Study on regulatory effects of safflower yellow on tau protein hyperphosphorylation in SH SY-5Y cell induced by okadaic acid / 中国药学杂志

ABSTRACT

OBJECTIVE: To investigate the regulating effects and its possible mechanism of safflower yellow (SY) on tau protein hyperphosphorylation in SH-SY 5Y cell induced by okadaic acid (OA). METHODS: Cell viability was measured by MTT colorimetric method. The cell apoptosis was determined with Hoechst 33342 after SH-SY 5Y cell were treated with SY. To determined the phos-phorylated tau protein of p-tau (T205), p-tau(S199) sites, and total GSK-3β, PP2A in SH-SY 5Y cell were determined using Western blotting. RESULTS: SY significantly increased survival rates of SH-SY5Y cell damaged by OA. Hoechst 33342 showed that SY decreased the apoptosis of SH-SY5Y cells. Western blotting analysis showed that tau protein content was increased compared to control group at p-tau (T205), p-tau (S199) sites. However, SY treatment significantly reduced tau protein content at p-tau (T205) and p-tau (S199) sites. PP2A content was significantly suppressed by OA, significantly increased by SY, GSK-3β content was significantly increased by OA and significantly decreased by SY. CONCLUSION: These results suggest that safflower yellow may have neuroprotective effect on OA-induced SH-SY 5Y cells injury, which may be associated with tau hyperphosphorylation at the enzyme level by activation of tau kinases or by a decline in the activities of tau phosphatases.