Papers by Vinay Raghavendra
SN Applied Sciences, 2018
Zinc oxide (ZnO) has broad applications in various areas. Green synthesis is an alternative to co... more Zinc oxide (ZnO) has broad applications in various areas. Green synthesis is an alternative to conventional physical and chemical methods. Green synthesis of nanoparticles is gaining importance due to its cost-effectiveness, reduction of toxic chemicals and extensive antimicrobial activity. Herein, we have discovered synthesis of zinc oxide nanoparticles (ZnONPs) using agro waste materials like sheep and goat faecal matter as a reducing agent. Synthesized ZnONPs were evaluated for their purity, particle size, morphological structure, using UV-visible spectroscopy, Fourier transforms infrared spectroscopy, X-ray diffraction and scanning electron microscope analysis. However, nanoparticles gain low crystallite size, they seemed to be uneven structures like spongy like and flower shaped particles. Obtained nanoparticles exhibit good antimicrobial activity and minimum inhibitory concentration against Salmonella typhimurium and Bacillus subtilis. Agro-waste based green synthesized ZnONPs possess small sized particles, enhances the good antimicrobial effect. This research leads to develop a new way of cost-effective synthesis and reducing usage of chemicals in further studies.
Cu2+ substituted Mg-Co ferrite has improved dc electrical resistivity and magnetic properties
Inorganic Chemistry Communications
Studies of in vitro antioxidant and anti-inflammatory activities of gold nanoparticles biosynthesised from a medicinal plant, Commiphora wightii
Materials Technology
BioNanoScience, 2022
The present research was aimed to synthesize and characterize silver nanoparticles (AaAgNPs) usin... more The present research was aimed to synthesize and characterize silver nanoparticles (AaAgNPs) using endophytic fungus, Alternaria alternata from the plant, Dendrophthoe falcata. The endophytic fungal water extract was used to prepare silver nanoparticles and the colour of the reaction mixture was changed to light brown colour after 24 h of incubation. The endophytic fungal phytochemicals might have aided in the bioreduction of silver nitrate to silver nanoparticles thus changing the colour of the reaction mixture. Both endophytic fungal extract and endophytic fungal extract mediated NPs shown different phytochemicals in GC-MS analysis. The synthesized silver nanoparticles were characterized using UV-visible spectroscopy, XRD, FTIR, EDX, DLS, SEM and TEM to study structure, size, and shape of the nanoparticles. The AaAgNPs found to be spherical with an average particle size of 66 to 88.6 nm. Significantly, the AaAgNPs have inhibited the growth of Bacillus cereus followed by Klebsiella pneumoniae, Pseudomonas aeruginosa, E.coli, Staphylococcus aureus, and Proteus mirabilis exhibiting antibacterial activity. Overall, the AaAgNPs had shown significant antibacterial property. The AaAgNPs had shown potent antioxidant activity in four different methods (DPPH radical scavenging assay, Hydrogen peroxide scavenging assay, Nitric oxide radical scavenging activity, Reducing power assay) and the activity was more compared to standard used. This is the pioneering report on the study of antibacterial and antioxidant activity of AaAgNPs, synthesized from endophytic fungus, Alternaria alternata of D. falcata.
Clinical and Experimental Immunology, 2001
SUMMARYGrowing evidence has supported the conclusion that melatonin, a pineal hormone, modulates ... more SUMMARYGrowing evidence has supported the conclusion that melatonin, a pineal hormone, modulates the immune function. In our previous study, we evaluated in vivo the potential role of melatonin in the regulation of the antigen specific T and B cells. In the present study, we observe that melatonin down-regulated the expression of the co-stimulatory molecule B7-1 but not B7-2 on macrophages. Further, melatonin encouraged the proliferation of anti-CD3 antibody activated CD4+ T cells only in the presence of antigen-presenting cells and promoted the production of Th2-like cytokines. Furthermore, it failed to influence the activity of B cells in a T-independent manner. Melatonin suppressed the release of TNF-α by LPS or IFN-γ activated macrophages but failed to inhibit nitric oxide (NO) release. Thus the study shows that melatonin can engineer the growth of unprimed CD4+ T cells if both the signals are provided by antigen-presenting cells. However, it could not regulate the function of B...
T-2 toxin induces dermal inflammation and toxicity in mice: The healing potential of menthol
Environmental Research
Nanofabrication of cobalt-tellurium using Allium sativum extract and its protective efficacy against H2O2-induced oxidative damage in HaCaT cells
Environmental Research
Convalescent action of menthol against T-2 mycotoxin-induced toxicity: An in vitro study with HaCaT cells
Environmental Research
Journal of Medicinal Plants Research, Aug 18, 2011
Thirteen different endophytic fungi were isolated from different parts of Tabebuia argentea. Thes... more Thirteen different endophytic fungi were isolated from different parts of Tabebuia argentea. These endophytic fungal extracts were prepared, using ethyl acetate and evaluated for their phytochemical constituents. Aspergillus niger and Alternaria alternata yielded saponins, phenolic compounds, anthraquinones, steroids, cardiac glycosides and tannins. Other endophytes yielded less phytochemical compounds compared to plant extracts. Naphthoquinone (natural lapachol) was identified in A. niger and A. alternata. These two endophytes also exhibited significant antimicrobial activity against an array of pathogenic fungi and bacteria. Endophytic isolates of A. niger and A. alternata are of particular interest because they showed significant antagonistic activity against all tested bacteria and fungi at different range. The total antioxidant capacity and phenolic content of the fungal cultures ranged from 4299 to 5276 µmol/L and from 2.5 to 2.6 mg gallic acid/100 mL culture respectively. The fungal culture, endophytes, A. niger and A. alternata showed strongest antioxidant capacity, having the highest levels of phenolics. This is the first report of lapachol (naphthoquinone) producing endophytes and their antimicrobial and antioxidant activities. This investigation reveals that the metabolites produced by a variety of endophytic fungi can be a potential source of novel natural antimicrobials, antioxidants and anticancer agents.
Current Research in Environmental & Applied Mycology, 2014
Nigropsora sp. was isolated as an endophyte from a medicinal plant, Ginkgo biloba. Ethyl acetate ... more Nigropsora sp. was isolated as an endophyte from a medicinal plant, Ginkgo biloba. Ethyl acetate extract of the fungus was evaluated for antimicrobial and free radical scavenging (DPPH) activity. Ethyl acetate extract was effective against Escherichia coli (R-2046), Klebsiella sp. (R-2434), Staphylococcus aureus (ATCC 6538), Candida albicans (NCIM 3471) and Geotrichum sp. (NFCCI-2521) while it did not show activity against Saccharomyces cerevisiae (NFCCI-1248), Nodulisporium sp. (NFCCI-2264) and Syncephalastrum sp. (NFCCI-2269). The minimum inhibitory concentration (MIC) of ethyl acetate extract evaluated by tube broth dilution method was recoerded as 2.5mg/ml against all test organisms while by agar dilution method it was recorded as 1.25mg/ml against E. coli, 0.15625mg/ml against S. aureus and 0.3125mg/ml against Klebsiella sp. and C. albicans. The TLC-bioautography assay, used to screen the plant extracts for antimicrobial activity and localization of the active compounds indicated the presence of a number of inhibitory compounds with activity against tested microorganisms. Phytochemical analysis revealed the presence phenolic compounds and anthraquinones. Nigrospora sp. was also examined for in vitro antioxidant activity by DPPH radical scavenging assay. The ethyl acetate extract of the fungus showed potent antioxidant activity with IC 50 value of 9.28µg/ml compared to the IC 50 value of standard ascorbic acid, 1.74μg/ml.
Silk sericin conjugated magnesium oxide nanoparticles for its antioxidant, anti-aging, and anti-biofilm activities
Environmental Research
Bioengineering
The ayurvedic herb Emblica officinalis (E. officinalis) is a gift to mankind to acquire a healthy... more The ayurvedic herb Emblica officinalis (E. officinalis) is a gift to mankind to acquire a healthy lifestyle. It has great therapeutic and nutritional importance. Emblica officinalis, also known as Indian gooseberry or Amla, is a member of the Euphorbiaceae family. Amla is beneficial for treating illnesses in all its forms. The most crucial component is a fruit, which is also the most common. It is used frequently in Indian medicine as a restorative, diuretic, liver tonic, refrigerant, stomachic, laxative, antipyretic, hair tonic, ulcer preventive, and for the common cold and fever. Hyperlipidemia is also known as high cholesterol or an increase in one or more lipid-containing blood proteins. Various phytocompounds, including polyphenols, vitamins, amino acids, fixed oils, and flavonoids, are present in the various parts of E. officinalis. E. officinalis has been linked to a variety of pharmacological effects in earlier studies, including hepatoprotective, immunomodulatory, antimicro...
Bioagents such as Trichoderma harzianum, Pseudomonas fluorescens and Bacillus subtilis were isola... more Bioagents such as Trichoderma harzianum, Pseudomonas fluorescens and Bacillus subtilis were isolated from cotton rhizosphere soil and tested individually for their effectiveness in controlling bacterial blight of cotton caused by Xanthomonas campestris pv. malvacearum (Xcm). Talc based formulations were prepared and used for seed treatment at different concentrations for assessing their ability to stimulate plant growth and to control bacterial blight disease. Among bioagents, P. fluorescens and T. harzianum proved to be effective in controlling disease under field conditions. Other than direct action, these bioagents triggered the defense related enzymes involved in synthesis of phenols. Higher activity of peroxidase, phenylalanine ammonia-lyase, polyphenol oxidase and -1,3-glucanase was observed in P. fluorescens and T. harzianum treated cotton plants after challenge inoculation with Xcm. Seed treatment with these bioagents enhanced the seed germination and growth parameters agai...
Biosciences, Biotechnology Research Asia, 2004
Seed treatment with Gaucho (an insecticide) and Krilaxyl (a fungicide) at the concns. of recommen... more Seed treatment with Gaucho (an insecticide) and Krilaxyl (a fungicide) at the concns. of recommended dosages, below recommended, above recommended and in combination dosages were done on Mungbean cv. PS-116 at 12, 24 and 48 h exposure periods. Wet treatment of both the pesticides exhibited non significant variations on germination and they varied in respect of root length and shoot length at recommended and higher dosages of longer exposure periods. The calcd. results of vigour index, tolerance index were decreased and the percent phytotoxicity was increased along with the increase in concns. over control. The content of chloroplast pigments, (Chlorophyll 'a', 'b', total chlorophyll and carotenoid) were also reduced drastically at higher and in combination dosages of both the pesticides at all the exposure periods. Lower concns. of lower exposure periods did not induce much change on germination and other parameters. [on SciFinder(R)]
Functional Foods from Mushroom
Microbial Functional Foods and Nutraceuticals, 2017
Phyton-T: an extract of seaweed (Sargassum wightii) induces defense enzymes against late blight and enhances quality of potato
Late blight (Phytophthora infestans (Mont.) De Barry) is a major threat to potato cultivation. Th... more Late blight (Phytophthora infestans (Mont.) De Barry) is a major threat to potato cultivation. The disease is esp. disastrous during rainy season from May to Sep. Phyton-T, a com. developed aq. seaweed ext. was evaluated for its efficacy on potato. Tuber soaking and foliar spray in combination with Phyton-T (0.4%) and mancozeb (0.3%) for three times at 15 days intervals reduced the disease incidence up to 80% when compared to control. In addn., there was an increased growth in terms of branches and plant height as well as enhanced chlorophyll a b, reducing and non-reducing sugars and well correlated with increased activity of defense related enzymes viz, peroxidase, phenylalanine lyase and polyphenol oxidase. The same treatment shows a very effective in crop yield (no. and wt. of tubers). Disease was not controlled effectively by tuber soaking and foliar spray with only mancozeb or Phyton-T. [on SciFinder(R)]
INTRODUCTON The use of plants for treating diseases is as old a s the human generations. Popular ... more INTRODUCTON The use of plants for treating diseases is as old a s the human generations. Popular observations on the use and efficacy of medicinal plants significantly contribute to the disclosure of their therapeutic properties. India is the gateway of medicinal plant s in the world with a rich source for food and medicine. From past several decades more importance are given to the research on medicinal and some plants were already tested for ABSTRACT Kalanchoe pinnata is a succulent perennial plant which is commonly k nown as ‘air plant’. The anti-diabetic activity of Kalanchoe pinnata leaf extracts was investigated in alloxan induced diabetic swiss albino mice. A comparison was made between the action of different extracts of K. pinnata and a known antidiabetic drug glibenclamide. Hypoglycemic activity, determination f blood glucose by glucose oxidase method and tot al cholesterol was performed in experimental diabetic m e. Dose selection was made on the basis of acute oral toxic...
Journal of Drug Delivery Science and Technology, 2021
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Journal of Environmental Protection, 2017
Biobeneficiation processes involving the separation of valuable minerals from ores and materials ... more Biobeneficiation processes involving the separation of valuable minerals from ores and materials using conventional flotation and flocculation methods have been shown to be promising in recent years. There is an enormous potential to utilize microorganisms as flocculating agents, flotation collectors and/or depressants. The study involves Biobeneficiation of oxide minerals using Bacillus subtilis. Characterization of minerals (hematite, corundum, calcite and quartz) was carried out through XRD, EDAX and FTIR techniques. FTIR of minerals before and after interaction with cells, cell free extract and extracellular proteins was carried out and it has been found that there is a shift or change in the peaks of functional groups. In presence of protein adsorption, amide peaks were found and in case of polysaccharide adsorption, carboxyl peaks were found which justify the flotation and flocculation results. MALDI-TOF was carried out to confirm the molecular weights of the extracted proteins and it was found that molecular weight of proteins on interaction with minerals was higher than that of uninteracted minerals.
Effectiveness of fungicides on seed borne mycoflora, seedling vigour and bio-chemical constituents during early emergence of Bhendi (Abelmoschus esculentus, L Moench) cv. Kiran
The effect of fungicidal seed treatments (Bavistin, Dithane M-45 and Metalaxyl) individually (0.3... more The effect of fungicidal seed treatments (Bavistin, Dithane M-45 and Metalaxyl) individually (0.3%) and in combination against seed-borne pathogens, germination, seedling vigor and biochem. constituents during early emergence of bhendi (Abelmoschus esculentus, L. Moench). The seeds treated with Bavistin and Dithane M-45 (0.1%) were found to be the best in reducing fungi. The incidence of fungi were very high in control, but, they were reduced to the greater extent at incombination of Bavistin, Dithane M-45 (Mancozeb) and metalaxyl (0.1:0.1:0.1%). On the other hand, the treated samples hampered the appreciable seed germination, progressive in root shoot length, seedling vigour compared to untreated. Besides, the control showed decreasing trend in proteins, carbohydrates, amino acids and different non-significantly over treated seeds (individually and incombination). The incombination of Bavistin, Metalaxyl and Dithane M-45 showed significant increase of biochem. constituents. In conclusion, the present findings on bhendi seeds treated individually and incombination of Carbendazim, Metalaxyl and Dithane M-45 indicating the control of seed-borne mycoflora and with enhancement of germination, seedling vigour and biochem. constituents during early emergence. [on SciFinder(R)]
Uploads
Papers by Vinay Raghavendra