Protective effect of safflower injection on spinal cord injury in rats

[Objective] To study the protective effects of safflower on the experimental spinal cord injury(SCI) model with weight-dropping method in adult rats.[Method]Seventy-two SD rats were randomly divided into 4 groups:sham-operation group(group A),spinal cord injury group(group B),methylprednisolone sodium succinate(MPSS) group(group C),and safflower group(group D).Animal models of spinal cord injury were induced with weight-dropping method.In the C and D groups,MPSS of 30 mg/kg and safflower of 100 mg/kg was respectively injected by intraperitoneal immediately after modeling.The locomotor function of the hind limbs were evaluated at 1,24 and 48 hours after SCI,and the histopathological study,tissue water content,as well as lactic acid(LD),lactic dehydrogenase(LDH),superoxide dismutase(SOD) and malondialdehyde(MDA) changes in the spinal cord were observed at 1,24 and 48 hours after modeling.[Result]The hind limb locomotor function of the rats in group A was completely recovered.Compared with that in group B,the hind limb locomotor function of rats in groups C and D was improved at 24 and 48 hours,with significant improvement at 24 hours(P0.05) and even more significant difference at 48 hours(P0.01).In group A,the tissue structure was well preserved.In group B,the nerve tissue showed multifocal leukoencephalopathy bleeding and a number of nerve cells and Nissl bodies disappeared.The nucleus became small because of pycnosis.In group C,the injury of the nerve tissue was mild,the cells appeared swelling and the cytoplasm was homogeneous.The tissue situation in group D was similar to those in group C.Tissue water content in groups B,C and D were all significantly higher than that in group A(P0.05) after modeling.And tissue water content in group D was lower than that in group B at 24 hours(P0.05),even more significantly lower at 48 hours(P0.01).There were no significant difference between groups B and C.Compared with those in group A,LD content and LDH activity were obviously higher in group B after SCI(P0.01).And LD content and LDH activity in group C and D were lower than those in group B(P0.05),even more significantly lower at 48 hours(P0.01).The MDA content was increased and the SOD activity was reduced obviously in the group B,then both were significantly different compared with those in group A(P0.01).In groups C and D at 24 hours,the MDA content was reduced and the SOD activity was increased obviously,They were significantly different compared with those in group B(P0.05).There were little differece in LD content,LDH activity,MDA content,SOD activity between group C and group D.[Conclusion]Like MPSS,safflower injection observably promotes the function recovery of spinal cord after injury,alleviates secondary spinal cord injury and effectively protects the spinal cord from injury.