Abstract: Objective: To investigate the ability of Phaeoporus obliquus saponins in scavenging the fat accumulation of liver cells,and to clarify its effect on the prevention of non-alcoholic fatty liver disease(NAFLD). Methods: The safe concentrations of Phaeoporus obliquus in the HepG2 cells was selected by MTT method. The cells treated with 60.000,6.000,0.600,0.060,and 0.006 g·L^-1 Phaeoporus obliquus saponins were regarded as treatment groups;the blank well without drugs and cells was regarded as control group,and the HepG2 cells without drugs were regarded as model group.The survival rates of HepG2 cells in various groups were detected by MTT method;the clearance rates of triglyceride(TG) in the HepG2 cells in various groups were detected;the morphology of HepG2 cells was detected by oil red O staining. Results: The optimum extraction condition of Phaeoporus obliquus saponins were as followed:the liquid ratio was 1:15,the extraction temperature was 30℃,the extraction time was 30 min, and the ultrasonic power was 50%.Compared with control group,the survival rate of HepG2 cells in 0.060 g·L^-1 Phaeoporus obliquus saponins group was decreased and the clearance rate of TG was increased(P<0.05),and the lipid interfusion in cells was significantly reduced.Compared with control group,the survival rate of HepG2 cells in 0.600 g·L^-1 Phaeoporus obliquus saponins group was decreased and the clearance rate of TG was increased(P<0.01),and the number of lipid drops was significantly reduced. Conclusion: The extraction rate of Phaeoporus obliquus saponins is obviously improved under the optimum extraction conditions and it has good in vitro lipid-lowering activity,and it has better preventive effect on NAFLD.

Key words: Phaeoporus obliquus, saponins, fat accumulation, triglyceride, HepG2 cells