Dihydromyricetin inhibits PC12 cell injury induced by 1-methyl-4-phenylpyridinium by up-regulating autophagy activity / 中国药理学与毒理学杂志

ABSTRACT

OBJECTIVE To observe the effect of dihydromyricetin (DMY) on cell injury induced by 1-methyl-4-phenylpyridinium (MPP+) in PC12 cells and explore the possible mechanism. METHODS After being pretreated with DMY 5, 10, 20, 40 and 80 μmol · L-1 for 0.5 h, PC12 cells were incubated with DMEM culture medium including autophagy inhibitor 3-methyladenine (3-MA) 10 mmol · L-1 and MPP+500μmol·L-1 for 48 h. MTT Assay was used to test the viability of PC12 cells. The level of lactate dehy-dregenase (LDH) was measured colorimetrically. The ultrastructure of PC12 cells was observed under transmission electron microscope. Expressions of autophagy related protein, Beclin-1, microtubule-associated protein light chain 3 (LC3) and p62 were measured by Western blotting. RESULTS Compared with cell control group, the cell survival rate was significantly decreased, the level of LDH was signifi-cantly increased, the number of autophagosomes was obviously decreased, the percentage of autophagic vacuoles in the total cytoplasm area was significantly decreased (P<0.05), expression of Beclin-1 and LC3-Ⅱ and the ratio of LC3-Ⅱ to LC3-Ⅰ were significantly down-regulated (P<0.05) and the expres-sion of p62 was significantly up-regulated in MPP+group (P<0.05). Compared with MPP+group, the cell survival rate was significantly increased, while the level of LDH was significantly decreased in MPP++DMY 10-80 μmol · L-1 group (P<0.05). Compared with MPP+ group, the number of autophagosomes obviously increased, the percentage of autophagic vacuoles in the total cytoplasm area was significantly increased, the expression of Beclin-1 and LC3-Ⅱ and the ratio of LC3-Ⅱ to LC3-Ⅰwere significantly up-regulated and the expression of p62 was significantly down-regulated in MPP++DMY 20 μmol · L-1 group (P<0.05). Compared with MPP++DMY 20μmol · L-1 group, the cell survival rate was significantly decreased, but the level of LDH was significantly increased in MPP ++DMY+3-MA group (P<0.05). CONCLUSION DMY may inhibit the cell injury induced by MPP+in PC12 cells, and the mechanism may be related to the up-regulation of autophagy activity induced by DMY.