165. An ursolic acid-enriched extract of Cynomorium songaricum protects against carbon tetrachloride hepatotoxicity and gentamicin nephrotoxicity in rats possibly through a mitochondrial pathway: A comparison with ursolic acid.

Chen J, Wong HS, Leung HY, Leong PK, Chan WM, Chen N, Ko KM

Division of Life Science, Hong Kong University of Science and Technology, Clear water bay, Hong Kong.

Cynomorium songaricum, which is an herbal tonic for treating impotence in Chinese medicine, serves as a popular health-promoting or invigorating food in China, particularly in the Inner Mongolia Province. Recent studies have shown that HCY2, an active fraction of C. songaricum, and its major ingredient ursolic acid (UA), protect against myocardial ischemia/reperfusion injury in rats. In the present study, we further investigated the effects of HCY2 or UA on carbon tetrachloride (CCl4) hepatotoxicity and gentamicin nephrotoxicity in rats. The results indicated that HCY2 pretreatment protected against CCl4 hepatotoxicity and gentamicin nephrotoxicity, as evidenced by the significant inhibition of plasma aspartate aminotransferase and alanine aminotransferases activities as well as decreases in plasma creatinine and blood urea nitrogen levels, respectively. The hepatoprotection and nephroprotection were associated with the improvement in mitochondrial functional ability, as assessed by the measurement of ATP generation capacity, as well as the enhancement in glutathione redox status, possibly through the induction of mitochondrial uncoupling in rat liver and kidney tissues. However, UA pretreatment at doses equivalent to those of HCY2 was found to protect against CCl4 hepatotoxicity but not gentamicin nephrotoxicity in rats. The discrepancy between HCY2 and UA may be related to the bioavailability of UA to kidney tissue in rats.