Protective Effect Of Edaravone Combined With Methylprednisolone On Nervous Tissue Of Rats With Acute Spinal Cord Injury

Objective:Acute spinal cord injury is one of the traumatic nervous system diseases,which can cause the weakening or loss of nerve function below the level of injury.The pathological development of acute spinal cord injury includes primary injury and secondary injury.Studies have shown that secondary injuries such as edema and inflammatory response can be effectively controlled after spinal cord injury,which can reduce cell apoptosis,reduce the degree of sensory and motor damage below the injury plane,and promote the recovery of nerve function.Edaravone(EDA)is a free radical scavenger that can slow down and control secondary spinal cord injury and has protective effect on nerve cells during acute spinal cord injury.Currently,Methylprednisolone(MP)is the first clinical choice for acute spinal cord injury.However,because of its large dosage,MP often causes digestive system,endocrine system disorders and many other adverse reactions.In this research,we investigated the protective effect of EDA combined with MP on nerve tissue of rats with acute spinal cord injury.Methods:165 adult SD rats were randomly divided into 5 groups(n=33): sham group,ASCI group,EDA therapy group(0.3mg/100g),MP therapy group(3mg/100g),and combination therapy group(EDA 0.3mg/100g+MP 1.5mg/100g).The modified Allen method was used to make the T10 segment ASCI model.The rats were scored on the 1st,2nd,7 and 14 th day after operation with the hindlimb kinematics scoring standard(BBB score).The moisture content of spinal cord injury tissues in each group was measured on the 1st,2nd,7th day after operation with the dry and wet weight method.The apoptosis rate of neuron cells in ASCI tissue was measured by TUNEL method.Western blot assays were used to detect the changes of Bcl-2,Bax,and Casapse-3 in ASCI tissues.Results:1.Compared with that of the ASCI group,the BBB score of rats of each therapy group was significantly increased(P<0.05);the water content of spinal cord injured tissues was significantly decreased(P<0.05).Moreover,compared with that of the ASCI group,the apoptosis rate of neuron cells and the expression of Bax and Caspase-3 in tissues of each therapy group were significantly decreased(P<0.05);the expression of Bcl-2 in tissues was significantly increased(P<0.05).2.Compared with that of the EDA or the MP therapy groups,the BBB score of rats of the combination therapy group was significantly increased(P<0.05).On the 1st day after operation,there was no significant difference in water content of spinal cord injury tissues between each therapy group(P > 0.05).On the 2nd day after operation,compared with that of the EDA or the MP therapy groups,the water content of the combined therapy group was significantly decreased(P<0.05).On the 7th day after the operation,compared with that of the EDA therapy group,the water content of the combined therapy group was significantly decreased(P<0.05).There was no significant difference in water content between the MP and the combined therapy groups(P > 0.05).Furthermore,compared with that of the EDA or the MP therapy groups,the apoptosis rate of neuron cells and the expression of Bax and Caspase-3 in tissues of the combined therapy group were significantly decreased(P<0.05);the expression of Bcl-2 in tissues was significantly increased(P<0.05).Conclusions: In rats with ASCI,the combined therapy of EDA with MP induces the inhibition of both the nerve tissue edema and the apoptosis of neuron cells in the injured tissues.Additionally,this method of combined therapy decreases the treated dosage of MP.