Research on phytoestrogenic effects and their mechanisms of Jiaoai tang and Shenqi Jiaoai tang

Objective: To study the phytoestrogenic effects and their possible mechanisms of Jiaoai tang and Shenqi Jiaoai tang through the tests in mice and ER (+) MCF7 cells. Method: Sixty kunming mice weighing 9-12 g were randomly divided into 6 groups: solvent control group (administrated equal dose of diswater), diethylstilbestrol control group (administrated diethylstilbestrol at a dose of 0.35 mg·kg-1·d-1) and 4 Chinese medicine treated groups (administrated low or high doses of Jiaoai tang and Shenqi Jiaoai tang at 2.5 g·kg-1·d-1 or 5.0 g·kg-1·d-1 respectively). After administration for 4 days, the mice were sacrificed; uterus was removed and weighed, uterus rate was calculated. The blood serum was also separated. The proliferation rate of MCF7 cells influenced by Jiaoai tang and Shenqi Jiaoai tang was determined by MTT assay. PS2, ERα and ERβ mRNA expression was quantified by Real-time PCR assay. Estrogen receptor antagonist ICI182, 780 was employed as a tool. Result: Administration of Jiaoai tang and Shenqi Jiaoai tang at high dose significantly increased uterus rate in mice (P <0.05). The pharmacological serum from two high-dosage groups of Chinese herbal medicine decoction significantly enhanced proliferation rate of MCF7 cells (P < 0.05 or 0.01), while their effects were blocked by ICI182, 780 (P < 0.05 or 0.01). The pharmacological serum could cause elevation of pS 2 level (P < 0.01) which would be obviously inhibited by ICI182, 780 (P < 0.01). ERα and ERβ mRNA levels were also elevated significantly (P < 0.05 and P < 0.01 respectively). Conclusion: Jiaoai tang and Shenqi Jiaoai tang have phytoestrogenic effects, which were attained via ER pathway. They can also increase the mRNA levels of estrogen receptor subtypes, especially ERβ.