Effects of vitamin E and linoleic acid supplementation on lipid peroxidation and cytotoxicity in human keratinocytes.
Toxicologist 1992 Feb; 12(1):174
Cultured human keratinocytes (HK) grown in serum-free medium become deficient in polyunsaturated fatty acids (PUFA) derived from linoleic acid (LA) and this renders HK less responsive to lipid peroxidation and cytotoxicity induced by t-butyl hydroperoxide (BHP). We have previously shown that linoleic acid supplementation (LA-SUP) reverses this condition. Since the growth medium also lacks the antioxidant vitamin E, we investigated the effects of vitamin E succinate supplementation (E-SUP) on BHP-induced lipid peroxidation and cytotoxicity in HK. HK were cultured in medium (modified MCDB153) with combinations of E-SUP (2microM) and/or LA-SUP (10 microM) for 5 days prior to a 2 hour exposure to BHP (1mM). Lipid peroxidation was quantitated by the appearance of thiobarbituric acid-reactive substances (TBARS) and cytotoxicity by the appearance of lactate dehydrogenase (LDH) in the incubation buffer. BHP treatment of unsupplemented HK did not affect LDH release, but significantly increased TBARS. BHP treatment of LA-SUP cells resulted in a further increase in TBARS release (3-fold), and also increased LDH release (2- fold) indicating a cytotoxic effect. E-SUP prevented the effect of BHP on LDH release in LA-SUP cultures. E-SUP also attenuated the effect BHP on TBARS release, but did not prevent the ability of LA-SUP to increase TBARS release in response to BHP. These results suggest that LA and E nutrition of HK should be considered in effects related to toxicity mediated by lipid peroxidation, particularly, in cells grown in serum-free medium.
Analytical-methods; Chemical-analysis; Cell-cultures; Cellular-reactions; Cell-culture-techniques
The Toxicologist. Society of Toxicology 31st Annual Meeting, February 23-27,1992, Seattle, Washingtion