摘要Nerve scarring after peripheral nerve injury can severely hamper nerve regeneration and functional recovery.Further,the anti-inflammatory cytokine,interleukin-10,can inhibit nerve scar formation.Saikosaponin a (SSa) is a monomer molecule extracted from the Chinese medicine,Bupleurum.SSa can exert anti-inflammatory effects in spinal cord injury and traumatic brain injury.However,it has not been shown whether SSa can play a role in peripheral nerve injury.In this study,rats were randomly assigned to three groups.In the sham group,the left sciatic nerve was directly sutured after exposure.In the sciatic nerve injury (SNI) + SSa and SNI groups,the left sciatic nerve was sutured and continuously injected daily with SSa (10 mg/kg) or an equivalent volume of saline for 7 days.Enzyme linked immunosorbent assay results demonstrated that at 7 days after injury,interleukin-10 level was considerably higher in the SNI + SSa group than in the SNI group.Masson staining and western blot assay demonstrated that at 8 weeks after injury,type Ⅰ and Ⅲ collagen content was lower and nerve scar formation was visibly less in the SNI + SSa group compared with the SNI group.Simultaneously,sciatic functional index and nerve conduction velocity were improved in the SNI + SSa group compared with the SNI group.These results confirm that SSa can increase the expression of the anti-inflammatory factor,interleukin-10,and reduce nerve scar formation to promote functional recovery of injured sciatic nerve.