Objective:To clarify the analgesic effects of Wutoutang (WTT) on neuropathic pain (NP) mice and explore the mechanism of its effect on the descending inhibitory system. Method:ICR mice were randomly divided into the Sham operation group

spinal cord ligation (SNL) group

pregabalin (PGB) group

WTT high

middle and low dose (WTT-H

WTT-M and WTT-L) groups. The L5 spinal nerve was stripped in mice of Sham group

and was stripped and then tightly ligated in other groups. After that

the mice were gavaged with saline

12.60

6.30 and 3.15 g·kg-1WTT

and 0.025 g·kg-1 prebahrain respectively for 21 days. The analgesic efficacy of WTT was identified by the Von Frey method; the protein expression levels of brain derived neurotrophic factor (BDNF) and 5-hydroxytryptarnjne (5-HT) in key brain regions of descending inhibitory system

the anterior cingulate cortex (ACC)and the rostral ventromedial medulla (RVM) for example

were detected in each group by enzyme-linked immunosorbent assay (ELISA); and the protein expression levels of phosphorylated-extracellular signal-regulated kinase (p-ERK) and postsynaptic density protein-95 (PSD-95) were analyzed by Western blot assay. Result:At day 21 of administration

the mechanical pain threshold value was significantly decreased in model group as compared with the Sham operation group (P<0.01)

and the expression levels of 5-HT and BDNF in RVM and ACC were also decreased (P<0.05)

while the proteinexpression levels of p-ERK and PSD-95 were elevated(P<0.05). Themechanical pain threshold valuein WTT groups was significant higher than that in SNL group (P<0.01)

and both the mentioned 5-HT and BDNF expression levels were increased (P<0.05)

while the protein expression levels of p-ERK and PSD-95 were inhibited by WTT. Conclusion:WTT can alleviate NP in mice

and the mechanismmay be associated with regulating the expression levels of 5-HT

BDNF

p-ERK and PSD-95 proteins in RVM and ACC of descending inhibitory system.