Genistein and nutrigenomics
-
1
Aristotle University of Thessaloniki, Department of Pharmacology, Greece
Phytoestrogens belong to a group of compounds, readily available in diet and especially in soy products and vegetables, which have recently attracted significant attention due to their wide consumption by the public and their ability to exert estrogenic actions in several tissues. The isoflavone genistein (4,5,7-trihydroxyisoflavone) is a phytoestrogen mainly found in soy beans, which has a chemical structure similar to steroidal estrogens. The dietary form of genistein is being hydrolyzed by the intestinal microflora to its bioactive aglycone form, while its serum concentrations depend exclusively on the respective daily intake. It is still unclear which are the crucial life periods that genistein affects human tissues (beyond pregnancy, lactation and early development) and whether single nucleotide polymorphisms (SNPs) in human genome can cause alterations to this interaction and/or responsiveness. Genistein is structurally similar to mammalian estradiol and can bind to both α and β isoforms of estrogen receptor (ER-α and ER-β, respectively). However, its binding affinity to ER-β is almost 20 times higher than to ER-α and their efficacies of activating the binding of ER-β to estrogen response elements (ERE) of target genes are 500-850 times higher than that of activating the binding of ER-α to ERE. This selective receptor binding confers on genistein the ability to regulate physiological functions in a different way from estrogen. Several other studies indicated the antiestrogenic effect of genistein, suggesting that genistein either competitively inhibits estrogens’ binding to the ERs, and thus hinders the transactivation of estrogen-responsive genes, or acts through the inhibition of enzymes implicated in the metabolism of estrogens. Genistein also acts as a transcription factor and is involved in DNA methylation processes, as well. The typical genistein intake in western populations ranges from 5 to 50 μg/kg/day (estimated to mean consumption of 1-2 mg/day), while toxicity studies on rodents showed that doses up to 500 mg/kg/day have a low order of toxicity. Genistein has been investigated as for its interaction with genes expression and these effects seem to implicate: bone health, prevention of breast and prostate cancer –with contradictory results as regards their supplementation therapy in these cancer types, protection of the vascular endothelium, regulation of leukocyte adhesion and limiting the inflammation and oxidative effects on tissues, hypolipidemic effects and prevention of cardiovascular disease, improvement of menopausal symptoms, antithyroid effects, inhibition of pancreatic cancer cell invasion, protection of the irradiated lung tissue, growth inhibition in nasopharyngeal carcinoma cells, protection against stress-mediated neuronal degeneration, improvement of skin repair and skin protection against UVB irradiation. Overall, existing data are inconsistent and inadequate in supporting most of the suggested health benefits of consuming genistein, and thus more research on the field should be conducted.
Keywords:
Genistein,
Nutrigenomics,
Diet
Conference:
8th Southeast European Congress on Xenobiotic Metabolism and Toxicity - XEMET 2010, Thessaloniki, Greece, 1 Oct - 5 Oct, 2010.
Presentation Type:
Poster
Topic:
Nutrigenomics
Citation:
Kyriakidis
I
(2010). Genistein and nutrigenomics.
Front. Pharmacol.
Conference Abstract:
8th Southeast European Congress on Xenobiotic Metabolism and Toxicity - XEMET 2010.
doi: 10.3389/conf.fphar.2010.60.00151
Copyright:
The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers.
They are made available through the Frontiers publishing platform as a service to conference organizers and presenters.
The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated.
Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed.
For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions.
Received:
28 Oct 2010;
Published Online:
04 Nov 2010.
*
Correspondence:
Dr. Ioannis Kyriakidis, Aristotle University of Thessaloniki, Department of Pharmacology, Thessaloniki, Greece, kyriakidis@med.uoc.gr