Hypoglycemic Activity of Purified Polysaccharides from Inonotus obliquus in Vitro

The crude polysaccharides from Inonotus obliquus were obtained by water extraction and alcohol precipitation. And the crude polysaccharides were separated and purified from DEAE-52 cellulose column to obtain two kinds of polysaccharides(EIOP1 and EIOP2). A-Glucosidase inhibitory activity,glucose consumption of normal HepG2 cells,and insulin-resistant HepG2 cells were used as the main indicators to investigate the hypoglycemic activity of different concentrations of two purified polysaccharides from Inonotus obliquus(10,20,40,80,160,and 320 μg/mL). α-glucosidase inhibitory activity used acarbose as a positive control,and glucose consumption experiment was used with metformin as a positive control. The results showed that the α-glucosidase inhibitory activity of EIOP1 and EIOP2 were higher than that of the positive control group acarbose and crude polysaccharide,and the IC₅₀ values were 39.18 and 29.87 μg/mL,respectively. The concentration of EIOP1 on HepG2 cells was extramly significant higher than that of the control group at a concentration of 80 μg/mL(P<0.01). The promotion effect was the best,which was 30.62% higher than that of the control group. When the concentration of EIOP2 was 40 μg/mL,the glucose consumption was extramly significant higher than that of the control group,which was 75.99% higher than the control(P<0.01). The glucose consumption experiment of IR-HepG2 cells showed that EIOP1 had the best promotion effect at the concentration of 40 μg/mL,which was 30.00% higher than that of the IR group. The concentration of EIOP2 was the best at the concentration of 80 μg/mL. The IR group increased by 90.49%,which was higher than that of the Met group(P<0.01). Therefore,the purified polysaccharide of Inonotus obliquus would had a promoting effect on glucose consumption in normal HepG2 cells and insulin-resistant HepG2 cells,and better inhibitory activity against α-glucosidase than the crude polysaccharides.