Evaluation of the estrogenic activity of the constituents in the fruits of Vitex rotundifolia L. for the potential treatment of premenstrual syndrome.

The ethanol extract of the fruits of Vitex rotundifolia (VRE) and its four major compounds (casticin, luteolin, rotundifuran and agnuside) were tested for their estrogen-like activity by using the modified cell proliferation assay (E-SCREEN assessment system), as well as the estrogen receptor (ER(alpha)), estrogen receptor-regulated progesterone receptor and pS2 mRNA expression in MCF-7 cells. The results showed that only agnuside and rotundifuran could stimulate the proliferation of MCF-7 cells. These actions were dose dependent (range from 100 nM to 10 microM) and could be significantly inhibited by the specific estrogen receptor antagonist ICI 182,780. The estrogen receptor ER(alpha) and the estrogen receptor-regulated progesterone receptor and pS2 mRNA levels were increased by treatment with rotundifuran and agnuside within 24 h, and the effects could be reversed by ICI 182,780. The standardization of the extract and constituents were carried out by means of a high-performance liquid chromatography-fingerprint. It was concluded that VRE and its compounds showed estrogen-like activity and that the estrogenic effects of rotundifuran and agnuside were mediated by the estrogen inducible gene, which may be useful in regulating the hormone levels to treat related diseases. However, further studies are required to assess the physiological significance of VRE in animals and man.