Retinol - the first in a row of vitamins for the skin

The sad experience of the Eskimos and the successful Egyptians were explained only in the middle of the twentieth century. In 1930 Moore (Moore) synthesized retinol from carotenoids and began to study its effect on the body. And only in 1943 it was finally proved that it was retinol that was the culprit of the unhappiness of the fearless Arctic explorers and the last hope of the blind Egyptians. The article by Moore and Rohdal, published in the Biochemical Journal, was truly sensational. It turned out that the polar bear liver contains so much retinol (18,000-27,000 IU / g) that the consumption of even a small piece (say 250 g) exceeds the daily norm of retinol by more than 1000 times.

Deficiency of retinol is no less dangerous than its excess. Inadequate intake of retinol in the body eventually leads to an irreversible loss of vision, a drop in resistance to infection, the emergence of all sorts of skin problems and even death. Substances necessary for normal life and even for the very existence of the human body, scientists called "vitamins" (from Latin vita - life) to emphasize their significance. Retinol became the first in their series, receiving the honorary title of vitamin A.

Cells are very sensitive to the concentration of retinol, and any, even a slight deviation from the norm affects their vital activity. The mammalian organism has a reliable system of regulation, allowing to control and maintain the concentration of retinol at the proper level. Vitamin A is synthesized in cells of the intestinal mucosa from beta-carotene, which comes with plant food. Here, with the participation of the enzyme dioxygenase, beta-carotene is split into two retinal molecules, which are then reduced to retinol. The amount of synthesized retinol is strictly regulated to prevent intoxication of the body. Further, retinol enters the liver, where it is deposited in stellate cells mainly as esters. Hence, as necessary, retinol is delivered to other organs, including the skin.

The mechanism of cellular regulation of retinoid metabolism is a complex but precise and well-established system. It includes a variety of enzymes and binding proteins that provide for the capture, metabolism, deposition and transport of retinoids within the cell.

Over time, scientists have found substances that have similar effects to vitamin A. Synthetic and natural compounds, the mechanism of action of which is similar to retinol, began to be called retinoids and used to treat a variety of diseases, including skin diseases.

Retinol rejuvenates the skin

Being a derivative of vitamin A, retinol stimulates the production of collagen, a natural component of the dermis, which makes the skin look more youthful. The results of one of numerous studies showed that 36 women aged 80 and older who applied ointment with 0.4% retinol on the skin of the hand, after 24 weeks, marked changes in skin condition. The patch of skin on which the ointment with retinol was applied became more smooth, elastic and elastic.

Retinol makes the skin healthier

Retinol allows you to get rid of depigmentation, lines and wrinkles, to correct the texture of the skin, to align its tone and color. As a result of the use of retinol, the skin looks healthier and more even.

Retinol stimulates cell replacement

Regular exfoliation is the guarantee of a young looking skin: dead cells are removed, and new, healthy cells form the surface layer of the skin. Thanks to regular exfoliation, the skin becomes smoother, and a variety of cosmetics work more efficiently, freely penetrating into the deepest layers of the skin. The layer of dead cells does not allow beneficial ingredients to penetrate deep into the skin.

Retinol treats acne

Retinol not only reduces the signs of skin aging, but also helps to solve the problem with acne, say dermatologists. Acne affects almost 50% of adult women, and treating aging skin from acne can be a really difficult problem. Fortunately, thanks to the exfoliating properties of retinol, its action allows curing acne: regularly removed dead cells do not clog pores, which most beneficially affects the condition of acne-prone skin.

Retinol is safer than retinoids

Being, like retinol, derivatives of vitamin A, retinoids are available only on the recommendation of a dermatologist. Although retinoids are much more effective than drugs that are sold in a pharmacy without a prescription, they have a significant drawback - the use of retinoids can cause irritation and redness of the skin. Retinol, at the same time, acts on the skin much softer, turning into retinoic acid - a key ingredient in drugs prescribed by a dermatologist - slowly and gradually. Retinol is ideal for women with sensitive skin, prone to irritation.

Retinoic cosmetics

The first company that took the liberty of releasing a reminoic acid remedy for the cosmetic market was Ortho Parmaceutical Corp., a wholly owned subsidiary

Johnson & Johnson. In 1971, the public was presented with a preparation for the treatment of acne "Retin-A" (0.1% tretinoin), which quickly gained popularity. After 25 years, in 1996, Ortho Parmaceutical released one more remedy, Renova, designed to prevent senile skin changes and recovery from photodamage. "Renova" contains 0.05% tretinoin, encased in a soft cream base, and is used to combat fine wrinkles and hyperpigmentation. Consumers appreciated retinoic drugs, and a successful series of Ortho Parmaceutical was followed (though with great care) by a number of other companies. Retinovaya cosmetics very accurately blended with modern cosmetology, gradually overgrown household frames and acquiring features of medical discipline.

Retinoids penetrate the skin directly through the stratum corneum (the transepidermal pathway) or through the excretory ducts of the glands (the transfollicular pathway). In the skin, a retinoid concentration gradient is created, decreasing towards the dermis. In the epidermis, retinoids control the processes of keratinization and pigmentation, and in the dermal layer contribute to the restoration of the intercellular matrix, gradually degrading during aging or UV irradiation. The transphollicular pathway allows to obtain an increased concentration of retinoids directly in the follicles, which is especially valuable in the treatment of follicular pathologies, for example acne.

Every year, the leading dermatological journals of the world publish the results of studies of retinoic drugs, including cosmetic ones. Long-term clinical trials involving parallel histological analysis are of great value, which makes it possible to compare the visible effects with the morphological changes in the skin.

For deeper cleaning, special surface peels can be used, softening the stratum corneum and removing dead cells. Most often, these peelings include fruit acids (glycol pi-lingas), and peeling agents containing enzymes (enzymatic peelings) are also found. Another category of drugs that make up the cosmetic series are those that soothe, soften, nourish, protect and regenerate the skin. Their task is to prevent the occurrence of side effects associated with the action of retinol (erythema, inflammation, redness, etc.), or to alleviate the patient's condition in the event of already arising unpleasant sensations.

An indispensable condition when using such a cosmetic series is a clear observance of the sequence of application of the preparations. Only in this case it is possible to achieve positive results and avoid complications. Clinical studies show that such a comprehensive approach fully justifies itself in the case of mild to moderate acne, photodamaged and fading skin. The medical press also reported on the successful treatment of white striae by a combination of preparations containing glycolic acid (20%) and tretinoin (0.05%) in a soft cream base.

Complications and contraindications to the use of retinoic cosmetics

When using retinoic cosmetics in some cases, reddening of the skin, temporary peeling, rarely - blisters, increased sensitivity to sunlight. This should be taken into account when developing the formulation, if possible, selecting the components in such a way as to reduce the risk of side effects. Among the contraindications to the use of retinoic cosmetics - the simultaneous reception of photosensitizing drugs from the groups of thiazides, tetracyclines, fluoroquinolones, phenothiazines, sulfonamides.

I would especially like to note the problem of using retinoic cosmetics in pregnant women. Despite the fact that the concentration of retinoids in cosmetic products is small and it is believed that they are not practically absorbed into the blood, it is better to be reinsured and to refrain from using it. It should be remembered that vitamin A has a strong teratogenic effect and that retinoic medicines for pregnant women are categorically contraindicated.

[1], [2], [3], [4], [5]