Akhilesh Dubey

Study on antioxidant activity of common dry fruits

This study investigates the antioxidant activity of different dry fruits (almonds, walnut, cashew nut, raisins, chironji) through several chemical and biochemical assays: reducing power, lipid peroxidation damage in biomembranes, determination of antioxidant enzymes activity (SOD and CAT). To estimate the total phenolic content, the assay using Folin-Ciocalteu reagent was used. The EC(50) values were calculated for all the methods in order to evaluate the antioxidant efficiency of each dry fruit. The results obtained were quite heterogenous, revealing significant differences among the dry fruits. The methanolic extract of walnut showed the higher value of antioxidant activity based on lipid peroxidation assay. The higher phenolic content was found in walnuts followed by almonds cashew nut, chironji and least phenolic content was found in raisins. Walnut revealed the best antioxidant properties, presenting lower EC(50) values in all assays except in antioxidant enzymatic activity.

Oxidative Stress and Nano-Toxicity Induced by TiO2 and ZnO on WAG Cell Line.

Metallic nanoparticles are widely used in cosmetics, food products and textile industry. These particles are known to cause respiratory toxicity and epithelial inflammation. They are eventually released to aquatic environment necessitating toxicity studies in cells from respiratory organs of aquatic organisms. Hence, we have developed and characterized a new cell line, WAG, from gill tissue of Wallago attu for toxicity assessment of TiO2 and ZnO nanoparticles. The efficacy of the cell line as an in vitro system for nanoparticles toxicity studies was established using electron microscopy, cytotoxicity assays, genotoxicity assays and oxidative stress biomarkers. Results obtained with MTT assay, neutral red uptake assay and lactate dehydrogenase assay showed acute toxicity to WAG cells with IC50 values of 25.29±0.12, 34.99±0.09 and 35.06±0.09 mg/l for TiO2 and 5.716±0.1, 3.160±0.1 and 5.57±0.12 mg/l for ZnO treatment respectively. The physicochemical properties and size distribution of nanoparticles were characterized using electron microscopy with integrated energy dispersive X-ray spectroscopy and Zetasizer. Dose dependent increase in DNA damage, lipid peroxidation and protein carbonylation along with a significant decrease in activity of Superoxide Dismutase, Catalase, total Glutathione levels and total antioxidant capacity with increasing concentration of exposed nanoparticles indicated that the cells were under oxidative stress. The study established WAG cell line as an in vitro system to study toxicity mechanisms of nanoparticles on aquatic organisms.

In vitro cytotoxicity assessment of two heavy metal salts in a fish cell line (RF)

Abstract Labeo rohita (rohu) is one of most important of Indian major carps, which is highly ranked among the important freshwater aquaculture species in the world. Heavy metals are major risk factors for aquatic health, which are biomagnified through the food chain. The present study was carried out to investigate the effect of different divalent salts of two heavy metals, such as zinc (ZnCl2, ZnSO4 and ZnNO3) and cadmium (CdCl2 and CdSO4), in an established fish cell line, RF developed from fin tissue of L. rohita. The RF cell line was used for assessment of heavy metal cytotoxicity through various endpoint assays, including maximum tolerated dose (MTD) determination, 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay, neutral red (NR) uptake assay, and Coomassie brilliant blue (CBB) assay. Results revealed that these heavy metal salts were cytotoxic to the RF cell line at varied concentrations. MTD values were found to be 1.563, 3.125, 6.25, 12.5 and 25 mg/L for CdCl2, CdSO4, ZnCl2, Zn(NO3)2 and ZnSO4, respectively. The half-maximal inhibitory concentration values calculated by MTT, NR and CB assay were 53.83 ± 7.02, 58.03 ± 9.12 and 79.20 ± 15.27 for ZnSO4, 26.44 ± 7.01, 36.60 ± 7.82 and 155.6 ± 14.75 for Zn(NO3)2, 20.26 ± 17.95, 16.94 ± 7.05 and 87.54 ± 7.58 for ZnCl2, 5.166 ± 0.57, 15 ± 1 and 41.80 ± 8.38 for CdSO4 and 4.966 ± 0.56, 9.56 ± 1.73 and 20.93 ± 4.47 for CdCl2. This study establishes the RF cell line as an in vitro tool for assessment and monitoring of heavy metal concentration in the aquatic environment.