Study on in vitro hypoglycemic effect and mechanism of Polygonum capitatum / 中草药

ABSTRACT

Objective: To investigate the hypoglycemic targets of Polygonum capitatum. Methods: Human liver cancer HepG2 cells were adopted to detect the supernatant culture medium glucose content, and the effect on PPAR-α and GLUT4 gene expression was investigated by qRT-PCR after treatment of P. capitatum extracts (PCB). INS-1 cells similar to islet β cells, divided into drug protection group and repair group, were adopted to determine the cell proliferation activity by MTT; The intracellular SOD and MDA levels were measured by biochemical method; The Cyt C and Caspase-3 protein expression levels were detected by Western blotting. Adopting maltose as substrate of α-glycosidase enzyme inhibition model, the inhibitory efficiency of PCB on glycosidic enzyme was determined. Results: PCB group significantly promoted the absorption of HepG2 cells to supernatant glucose and increased the expression of PPAR-α and GLUT4 genes significantly. Aim at protection and repair of INS-1 cells, PCB group significantly increased cell vitality and SOD level, reduced MDA level compared with model group, and at the same time significantly reduced Cyt C and Caspase-3 protein expression levels. PCB had inhibitory activity to α-glycosidase enzymes, with IC50 of 11.53 mg/mL. Conclusion: PCB could significantly increase the PPAR-α and GLUT4 genes expression to promote the absorption of HepG2 cells to supernatant glucose by blocking the Cyt C-Caspase-3 pathways to reduce apoptosis of islet cells which were damaged by STZ and by raising SOD and declining MDA to improve INS-1 cell oxidative stress; What’s more it has inhibitory activity to α-glycosidase enzymes.