It is well known that certain plant metabolites can exert estrogenic activity. There
are an increasing number of studies concerning the effects of phytoestrogen-rich diets
which demonstrate that these plant metabolites have protective effects on estrogen-related
conditions, such as menopausal symptoms, and estrogen-related diseases, such as prostate
and breast cancers, osteoporosis and cardiovascular diseases [1].
Because beneficial effects on menopausal symptoms are often reported by women drinking
regularly Noni fruit juice (Morinda citrifolia L.), we investigated the estrogenic capacity of Noni fruits in two in vitro assays, the estrogen receptor binding assay with both estrogen receptors, ER-α and ER-β, and the estrogen-receptor dependent induction of alkaline phosphatase in Ishikawa
cells. Hexane extracts prepared from Noni fruit puree exhibited high activity in both
systems. A preferential binding for ER-β was observed (ED50(ER-α)/ED50(ER-β)=2.33). Further analysis and fractionation of these extracts by HPLC showed that
one compound is responsible for almost all the activity. The isolation of this constituent
was performed by HPLC and will be followed by its characterisation with 1- and 2-dimensional
NMR techniques and Mass spectrometry.
Reference: 1. Cos, P. et al. (2003), Planta Med. 69: 589–599.