Regulation of SIRT1/AMPK/PGC-1α Signaling Pathway by Polygonatum Polysaccharide Improves H₂O₂-induced Oxidative Damage in HT22 Cells

OBJECTIVE To study the effects of Polygonatum polysaccharides on H₂O₂-induced oxidative injury in HT22 cells, and effect on key signaling molecules in SIRT1/AMPK/PGC-1α signaling pathway. METHODS The oxidative injury model of HT22 cells induced by H₂O₂ was established. The effect of Polygonatum polysaccharides on the cell viability and lactate dehydrogenase(LDH) release of HT22 cells were observed. The levels of antioxidant enzyme activities of superoxide dismutase(SOD), malondialdehyde(MDA) activity and glutathione(GSH) activity, mitochondrial respiratory chain enzyme complexes Ⅰ activity and adenosine triphosphate(ATP) were determined by respective kits. Meanwhile, Western blotting was used to detect the protein expression of SIRT1, AMPK, p-AMPK and PGC-1α. RESULTS Compared with the model group, Polygonatum polysaccharides(100, 200, 400 µg·mL^-1) could significantly enhance the cell vitality(P<0.05 or P<0.01), reduce the release of LDH(P<0.05 or P<0.01), reduce the production of MDA(P<0.05 or P<0.01), increase the activities of SOD and GSH(P<0.05 or P<0.01), increase the contents of ATP and the activity of mitochondrial respiratory chain enzyme complexes Ⅰ. In addition, SIRT1, p-AMPK and PGC-1α protein expressions in cells were up-regulated by Polygonatum polysaccharides. CONCLUSION Polygonatum polysaccharides can enhance the intracellular antioxidant activity to enhance the survival rate of HT22 cells, improve mitochondrial function, thus protect the cells from oxidative injury. And its mechanism is related to the activation of SIRT1/AMPK/PGC-1α signaling pathway.