aegypti treated with Ze-AuNPs showed the loss of upper head hair, lower head hair, antenna hair, lateral hair and caudal hair. Overall, the study concludes that Ze-AuNPs have excellent antibacterial, antibiofilm effects and has ability to control the larval populations of A. aegypti mosquitoes.

A Facile One-Pot Synthesis of Eco-Friendly Nanoparticles Using Carissacarandas: Ovicidal and Larvicidal Potential on Malaria, Dengue and Filariasis Mosquito Vectors

Abstract: Mosquito-borne diseases represent a major human and animal health problem in all tropical and subtropical countries worldwide. In this study, we investigated the one-pot synthesis of silver nanoparticles (AgNPs) using a cheap leaf extract of Carissa carandas (Apocynaceae). Bio-reduced AgNPs were characterized by UV–visible spectrophotometry, Fourier transform infrared spectroscopy, X-ray diffraction analysis, atomic force microscopy, scanning electron microscopy and transmission electron microscopy. The acute toxicity of C. carandas extract and green-synthesized AgNPs was evaluated on eggs and larvae of Anopheles stephensi, Aedes aegypti and Culex quinquefasciatus. AgNPs showed high toxicity against A. stephensi, A. aegypti, and C. quinquefasciatus larvae with LC50 values of 14.33, 15.69 and 16.95 μg/mL, respectively. A single treatment with AgNPs tested at 60 μg/mL led to no egg hatchability. The egg rafts of C. quinquefasciatus were more resistant to the toxic action of AgNPs if compared to A. aegypti and A. stephensi. C. carandas-fabricated AgNPs were found safer to non-target organisms Anisops bouvieri, Diplonychus indicus and Gambusia affinis, with LC50 ranging from 1097.87 to 17249.89 µg/ml. Overall, this research shed light on the mosquitocidal potential of C. carandas, a potential bio-resource for rapid, cheap and effective synthesis of poly-disperse and stable silver nanocrystals.

Comparative study of biofiltration process for treatment of VOCs emission from petroleum refinery wastewater—A review

Abstract: Volatile organic compounds (VOCs) and many in-organic hazardous air pollutants are generated from wastewater of petroleum refinery. Due to the regulatory norms and urgency of treating these hazardous compounds, implementation of suitable technology is necessary. Among many conventional methods, biofiltration is acquiring high importance due to its environment friendly process and cost effectiveness. Operating data, lab experiments and literature review suggests that biofiltration can easily achieve removal efficiency of >90% VOCs and odor in a controlled environment. Hence this process is widely gaining popularity across Europe, Japan, US and other countries. However, due to the complexity in biodegradation and bioactivity, a complete understanding about the process, mechanism of biofilter is needed. In laboratory VOC removal experiment may be effective, but in actual operating condition with multi-component VOCs and in-organics require proper design and optimum operating atmosphere. Also, there are many full scale biofilters installed worldwide, there are less comprehensive review on VOC removal by biofiltration generated in petroleum wastewater treatment plants. In this paper, bio-treatability of VOCs found in refinery wastewater, different bio-reactors, reaction kinetics, designing and operating parameters are discussed. It also outlines the advantages, disadvantages and problems associated with biofiltration.

Linalool prevents oxidative stress activated protein kinases in single UVB-exposed human skin cells

Abstract: Ultraviolet-B radiation (285–320 nm) elicits a number of cellular signaling elements. We investigated the preventive effect of linalool, a natural monoterpene, against UVB-induced oxidative imbalance, activation of mitogen-activated protein kinase (MAPK) and nuclear factor kappa-B (NF-κB) signaling in HDFa cells. We observed that linalool treatment (30 μM) prevented acute UVB-irradiation (20 mJ/cm 2) mediated loss of activities of antioxidant enzymes in HDFa cells. The comet assay results illustrate that linalool significantly prevents UVB-mediated 8-deoxy guanosine formation (oxidative DNA damage) rather than UVB-induced cyclobutane pyrimidine (CPD) formation. This might be due to its ability to prevent UVB-induced ROS formation and to restore the oxidative imbalance of cells. This has been reflected in UVB-induced overexpression of MAPK and NF-κB signaling. We observed that linalool inhibited UVB-induced phosphorylation of ERK1, JNK and p38 proteins of MAPK family. Linalool inhibited UVB-induced activation of NF-κB/p65 by activating IκBa. We further observed that UVB-induced expression of TNF-α, IL6, IL-10, MMP-2 and MMP-9 was modulated by linalool treatment in HDFa cells. Thus, linalool protects the human skin cells from the oxidative damages of UVB radiation and modulates MAPK and NF-κB signaling in HDFa cells. The present findings substantiate that linalool may act as a photoprotective agent against UVB-induced skin damages.

Toxicity of herbal extracts used in ethno-veterinary medicine and green-encapsulated ZnO nanoparticles against Aedes aegypti and microbial pathogens

Abstract: Dengue and chikungunya are arboviral diseases mainly vectored by the mosquito Aedes aegypti. Presently, there is no treatment for these viral diseases and their prevention is still based on vector control measures. Nanopesticides fabricated using herbal extracts as reducing and capping agents currently represent an excellent platform for pest control. In this scenario, the present study assessed the acute toxicity of seven plants employed in ethno-veterinary medicine of southern India, as well as the green synthesis of zinc oxide nanoparticles, on third-instar larvae of A. aegypti. Larvae were exposed to extracts of the seven plants obtained with solvents of different polarity (acetone, ethanol, petroleum ether, and water) for 24 h. Maximum efficacy was observed for Lobelia leschenaultiana leaf extracts prepared using all the four solvent extracts (LC50 = 22.83, 28.12, 32.61, and 36.85 mg/L, respectively). Therefore, this plant species was used for the synthesis and stabilization of ZnO nanoparticles based on its maximum efficacy against third-instar larvae of A. aegypti. L. leschenaultiana-encapsulated ZnO nanoparticles showed 100% mortality when tested at 10 mg/L, the LC50 was extremely low, 1.57 mg/L. Zinc acetate achieved only 65.33% when tested at 60 mg/L, with a LC50 of 51.62 mg/L. Additionally, ZnO nanoparticles inhibited growth of Pseudomonas aeruginosa, Proteus vulgaris, Shigella sonnei, and Vibrio parahaemolyticus and also inhibited biofilm formation on selected microbila pathogens, showing impact on EPS production and hydrophobicity. Overall, our results suggest that L. leschenaultiana-fabricated ZnO nanoparticles have a significant potential to control A. aegypti mosquitoes and Gram-negative bacterial pathogens.

Neuroprotective effect of Demethoxycurcumin, a natural derivative of Curcumin on rotenone induced neurotoxicity in SH-SY 5Y Neuroblastoma cells

Abstract: Mitochondrial dysfunction and oxidative stress are the main toxic events leading to dopaminergic neuronal death in Parkinson’s disease (PD) and identified as vital objective for therapeutic intercession. This study investigated the neuro-protective effects of the demethoxycurcumin (DMC), a derivative of curcumin against rotenone induced neurotoxicity. SH-SY5Y neuroblastoma cells are divided into four experimental groups: untreated cells, cells incubated with rotenone (100 nM), cells treated with DMC (50 nM) + rotenone (100 nM) and DMC alone treated. 24 h after treatment with rotenone and 28 h after treatment with DMC, cell viability was assessed using the MTT assay, and levels of ROS and MMP, plus expression of apoptotic protein were analysed. Rotenone induced cell death in SH-SY5Y cells was significantly reduced by DMC pretreatment in a dose-dependent manner, indicating the potent neuroprotective effects of DMC. Rotenone treatment significantly increases the levels of ROS, loss of MMP, release of Cyt-c and expression of pro-apoptotic markers and decreases the expression of anti-apoptotic markers. Even though the results of the present study indicated that the DMC may serve as a potent therapeutic agent particularly for the treatment of neurodegenerative diseases like PD, further pre-clinical and clinical studies are required.

Biodegradation of textile dyeing industry wastewater using modified anaerobic sequential batch reactor – Start-up, parameter optimization and performance analysis

Abstract: In this study a novel modified anaerobic sequential batch reactor (MASBR) was employed to treat the textile dyeing industry wastewater. The anaerobic sequential batch reactor (ASBR) was modified by the addition of a sorbent (ground nut shell powder) and plastic media. The start-up phase of the MASBR was observed over a period of 80 days. Statistical based experiments were performed in order to optimize the parameters viz., sorbent dosage and particle loading, and to study the interactive effects using response surface method (RSM). At the optimized conditions, experiments were performed at various organic loading rates by varying initial textile dye wastewater concentration and hydraulic retention time (HRT). The anaerobic biodegradation of textile dyeing wastewater in the MASBR was analyzed in terms of decolorization, COD reduction, biogas production, volatile fatty acids (VFA) at different organic loading rate (OLR) between 0.110 and 0.650 kgCOD/m3 d. A maximum decolorization of 94.8% and COD reduction of 97.1% were obtained in the MASBR. The novel sorbent utilized in the study was characterized using FTIR and SEM analysis.

Optimization of rhamnolipid biosurfactant production from Serratia rubidaea SNAU02 under solid-state fermentation and its biocontrol efficacy against Fusarium wilt of eggplant

Abstract: This work was aimed to explore rhamnolipid production under solid state fermentation using a potential substrate mahua oil cake and to evaluate the biocontrol efficacy of rhamnolipid against Fusarium wilt of eggplant. The combination of Response Surface Methodology and Central Composite Design was employed to optimize higher biosurfactant production. Therefore, four factors viz., substrate concentration, inoculum size, pH and temperature were selected for optimization of rhamnolipid production. The results revealed that the optimum conditions for reduction of surface tension were mahua oil cake 7.78 g, 2.4 ml inoculum size (1 × 108 cells/ml), pH 7 and 30° C temperature. To evaluate the biocontrol efficacy the application of rhamnolipid at various concentrations (0, 100, 250 and 500 μg/ml) by soil and foliar application were employed in the pot culture assay. In vitro study indicated that rhamnolipid producing strain SNAU02 was the most effective antagonist against Fusarium oxysporum f. sp. melongenae and used for pot culture study. On the basis of economic analysis, treatment T9 (Fusarium oxysporum f. sp. Melongenae ( × 106 spores/ml) + 50 ml of 250 μg biosurfactant/ml to soil + foliar spraying of biosurfactant (250 μg/ml) ranked among the efficacious treatments and was just as effective as a synthetic fungicide. In control treatment, occurrence of disease severity and disease incidence was observed from early stage of crop growth until harvest stage. The pot experiment results indicated that SNAU02 rhamnolipid could be a promising agent in the biocontrol of Fusarium wilt of eggplant, which might help to minimize the yield loss of eggplant.

Eco-friendly fabrication of Ag nanostructures using the seed extract of Pedalium murex, an ancient Indian medicinal plant: Histopathological effects on the Zika virus vector Aedes aegypti and inhibition of biofilm-forming pathogenic bacteria.

Abstract: The control of Zika virus mosquito vectors and well as the development of drugs in the fight against biofilm-forming microbial pathogens, are timely and important challenges in current bionanoscience. Here we focused on the eco-friendly fabrication of Ag nanostructures using the seed extract of Pedalium murex, an ancient Indian medicinal plant. Initial confirmation of Ag nanoparticles (AgNPs) production was showed by a color change from transparent to dark brown. The UV-Visible spectrum (476nm), X-ray diffraction peaks (101, 200, 220 and 311) and Fourier transform infrared spectroscopy shed light on the production of green-capped AgNPs. Morphological structure analysis using HR-TEM showed that the AgNPs were mostly hexagonal in shape with rough edges, and a size of 20-30nm. The larvicidal potential of P. murex seed extract and AgNPs fabricated using the P. murex seed extract (Pm-AgNPs) was tested on fourth instar mosquito larvae of the Zika virus vector Aedes aegypti. Maximum efficacy was achieved by Pm-AgNPs against Ae. aegypti after 24h (LC50 34.88; LC90 64.56mg/ml), if compared to the P. murex seed extract. Histopathological analyses showed severe damages to the hindgut and larval muscles in NPs-treated Ae. aegypti larvae. The sub-MIC concentrations of Pm-AgNPs exhibited significant anti-biofilm activity against Gram positive (Enterococcus faecalis, Staphylococcus aureus) and Gram negative (Shigella sonnei, Pseudomonas aeruginosa) bacterial pathogens, as showed by EPS and MTP assays. Light and CLSM microscopic studies highlighted a significant impact of P. murex seed extract and Pm-synthesized AgNPs on the surface topography and architecture of bacterial biofilm, both in Gram positive and Gram negative species. Overall, results reported here contribute to the development of reliable large-scale protocols for the green fabrication of effective mosquito larvicides and biofilm inhibitors.