The effect of green tea on the activity of aldehyde dehydrogenase (ALDH) in the liver of rats during chronic ethanol consumption.

PURPOSE Alterations in the redox state during chronic ethanol consumption are associated with the oxidation of ethanol via alcohol and aldehyde dehydrogenase. Among various antioxidants present in food, strong antioxidative effects have been attributed to polyphenols of green tea. The aim of the present study was to investigate the effect of green tea consumption during chronic ethanol intake on the activity of aldehyde dehydrogenase in the liver of rats during maturation and aging. MATERIALS AND METHODS The activity of ALDH was measured in the livers of rats aged 2 (young), 12 (adult) and 24 months (old). The rats were fed with a control liquid Lieber DeCarli diet, control liquid diet containing green tea (3 g/l), ethanol liquid diet (with increasing ethanol dose from 2.3% to 7%) and ethanol liquid diet containing green tea. RESULTS Chronic ethanol consumption significantly increased the liver ALDH activity in young and adult rats but decreased this activity in old animals. The drinking of green tea did not alter ALDH activity in ethanol-consuming rats. Drinking green tea alone significantly increased ALDH activity in young and adult rats but did not alter this activity in old rats. CONCLUSIONS These results demonstrate that green tea administered during chronic ethanol consumption does not prevent the changes in the hepatic ALDH activity in the rats at each age.