OBJECTIVE:To investigate the hormone-like activities of Kuntai capsule (KTC) in the uteri of ovariectomized rats and immature rabbits.METHODS:Following bilateral ovariectomy,rats were randomly divided into six groups including sham group,control group,estradiol valerate group,KTC 0.24,0.6,and 1.5 g/kg groups.The rats were treated with 0.5％ CMC-Na,estradiol valerate and KTC (0.24,0.6,and 1.5 g/kg),respectively for 28 consecutive days.Then the estrous cycle,uterine changes and pathological changes were examined.Serum levels of estradiol (E2),and progesterone (P4) were measured by enzyme-linked immunosorbent assay (ELISA).Protein levels of estradiol receptor (ER),progesterone receptor (PR),vascular endothelial growth factor (VEGF),proliferating cell nuclear antigen (PCNA) and nuclear-associated antigen-67 (Ki-67) in uterine tissues were detected by west blot.Immature rabbits were estrogen-primed prior to intragastric administration with KTC for 6 d consecutively.Then,the uteri underwent hematoxylin-eosin staining to observe endometrial transformation.RESULTS:Compared with the control group,0.6 and 1.5 g/kg KTC markedly decreased the uterine organ coefficient and endometrial thickness (P ＜ 0.05).The serum level of P4 was increased in the KTC 0.6 g/kg group (P ＜ 0.05).There were no signifi cant variations in the serum level of E2 in the KTCgroups compared with the control group.ERβ,but not ERα,was markedly upregulated after KTC administration (P ＜ 0.05).Furthermore,1.5 g/kg KTC significantly decreased the protein level of PRA (P ＜ 0.05) and 0.6 g/kg KTC increased the protein level of PRB in the uteri (P ＜ 0.05).VEGF was highly expressed after treatment with 0.24 and 0.6 g/kg KTC,and Ki-67 was markedly reduced in ovariectomized rats treated with 1.5 g/kg KTC.No difference was found in the expression of PCNA.KTC 0.24 and 0.6 g/kg promoted endometrial transformation in immature rabbit uteri.CONCLUSION:KTC does not demonstrate obvious estrogen-like effect on uteri after ovariectomy,but it does exhibit weak progestogen-like effect,by which mechanism of action is yet to be further investigated.