AbstractIn the present study, we examined the therapeutic effects of pentacyclic triterpenes, oleanolic acid (OA) and maslinic acid (MA), on hyperlipidemia in a high‐cholesterol diet model. Hyperlipidemia was induced in male Sprague‐Dawley rats by feeding with a high‐cholesterol diet (HCD) for 30 days. MA and OA were supplemented (100 mg/kg body wt/day) during the last 15 days. The levels of serum total cholesterol (TC), triglyceride (TG), high‐density lipoprotein‐cholesterol (HDL‐C), and low‐density lipoprotein‐cholesterol (LDL‐C) increased in hyperlipidemic rats. An apparent increase in the expression of Acyl‐CoA cholesterol acyltransferase (ACAT) mRNA was seen in HCD‐fed rats. The activities of hepatic marker enzymes that serve as indices of cellular injury were also altered in HCD‐fed rats. Treatment with triterpenes modulated the abnormalities induced by hyperlipidimia. Lipid accumulation was decreased in histological findings. Elevated hepatic glycogen content (P<0.05) in triterpene groups was observed compared with HCD‐fed groups. Furthermore, ACAT gene expression was suppressed compared with hyperlipidemia‐induced groups without triterpenes. It can be concluded that triterpene treatment possesses therapeutic effects on diet‐induced hyperlipidemia by inhibiting the intestinal absorption and storage of cholesterol. Drug Dev Res 68:261–266, 2007. © 2007 Wiley‐Liss, Inc.