Cinchonain Ib alleviates the cerebral ischemia-reperfusion injury by regulating mitophagy through AKT/mTOR signaling pathway.

Cinchonain Ib has demonstrated numerous potential pharmacological properties. However, its therapeutic efficacy against cerebral ischemia-reperfusion (IR) injury and underlying molecular mechanisms remained elusive. The mitophagy has been widely studied and demonstrated to play a critical role in the pathogenesis of IR, and currently therapeutic drugs were inefficient. This study aimed to investigate the effects of cinchonain Ib against IR and elucidate its underlying mechanism. We explored the role of cinchonain Ib using neuroblastoma (N2a) cell exposed to oxygen-glucose deprivation/reperfusion (OGD/R), and mice subjected to middle cerebral artery occlusion (MCAO). The results indicated that cinchonain Ib supplementation effectively ameliorated IR injury due to the mitigations of cell death and mitophagy through AKT/mTOR signaling pathway. In MCAO mice model, cinchonain Ib administration significantly reduced neuronal death, enhanced neurological recovery, and attenuated mitophagy. Furthermore, in the N2a-induced OGD/R model, cinchonain Ib exerted an inhibitory effect on the cell death, mitochondrial reactive oxygen species and mitophagy. Western blot analysis revealed that cinchonain Ib inhibited the activation of the AKT/mTOR signaling pathway, consequently attenuating mitophagy and mitigating the IR injury. Overall, our data indicated that cinchonain Ib was a promising therapeutic agent for early prevention and treatment of ischemic stroke.