Estrogen and its receptor are exceptional in that a host of natural compounds target estrogen signaling either directly or through other molecular pathways. This unique feature offers scientists a myriad of compounds to be explored as potential treatments for endometriosis and other estrogen-related conditions.
A comprehensive review of natural compounds by researchers at the Birla Institute of Technology in India demonstrated that some of the substances are in fact already included in drugs approved by the U.S. FDA for other conditions.
Repurposing such drugs for endometriosis and other estrogen related conditions could therefore be a cheaper, faster way to allow more treatment options to reach patients. However, many of these therapies remain untested in preclinical and clinical studies before potentially benefiting patients.
The review, “Compounds of Natural Origin and Acupuncture for the Treatment of Diseases Caused by Estrogen Deficiency,” published in the Journal of Acupuncture and Meridian Studies, largely covers substances with a proven effect only in so-called in-experiments, studying cells and molecules in lab dishes.
Natural compounds have served as a base for pharmaceutical development since ancient times, and they continue to be a source from which drug developers seek leads and inspiration. In the years 2000 to 2010, 50 percent of all small drug molecules were related either directly or indirectly to natural products.
Among the reviewed substances, there are compounds acting directly on estrogen receptors, such as 8-Prenyl naringenin, shown to reduce hot flashes after removal of the ovaries. Other compounds, such as apigenin, ellagic acid, and gallic acid, have so far been shown to interact with estrogen receptors only in vitro.
In addition to acting directly on estrogen receptors, estrogen signaling can be manipulated through other molecular pathways. The aromatase enzyme, producing estrogens from the male sex hormones androgens, is effectively blocked by drugs already on the market. In addition to these synthetic drugs, natural compounds chrysin, enterodiol, resveratrol, and a host of other factors have been shown to block the enzyme.
Importantly, research shows that aromatase inhibitors might be a valuable addition to existing endometriosis treatment.
AhR (aryl hydrocarbon receptor) blocks estrogen signaling on a genetic level, and might also contribute to increased breakdown of estrogen receptors and lower estrogen production.
Indole-3-carbinol, present in vegetables such as cauliflower, cabbage, and broccoli, and resveratrol, a compound found in grapes and berries, act on the AhR receptor, but again, studies have only been performed in lab dishes.
While it might be tempting to try herbal medicine when prescription drugs are not adequately treating a condition, it is important to remember that a study showing effects in the lab do not necessarily mean that the same process will happen if we eat a substance.
Complex processes guard absorption, distribution, metabolism, and excretion of a substance, and it is possible that a substance will not reach high enough concentrations in the blood to have an effect.
Herbal medicines might also interact with prescription drugs, either causing side effects or lowering the effect of the prescription medicine.