Beta-asarone attenuates ischemia-reperfusion-induced autophagy in rat brains via modulating JNK, p-JNK, Bcl-2 and Beclin 1.

Abstract

Beta-asarone has significant pharmacological effects on the central nervous system. It can attenuate neuronal apoptosis, but its effects on the brain ischemia-reperfusion-induced autophagy have not been reported yet. Our study was a two-stage procedure: evaluation of β-asarone effects on the autophagy at first, and then analysis of the possible mechanism. The middle cerebral artery occlusion (MCAO) model was adopted to make the brain injure and Beclin 1 was used to evaluate the autophagy. We hypothesized that the mechanism might be related to c-Jun N-terminal kinases (JNK), phospho-JNK (p-JNK), Bcl-2 and Beclin 1. To test this hypothesis, we evaluated JNK, p-JNK, Bcl-2 and Beclin 1 levels with flow cytometry. Additionally, we divided the brain into three regions: ischemic region, ischemic penumbra, and normal region, and analyzed them respectively. We found, compared to both groups II (model control) and III (low dose), Beclin 1 levels in groups IV (medium dose) and V (high dose) were significantly decreased. Beclin 1, JNK and p-JNK levels in groups VII (β-asarone) and VIII (JNK inhibitor) were significantly decreased, but Bcl-2 levels were significantly increased. Additionally, Beclin 1, JNK, p-JNK and Bcl-2 levels among the three regions had no significant differences. We conclude that β-asarone can attenuate the autophagy in a dose-dependent manner. The mechanism is likely that β-asarone can decrease JNK and p-JNK levels at first, and then increase Bcl-2 level, finally interfere with the functions of Beclin 1 during the execution of autophagy. Additionally, β-asarone can attenuate autophagy in a widespread manner.