RESUMEN
ETHNOPHARMACOLOGICAL RELEVANCE: In China, Hordei Fructus Germinatus (HFG) is the germinated and dried fruit of Hordeum vulgare L, which is commonly used in clinical Chinese medicine. Traditional Chinese Medicine (TCM) theory holds that HFG can be both medicinal and edible, which means that it is derived from food medicine. Raw HFG and roasted HFG are used to treat hypogalactia, hyperprolactinemia and indigestion. In recent years, the lactogenic and galactophygous effects of HFG have attracted increasing attention. Nevertheless, there is much confusion over the use of raw and processed HFG, and the mechanism of its lactogenic effect seems remains poorly understood. AIM OF THE STUDY: This study aimed to explore the lactogenic effect of raw HFG and roasted HFG on rats with overloaded lactation and to reveal the underlying molecular mechanism. MATERIALS AND METHODS: Raw and processed HFG water decoctions were given to overloaded lactation model rats at a dose of 1.7800 g kg-1·d-1, and the control group was given the same volume of water. The lactogenic effect of raw and processed HFG was evaluated by measuring daily lactation, body weight and pup body weight, serum PRL, E2, and GH contents after parturition, and the pathological characteristics of mammary tissue sections. cDNA microarrays can be used to screen diverse gene expression patterns and signaling pathways related to prolactin. The expression of relevant differentially expressed genes was verified by real-time PCR and western blotting. RESULTS: In vivo experiments demonstrated that the raw HFG water decoction stimulated mammogenesis, accelerated the transformation of the lobular acinar system, resulted in denser mammary epithelial cells and thicker glandular ducts that were full of milk and facilitated the secretion of milk. Moreover, HFG increased PRL, E2, and GH levels, pup body weight, daily lactation and the body weight of lactating rats. Following gene chip identification, KEGG pathway enrichment analysis revealed genes that were highly related to prolactin in the prolactin signaling pathway and JAK-STAT signaling pathway, and the main differentially expressed genes were Jak2 (down), Stat5α (up), cyclin D1 (up), SOCS1 (up), CISH (down) and PRLR (up). Compared with the control group, RT-PCR results indicated that Jak2 and CISH were downregulated and that Stat5α, cyclin D1, SOCS1 and PRLR were upregulated. Western blot assays showed that PRLR, STAT5α and cyclin D1 levels in the mammary glands of the raw HFG water decoction group were significantly increased, which was consistent with the results of cDNA microarray screening. CONCLUSION: The present study reveals that raw HFG effectively enhances lactation in rats, possibly by influencing the prolactin/JAK-STAT signaling pathway.