ABSTRACT
Objective:To observe the effects of modified Xuanfuhua Decoction on pain behaviour and spinal cord neuroinflammation mediated by phosphorylated mitogen-activated protein kinase p38 (p38MAPK) signaling pathway in rats with sciatic nerve injury; To analyse the mechanism of its effects.Methods:Totally 108 SD rats were randomly divided into sham-operation group, model group, pregabalin group, decoction low-, medium- and high-dosage groups, with 18 rats in each group. The CCI model was established by ligation of sciatic nerve in other groups except sham-operation group. On the postoperative day, the decoction low-, medium-, high-dosage groups were gavaged with 2.5, 5.0 and 10.0 g/kg of modified Xuanfuhua Decoction concentrate, respectively. The pregabalin group was gavaged with 15 mg/kg of pregabalin. The sham-operation group and the model group were gavaged with equal amounts of saline once/d for 15 days. Pain behavioural assays were performed before, on the 3rd, 7th, 11th and 15th day of administration respectively. The levels of interleukin (IL)-1β, tumour necrosis factor-α (TNF-α), IL-10 were detected by ELISA method. The expressions of Toll-like receptor 4 (TLR4), nuclear factor-κB p65 (NF-κB p65) were detected by immunohistochemistry staining. The phosphorylated p38MAPK (p-p38MAPK) were measured in the spinal cord by Western blot.Results:Compared with the model group, the scores of spontaneous pain in decoction high-dosage group decreased ( P<0.05), the thermal foot shrinkage latency (TWL) was prolonged ( P<0.05), and the mechanical foot shrinkage reflex threshold (MWT) increased ( P<0.05); the levels of IL-1β and TNF-α in spinal cord tissue of decoction low-, medium- and high-dosage groups decreased ( P<0.05), the level of IL-10 increased ( P<0.05), the average gray values of TLR4 and NF-κB p65 in spinal cord decreased ( P<0.05), and the expression of P-P38MAPK protein decreased ( P<0.05). Conclusion:Modified Xuanfuhua Decoction can effectively improve neurogenic pain in CCI rats, and the mechanism may be related to inhibition of p38MAPK-TLR4 signaling pathway activation-mediated spinal cord neuroinflammation.