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

Abstract

Lindane, a toxic insecticide from the persistent organic pollutants (POP’s) group, may act as an endocrine disrupter affecting crucial tissues of reproductive system. In this study a Chinese Hamster Ovary cell line (CHO-K1) was applied to assess the potential of lindane cytotoxicity at the cellular level. The methods of Trypan blue exclusion, MTT and Kenacid blue assays were used to assess cytotoxicity and confirmed a decrease in the number of viable CHO-K1 cells at 34.4–344 μM lindane during 24, 48 and 72 hours of exposure. The cell proliferation tests showed significant inhibition (p < 0.025–0.001 vs control) and a progressive increase in toxicity with increasing lindane concentrations. Corresponding IC₅₀ values were determined with each applied method. After 72 h of lindane exposure, IC₅₀ values were 184 μM according to the Trypan blue method and 272 and 256 μM with the Kenacid blue and MTT assays, respectively. Morphological changes induced by the cytotoxicity of lindane were followed by the fluorescence microscopy and only necrotic cells were detected. Vitamin E (25 and 50 μg/mL) was used for protection of ovarian cells against lidane-induced oxidative stress damage, and lipid peroxidation was postulated as a possible mechanism of lindane toxicity. The viability of cells pre-incubated with vitamin E was significantly enhanced (up to p < 0.025) compared to the results observed in cells exposed to lindane only, but vitamin E treatment could not prevent complete lindane-induced cytotoxicity. Results suggest that vitamin E may exert a slightly protective role in cell defense against lipophilic pro-oxidant xenobiotics such as lindane.

Keywords::

• CHO-K1 cells
• cytotoxicity
• IC₅₀ values
• lindane
• vitamin E

Acknowledgements

This study was supported by the Ministry of Science, Education and Sports of the Republic of Croatia, grants No. 0582184-2232 and No. 0582184-2414.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.