Lipid-lowering effect of hydroalcoholic extracts of Gynura procumbens in Chemical- and High-fat diet-induced hyperlipidemic rats

Abstract

Objective: The present study was carried out to investigate lipid-lowering effect of hydroalcoholic extracts of Gynura procumbens in chemical- and high-fat diet (HFD)-induced hyperlipidemic rats. Materials and Methods: The lipid-lowering effect of hydroalcoholic extracts was investigated in poloxamer-407 (P-407)-induced acute hyperlipidemic rat model. The most active extract was subjected to phytochemical analysis by high-performance liquid chromatography-ultraviolet (HPLC-UV) using phenolic acids as marker compounds and evaluated in HFD-induced chronic hyperlipidemic rats. Results: The evaluation on hydroalcoholic extracts of G. procumbens showed that 95% ethanolic extract (95EEGP) was the most potent extract that significantly reduced serum total cholesterol (TC, P < 0.05) and triglycerides (TG, P < 0.001) levels. The 95EEGP contained 7.18, 3.20, 28.31, and 9.72 mg/g dried extract of chlorogenic acid (CA), 3,4-dicaffeoylquinic acid (3,4DC), 3,5DC, and 4,5DC, respectively. The extract at doses of 200 and 500 mg/kg significantly reduced serum TC, TG, low-density lipoprotein-cholesterol (LDL-C), and atherogenic index (A. I.) levels of the P-407-induced hyperlipidemic rats, in a dose-dependent manner (P < 0.01 or better) but had no effect on high-density lipoprotein-cholesterol (HDL-C). On HFD-induced hyperlipidemic rats, the 95EEGP at doses of 250, 500, and 1000 mg/kg significantly reduced the serum TC, TG, LDL-C, and A. I. levels (P < 0.05 or better) while increased serum HDL-C (P < 0.001). The effect was dose-dependent showing comparable effect to that of atorvastatin at moderate and high doses. Conclusion: The present study demonstrated the lipid-lowering potential of the 95EEGP of G. procumbens in chemical- and HFD-induced hyperlipidemic rat models. Further investigations are warranted to elucidate its mechanism of its lipid-lowering action. Abbreviations used: HFD, high-fat diet; P-407, poloxamer-407; 95EEGP, 95% ethanolic extract; TC, total cholesterol; TG, triglycerides; 3,4DC, 3,4-dicaffeoylquinic acid; 3,5DC, 3,5-dicaffeoylquinic acid; 4,5DC, 4,5-dicaffeoylquinic acid; LDL-C, low-density lipoprotein-cholesterol; A. I., atherogenic index; HDL-C, high-density lipoprotein-cholesterol; CVD, cardiovascular disease; HMG CoA, 3-hydroxy-3-methylglutaryl coenzyme A; G. procumbens, Gynura procumbens; HPLC-UV, high-performance liquid chromatography-ultraviolet; CA, chlorogenic acid; 75EEGP, 75% ethanolic extract; 50EEGP, 50% ethanolic extract; 25EEGP, 25% ethanolic extract; AEGP, water extract; MeOH, methanol; SEM, standard error mean; VLDL-C: Very low-density lipoprotein-cholesterol.