[Selected phytoestrogens with potential beneficial effects on risk of certain environmental diseases]

Evidence has been accumulated that some phytoestrogens act as protective factors against development of cancer and also cardiovascular diseases. These are phytoestrogens of isoflavone and lignane series, found especially in soy. Beneficial effect of these compounds may be explained by a complexity of their actions at various levels: they interact with estrogen receptors, some of them are inhibitors of the key enzymes responsible in the final effect for cell growth and proliferation, and, due to their chemical nature they are scavengers of free radicals. In the presented work the authors, in collaboration with Finnish partners from the University of Helsinki, developed original immunoassays for determination of main phytoestrogens of isoflavone series--daidzein, genistein, formononoetin, biochanin A, their metabolite equal and lignane enterolactone. The methods are sensitive enough for follow-up of actual levels of phytoestrogens in serum. By using these methods, the levels of phytoestrogens in Czech population have been established. The group of patients suffering from osteoporosis has been investigated, too. Significantly lower levels of isoflavonoids in comparison with sex- and age-matched healthy subject have been found in the patients. The methods have also enabled us to follow up the dynamics of these compounds in the organism, as well as to determine their content in food and its sources. The original detection and quantification of four above mentioned isoflavonoids in beer is an example.