Biol. Pharm. Bull. 29(4) 838—840 (2006)

ral sources, it is important that relevant models of human liver toxicosis are used in order to identify agents with therapeutic potential. Liver toxicity induced by the chemicals and drugs has been recognized as a toxicological problem for a long time. Some of drugs are given for prolonged period of time and in high doses lead to the serious clinical concern. Therefore, it is valuable to use the hepatotoxic agents that are more relevant to human liver toxicosis such as some drugs with liver toxic effect as their adverse effect. Tacrine (1,2,3,4-tetrahydro-9-aminoacridine hydrochloride) is the one of such category of drugs. Tacrine is an acetylcholinesterase inhibitor that is approved for the treatment of Alzheimer’s disease. However, tacrine treatment for Alzheimer’s disease results in reversible hepatotoxicity in 30—50% of patients, which seriously limits its clinical use. Accordingly, the identification of constituents in natural products that have protective effects on tacrine-induced hepatotoxicity would be valuable. In the present study, an immortalized human hepatoma cell line, Hep G2 was employed to screen for agents that protect against tacrine-induced hepatotoxicity. This cell-line was chosen because it retains many cellular functions often lost by primary hepatocytes, e.g., the expression of hepatocyte-specific cell surface receptors and the synthesis and secretion of plasma proteins. During the course of our continuing screening studies for natural hepatoprotective agents, we found that the CHCl3-soluble fraction of the MeOH extract of the root barks of Cudrania tricuspidata BUREAU (Moraceae), which is one of the traditional Chinese medicines used for the treatment of lumbago, hemoptysis, and contusion, showed promising hepatoprotective activity. We describe the isolation and identification of the hepatoprotective constituents in C. tricuspidata root barks.