Hypolipidemic effects of Sophora flavescens and its constituents in poloxamer 407-induced hyperlipidemic and cholesterol-fed rats

In this study, we investigated the hypolipidemic effects of Sophora flavescens in poloxamer 407-induced hyperlipidemic and cholesterol-fed rats. The MeOH extract and 4 fractions of S. flavescens were administered at doses of 250 and 100 mg/kg body weight, respectively, once a day for 3 d to the poloxamer 407-induced hyperlipidemic rats. Serum lipid levels such as total cholesterol (TC), triglycerides (TG), and low-density lipoprotein-cholesterol (LDL-C) were markedly elevated in the poloxamer 407-induced hyperlipidemic control rats, while lipid levels were significantly decreased in the rats administered the MeOH extract or 4 fractions of S. flavescens. In addition, serum high-density lipoprotein-cholesterol (HDL-C) was reduced in the poloxamer 407-induced hyperlipidemic control rats. However, oral administration of both the MeOH extract and 4 fractions significantly increased HDL-C levels. Of the tested fractions, the EtOAc fraction showed the strongest lipid-lowering effect, as well as a high antiatherogenic potential with atherogenic index (A.I.) values of less than 1.92. We also investigated the hypolipidemic effects of the main compounds of the EtOAc fraction, kurarinol and kuraridinol, using the hyperlipidemic and hypercholesterolemic animal models. Here, elevated TC, TG, and LDL-C levels in the poloxamer 407-induced hyperlipidemic and cholesterol-fed rats were significantly reduced after oral administration of the compounds, and HDL-C levels had a significant increase. Furthermore, A.I. values were lowered by administering kurarinol and kuraridinol. In particular, kuraridinol exhibited stronger protective activities against hyperlipidemia than kurarinol. These results suggest that S. flavescens and its constituents may be effective cholesterol-lowering agents and useful for preventing hypercholesterolemic atherosclerosis.