Forage Legumes as Sources of Bioactive Phytoestrogens for Use in Pharmaceutics: A Review

Background: Alfalfa and red clover are the most widespread and most important perennial legumes, primarily used as a high-quality feed for livestock. Both alfalfa and red clover, as well as some other plant species from Fabaceae family, are a rich natural source of phytoestrogens, nonsteroidal compounds with an estrogenic activity whose beneficial effects in the prevention and treatment of many diseases are demonstrated in numerous scientific studies. Objectives: Nowadays, various herbal preparations are present on the world market and their use is constantly increasing, as well as the growing demands of consumers for environmentally sound and health-safe production of plant species used as sources of active substances. Because of their widespread distribution, the possibility of organic breeding, and also significant increases in surface area under genetically modified crops in most EU countries, alfalfa and red clover have become more interesting alternative sources of phytoestrogens. The most common phytoestrogens in these forage legumes are genistein, daidzein, glycitein, formononetin, biochanin, coumestrol, kaempferol and apigenin. The content of these substances is significantly influenced by a number of factors including genotype, environment, production technology, plant maturity stage, and individual plant parts. Conclusion: Available evidence suggests that forage legumes represent high promising sources of health-promoting phytoestrogens. Due to numerous favorable features, they can find commercial application in different industries such as pharmaceutical, nutraceutical, cosmetic, and agriculture.