Objective: To study the estrogen-like effects of puerarin and total isoflavones from Pueraria lobata (TIP) in vivo.
Methods: Puerarin and TIP were orally administrated to ovariectomized rats, infancy or adult mice and estrogen-treated mice at the doses of 150, 300 and 600 mg/kg for 5-9 days. The estrogen-like effects were measured by viginacytology and uterus or ovary weights.
Results: Puerarin and TIP significantly promoted uterus growth in ovariectomized rats and infancy mice, increased the ratios of keratocytes in vaginal smear in ovariectomized rats. The sexual cycle was partially recovered in dose-dependent manner. In E2-treated mice, puerarin and TIP obviously inhibited the growth of vigina induced by E2. No obvious effect was observed in normal adult mice.
Conclusion: The results showed that puerarin and TIP acted as weak estrogen-like effect on estrogen-deficiency animals, while no effect on normal-estrogen level ones, but as antiestrogen-like effect in high-estrogen-level ones. These results suggested that puerarin and TIP possessed property of partial agonist of estrogen receptor.