Vitamin E protects ovary cells against polychlorinated biphenyl induced toxicity

Polychlorinated biphenyls (PCBs) are ubiquitous persistent organic pollutants unintentionally released from anthropogenic sources. Among all PCBs congeners, PCB-153 is usually the most abundant in the environment and exhibits the highest concentrations across most tissue samples from regional (Croatia) animal specimens. Toxic potential of PCBs has been linked to various deleterious effects on human health. This study was focused on PCB 153 effects at ovarian cellular level with the intention of reducing toxic potential by vitamin E. Chinese hamster ovary cells (CHO-K1) were exposed to different concetrations of PCB 153 (10- 100 μM), and cytotoxicity was determined by MTT method. Inhibitory effects on CHO-K1 cells were observed at all concentrations of PCB153 as confirmed with determined IC50 values: 117.96 μM after 24 hours, 112.79 μM after 48 hours and 86.71 μM after 72 hours. Statistically significant inhibition of cellular proliferation was detected already after 24 hours with 75 µM PCB 153 (p<0.05) and therefore this concentration was further used in evaluation of possible protective effect of vitamin E (50 - 150 μM). In the presence of vitamin E, increase of viability was determined by different methods with distinct endpoints: MTT, Trypan blue, Neutral red and Kenacid blue. Statisticly significant protective effects were determined for 75 -150 μM vitamin E with Trypan Blue and MTT methods. Malondialdehyde as one of the toxic products of lipid peroxidation and ROS (Reactive Oxygen Species) formation, were used in oxidative stress evaluation, and results confirmed the antioxidative capacity of vitamin E.