Abstract: AIM: To investigate the effect of an effective component total sterone (TSR) of Echinops latifolius Tausch, the main component of a Chinese patent medicine Cuiru Keli (national drug standard WS3-413 (Z-085)-2003 (Z), on lactation and its possible mechanism. METHODS: After mating between male and female SD rats, 60 female rats were randomly divided into normal control group, model group, TSR low-dose and high-dose groups and prolactin granule positive control group, with 12 female rats in each group and 8 newborn rats in each nest. In addition to the normal control group, the rats in each group were intraperitoneally injected with levodopa 2 mg/kg once a day for 7 days from the second day of delivery. The rats in the normal control group were given normal saline by gavage once a day for 14 days. From the beginning of self-sufficiency, the single lactation of the female rats was measured every day until the 14th day, and then the female rats in each group were killed. Pathological HE staining was used to observe the morphological changes of mammary gland tissue in each group. ELISA was used to detect the levels of serum prolactin (PRL) and 5-hydroxytryptamine (5-HT). Immunohistochemistry was used to detect the distribution of PRL in mammary gland tissue of each group. Furthermore, Real-time qPCR was used to detect the expression of milk protein, milk fat related genes β-casein, FAS, ACC and the expression of canonical Wnt signaling pathway related genes β-catenin, c-Myc, CCND1, SFRP4, DNMT1, MeCP2 in mammary gland of each group. RESULTS: Both low and high dose TSR could significantly increase the single lactation volume, improve the pathological morphology of mammary gland, and increase the serum levels of PRL and 5-HT. TSR increased the distribution of PRL and up-regulated the expression of milk protein, milk fat related genes β-casein, FAS, ACC and canonical Wnt signaling pathway related genes β-catenin, c-Myc, CCND1, SFRP4, DNMT1, MeCP2.CONCLUSION: TSR can significantly promote lactation in lactation deficient rats, and its mechanism may be related to promoting the release of PRL and 5-HT in serum, increasing the distribution of PRL in mammary gland, up-regulating the milk protein and milk fat related genes and activating the canonical Wnt signal.

Key words: Cuiru Keli, Echinops latifolius Tausch, total sterone, postpartum hypogalactia, prolactin