Isoflavones: Vegetable Sources, Biological Activity, and Analytical Methods for Their Assessment

Abstract

Phytoestrogens are natural compounds found in various plant species and they have the ability to bind to the estrogenic receptors, exerting agonist and/or antagonist effects. The main classes of phytoestrogens are isoflavones, lignans, and coumestranes. Isoflavones are plant bioactive nonsteroidal polyphenolic metabolites with antioxidant properties. They have a very close structure with 17β-estradiol and possess estrogenic/antiestrogenic effects. The main dietary source of isoflavones is soy (Glycine max L.). Other legumes, such as red clover (Trifolium pratense L.), alfalfa (Medicago sativa L.), and Genista species, have important content in isoflavones, showing nutritional or phytotherapeutic interest. In plants, isoflavones can be found mainly as non-active glycosides which are converted after ingestion, in the corresponding aglycones (e.g., genistein, daidzein) that have pharmacological activity. Many studies have demonstrated the benefits of dietary isoflavones in menopause and multiple chronic pathologies, including cardiovascular diseases, osteoporosis, and hormonal cancers. Dietary intake of isoflavones is widespread, mainly due to the consumption of soybean products. Analytical methods applied for the quantification of isoflavones allow both assessment of dietary intake of isoflavones and highlighting natural sources with phytotherapeutic potential. Health benefits of isoflavones justify the interest for this class of functional food; therefore, further clinical and epidemiological studies are required.

The Role of Vitamin K in Humans: Implication in Aging and Age-Associated Diseases

“…In an intervention study, the use of 150 µg VK1 per day, in combination with physiological relevant doses of genistein, an important isoflavone [67], vitD, and polyunsaturated fatty acids (eicosapentaenoic and docosahexaenoic acids), could reduce fracture risk, at least at the hip, and prevent osteoporosis in postmenopausal women [68]. On one hand, VK2 supplementation might enhance the efficacy of vitD in bone and muscle health, improve bone quality, and reduce fracture risk in osteoporotic patients.…”

Health Benefits of Nut Consumption in Middle-Aged and Elderly Population

“…In pistachios, the small amounts of genistein, (-) epigallocatechin-3-gallate (EGCG) or resveratrol can act synergistically through common or complementary action pathways with proven antioxidant and anti-aging activity. Thus, the flavonoid (isoflavone) genistein has demonstrated antioxidant, chemopreventive, and chemotherapeutic effects [161]. Growing evidence suggests that EGCG, also present in pecans and hazelnuts, can contribute to the anti-cancer potential [162].…”

Flavonoids Alleviate Peripheral Neuropathy Induced by Anticancer Drugs

“…Flavanols–which include catechins and epicatechin–are the 3-hydroxy derivatives of flavanones [ 26 ]. Isoflavones have estrogenic properties and structures that include 3-phenyl-benzopyrone [ 27 ]; the main isoflavones are genistein, daidzein, biochanin A, and glycitein. Anthocyanins’ basic structural unit is the flavylium cation (2-phenylbenzopyrilium); this confers a positive charge on the oxygen skeleton.…”

“…Furthermore, the histamine/H1R complex leads to the activation of PLA2, which increases the conversion of phospholipase to arachidonic acid. Arachidonic acid is subsequently converted to 12-HPETE, which sensitizes TRPV1 [ 26 , 27 ].…”