Effects of tanshinone IIA on the expressions of p53, pp53 and apoptosis in the rats with Alzheimer's disease

Abstract

To observe effects of tanshinone (Tan) IIA on the apoptosis and expressions of p53 and pp53 in brain tissues of rats with Alzheimer's disease (AD). Thirty male Sprague-Dawley rats were randomized into 3 groups: Sham, AD, and Tan IIA groups. The AD models were established by injecting Aβ into the hippocampus of rats. Brain tissues were collected and paraffin sections were prepared to assess pathological changes. The expression of p53 and pp53 was detected by immunohistochemical staining and Western blot. Apoptosis was detected by TUNEL assay. There was no Aβ staining in the sham group, and the difference of Aβ staining between the AD group and the Tan IIA group was not significant (P>0.05). The expressions of p53 and pp53 were significantly higher in the AD group than those in the control group (P<0.05). The number of apoptotic cells in the AD group was significantly higher than that in the sham groups (P<0.05). Treatment of Tan IIA for AD rats significantly reduced the numbers of apoptotic cells (P<0.05). Aβ can increase the expression of p53 and pp53, and the number of apoptotic cells. Tan IIA treatment may inhibit apoptosis by down-regulation of p53 and pp53 in rats, and in turn to protect neurons.