Cannabidiol alleviates hemorrhagic shock-induced neural apoptosis in rats by inducing autophagy through activation of the PI3K/AKT pathway.

Recently, several studies have reported that the pharmacological effects exerted by cannabidiol (CBD) are partially related to the regulation of autophagy. Increasing evidence indicates that autophagy provides protection against ischemia-induced brain injury. However, the protective effect of CBD against mitochondrial-dependent apoptosis in hemorrhagic shock (HS)-induced brain injury has not been studied. In the present study, we observed the protective effects of CBD against neural mitochondrial-dependent apoptosis in a rat model of HS. In addition, CBD increased Beclin-1 and LC3II expression and reduced P62 expression, which were indicative of autophagy. CBD treatment attenuated the neural apoptosis induced by HS, as reflected by restoring mitochondrial dysfunction, downregulation of BAX, neuro-apoptosis ratio and NF-κB signaling activation, and upregulation of BCL2 in the cerebral cortex. Such protective effects were reversed by 3-Methyladenine, a specific autophagy inhibitor, indicating that the protective effects of CBD treatment involved autophagy. LY294002, a PI3K inhibitor, significantly inhibited CBD-induced autophagy, demonstrating that PI3K/AKT signaling is involved in the CBD's regulation of autophagy. Furthermore, we found that CBD treatment upregulated PI3K/AKT signaling via cannabinoid receptor 1. Therefore, these findings suggested that CBD treatment protects against cerebral injury induced by HS-mediated mitochondrial-dependent apoptosis by activating the PI3K/AKT signaling pathway to reinforce autophagy.