Isoflavones, substances with multi-biological and clinical properties

Isoflavones, rich in soybean, are currently receiving much attention because of their potential role in preventing and treating cancer and other human chronic diseases. The present review provides an overview of the recent results in this research field. Data from epidemiological reports and laboratories have shown that isoflavones have multi-biological and pharmacological effects in animals and humans. These include estrogenic and antiestrogenic effects, cell signalling conduction, as well as cell growth and death. Based on these properties, soy protein and isoflavones have been associated with reduced incidences of breast and prostate cancers, cardiovascular diseases or osteoporosis, and exhibit some other favorable effects. The mechanism through which isoflavones may exert the above-mentioned functions are not only based on the estrogenic properties of isoflavones, but also on their role as protein tyrosine kinase inhibitors, as regulators of gene transcription, modulators of transcription factors, antioxidants, as well as by altering some enzyme activities. However, to draw a clear conclusion regarding the clinical use of isoflavones further investigation would be required, although only a few effects of short- or long-term use of soy proteins are known in humans.