OBJECTIVETo study the effect of Bushen Wenyang Huayu Recipe (BSWYHYR) on nerve growth factor (NGF) and transient receptor potential vanilloid receptor I (TRPV1) in experimental endometriosis (EMT), and to explore its mechanism for treating EMT-induced pain.

METHODSTotally in-bred line BALB/c 75 female mice were divided into five groups, i.e., the sham-operation group, the model group, the high dose BSWYHYR group, the low dose BSWYHYR group, the gestrinone group, 15 in each group. Writhing response was observed in each group. Serum contents of NGF were detected using ELISA. Expression levels of NGF and TRPV1 in uterus and ectopic foci were detected using immunohistochemical staining SP and Western blot. mRNA expression levels of NGF and TRPV1 in uterus and ectopic foci were detected by Real-time PCR.

RESULTSThe serum NGF content in the model group was higher than that in the sham-operation group (P < 0.01), and there was positive correlation between NGF and the writhing frequency (r = 0.574, P < 0.01). Compared with the model group, serum levels of NGF significantly decreased in the 3 treatment groups (P < 0.05). Compared with the sham-operation group, mRNA and protein expression levels of NGF and TRPV1 increased significantly in the model group (P < 0.01). Protein expression levels of NGF and TRPV1 decreased significantly in the 3 treatment groups, when compared with the model group (P < 0.01). mRNA expression levels of NGF and TRPV1 decreased most in the high dose BSWYHYR group (P < 0.01). NGF in uterus and ectopic foci was positively correlated with protein and mRNA expression levels of TRPV1 (P < 0.01).

CONCLUSIONSNGF and TRPV1 participated in the occurrence of pain in EMS. BSWYHYR played an important role in inhibiting EMT-induced pain through reducing the up-regulation of NGF on TRPV1.