Effects of ethanol extracts from Adzuki bean (Phaseolus angularis Wight.) and Lima bean (Phaseolus lunatus L.) on estrogen and progesterone receptor phenotypes of MCF-7/BOS cells.

In this study, the possible molecular mechanisms involved in the estrogen-like activities of ethanol extracts from two common Chinese legumes, i.e. Adzuki bean (Phaseolus angularis Wight.) and Lima bean (Phaseolus lunatus L.) were investigated. Reverse transcription-polymerase chain reaction (RT-PCR) measurement and western blot analysis were conducted to detect the functional mRNA and protein expressions, while immunofluorescence was used to determine the estrogen receptor (ER) intracellular distribution in the MCF-7/BOS cell line. The results indicated that (1) both mRNA and protein levels of progesterone receptor (PR) in the cell line increased after 48 h treatment with the extracts compared with those in the control; (2) Adzuki and Lima bean extracts might alter the ER intracellular distributions in two different manners: for the Adzuki bean, the ER appeared in both cytoplasm and nucleus, while for the Lima bean, it exhibited the same pattern as that of estradiol in which the ER almost disappeared in the nucleus and mainly occurred in the cytoplasm. Above all, the results showed a novel pattern of ER intracellular distribution in the MCF-7/BOS cell line upon exposure to Adzuki bean extract, suggesting that different pathways were involved in the estrogen-like activities of the ethanol extracts of Adzuki bean and Lima bean.