The effects of L-Tetrahydropalmatine on the expression of Bcl-2 and Bax in rats after acute global cerebral ischemia and reperfusion

To investigate the effects of L-Tetrahydropalmatine (L-THP) on the expressions of bcl2, bax and neuronal apoptosis after cerebral ischemia and reperfusion, 60 Wistars rats were randomly divided into 3 groups: sham-operation group (group S, n = 20), ischemic-reperfusion group treated with saline (group I, n=20) and ischemia-reperfusion group treated with L-THP (group T, n=20) . The rat model of global cerebral ischemia and reperfusion was induced by Pulsinelli's four-vessel occlusion method. The expression of bcl-2 and bax mRNA was detected by in situ hybridization and reverse transcriptional polymerase chain reaction (RT-PCR). The number of apoptotic neurons was examined by terminal deoxynucleotidyl-transferase (TdT)-mediated dUTP nick end-labeling (TUNEL) method. Compared with group S, the expression of bcl-2 and bax mRNA in group I was increased significantly (P＜0.01), and the number of apoptotic neurons increased either (P＜0.01). After L-THP treatment, the expression of bcl-2 mRNA was up-regulated (P＜0.01) and that of bax mRNA was down-regulated (P＜0.01); the number of apoptotic neurons was decreased (P＜0.01). Our results indicated that bcl-2 may suppress apoptosis and bax promote apoptosis after cerebral ischemia and reperfusion. L-THP could ameliorate cerebral ischemia and reperfusion damage by reducing the apoptosis through regulating bcl-2 and bax.