Author/Editor		Korošec, Ladko
Title		Fitoestrogeni in njihovi vplivi na raka - zavezniki ali sovražniki?
Translated title		Phytoestrogens and cancer - allies or foes?
Type		članek
Source		In: Gašperlin L, Žlender B, editors. Karcinogene in antikarcinogene komponente v živilih. 24. Bitenčevi živilski dnevi; 2006 nov 9-10; Ljubljana. Ljubljana: Biotehniška fakulteta, Oddelek za živilstvo,
Publication year		2006
Volume		str. 189-97
Language		slo
Abstract		Phytoestcogens are natural, nonsteroidal plant-derived compounds with structural and funcrional similarity to genuine 17beta-estradiol, possesing estrogenic activity. They are principally flavonoid polyphenolics: isoflavones (genistein, daidzein, biochanin-A, formononetin, glycerin), non-flavonoid polyphenolics: lignans (enterolacton, enterodiol), coumestan: coumestrole, lactone: ceralenone, and steroles (sitosterol-A,-B). Phytoestrogens exhibit weak partial estrogen agonist activity. In vitro studies indicated that phytoestrogens have only slight binding affinity of estradiol for estrogen receptors (ER), that led to interpretation that phytoestrogens are to 10,000 times weaker than estradiol. Phytoestrogens binding to beta-type estrogens receptors (ER-beta), activate cardioprotective and bone-stabilizing metabolic processes, but also down-regulate the activity of the a-type estrogens receptors (ER-alpha). Phytoestrogens have earned great attention recently because of their beneficial effects on the skeletal and cardiovascular systems, atherosclerosis, osteoporosis, and the prevention of cancer. Isoflavones help to prevent pxostatic, breast, stomach, lung endometrial, skin, and colon malignomas. Some reports show that phytoestrogens may contribute to the breast, prostate, and bladder cancer risk and also to infant leukemia. In vitro animal experiments showed that the biological effect of phytoestrogens may be organ-specific, inhibiting cancer development in some sites, yet showing no effect or an enhancing effect on cancerogenesis on other tissues. To clearify these opposite effects of phytoestrogens we should obtain more information. That is why well-designed experimental studies are required.
Descriptors		NEOPLASMS FLAVONES RECEPTORS, ESTROGEN NUTRITION