Protective Effect of Astragalus Polysaccharide Against High glucose‐induced Endoplasmic Reticulum Stress by Activation of AMP‐activated Protein Kinase in Human HepG2 Cells

OBJECTIVE Astragalus polysaccharide (APS) activates AMP‐activated protein kinase (AMPK) and attenuates endoplasmic reticulum (ER)stress. We investigated whether AMPK is required for the attenuation of high glucose‐induced ER stress of APS in human HepG2 cells. RESEARCH DESIGN AND METHODS HepG2 cells were exposed to low glucose (5.5mmol/L) or high glucose (30mmol/L) for 24 h. The expression of ER stress‐related marker (p‐perk) was evaluated with or without APS by western blotting analysis. RESULTS We found that high glucose‐induced p‐perk expression was significantly inhibited by pretreatment with APS, We also found that this effect of APS was mimicked by 5‐aminoimidazole‐4‐carboxyamide‐1‐β ‐D‐ribofuranoside (AICAR), a pharmacological activator of AMPK.In parallel, Compound C, an inhibitor of AMPK, abrogated the effect of APS on p‐perk expression. CONCLUSIONS These data suggest that APS can protect HepG2 cells against high glucose‐induced ER stress by activation of AMPK. (This work was supported by the National Natural Science Foundation of China (No. 30370673))