Isoflavones are safe compounds for therapeutical applications – Evaluation ofin vitrodata

Abstract

Isoflavone-rich food and food supplements have gained increasing popularity also in the Western world. Their weak estrogenic effect has been considered as a potential risk, although all epidemiological studies and clinical trials show a significant cancer protection and decreased risk of cardiovascular diseases. In vitro data suggest that the concerted action of the isoflavones and their metabolites show antiproliferative behaviour, reduce angiogenesis, reduce tumor progression and exert antiinflammatory effects. For the evaluation of the biological effects, special emphasis has to be put on the concerted action between the isoflavones and their metabolites. For instance, while isolated genistein shows some growth promoting effect at low concentrations, the metabolite equol or soy extract show growth retardation as well as higher concentrations of genistein do. The isoflavones have multiple affinities to other members of the steroid hormone receptor superfamily. The beneficial effect on metabolic diseases and weight reduction by isoflavone consumption can be partly explained by its affinity for the PPAR family. In light of the in vitro experiments, together with the epidemiological observations and the clinical experience, isoflavones can be considered as safe compounds and their consumption as food and food supplements has to be promoted.

Antagonism of human formyl peptide receptor 1 (FPR1) by chromones and related isoflavones

“…These compounds, along with their synthetic analogues, possess a wide variety of biological activities, including antiinflammatory, antiproliferative, antiosteoporotic, antihyperglycemic, antifungal, antiviral, antiparasitic, antioxidant, and cardiovascular effects [50–55]. Although reactive oxidant scavenging activity of flavonoids/isoflavones may contribute to modulation of phagocyte functional activity [56, 57], these compounds also interact with other cellular targets, including receptors, enzymes, and other macromolecules (for review [58–60]). Such properties include actions upon peroxisome proliferator-activated receptor isoforms, estrogen receptors, tyrosine kinases, DNA topoisomerase II, and NF-κB activation [61–63].…”

Antagonism of human formyl peptide receptor 1 with natural compounds and their synthetic derivatives

“…Binding of these compounds to FPR1 and effects on Ca 2+ mobilization were not reported. It should be noted that some flavonoids and isoflavones can also interact with other cellular receptors and enzymes that cross-talk with FPR1 signaling (reviewed in [98–100]).…”

The Role of Soy in Vegetarian Diets

“…Independent of ER binding, isoflavones and especially genistein, hold the potential to exert physiological effects since they affect signal transduction pathways by inhibiting the activity of many enzymes (e.g., tyrosine protein kinase, mitogen activated kinase, and DNA topoisomerase) and regulating cellular factors that control the growth and differentiation of cells [20,21]. However, the relevance of many of these effects is unclear as the in vitro concentrations at which these effects occur in most instances are far higher than can be achieved in vivo , although there is also evidence indicating that the in vitro data underestimate the in vivo potency of isoflavones [22,23].…”