Estrogenic analysis of ten Thai medicinal plants used for treating menstrual irregularity by ERα and ERβ yeast two-hybrid systems

Introduction

Several traditional Thai medicinal plants have historically been utilised to alleviate menstrual irregularities. While it is hypothesised that phytoestrogens are pivotal in their medicinal efficacy, more empirical evidence is needed to verify this assumption. Furthermore, our understanding of the estrogenic effects mediated by estrogen receptors (ERα and ERβ) and their alterations post-intestinal enzymatic digestion is limited. This study aims to assess the estrogenic activity of 10 medicinal plants before and after in vitro simulated gastrointestinal digestion using yeast two-hybrid (Y2H) systems.

Methods

Y2H systems were constructed based on the interaction between the ligand-binding domain of estrogen receptors and the receptor interaction domain of coactivators. The medicinal plants were extracted in water at 95 °C for 1 hour or in 70% ethanol for 24 hours (1: 8 w/v). Their estrogenic activities before and after in vitro gastrointestinal digestion were determined using Y2H systems.

Results

The majority of ethanol extracts exhibited higher estrogenic activity compared to water extracts, with detection notably facilitated by the ERβ-Y2H system. This study represents the first documentation of the estrogenic activities of Dendrolobium lanceolatum and Morinda coreia, both prominently identified by the ERβ-Y2H system. Specifically, the D. lanceolatum extract demonstrated the highest estrogenic activity, showing a significant enhancement following gastrointestinal enzymatic digestion, suggesting the presence of active metabolites.

Conclusions

These findings advance our understanding of the estrogenic properties of medicinal plants for treating menstrual irregularities, clarifying their effects on estrogen receptor subtypes and post-hydrolysis activities. Such insights are vital for determining their potential as alternative medicines.