Protective Effect Of Cannabidiol On Skeletal Muscle Injury In Rats Of Exhaustive Exercise

Objective: Cannabidiol(CBD),a monomeric compound of cannabis,was validated to improve the effects and mechanisms of skeletal muscle injury in rats undergoing exhaustive exercise.Methods: The SD rats were randomly divided into the quiet control group(control group,n=6),the model group(model group,n=6),the CBD low dose group(50 mg/kg,n=6),the CBD high dose group(100 mg/kg,n=6).The seven-day exhaustion exercise scheme of rats was adopted.The initial speed was 10 m/min for 15 min and increased by 1to 2 m/min until exhaustion at 20 m/min.The gastrocnemius was quickly separated after blood was taken under anesthesia and cervical dislocation was executed.The biochemical indexes of LDH,CK,MDA,GSH-Px,SOD,T and Cor in the serum of the rats were determined by ELSA.Gastrocnemius was stained by HE,ROS and immunohistochemistry.The genes related to the repair of exercise-induced skeletal muscle injury by CBD were predicted through network pharmacology and transcriptome sequencing.Western Blot analysis was performed to detect the expression of AMPKα2,HIF-1α,BNIP3,NIX,IL-6,NF-κB,TNF-α,Keap1,IL-10,Nrf2 and HO-1.Results:1.Compared with the control group,the levels of Cor,MDA,CK and LDH were significantly increased in the model group.while SOD,GSH-PX,T and T/Cor ratios were significantly decreased;In the model group,the ROS staining was more red and less blue.In the model group,HE staining inflammatory cells of gastrocnemius muscle were infiltrated seriously,muscle fibers were broken,and some nuclei were displaced.In the model group,the protein expressions of HO-1,Nrf2 and IL-10 in skeletal muscle were significantly decreased,while the protein expressions of Keap1,NF-κB,TNF-α,IL-6,AMPKα2,HIF-1α,BNIP3 and NIX were significantly increased.2.Transcriptome sequencing results of the model group and the control group showed that BNIP3 and HIF-1 signaling pathway related genes were highly correlated with exercise-induced skeletal muscle injury.3.Through network pharmacology analysis,it was found that the repair function of CBD on exercise-induced skeletal muscle injury was enriched in the HIF-1 signaling pathway.Compared with the model group,the levels of LDH,NF-κB,KEAP1,IL-6,AMPKα2 and HIF-1α were significantly decreased in the CBD low-dose exhaustive exercise group,while the T/Cor,HO-1 and NRF2 were significantly increased in the CBD low-dose exhaustive exercise group.Compared with the model group,the levels of CK,LDH,Cor,NF-κB,KEAP1,IL-6,TNF-α,AMPKα2,HIF-1α,BNIP3 and NIX in the CBD high-dose exhaustive exercise group were significantly decreased.T/Cor,GSH-PX,HO-1,NRF2 and IL-10 were significantly increased.4.Compared two groups of CBD exercise exhaustion groups,the results of ROS staining showed that the nuclear fluorescence staining was less red in the CBD high-dose exercise exhaustion group.The results of HE staining showed that inflammatory cells infiltrated less and the distribution of nuclei was relatively normal,and the repair of skeletal muscle injury was better than that of the CBD low-dose exercise exhaustion group.Conclusion: CBD may reduce oxidative stress and inflammation through AMPKα2/HIF-1α/BNIP3/NIX pathways,thereby repairing exercise-induced skeletal muscle damage.