Abstract: Objective To investigate the protective effect of glycyrrhizic acid on neurons in rats with cerebral ischemia / reperfusion. Methods An cerebral ischemia-reperfusion model was constructed in rat primary neurons in vitro by oxygen glucose deprivation reperfusion (OGD/ R) method. The changes of cell morphology were observed by microscope, and the expression of neuron-specific enolase ( NSE) was observed by immunofluorescence staining. The damaged neurons were treated with glycyrrhizic acid, and the CCK-8 method was performed to detect the viability of neuronal cells, and the level of LDH released from neurons was detected by using the lactate dehydrogenase (LDH) -cytotoxicity assay kit. The AMPK activator AICAR was used to activate the AMPK/ mTOR pathway in neurons, and the Western blotting assay was used to detect the expression levels of AMPK/ mTOR pathway-related proteins and autophagy-related proteins. Results Glycyrrhizic acid inhibited the OGD/ R-induced enhancement of neuronal LDH level and the expression levels of autophagy-related proteins Beclin 1 and LC3-Ⅱ, and the suppression of cell viability. The OGD/ R induced activation of AMPK/ mTOR pathway was also suppressed after glycyrrhizic acid treatment. Conclusion Glycyrrhizic acid exerts a protective effect on neurons in rats with cerebral ischemia-reperfusion by inhibiting neuronal autophagy through AMPK/ mTOR pathway.

Key words: cerebral ischemia-reperfusion, oxygen glucose deprivation reperfusion, glycyrrhizic acid, autophagy, AMPK/ mTOR, neuron protection