Effect of ethanol consumption and vitamin E supplementation on in vivo lipid peroxidation in rats

This study investigated the effects of short and long term vitamin E supplementation on ethanol induced lipid peroxidation in rats. Groups of rats were fed liquid diets in which ethanol provided 36% of the total calories (v/v) for 28 days or 18 months. The 28-day fed rats received supplemental alpha tocopherol 142 IU/kg of diet while those fed ethanol for 18 months were injected i.p. with 528 IU alpha tocopherol/kg body weight/day for 2 days prior to termination. At the end of the feeding period, ethane exhalation, conjugated dienes and lipid fluorescence were estimated as indices of free radical mediated products. Rats fed the ethanol diets for 28 days and 18 months exhaled more ethane than pair-fed controls. Increases in conjugated dienes and lipid fluorescence were observed in both the 28 day and 18 month groups of alcohol fed rats (p<0.05). Supplementation of the ethanolic diet with alpha tocopherol in the 28 day fed rats reduced conjugated dienes and lipid fluorescence (p<0.05) to values similar to controls; and also reduced ethane exhalation to near control levels (p<0.05). Rats fed ethanol for 18 months and given i.p. vitamin E injections showed reduced ethane exhalation but no reduction in the accumulative indices (lipid fluorescence) of lipid peroxidation. Thus, vitamin E act by reducing on-going in vivo lipid peroxidation thus preventing the accumulation of lipid peroxide products. In the present study, vitamin E probably acted as a free radical scavenger in retarding alcoholic liver damage.