genisteini

Genistein is an isoflavone flavonoid and a phytoestrogen primarily found in soybeans and other legumes. Its chemical name is 4',5,7-trihydroxyisoflavone and its molecular formula is C15H10O5. In foods, genistein occurs mainly as the glycoside genistin, which can be hydrolyzed in the intestine to the active aglycone genistein.

Genistein is produced by plants as a secondary metabolite via the phenylpropanoid pathway. It is abundant in soy products and is also present in smaller amounts in other legumes. As a dietary flavonoid, it contributes to the characteristic phytochemical profile of soy-rich foods.

Genistein acts as a phytoestrogen, with the ability to bind estrogen receptors, particularly estrogen receptor beta, and can exert estrogenic or antiestrogenic effects depending on tissue context and endogenous estrogen levels. It also exhibits tyrosine kinase inhibition, antioxidant activity, and influences various cell signaling pathways and gene expression. These properties underlie much of the interest in its potential health effects.

Health effects evidence is mixed. Observational studies and some clinical trials have explored potential benefits for bone health, cardiovascular risk factors, and certain cancers, but results are inconsistent and context-dependent. High-dose genistein or soy isoflavone supplements may interact with hormone-sensitive conditions or medications, and dietary soy is generally considered safe for most people. As with many phytochemicals, more research is needed to define its benefits and risks across populations and health outcomes.

Bioavailability after oral intake is relatively limited due to poor solubility and extensive metabolism. Genistein glycosides are converted to the aglycone in the gut, then absorbed and later conjugated to glucuronides or sulfates. Gut microbiota can influence the broader isoflavone metabolome, though equol production derives mainly from daidzein rather than genistein.