PT - JOURNAL ARTICLE AU - Liu, J AU - Liu, Y AU - Madhu, C AU - Klaassen, C D TI - Protective effects of oleanolic acid on acetaminophen-induced hepatotoxicity in mice. DP - 1993 Sep 01 TA - Journal of Pharmacology and Experimental Therapeutics PG - 1607--1613 VI - 266 IP - 3 4099 - http://jpet.aspetjournals.org/content/266/3/1607.short 4100 - http://jpet.aspetjournals.org/content/266/3/1607.full SO - J Pharmacol Exp Ther1993 Sep 01; 266 AB - Oleanolic acid (OA) is a triterpenoid compound that has been shown to protect against a number of hepatotoxicants, and is used in China to treat hepatitis. In the present study, we examined the effect of OA on acetaminophen (AA)-induced acute liver injury in mice and the mechanism(s) of protection. OA pretreatment (25-100 mg/kg s.c. for 3 days) remarkably decreased AA (500 mg/kg i.p.)-induced liver damage in mice, as indicated by decreased serum activities of alanine aminotransferase and sorbitol dehydrogenase, as well as by histopathological observation. Additionally, OA pretreatment mitigated AA (300-450 mg/kg i.v.)-induced depletion in liver glutathione (GSH) content. The protective effect was not evident until 24 hr after a single s.c. injection of OA (300 mg/kg) and lasted for 72 hr. To examine the mechanism of this protection, the biliary and urinary excretion of AA and AA metabolites were measured for 2 hr after AA administration (150 mg/kg i.v.) in bile duct-cannulated mice. OA pretreatment resulted in an increased urinary excretion of AA-glucuronide and a decreased biliary excretion of AA-GSH. Microsomes from OA-pretreated mice, incubated in vitro with AA, produced less benzoquinoneimine intermediate than controls, as determined by the formation of AA-GSH. Hepatic subcellular distribution of [3H] AA to the nuclear fraction was also decreased by OA. OA pretreatment of mice had no influence on liver UDP-glucuronic acid concentration, but increased hepatic glucuronosyltransferase activity toward AA. In summary, OA pretreatment dramatically protects against AA-induced hepatotoxicity in mice.(ABSTRACT TRUNCATED AT 250 WORDS)