Effects of Sodium aescinate on heat pain and spinal neural apoptosis in rats after sciatic nerve ligation

Objective To observe the effects of Sodium aescinate on heat pain and spinal neural apoptosis in rats after sciatic nerve ligation.Methods Ninty SD rats were randomly divided into normal control group(NC group),chronic constriction injury(CCI) model group(CCI group) and therapy group,with 30 rats in each group.CCI models were made by sciatic nerve middle part ligation method.Rats in therapy group were given 0.1% sodium aescinate 5 mg/(kg·d) after operation,while the rats in CCI group were treated with equivalent normal salinet.The heat pain of 5 rats in each group were tested at 1 d before operation,and 5 rats in each group were sacrificed after the test of heat pain at 8 h,1 d,3 d,7 d,14 d and 21 d after operation,respectively.The number of neuronal apoptosis in spinal tissue at the segment of relevant injury and the expression of tumor necrosis factor-α(TNF-α) were detected by TUNEL method and immunohistochemistry method,respectively.Results There was no significant difference of heat pain at 1 d before operation between each groups.The heat pain in CCI group and therapy group was more sensitive than that in NC group(all P0.05).The heat pain in therapy group was less sensitive than that in CCI group(all P0.05).The quantity of neuronal apoptosis in CCI group and therapy group was significantly more than that in NC group(all P0.05);and which in therapy group was significantly less than that in CCI group(all P0.05).The expression of TNF-α in CCI group at 8 h-14 d after operation and therapy group at 8 h-7 d after operation were significantly higher than that in NC group(all P0.05);which began to increase at 8 h after operation,and reached the highest at 3 d after operation,then gradually decreased(all P0.05);and which reached the level of NC group at 21 d and 14 dafter operation,respectively.Conclusions Sciatic nerve ligation can lead neuropathic pain and spinal neuronal apoptosis.Sodium aescinate can relief the enhancement of heat pain of rats after the sciatic nerve ligation,which may be related with its effects of reducing the expression of TNF-α at spinal dorsal horn and inhibiting the neuronal apoptosis.