Resveratrol, isoflavones and puerarin have favorable in vivo results in endometriosis studies

Dietary phytoestrogens and endometriosis

Key Points

Highlights:

• The realities that estrogen is a major factor for endometriosis pathogenesis and phytoestrogens are common in a variety of foods, lifestyle and dietary factors and theri relationship with endometriosis attract particular attention.

What’s done here:

• This is a comprehensive review of the risks of phytoestrogen intake related to endometriosis.
• The findings from laboratory observations in animal endometriotic models and human intervention trials were analyzed.

Key results

• Phytoestrogens have a mechanistic dilemma, may be estrogenic or antiestrogenic, as there is an interplay between phtoestrogens and background estrogens.
• Phytoestrogen type-specific responses are dose-dependent, and phytoestrogen dose extrapolatable to humans is of utmost importance in laboratory experiments. 
• Resveratrol, isoflavones, and puerarin revealed a favorable outlook in endometrial primary cultures and animal models.
• Only resveratrol a molecule existing in grapes, wines, berries, and nuts yielded positive results in human intervention trials. 

Limitations of the studies

• The present animal models are limited in reflecting the natural course of endometriosis, especially the initial stage.
• Epidemiological studies based on questionnaires on the intake of dietary ingredients have some disadvantages of information inaccuracy.
• Women with different endogenous estrogen levels may respond differentially to dietary phytoestrogen intake.

Lay Summary

Xia Cai and associates from research units located in China published their review article on the relationship between phytoestrogens and endometriosis in the scientific periodical named “Pharmacology”.

The great variation in the prevalence of endometriosis raises questions in regard to lifestyle, effects of certain environmental factors besides genetic vulnerability. Phytoestrogens affect estrogen-mediated responses by binding to estrogen receptors. Laboratory studies and epidemiological observations have been performed to reveal the causal relationship between phytoestrogens and endometriosis. Phytoestrogens may regulate the expression of key endometriosis-related genes, modifying the pathological processes of endometriosis like inflammatory responses, cell division, invasion, and vascularity.

Resveratrol, isoflavones, and puerarin have been found to yield a favorable outlook in endometrial primary cultures and animal models. In spite of this, resveratrol is the only compound that yielded positive results in human intervention trials. This phytoestrogen is an important dietary factor since it is widely present in grapes, wine, berries, and nuts. The complicated relations between phytoestrogens and endogenous estrogens might explain the somewhat discrepant or opposite actions of phytoestrogens reported by different laboratories.

There are several major drawbacks to the reviewed studies. The rodent animal models presently are limited in reflecting the natural course of the disease, especially the initial stage of endometriosis. The selection of proper doses of phytoestrogens that could be extrapolated to humans is very important in laboratory models. Epidemiological studies based on questionnaires on the intake of dietary ingredients have some disadvantages of information inaccuracy. Besides, women with different endogenous estrogen levels may respond differentially to dietary phytoestrogen intake.

Future analyses would help to properly assess the phytoestrogens’ effects on endometriosis and their potential value for both preventive and therapeutic applications.

Research Source: https://pubmed.ncbi.nlm.nih.gov/34198709/