Effects of astragaloside IV combined with active components of Panax notoginseng on apoptosis and endoplasmic reticulum stress in brain tissues after cerebral ischemia-reperfusion in mice / 中草药

ABSTRACT

Objective: To probe the effects and mechanisms of astragaloside IV combined with the active components from Panax notoginseng on apoptosis of nerve cells through endoplasmic reticulum stress (ERS) after cerebral ischemia-reperfusion (I/R) in mice. Methods: C57BL/6 mice were randomly divided into Sham, model, astragaloside IV (AST IV), ginsenoside Rg1 (Rg1), ginsenoside Rb1(Rb1), notoginsenoside R1 (R1), four active components combination, AST IV + Rg1, AST IV + Rb1, AST IV + R1 and Edaravone group, pretreated for 3 d. After 1 h of the last administration, the model of cerebral I/R injury was established by bilateral common carotid artery (CCA) ligation followed by reperfusion, then TUNEL method was used to detect the apoptosis in hippocampal CA1 and apoptosis rate was calculated; The expression of cysteine aspartic acid specific protease (Caspase-3), glucose regulated protein 78 (GRP78), Caspase-12 and phosphorylated C-Jun amino terminal enzyme (p-JNK1/2) proteins in brain tissues was tested by Western-blotting at 24 h after reperfusion. Results: After cerebral ischemia for 20 min followed by reperfusion 24 h, the apoptosis rate of nerve cell in hippocampal CA1 and the expression of Caspase-3 protein in brain tissues were increased. All drugs could decrease the apoptosis rate and inhibit Caspase-3 protein expression. Furthermore, the decreased effects of AST IV + Rg1 and AST IV + R1 on the apoptosis rate and Caspase-3 protein expression were better than those of the active components alone; In the four active components combination, the decrease of the apoptosis rate was stronger than that of the four active components alone and the inhibition of AST IV + Rb1 on Caspase-3 was greater than that of the four active components alone as well as AST IV + Rb1 and AST IV + R1. After the cerebral I/R, the expression of GRP78 and Caspase-12, p-JNK1/2 proteins were up-regulated. AST IV, Rg1, R1, and the combinations could further increase GRP78 protein expression in brain tissues, and the effect of the combinations was better than that of the active components alone; The effect of the four active components combination was better than that of AST IV + Rb1 and AST IV + R1. R1, the four active components combination, AST IV + Rg1, and AST IV + R1 could down-regulate Caspase-12 protein, and the effect of the four active components combination was more obvious than that of the four active components alone and AST IV + Rb1. The expression of p-JNK1/2 in AST IV, Rg1, the four active components combination, AST IV + Rg1, and AST IV + Rb1 was decreased, the decrease in the four active components combination was stronger than that in the four active components alone as well as AST IV + Rg1 and AST IV + R1. Conclusion: AST IV combined with the effective components from P. notoginseng has the potentiation on the inhibition of apoptosis, and the mechanism underlying might be associated with relieving ERS via different links. AST IV + Rb1 might affect JNK pathway and AST IV + R1 might act on the Caspase-12 pathway; Moreover, the four active components combination and AST IV + Rg1 could act on both Caspase-12 and JNK.