Renu Bhatt

Simultaneous production of detergent stable keratinolytic protease, amylase and biosurfactant by Bacillus subtilis PF1 using agro industrial waste

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Arsenic resistance and accumulation by two bacteria isolated from a natural arsenic contaminated site.

Forty‐three indigenous arsenic resistant bacteria were isolated from arsenic rich soil of Rajnandgaon district in the state of Chhattisgarh, India by enrichment culture technique. Among the isolates, two of the bacteria (As‐9 and As‐14) exhibited high resistance to As(V) [MIC ≥ 700 mM] and As(III) [MIC ≥ 10 mM] and were selected for further studies. Both these bacteria grew well in the presence of arsenic [20 mM As(V) and 5 mM As(III)], but the isolate As‐14 strictly required arsenic for its survival and growth and was characterized as a novel arsenic dependent bacterium. The isolates contributed to 99% removal of arsenic from the growth medium which was efficiently accumulated in the cell. Quantitative estimation of arsenic through Atomic Absorption Spectrophotometer revealed that there was >60% accumulation of both As(V) and As(III) by the two isolates. Scanning Electron Microscopic analysis showed a fourfold increase in bacterial cell volume when grown in the presence of arsenic and the results of Transmission Electron Microscopy and energy‐dispersive X‐ray spectroscopy proved that such an alteration was due to arsenic accumulation. Such arsenic resistant bacteria with efficient accumulating property could be effectively applied in the treatment of arsenic contaminated water.

Reactive oxygen species: sources, consequences and targeted therapy in type 2 diabetes.

Abstract Oxidative stress has been considered as a central mediator in the progression of diabetic complication. The intracellular reactive oxygen species (ROS) leads to oxidative stress and it is raised from the mitochondria as well as by activation of five major pathways: increased polyol pathway flux, activation of protein kinase C (PKC) pathway, increased formation of advanced glycation end products (AGEs), over activity of hexosamine pathway and increased production of angiotensin II. The increased ROS through these pathways leads to β-cell dysfunction and insulin resistance, responsible for cell damage and death. This review not only highlights the sources of ROS production and their involvement in the progression of diabetes, but also emphasizes on pharmacological interventions and targeting of ROS in type 2 diabetes. This review summarizes the ROS as potential therapeutic targets, based on a putative mechanism in the progression of the diabetes. It also summarizes current knowledge of ROS activation in type 2 diabetes as well as ROS as a possible target for its treatment. Eventually, it would be a promising target for various strategies and drugs to modulate ROS levels in diabetes.

Exiguobacterium mediated arsenic removal and its protective effect against arsenic induced toxicity and oxidative damage in freshwater fish, Channa striata

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Protective role of Emblica officinalis hydro-ethanolic leaf extract in cisplatin induced nephrotoxicity in Rats

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Hedychium coronarium Rhizomes: Promising Antidiabetic and Natural Inhibitor of α-Amylase and α-Glucosidase

Abstract Hedychium coronarium Koen., commonly known as ginger lily, is considered an endemic medicinal plant. In the present study, the antidiabetic action of its rhizomes was investigated by α-amylase and α-glucosidase inhibition assay, and the active compounds were identified through bioactivity guided isolation technique. Among the six different extracts, the EA extract has shown highest inhibition, and the subfractions from active EA extract were separated by silica gel column chromatography. The subfraction showing highest inhibition was investigated for its chemical composition by high-resolution liquid chromatography–mass spectroscopy (HRLC-MS/MS). The fatty acids such as suberic acid and terpenes such as triparanol, ginkgolide C, and swietenine were found to be the major compounds in the subfractions. The present work revealed that H. coronarium rhizome extract and its active constituent could be used as a natural inhibitor of these two carbohydrate-metabolizing enzymes and may play a key role in the management of diabetes.

Improved biotransformation of arsenic by arsenite oxidase – Chitosan nanoparticle conjugates

Recent developments in the potential use of nanoparticles as carriers of enzyme have attracted great attention. In the present study, arsenite oxidase (AOase) enzyme capable of transforming the more toxic arsenite [As(III)] to the less toxic arsenate [As(V)] was extracted from an arsenic resistant bacterium (Exiguobacterium sp. As-9) and partially purified. Chitosan nanoparticles were prepared on the basis of ionic gelation of chitosan with tripolyphosphate (TPP) anions. The purified AOase was immobilized efficiently by physical adsorption on to chitosan nanoparticles and were characterized for particle size, morphology, zeta potential, AOase loading efficiency and in vitro transformation assay. The chitosan nanoparticles were spherical in shape with the average diameter of 100nm which increased to 294nm upon successful loading of AOase. Under optimized conditions, the loading capacity of the chitosan nanoparticle was determined to be 71% for AOase. Further, immobilization also increased the stability of AOase at varying temperature (4-37°C) and pH (5-10) for a period of 30days with the increased enzymatic activity (159.57Uml-1). It also facilitated increased biotransformation (89%) of As(III) to As(V). A conceptual understanding of biological responses to AOase loaded chitosan nanoparticles is needed for the development of novel methods of drug delivery.