A Comparative Study of the Cytotoxic Effects and Oxidative Stress of Gossypol on Bovine Kidney and HeLa Cell Lines

Background:  Cotton seed is one of the main sources of protein in animal feeds, containing gossypol, which has been shown to have toxic effects. Results reported by various studies also indicate the anti-cancer effects of gossypol on various cell types. However, its toxic effects on human and animal cells have not been fully established. This study was planned to investigate, for the first time, the cytotoxic effects and oxidative stress induced by gossypol on normal bovine kidney (BK) and HeLa cell lines, representing typical healthy and cancer cells, respectively. Methods: The BK and HeLa cell lines were treated for 24, 48 or 72 hours with 5, 10 or 20 ppm of gossypol (+/-). The cellular bio-availability and cytotoxicity were measured by MTT assay. The catalase and malondialdehyde (MDA) levels were also measured to represent the oxidative stress parameters. Results: The percentages of cytotoxicity in BK and HeLa cell lines were calculated at a gossypol concentration of 5, 10 and 20 ppm over 24, 48 or 72 hours of incubation, respectively. The IC50 values were also determined for the two cell lines. No changes in the catalase and lipid peroxidase activities were observed in either cell line. Conclusions: The percentage of the gossypol cytotoxicity was concentration-dependent. By comparing the IC50 in both cell lines using ANOVA analysis, a significant difference was observed, suggesting that Hela cells were less sensitive to gossypol than the BK cells. Lack of changes in the oxidative stress, as tested by catalase and MDA assays, demonstrated that gossypol did not induce oxidative stress in either cell line.