Effect of Nourishing “Yin”-Removing “Fire” Chinese Herbal Mixture on Hypothalamic NKB/NK3R Expression in Female Precocious Rats

Aim. The present study aims to investigate the effects of nourishing "Yin"-removing "Fire" Chinese herb mixture on the hypothalamic NKB/NK3R expression in female precocious model rats. Materials and Methods. Female Sprague-Dawley rats were randomly divided into four groups: normal (N), central precocious puberty (CPP) model (M), CPP fed with Chinese herbal mixture (CHM), and CPP fed with normal saline (MS). Rats on postnatal day 5 were given a single subcutaneous injection of 300 μg to establish CPP model rats. Rats of CHM and MS groups were continuously administered with nourishing "Yin"-removing "Fire" Chinese herb mixture or saline since postnatal day 15. The expressions of hypothalamic NKB/NK3R were detected by means of real-time PCR, western blot, and immunofluorescence histochemistry. Results. The day of vaginal opening and establishment of two regular estrous cycles were delayed in the CHM group compared with M and MS groups. The expression of hypothalamic NKB/NK3R mRNA and protein in the arcuate nucleus (ARC) and medial preoptic (MPO) area were decreased significantly in the CHM group compared with the M and MS groups on the day of onset-puberty. Conclusions. These results indicate that the NKB/NK3R signaling pathway might be involved in the effect of herbal mixture treatment on CPP.