Effects of vitamin E on lindane induced cytotoxicity in Chinese Hamster Ovary cell line

Abstract

Chinese Hamster Ovary (CHO K1) cell line was introduced in order to reduce the expensive and regulated tests in different animal species usually used for the safety assessment of pesticides. Lindane (gamma-hexachlorocyclohexane) is an insecticide with restricted permission of usage, declared as a highly toxic compound and their residues in the environment may present also a risk for the reproductive processes. The in vitro effects of the antioxidant alpha-tocopherol, vitamin E, on lindane induced cytotoxicity was studied by two different bioassays: Trypan Blue exclusion method and Kenacid Blue method. The cells were maintained at 37 ˚ C in an atmosphere of 95% air and 5% CO_2 in the medium Dulbecco’ s MEM supplemented with 5% newborn calf serum. The biomass was produced in T-bottles, cells were separated in the early logarithmic phase of growth and seeded on 6-multiwell plates. Initial concentration of CHO cells was 2x10^4 cells/mL/well. Target cells were preincubated with two different concentrations of vitamin E (25 micro g/mL and 50 micro g/mL) for 24 hours, and then treated up to 100 micro g/ml of lindane. Cytotoxicity of lindane was determined after 72 hours in the presence or absence of vitamin E. The applied concentration of lindane markedly inhibited the cell growth. When target cells were preincubated with higher dose of vitamin E (50 micro g/mL), the cell viability was significantly enhanced compared to the observed results in cells exposed only to lindane. These results suggest that vitamin E may exert a protective role in cell defence against lipophilic xenobiotics such as lindane.