Lindane-induced cytotoxicity and the role of vitamin E inChinese hamster ovary(CHO-K1) cells

Resveratrol ameliorates ortho- polychlorinated biphenyls' induced toxicity in ovary cells

Polychlorinated biphenyls (PCBs) can induce chronic oxidative stress, inflammation, and cell death, leading to coronary heart disease, endothelial dysfunction, neurotoxicity, cancer, obesity, type 2 diabetes, reproductive dysfunction, etc. The aim of this study was to investigate possible protective effect of resveratrol (2.5-20 μM) in ovarian cells exposed to PCBs. An emphasis was on identifying mechanisms of resveratrol action upon distinct structure of the individual PCB congener-planar dioxin-like PCB 77 and non-planar di-ortho-substituted PCB 153. Multiple toxicity endpoint analysis was performed. Cell viability/proliferation was assessed by Trypan Blue exclusion method, Neutral Red, Kenacid Blue, and MTT bioassays. The level of oxidative stress was measured by fluorescent probes, and flow cytometry was applied to evaluate the mode of cell death. Resveratrol applied alone did not affect cell proliferation and viability in doses up to 20 µM, although significant antioxidative activity was observed. Toxic effects of ortho-PCB 153 (cytotoxicity, oxidative stress, and cell death) were mitigated by resveratrol. On the contrary pre-incubation with resveratrol did not result in cell viability protection when planar PCB 77 was applied. This indicates that resveratrol efficacy may be linked to specific structure of the individual congener, suggesting nutritional modulation of environmental insults caused by ortho-PCBs. We point out the importance of resveratrol dosage considering that synergistic cytotoxic effect with both PCB congeners is observed at concentrations ≥ 10 μM.

Lindane removal in contaminated soil by defined microbial consortia and evaluation of its effectiveness by bioassays and cytotoxicity studies

Lindane contamination in different environmental matrices has been a global concern for long. Bacterial consortia consisting of Paracoccus sp. NITDBR1, Rhodococcus rhodochrous NITDBS9, Ochrobactrum sp. NITDBR3, NITDBR4 and NITDBR5 were used for the bioremediation of soil artificially contaminated with lindane. The bacteria, Paracoccus sp. NITDBR1 and Rhodococcus rhodochrous NITDBS9, have been selected based on their lindane degrading capacity in liquid culture conditions (~80-90 %). The remaining three bacteria were chosen for their auxiliary properties for plant growth promotion, such as nitrogen fixation, phosphate solubilization, indole-3-acetic acid production and ammonia production under in vitro conditions. In this study, market wastes, mainly vegetable wastes, were added to the soil as a biostimulant to form a biomixture for assisting the degradation of lindane by bioaugmentation. Residual lindane was measured at regular intervals of 7 days to monitor the biodegradation process. It was observed that the consortium could degrade ~80% of 50 mg kg^-1 lindane in soil which was further increased in the biomixture after six weeks of incubation. Bioassays performed on plant seeds and cytotoxicity studies performed on human skin fibroblast and HCT116 cell lines revealed that the groups contaminated with lindane and treated with the bacterial consortium showed lower toxicity than their respective controls without any bacteria. Hence, the use of both pesticide degrading and plant growth-promoting bacteria in a consortium can be a promising strategy for improved bioremediation against chemical pesticides, particularly in soil and agricultural fields, simultaneously enhancing crop productivity in those contaminated soil.