Can women's health botanicals prevent estrogen carcinogenesis?

Breast cancer is the second most common malignancy among women becoming even more prevalent with age. Three major pathways are considered to be important in estrogen carcinogenesis: A) The hormonal ERα-mediated pathway leading to stimulation of tissue growth; B) chemical pathways involving estrogen metabolism to reactive intermediates which damage DNA; and C) the inflammatory pathway enhancing the formation of genotoxic estrogen metabolites. The botanicals, Glycyrrhiza species, Humulus lupulus, and Angelica sinensis, are frequently used as alternatives to hormone therapy mainly due to their estrogenic activities. Recent evidence suggests that these botanicals have potential to prevent estrogen carcinogenesis through diverse pathways. In vitro and in vivo studies have shown that A. sinensis constituents can reduce the ERα-mediated effects of estrogens (pathway A). All three botanicals induce detoxification enzymes that can facilitate the removal of genotoxic estrogen metabolites (B). Interestingly, only one Glycyrrhiza species (G. inflata) reduces the formation of genotoxic estrogen metabolites (B). All three botanicals possess anti-inflammatory activities that might reduce inflammation in estrogen carcinogenesis (C). These findings highlight the importance of multi-factorial standardization to all bioactive markers including cytoprotective compounds, in order to achieve prevention of estrogen carcinogenesis.