Aim:To study the effects of osthole on hyperlipidemic fatty liver and investigatethe possible mechanisms.Methods:A rat model with hyperlipidemic fatty liverwas successfully established by feeding fatty milk for 6 weeks.The experimentalrats were then treated with 5-20 mg/kg osthole for 6 weeks.The mouse hyperlipi-demic model was induced by feeding fatty milk when they were treated with 10-20mg/kg osthole for 3 weeks.Results:After treatment with osthole,the levels of ratserum total cholesterol(TC),triglyceride(TG)and low density lipoprotein-choles-terol significantly decreased as compared with the fatty liver model group(P<0.05or P<0.01).Hepatic weight and its coefficient,the hepatic tissue contents of TC,TG,and malondialdehyde,also significantly decreased(P<0.05 or P<0.01).Infatty milk-induced hyperlipidemic mice,the post-heparin plasma activities of lipo-protein lipase(LPL),hepatic lipase(HL),and total lipase(TL)significantlyincreased after treatment with 10-20 mg/kg osthole for 3 weeks(P<0.05 or P<0.01).Importantly,the histological evaluation of rat liver demonstrated that ostholedramatically decreased lipid accumulation(P<0.01).Conclusion:Osthole wasfound to have therapeutic effects on fatty milk-induced rat fatty liver;the mecha-nisms might be associated with its anti-oxidation and the elevation of the activi-ties of LPL and HL. Aim:To study the effects of osthole on hyperlipidemic fatty liver and investigate the possible mechanisms.Methods:A rat model with hyperlipidemic fatty liverwas successfully established by feeding fatty milk for 6 weeks.The experimental rats were then treated with 5-20 mg/kg osthole for 6 weeks.The mouse hyperlipi-demic model was induced by feeding fatty milk when they were treated with 10-20mg/kg osthole for 3 weeks.Results:After treatment with osthole,the levels of ratserum total cholesterol(TC),triglyceride(TG )and low density lipoprotein-choles-terol significantly decreased as compared with the fatty liver model group(P<0.05or P<0.01).Hepatic weight and its coefficient,the hepatic tissue contents of TC,TG,and malondialdehyde,also significantly decreased (P<0.05 or P<0.01). Infatty milk-induced hyperlipidemic mice, the post-heparin plasma activities of lipo-protein lipase (LPL), hepatic lipase (HL), and total lipase (TL) significant increased increased after treatment with 10- 20 mg/kg osthole for 3 week s(P<0.05 or P<0.01).Importantly,the histological evaluation of rat liver showed that ostholedramatically decreased lipid accumulation(P<0.01).Conclusion:Osthole was found to have therapeutic effects on fatty milk-induced rat fatty liver;the mecha -nisms might be associated with its anti-oxidation and the elevation of the activities of LPL and HL.