Abstract: OBJECTIVE: To evaluate the protective effects of Lubeikangru formula(LF) on hyperplasia of the mammary glands(HMG) induced by estrogen and progesterone in mice.METHODS: Female mice were divided randomly into five groups: normal, model, tamoxifen(3 mg/kg),Rupixiao(900 mg/kg) and LF(900 mg/kg). All mice except those in the normal group were treated sequentially with estradiol and progesterone to induce HMG. From the tenth day of induction, mice in normal and model groups received distilled water and mice in the other groups were given the corresponding drugs by gavage, once a day, for 30 d.At the end of treatment, the mammary glands, ovaries, hypothalamus, and serum was collected for whole-mount and hematoxylin and eosin(HE)staining, enzyme-linked immunosorbent assays(ELISAs), or western blotting.RESULTS: Whole-mount and HE staining of mammary glands showed that LF rescued(at least in part) the hyperplasic morphology of the mammary glands, and the number of branch points decreased after LF treatment(P < 0.05). ELISAs revealed that levels of estrogen and progesterone were decreased following LF treatment, whereas levels of gonadotropin-releasing hormone, follicle-stimulating hormone, and luteinizing hormone were increased in serum and tissues. Western blotting confirmed that LF treatment led to a reduction in expression of phosphorylated(p)-Erk, p-p38 and p-c-Jun N-terminal kinase. LF was also confirmed to be safe by acute-toxicity tests.CONCLUSION: LF can protect the mammary glands of mice from estrogen-and progesterone-induced hyperplasia by adjusting hormone levels and regulating the mitogen-activated protein kinase pathway.

Key words: Hyperplasia, Mammary glands,animal, Hormones, Tamoxifen, Mitogen-activated protein kinases, Lubeikangru formulation