Phytoestrogens in cosmetology

Hormones in cosmetics? Taboo!

Adding synthetic estrogens to cosmetics today is problematic - the use of hormones in cosmetics has long been prohibited. Back in 1949, such a resolution was developed in the USA, in 1976 the EU declaration was adopted in Europe, and in 1998 in Russia. Hormonal drugs for internal or external use are prescribed only after a thorough examination, solely on the recommendation of an endocrinologist, who takes upon himself the responsibility to assert that a specific aesthetic problem is caused by hormonal imbalances, and it is impossible to correct it in any other way.

The ban on the use of synthetic hormones forces manufacturers of cosmetics based on placenta, amniotic fluid, sperm, embryonic cell extracts, etc. to necessarily prove the absence of hormones in these biologically active raw materials. Therefore, today possible solutions to this problem are being vigorously discussed. Even 90 years ago, the fact was established that the growth and development of all plants is controlled by special biological substances, so-called hormones. To distinguish these hormones from those of humans and animals, they were given the name “phytohormones.” It is generally accepted that the hormone-like components of plants affect skin cells similarly to hormones, but at the same time lack their aggressiveness. However, scientists, doctors and cosmetologists do not stop conducting heated debates about the feasibility and safety of using one or another biologically active substance. And most often, debates arise around the use of phytoestrogens in cosmetology and alternative medicine - substances that in some cases can behave like estrogens in the human body.

On the issue of terminology

Scientists managed to isolate a substance similar to human estrogens in the early 90s of the last century. Since then, phytohormones (in particular, phytoestrogens) have become quite popular ingredients in cosmetics and pharmaceuticals. However, there is still some confusion in terminology. The modern understanding of the term has expanded enormously, and now it is often used to simply mean a biologically active substance. For certain marketing purposes, many plant and animal ingredients can be called hormone-like substances. Some experts believe that there are actually no phytohormones, but that there are plant active substances that have nothing to do with hormones. And even more so, they are completely different from human hormones.

Phytohormones in the botanical literature are defined as compounds in the form of esters, formed in small quantities in one part of the plant, usually transported to another part of the plant and causing a specific growth or developmental effect through receptors.

The properties of phytohormones differ from the properties of animal and human hormones: the reactions of most plants to the action of phytohormones are nonspecific, the nature of the reaction depends on many reasons. Among them are the concentration of phytohormones, the state of the plants themselves, environmental conditions, and the polyfunctionality of phytohormones.

Phytohormones include auxins, gibberellins, cytokinins, abscisic acid and ethylene. These compounds are of different natures, but none of them has the properties of estrogens. Therefore, they cannot be called phytoestrogens.

Phytoestrogens are natural substances of plant origin that can locally imitate the effects of female sex hormones. Phytoestrogens are less biologically active than natural human estrogens and do not have the same effect on estrogen receptors as our own estradiol. Some phytoestrogens are “activators” (agonists), and some are “blockers” (antagonists), that is, they can exhibit both estrogenic and antiestrogenic effects; others have a double effect. These reactions are related to the dose and concentration of the substance and result from minor chemical changes in the arrangement of molecules. Due to the content of the phenolic ring, their chemical structure resembles the hormone 17-beta-estradiol. However, all primary phytoestrogens require laboratory chemical conversion to form a bioidentical form of human 17-beta-estradiol. Since the human body does not have the enzymes responsible for this conversion, phytoestrogen supplements do not provide the necessary 17-beta-estradiol. Sources of phytoestrogens include soybeans, red clover, grains - especially wheat germ, corn, alfalfa, licorice, ginseng, spinach, broccoli, hops, garlic, calendula, arnica, wild yam and many others. Phytoestrogens also include mycoestrogens produced by fungi that parasitize plants - these are mainly zeralenone (resorcinic acid lactone).

There are three main classes of phytoestrogens:

• isoflavones (genistein, daidzein),
• lignans (enterolactone, enterodiol),
• coumestans (coumestrol).

The most studied and actively used in cosmetology are isoflavones.

Flavonoids (flavones) are a group of natural heterocyclic compounds, most often of a glycosidic nature. These are polyoxy- or polymethoxy derivatives of flavone, flavanone, flavanonol, catechins and anthocyanides. These substances, like steroidal phytoestrogens, are not classified as phytohormones. Their content in plant tissue is very high (counted in milligrams), and they also exert their phytoestrogenic effect in a concentration very far from hormonal, namely 0.5–2%. A number of authors call these substances phenolic phytoestrogens. Flavonoids accumulate in various plant organs. Their biological activity is diverse: bactericidal, vitaminizing, antioxidant, antispasmodic, tonic. Flavonoids are characterized by low toxicity and combine well with other bioactive compounds, often enhancing their effect. Particularly effective in combination with ascorbic acid.

Flavonoids are yellow in color and poorly or not at all soluble in water. Many flavonoids, such as rutin, quercetin, hespericin, citrine and others, have capillary-strengthening properties. Contained in knotweed, thorns and other plants. Flavonoids such as quercetin and rutin are known to be actively used as pharmaceuticals. The use of flavonoids in professional and especially mass cosmetics is still limited.

Phytosterols are plant sterols, which are an integral part of the unsaponifiable fraction of vegetable oils. There are especially many of them in soybean, sunflower, and linseed oils. Phytosterols affect oxidative processes and metabolism, promote moisture retention and healing of the epidermis, that is, they have a softening and stimulating effect. Plant extracts such as nettle, burdock, coltsfoot, dandelion, chamomile, and mint also have these properties.

Initially, sterols were classified as phytoestrogens - they are lipophilic in nature, are an unsaponifiable part of vegetable fats and are not synthesized in the human body, but in their chemical structure they resemble human estrogens, therefore, according to the assumption of a number of authors, they can activate the same receptors on the surface of cells in humans. human, as estrogens.

The fundamental difference in the effects of human estrogens and steroidal phytoestrogens is this: steroidal phytoestrogens achieve the same effects as human estrogen, but only at concentrations 5,000 times or more greater than the concentration of estrogen. In other words, to obtain a certain effect, an amount of phytoestrogen must enter the skin cell from the outside that is 5,000 times greater than the dose of “native” estrogen produced by the body to obtain the same result. If we take, say, soybean oil as a source of phytoestrogen, then to obtain an estrogen-like effect on the skin it will not be enough to simply add the oil to a cosmetic preparation. Since it contains only 0.37% total sterols, the oil must be further processed to extract them and achieve the required concentration.

Phytoestrogens: mechanism of action and properties

Phytoestrogens act on the skin in the same way as their natural counterparts. There are specific receptors on the membranes of skin cells: estrogens fit them like a key to a lock. Hormones come into contact with receptors, and the most important processes are launched: cellular enzymes are activated, the rate of cell division increases.

The most important advantage of phytoestrogens is that they are well absorbed by the body and do not accumulate in it. However, this does not mean that they are absolutely harmless. Even relatively mild stimulation of the skin with phytoestrogens is considered anti-age therapy and must be strictly dosed. Excessive amounts of the same estrogens, in addition to the development of rosacea and thinning of the skin, can cause unpredictable consequences.

Almost all phytoestrogens are powerful antioxidants. In addition, they have bactericidal and antifungal properties. Creams with phytoestrogens activate microcirculation, relieve inflammation, improve skin tone and rejuvenate it. To deliver active substances to the deep layers of the skin, liposomes are often used in such cosmetic products. In addition to creams and masks, phytoestrogens can be included in chemical peels and mesotherapy preparations. Nutritional supplements based on phytoestrogens can also be beneficial - as drugs that have a general beneficial effect on a woman’s body.

Phytoestrogens can have a pronounced positive effect in the following conditions:

• prevention and correction of hormone-dependent skin aging in women during menopause,
• prevention and correction of skin photoaging,
• local therapy for seborrhea and acne,
• treatment of androgenetic alopecia,
• restoration and regeneration of the skin after grinding and deep peeling.

Their estrogen-like effect is manifested in activating the work of fibroblasts and stimulating cell division in the basal layer of the epidermis. In addition, phytoestrogens activate the synthesis of hyaluronic acid and collagen.

Promising from the point of view of maximum impact on the skin would be the development of a cosmetic series that uses phytosterols and flavonoids (substances with P-vitamin activity) and isoflavonoids. The developers have already created a number of drugs that combine fat-soluble phytosterols (nettle, flax, coltsfoot) with a complex of essential fatty acids that restore the lipid barrier, and water-soluble bioflavonoids (licorice, alfalfa, hops, clover), which have an antioxidant and anti-inflammatory effect , enhancing the biosynthesis of type III collagen and increasing skin density.

Researchers believe that phytoestrogens have a great future. True, research into hormone-like substances in plants is still in its early stages. It is important to understand that, unlike steroid hormones, phytoestrogens are not absorbed through the skin and do not have systemic effects. And since the substances contained in plant extracts themselves are little active, and the bulk of compounds with estrogen-like activity are formed in the intestines, you should not expect any pronounced hormonal effects from phytoestrogens applied to the skin.

However, it is worth noting that solving hormonal skin problems does not necessarily imply the use of hormonal agents. The same phytoestrogens (lignans and isoflavones), which have antioxidant effects, can inhibit the enzyme 5-alpha reductase and influence the secretion of cytokines, can be a useful weapon in the fight against hormonal problems. 5-alpha reductase is most effectively blocked by the isoflavones equol and genistein, as well as the product of microbial metabolism of lignans in the intestine, enterolactone. Since phytoestrogens do not have hormonal side effects, they can be successfully used in the treatment of androgenetic alopecia, acne, and oily seborrhea.

Sources of phytoestrogens

Today, science includes over 70 plant species containing hormone-like substances of plant origin. Most of them have estrogenic activity. In the plants themselves, phytoestrogens regulate the processes of growth and reproduction, provide protection from ultraviolet radiation, damage by fungi and other parasites.

The most studied and widespread at present are phytoestrogens extracted from soybeans . Soy contains the isoflavones genistein and daidzein. Recently, another phytoestrogen was discovered - glycitein, which is found mainly in soybean sprouts. Genistein and daidzein may be present in plants as aglycones or glycosides. In the intestine, glycosides are hydrolyzed under the influence of intestinal microflora and converted into the aglycones daidzein and genistein; daidzein is subsequently partially transformed into equol. As it turned out, isoflavone glycosides are practically incapable of causing an estrogenic response in cells. The aglycones genistein and daidzein have slightly higher estrogenic activity. However, the most significant contribution to the estrogenic effect of soy is made by equol, which in its structure most closely resembles estradiol.

Red clover contains isoflavonoids from the isoflavone group (biochanin-A and formononetin) and coumestans (coumestrol). Today, red clover, like soybeans, is widely used to prevent unpleasant symptoms of menopause. However, unlike soybeans, clover is not a food product and is classified as a medicinal plant. Accordingly, there is no data on its effect on the human body with long-term and regular use. According to scientists, there is also not yet enough experimental data to justify the use of red clover extract in hormone replacement therapy.

Alfalfa contains the phytoestrogen coumestrol and small amounts of formononetin. Alfalfa, like clover, by the way, causes reproductive disorders in sheep. The estrogenic effects of alfalfa extract in humans are still poorly understood.

Flax seeds contain phytoestrogens lignans, which are converted into enterolactone and enterodiol in the human intestine. In their biological action, lignans are similar to isoflavones.

Licorice root contains the isoflavone glabridin. Studies conducted on cancer cell cultures have shown that the effect of glabridin depends on its concentration. At low concentrations (10-9–10-6 M), glabridin stimulates the growth of cancer cells. In high concentrations (>15 µM), on the contrary, it suppresses their growth.

The phytoestrogen resveratrol, which has high antioxidant activity, was found in red grapes (including red wine).

Hops , which are an important ingredient in beer, contain the phytoestrogen 8-prenylnaringenin. Its activity is very high - women involved in harvesting and processing hops often experience menstrual disorders. The phytoestrogens content in beer is low enough to not cause concern.

Extracts of verbena, anemone, St. John's wort, mantle, shepherd's purse, motherwort, and yarrow have phytoestrogenic activity. As a rule, they do not cause adverse reactions.

A substance called epigran by its manufacturers is extracted from wheat sprouts . In addition to phytoestrogens, it contains plant enzymes. It is believed that epigran can improve the condition of any skin type. By the way, oils created on the basis of cereals were used in dermatology and cosmetology long before the era of phytoestrogens began. It’s just that in those days their effect was explained by the high content of polyunsaturated fatty acids, vitamins F, E and biologically active substances. Of course, no one questions the value of these components even now, but with the discovery of phytoestrogens, many processes have become much more understandable. Vegetable oils with the highest content of phytoestrogens are soybean, wheat germ, flax, pomegranate, date, etc. oils.

Today, many scientific works are devoted to the hormonal influence of phytoestrogens on the woman’s body. Scientists confirm the effectiveness of using products with phytoestrogens and certain properties of phytoestrogens, while some of their properties are still under research. At the same time, beauty industry specialists should pay attention to the quality of cosmetic products and their correct selection for each skin type in accordance with age restrictions.

First published: KOSMETIK international journal, No. 2(36), 2009, pp. 22-26