JinPeng Fang ¹ Mengtao Xu ¹ ZhengYue Qiu ¹ Tian Ye ¹ HongLing Jiang ¹ FengYi Qin ¹ Yuan Hu ¹ Faying Jiang ¹ JuHua Zhong ¹ Yishuo Zhu ¹ Lewei Zhao ¹ Xiubin Liu ² Zhixing Qing ^1,3* Jianguo Zeng ^1,3*

• ¹ Hunan Key Laboratory of Traditional Chinese Veterinary Medicine, Hunan Agricultural University, Changsha, China
• ² College of Animal Science and Technology, Hunan Agricultural University, Changsha, China
• ³ Datong Daylily Industial Development Research Institute, Shanxi, Datong, China

Hemerocallis citrina Borani was a traditional folk food used to promote the lactation of postpartum mothers in China, however, the active ingredients and corresponding mechanisms are still unknown. In this study, The lactogenic effect of alcoholic and aqueous extracts of H. citrina was primarily evaluated, and the aqueous extract (1000 and 2000 mg/kg) displayed significant lactationpromoting effects. Three eluates of aqueous extract (0%, 30%, and 50%HCW) further evaluated their lactogenic effect, and 30% and 50%HCW showed significant lactation-promoting activity. Nineteen ingredients, including high-content of rutin and isoquercetin, were then identified from 30% and 50%HCW by the ultra-performance liquid chromatography-quadrupole-time of flight-mass spectrometry(UPLC-Q-TOF-MS) method. Finally, the lactogenic effect of rutin and isoquercetin were evaluated, and both compounds displayed significant lactation-promoting activity. The mechanisms relative to the lactation-promoting active for H. citrina extracts and compounds are to stimulate the release of prolactin (PRL) and progesterone (P), as well as to induce the expression of prolactin receptor (PRLR) and improve the morphology of mammary tissue. This study first clarified the lactationpromoting active ingredients of H. citrina and the corresponding mechanisms, which provide new insight into the new lactation-promoting drug and promote the high-value utilization of H. citrina resources.