Chen ML, Tsai SH, Ip SP, Ko KM, Che CT
School of Chinese Medicine, The Chinese University of Hong Kong, Hong Kong, China
 Department of Biochemistry, Hong Kong University of Science & Technology, Clear Water Bay, Hong Kong, China
Long-term alcohol consumption has been reported to increase oxidative stress in multiple organs and accelerate the aging process. A previous study in our laboratory has shown that Wu-Zi-Yan-Zong-Wan (WZ), a "Yang-invigorating" Chinese herbal formula, protected against ethanol-induced toxicity in HepG2 cells transfected to express human CYP2E1, presumably by enhancing mitochondrial antioxidant status and functional ability. The present study aims to investigate whether WZ extract treatment can afford protection against chronic ethanol-induced oxidative stress (a major risk factor of aging) and mortality in rats. The effect of the extract (1.8 g, 4.5 g, and 9 g raw materials/kg per day) on chronic ethanol hepatotoxicity was investigated in rats receiving steady intragastric infusion of ethanol-containing liquid diet. The results showed that long-term (42 days) herbal co-treatment protected against chronic ethanol-induced mortality and hepatotoxicity and in rats, as evidenced by decreased plasma transaminases activities. The extract also suppressed the pathological development of fatty liver, as assessed by histopathological examination and the ratio of liver weight to body weight. The hepatoprotection afforded by the extract was associated with decreases in the extents of reactive oxygen species production, lipid peroxidation, and oxidative modification of proteins, as well as the reversal of altered mitochondrial reduced glutathione level. The results suggest that the suppressive effect of WZ on chronic ethanol-induced oxidative stress and mortality may be attributed to the antioxidant action, particularly in mitochondria.