Isoflavones are a class of phytochemical compounds belonging to the flavonoid group, predominantly found in plants from the legume family, such as soy (Glycine max) and red clover (Trifolium pratense). These compounds are known for their antioxidant, anti-inflammatory properties, and estrogen-like effects, making them useful in various cosmetic and medicinal applications. Isoflavones are used to enhance skin elasticity, reduce signs of aging, and protect against free radical damage.

Chemical Composition and Structure
Isoflavones have a structure similar to human estrogens, allowing them to bind to estrogen receptors in the body. Key isoflavones include genistein, daidzein, and glycitin. These compounds act as phytoestrogens, mimicking estrogen activity to some extent and offering benefits for skin, especially during aging processes.

Physical Properties
Isoflavones are typically available in powder or liquid extract form, soluble in both water and oils. Their color ranges from white to light beige, depending on the plant source and extraction method. They are easily incorporated into various cosmetic formulations, including anti-aging creams, serums, and lotions, due to their stability and compatibility with other ingredients.

Production Process
Isoflavones are primarily extracted from plants like soy or red clover through solvent-based or aqueous extraction processes. The plants are dried and macerated, followed by extraction to isolate the isoflavonoid compounds. The extract is then purified and concentrated to produce an isoflavone-rich product ready for use in cosmetic formulations and supplements.

Applications

• Medical: Isoflavones are used as dietary supplements to alleviate menopausal symptoms, such as hot flashes and bone density loss, due to their estrogen-like properties. They are also studied for their potential role in reducing the risk of cardiovascular diseases and osteoporosis (1). Isoflavones are considered to be chemoprotective, but may also be considered to be endocrine disruptors (2)

• Cosmetics: In skincare, isoflavones are valued for their ability to stimulate collagen production, improve skin elasticity, and reduce signs of aging such as wrinkles and fine lines. Their antioxidant properties protect the skin from free radical damage, making them suitable for anti-aging and regenerative formulations.

• Food: Isoflavones are often added to nutritional supplements and functional foods for their beneficial effects on hormonal, cardiovascular, and bone health, especially in postmenopausal women.

• Industry: In the cosmetic and nutraceutical industries, isoflavones are used as functional ingredients for their regenerative and antioxidant properties. They are commonly included in products targeting mature skin and supplements aimed at overall well-being.

Environmental and Safety Considerations
Isoflavones are generally considered safe for use in cosmetic products and supplements, although long-term use of high doses should be monitored to avoid potential side effects. Environmentally, isoflavones are biodegradable, and their production, when conducted through sustainable agricultural practices, has no significant negative impact on the environment.

References__________________________________________________________________________

(1) Nakai S, Fujita M, Kamei Y. Health Promotion Effects of Soy Isoflavones. J Nutr Sci Vitaminol (Tokyo). 2020;66(6):502-507. doi: 10.3177/jnsv.66.502. 

Abstract. Soybeans contain several physiologically active ingredients, such as soy phytosterol, soyasaponin, soy protein, and lecithin, and are therefore expected to express the functionalities of said ingredients. Among them, soy isoflavones have been studied in recent years for their various functions, including their obesity-preventing effect, blood glucose level reducing effect, osteoporosis and breast cancer risk reduction, and anti-oxidative effect, and several health promoting effects and disease preventing effects are expected. For example, it has been determined that soy isoflavones reduce body and fat weight in experiments in which mice were fed a diet containing soy isoflavones in studies on anti-obesity. Epidemiologic studies with humans have also shown that women who consume more soybeans have lower BMI than those who consume less. We previously found that soy isoflavones may have anti-obesity effects in myoblasts through the activation of transcriptional coactivator PGC-1β, which increases energy expenditure. In recent studies, a decrease in blood glucose level due to soy isoflavone was seen in an experiment in which diabetic model mice were fed a diet containing soy isoflavone. It has also been suggested that soy isoflavone intake may increase bone mineral density in postmenopausal women and reduce the risk of breast cancer. This review focuses on the actions of soy isoflavones known to date, including their anti-obesity and anti-diabetic effects, bone loss preventing effects, and cancer risk reduction effects, and introduces reports on the health promotion and disease prevention effects of soy isoflavones.

Yamagata K. Soy Isoflavones Inhibit Endothelial Cell Dysfunction and Prevent Cardiovascular Disease. J Cardiovasc Pharmacol. 2019 Sep;74(3):201-209. doi: 10.1097/FJC.0000000000000708. 

Abstract. Soybeans are among the most popular foods worldwide, and intake of soy-containing foods has been associated with many health benefits in part because of it structure similar to estrogen. Epidemiologic studies have demonstrated that soy consumption improves serum profiles of hypercholesterolemic patients. Several studies have also indicated an inverse relationship between the consumption of soy isoflavones and the incidence of cardiovascular diseases (CVD). Soy is a rich dietary source of isoflavones. The main soy isoflavones are daidzein and genistein; equol, another isoflavone and a major intestinal bacterial metabolite of daidzein, is generated by enterobacterial effects. Many isoflavones have antioxidative effects and anti-inflammatory actions, as well as induce nitric oxide production to maintain a healthy endothelium and prevent endothelial cell dysfunction. These effects may limit the development of atherosclerosis and CVD and restore healthy endothelial function in altered endothelia. Although the evidence supporting the benefits of soy isoflavones in CVD prevention continues to increase, the association between soy isoflavones and disease is not fully understood. This review summarized recent progress in identifying the preventive mechanisms of action of dietary soybean isoflavones on vascular endothelial cells. Furthermore, it describes the beneficial roles that these isoflavones may have on endothelial dysfunction-related atherosclerosis.

Taku K, Melby MK, Nishi N, Omori T, Kurzer MS. Soy isoflavones for osteoporosis: an evidence-based approach. Maturitas. 2011 Dec;70(4):333-8. doi: 10.1016/j.maturitas.2011.09.001. Epub 2011 Sep 29. PMID: 21958941.

(2) Křížová L, Dadáková K, Kašparovská J, Kašparovský T. Isoflavones. Molecules. 2019 Mar 19;24(6):1076. doi: 10.3390/molecules24061076. 

Abstract. Phytoestrogens are naturally occurring nonsteroidal phenolic plant compounds that, due to their molecular structure and size, resemble vertebrate steroids estrogens. This review is focused on plant flavonoids isoflavones, which are ranked among the most estrogenic compounds. The main dietary sources of isoflavones for humans are soybean and soybean products, which contain mainly daidzein and genistein. When they are consumed, they exert estrogenic and/or antiestrogenic effects. Isoflavones are considered chemoprotective and can be used as an alternative therapy for a wide range of hormonal disorders, including several cancer types, namely breast cancer and prostate cancer, cardiovascular diseases, osteoporosis, or menopausal symptoms. On the other hand, isoflavones may also be considered endocrine disruptors with possible negative influences on the state of health in a certain part of the population or on the environment. This review deals with isoflavone classification, structure, and occurrence, with their metabolism, biological, and health effects in humans and animals, and with their utilization and potential risks.