Abstract: To investigate the effect of tetrahydropyrimin (SQZJSM) on the phosphorylation of Tau protein in Alzheimers disease (AD) cell model and its possible mechanisms.AD cell model was established using PC-12 cell induced by Aβ_25-35 for 48 h.Cell viability was detected by MTS,the changes of nuclei and microtubules were observed by laser confocal microscopy,the expression of protein was detected by Western blot.The results showed that SQZJSM can improve the cell viability and microtubule morphology of model cells,reduce the expression of p-Tau(Ser396) and p-GSK-3β(Tyr216) and up-regulate the expression of p-GSK-3β(Ser9) and p-AKT significantly (P<0.05).PI3K inhibitor LY294002 can partial block the improvement of SQZJSM on model cells.The above results indicate that tetrahydrocorysamine can significantly reduce the hyperphosphorylation of Tau protein in AD cell model,thereby improving the morphology of cytoskeletal microtubules and enhancing cell viability.The mechanism may be related to activating PI3K/Akt signaling pathway,decreasing GSK-3β activity and improving the imbalance of protein kinase/protein phosphatase system.

Key words: Tetrahydrocorysamine, A&beta, _25-35, PC-12, Tau