β-Asarone Regulates ER Stress and Autophagy Via Inhibition of the PERK/CHOP/Bcl-2/Beclin-1 Pathway in 6-OHDA-Induced Parkinsonian Rats.

β-Asarone (1,2,4-trimethoxy-5-[(Z)-prop-1-enyl]benzene) is an essential component of Acorus tatarinowii Schott volatile oil. Previous research has observed that β-asarone effectively attenuated symptoms in parkinsonian rats and improved their performance, but the mechanism of this effect remains unclear. Other research has shown that endoplasmic reticulum (ER) stress plays an important role in the pathogenesis of Parkinson's disease (PD). The protein kinase RNA-like endoplasmic reticulum kinase (PERK) was observed in the nigrostriatal dopaminergic neurons of patients with PD. However, our group observed that ER stress and autophagy occurred in 6-hydroxy dopamine (6-OHDA)-induced parkinsonian rats, and ER stress might induce autophagy. We assume that the protective role of β-asarone in parkinsonian rats is mediated via the ER stress-autophagy pathway. To support this hypothesis, we investigated the expressions of glucose regulated protein 78 (GRP78), PERK phosphorylation (p-PERK), C/EBP homologous binding protein (CHOP), Bcl-2 and Beclin-1 in 6-OHDA-induced parkinsonian rats after β-asarone treatment. The results showed that the β-asarone group and PERK inhibitor group had lower levels of GRP78, p-PERK, CHOP and Beclin-1 while having higher levels of Bcl-2. We deduced that β-asarone might regulate the ER stress-autophagy via inhibition of the PERK/CHOP/Bcl-2/Beclin-1 pathway in 6-OHDA-induced parkinsonian rats.