Is an independent, complex and wise organ. At the very bottom is the hypodermis, which consists of adipose tissue. It is this fabric that retains moisture. Slightly higher and closer to the surface is the dermis, which has special cells for absorbing moisture from adipose tissue. Moisture goes up unhindered up to the stratum corneum. This is the last layer before moisture escapes. In other words, the lipid layer of the skin is a barrier to moisture release.
It is unambiguous that if something happens and it becomes thinner, then moisture freely leaves the skin and evaporates from the surface. Accordingly, very soon we will find a lack of moisture on our face. If the lipid layer is disturbed, the skin becomes dull and looks unkempt. The first wrinkles appear regardless of age, but due to a violation of the lipid layer.
- flabbiness
- dehydration of the skin,
- sagging,
- dryness,
- peeling,
- fine network of wrinkles.
Do not forget that a disturbed lipid barrier can become a channel for various bacteria to enter the skin. This causes skin irritation, as well as dermatitis, eczema, acne.
The lipid layer of the skin can be destroyed for a number of reasons:
- Washing your face with poor quality soap and hot water.
- Uncontrolled taking of ultraviolet baths.
- Frequent sudden changes in temperature.
- Physical stress, psychological experiences.
- Mechanical damage to the skin, for example, strong rubbing of the skin with a towel.
- Incorrectly selected face cosmetics.
The lipid barrier of the skin can be restored easily and quickly with a well-designed cosmetic program. Damaged lipid mantle leads to dehydration of the skin, and an increase in its sensitivity to negative factors. It is imperative to restore the damaged lipid layer. And for this, various fatty products including some oils.
This is due to the fact that the main components of the lipid layer are: oil, phospholipids, fatty acids, ceramides and cholesterol. Thus, if you correctly select an oil of a similar composition, it is possible to quickly restore the lipid layer. Natural oils are rich in phospholipids and fatty acids. Phytosterols in natural oils are able to replace the natural cholesterol of the lipid layer. Moreover, natural oils contain antioxidants.
The most suitable oils for restoring the lipid layer are burdock, grape seed oil, and linseed oil. These funds are perfect even for owners oily skin.
Ideally, the oil should be applied to the skin before going to bed, and after 5-10 minutes, the skin should be blotted. paper napkin... If in the morning you find that your skin is very oily, then it is permissible to rinse your face with water at room temperature. Remember not to use hot water on your face. The oil should be applied to the skin daily for a month. Already after two weeks, you will notice how the skin of the face has become more elastic and elastic. Dryness and dehydration disappeared, replaced by a blush and a healthy glow.
In addition to natural oils, you can use ready-made creams and serums to restore the lipid layer of the skin of modern well-known manufacturers. Many of them deserve the utmost attention. When choosing a product, pay attention to the ruler. It is important that this remedy is from the line that you are using at the moment. Remember that these products may contain natural oils. Study the composition carefully to prevent the possibility of an allergic reaction to a rather expensive cosmetic product.
How to cleanse your skin with oil
No need to rinse before using oils decorative cosmetics... The oil perfectly removes makeup. The whole procedure will take no more than 15 minutes. To do this, you need oil, a towel, or cloth.
Cleansing with oil goes through several stages.
The oil is perfectly absorbed, nourishes the skin, so no additional creams are required after cleansing with oil. If you are not applying oil to the eyes and lips, then add a couple of essential oils to it. It is very helpful to add tea tree or lavender oil. For aging and dry skin, neroli and rose oils are suitable.
With regular cleansing of the skin with oil, you will see how inflammation, peeling passes, the skin becomes fresh and smooth. The only downside to using oils is that it takes a little longer than usual. You will also need to change the towel frequently and you should pay attention to the quality of the oils. Good oil is not cheap.
You will notice the result of the restoration of the lipid layer very quickly as a clear improvement in the condition of your skin.
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The structural and functional health of the skin is largely related to the content and distribution of water in it. Dry skin entails its easy permeability to toxic and sensitizing substances, contributes to the development of immune disorders and the formation of allergic inflammation. Impaired hydration of the stratum corneum of the epidermis is the main cause of pathological desquamation of the epithelium and xerosis. Since corneocytes are cells devoid of a nucleus, dermatologists until recently did not treat the stratum corneum with due attention. But it turned out that by acting on the stratum corneum, you can not only achieve cosmetic effects, but also alleviate the symptoms of skin disease, improve the result from drug treatment and improve the patient's quality of life.
The basis of skin care for skin diseases is "corneotherapy", a system for restoring the functioning and integrity of the stratum corneum. In modern conditions, the line between cosmetic and pharmaceutical products is gradually blurring due to the complication of the formulation of cosmetic products. Modern cosmetics can affect physiological processes in the skin in the same way as a pharmaceutical drug does. The skill of the dermatologist is based on his ability to use various active and indifferent external therapies in therapy, achieving maximum success.
Numerous structures are involved in maintaining water balance that regulate the rate of transepidermal water loss and carry out the flow of water from the dermis to the epidermis. Obviously, for the full functioning of the skin, a supporting structure of corneocytes is necessary; when it is disturbed, trans-epidermal water loss increases, which leads to hyperplasia of the epidermis and hyperkeratosis. The stratum corneum serves as a sensor for the underlying layers. In the epidermis, the water balance is controlled by the stratum corneum and the components of the stratum corneum of the epidermis (natural moisturizing factor, skin lipids, sebum and keratin).
It is from the epidermis that the skin begins to dehydrate. This is due to the fact that the epidermis is devoid of blood vessels that could replenish moisture reserves in it, so the epidermis receives the bulk of the liquid from the dermis. Until recently, it was believed that water seeps into the upper layers of the skin according to the law of perfusion. Free amino acids formed during the breakdown of the filaggrin protein maintain a high osmotic pressure in corneocytes, which causes an influx of water, which is retained even at low humidity environment... However, in last years It was found that in maintaining a normal level of hydration of the epidermis, the mechanism of facilitated diffusion is also important, that is, the ingress of water molecules through water channels called aquaporins. Aquaporins are membrane proteins that form pores on the surface of cells through which water passes, as well as small water-soluble compounds such as glycerol and urea. For the discovery of these proteins in 2003, a group of American scientists led by Peter Egrom was awarded the Nobel Prize in Chemistry.
Having reached the surface of the skin, water tends to evaporate, but this is hindered by the stratum corneum. Despite the low water content in the stratum corneum - 15-20%, moisture retention is one of its main functions. The impermeability of the stratum corneum is due to the barrier properties of keratin, acylceramides and sebum. The epidermis is fairly well permeable towards its surface and almost impermeable in the opposite direction. At the same time, water and water-soluble substances penetrate the epidermis with great difficulty, while fat-soluble substances are much easier. To appreciate the important role of the stratum corneum of the epidermis in retaining moisture in the skin, it is necessary to clearly know its structure.
The stratum corneum is the end product of the differentiation of epidermal keratinocytes. In thin skin, it consists of 15-20 layers of horny scales, in thick skin it consists of hundreds of layers. The scales are arranged in columns one above the other, and each scale in projection covers 9-10 cells of the basal layer. The corneocyte has a 6-sided shape and each of the six sides is in contact with neighboring corneocytes, such a structure can be compared to a "quilt". The stratum corneum of the epidermis has a unique structure, which is called "briсk and mortar" ("brick and cement"), where the role of "bricks" are horny cells, and "cement" - intercellular lipids. On the cross section, the stratum corneum appears to be loose, porous, but this is only an appearance. This impression is created by the intercellular spaces, which make up a significant part of the stratum corneum. However, they are all filled with a special substance that sticks them together into an insurmountable barrier with lipids-acylceramides, which belong to the class of sphingolipids, or ceramides. For the first time, sphingolipids were isolated from brain tissue, so they got their second name - ceramides - from the Latin word cerebrum (brain). Later it was found that ceramides are involved in the construction of the epidermal barrier, forming a lipid layer between the horny scales. Ceramide and phospholipid molecules have hydrophilic "heads" (fragments that love water) and lipophilic "tails" (fragments that prefer fats). In the aquatic environment, polar lipid molecules independently group themselves in such a way that the hydrophobic tails are hidden from the water, and the hydrophilic heads, on the contrary, are turned into the aquatic environment. If there are few such lipids (and if the mixture of lipids and water is shaken well), then balls (liposomes) are formed. This property of polar lipids is used in the cosmetic industry in the production of liposomes.
Ceramides are composed of the fatty alcohol sphingosine (forms the "head") and one fatty acid ("tail"). If there are double bonds in a fatty acid, then it is called unsaturated, if there are no double bonds, then the acid is said to be saturated. Depending on which fatty acid is attached to the head of the ceramide, the lipid sheets built from them are more or less liquid. The hardest (crystalline) lipid sheets are formed by saturated tailed ceramides. Than longer tail ceramide and the more double bonds it contains, the more liquid the lipid structures are. In addition to the intercellular lipid layers discussed above, lipids covalently associated with corneocytes are found in the stratum corneum. These are special long-chain ceramides, the tails of which are represented by fatty acids with more than 20 carbon atoms in their chain. Long-chain ceramides act as rivets, holding together adjacent lipid sheets. Thanks to them, the multilayer lipid layer does not exfoliate and is an integral structure. Ceramides have recently become very popular ingredients in cosmetics. The popularity of ceramides is due to the role they play in maintaining the integrity of the epidermal barrier.
Due to the presence of a multilayer lipid layer between the stratum corneum, the stratum corneum is able to effectively protect the skin not only from the penetration of foreign substances from the outside, but also from dehydration. Diffusion of water through dry semi-solid keratin plates glued together in a continuous mass with ceramides is sharply reduced in comparison with living cells filled with liquid.
The main producers of intercellular cement are Orland's granules of the granular layer cells. It is they who, through exocytosis, release their contents into the intercellular space, where it turns into a lipid-rich intercellular cement with a lamellar structure. Thus, during keratinization, a hydrophobic epidermal barrier is formed, which not only prevents the penetration of harmful substances into the skin, but also participates in the regulation of water homeostasis in the dermis.
In addition to the mechanism of biomechanical impermeability of the stratum corneum, the moisture of the skin is maintained by moisture-retaining structures.
Epidermal moisture-retaining structures of the skin
1. Natural moisturizing factor (NMF) Is a whole complex of organic molecules on the surface of corneocytes, which has the ability to bind water. It includes free amino acids (40%); sodium pyroglutamate (12%); urea (7%); ammonia, creatinine and other organic compounds (17%); magnesium (1.5%); potassium (4%); calcium (1.5%); sodium (5%); dairy and citric acid, chloride and phosphate ions (12%). Disruption of their balance entails a change in the composition of NMF and, as a result, the inability of the skin to retain moisture. The elasticity of the stratum corneum also depends on the amount of moisture associated with NMF. Oily and normal skin has been shown to have more NMF than dry skin.
A decrease in filaggrin synthesis, which is observed, in particular, in ichthyosis and atopic dermatitis, leads to a decrease in the content of amino acids in the composition of NMF and a decrease in the water-holding capacity of the skin. Since the enzymes involved in the hydrolysis of filaggrin require a sufficient amount of moisture to function, the formation of amino acids NMF also decreases with the development of dryness of the stratum corneum. The result is vicious circle leading to chronic dryness of the skin.
The mineral composition of the natural moisturizing factor changes depending on the season, and it is these changes that cause a decrease in the moisture content of the stratum corneum in winter. In particular, in winter, the level of potassium, sodium, chlorides and lactic acid salts in the stratum corneum significantly decreases.
Frequent washing with hot water and soap can wash out amino acids and minerals from NMF, which also leads to the development of xerosis. The most dangerous combination of "soaking", such as prolonged exposure to a hot bath, and exposure to solvents and aggressive surfactants. The danger of surfactants is that they are able to interact with lipid films, since they, like polar lipids, have two regions - hydrophobic and hydrophilic, so they can be incorporated into the lipid layer, addressing them with their hydrophobic "tails". In this case, the heads of surfactant molecules are grouped together so that hydrophilic areas permeable to water appear in the lipid layer. Thus, the first consequence of the effect of surfactants on the stratum corneum is the dehydration of lipid membranes, the so-called "Wash-Out-Effect" - the effect of washing out own lipids.
Prolonged exposure to anionic surfactants promotes their deeper penetration down to the granular layer of the epidermis, which leads to the destruction of cell membranes of granulocytes - Orland granules, which are the main factory of intercellular lipids. As a result, the synthesis of lipids required for gluing corneocytes decreases.
That is why any cosmetic procedures, accompanied by "soaking" the skin, followed by its cleansing, should be completed with the use of moisturizers based on NMF.
2. Epidermal intercellular lipids (lipid barrier)- consist of cholesterol, ceramides and unsaturated fatty acids (omega-3, omega-6), the amount of which is in a strictly defined proportion in relation to each other. If the corneocyte contains only 3% lipids, then the intercellular cement - 80%. According to biochemical data, the following are found in the intercellular matrix: ceramides - ~ 40%, free fatty acids - ~ 20%, cholesterol and its esters - ~ 10%, cholesterol - ~ 15%, phospholipids - ~ 5%, squalene - ~ 10%. Cholesterol prevents excess rigidity and fragility of the ceramide layer. Free fatty acids are located around ceramides in the lipid layer and help maintain the water-repellent function of the skin, protect the water-soluble components of the stratum corneum from leaching due to the formation of a water-oil emulsion. If this proportion changes, the lipid layer between the horny scales is disrupted and, as a result, the barrier function is disrupted, moisture evaporates more intensively. Trying to prevent excess moisture loss, the skin slows down the physiological desquamation process, and cells begin to accumulate on the surface. Outwardly, this is manifested by excessive peeling, thickening of the stratum corneum, and a grayish tint. A striking example of this process is seborrhea. With seborrhea, the concentration of linoleic acid in the sebum decreases, which also leads to a violation of the integrity of the skin barrier and the emergence of an adaptive reaction in the form of an increase in the number of horny cells.
Among the lipids of the skin surface, epidermal lipids and lipids of the sebaceous glands are detected. Epidermal lipids make up a minority. The main components of epidermal lipids - free cholesterol and its esters - are formed during the breakdown of the membranes of the cells of the stratum corneum. It has been proven that epidermal lipids of the skin surface do not have a large effect on skin hydration, but represent a limiting membrane for water exchange.
Interestingly, the lipid composition of the stratum corneum is heterogeneous. The concentration of phospholipids decreases towards the surface, while the content of neutral lipids and ceramides, on the contrary, increases.
A change in the composition of epidermal lipids occurs in many diseases: atopic dermatitis, psoriasis, contact dermatitis, seborrhea, as well as in some physiological processes. For example, with atopic dermatitis, the metabolism of fatty acids is disturbed in the skin, and with ichthyosis, their decrease is observed (table). As a result, an inadequate protective hydrolipid layer is formed, which also leads to trasquat loss of water and facilitates the penetration of allergens and irritants.
3. Sebum. The functional value of sebum is very high, standing out from the secretory section of the sebaceous glands, filling their excretory ducts and the mouths of the hair follicles, the secret is distributed along the grooves of the skin and unevenly covers almost the entire surface with a layer of 7-10 microns. In one week, a healthy person secretes 100-200 g of sebaceous secretion, and with seborrhea 300 g or more. On the surface of the skin, sebum mixes with the secretion of the sweat glands and is emulsified. Thus, a thin water-lipid emulsion film (sebum) is formed. The water-lipid mantle, like a wax coating, protects against excessive solar radiation, waterlogging, harmful effects of the external environment, infections, prevents water evaporation and releases glycerin, which binds water from the atmospheric air and keeps it at the skin surface.
4. Keratin- the end product of the vital activity of the epidermis, characterized by resistance to mechanical, physical and chemical factors. According to some authors, keratin, like all proteins, is a colloid - it swells in water and binds water molecules.
If one or more water-retaining structures are disturbed (deficiency of components, structural changes, etc.), the water level in the stratum corneum drops. There is a violation of its structure, which entails a violation of the barrier properties. This means that the stratum corneum ceases to be an impenetrable barrier to water and its evaporation increases. The broken barrier can more easily penetrate microorganisms, chemical factors of aggression, which additionally support skin irritation and inflammation. Dry skin is an invariable symptom of various skin diseases, such as atopic dermatitis, psoriasis, eczema, etc. In recent years, an unreasonable position among practitioners has begun to be overcome, regarding neglect of such an important aspect as skin care and restoration of its barrier function in patients dermatoses. Therefore, the second part of the article will focus not only on the auxiliary therapy of cosmeceuticals during an exacerbation, but also on a very important issue - consolidating remission by actively restoring the integrity of the skin and its normal function with the help of medical and cosmetic products.
Literature
- Lomakina E.A. The role of the barrier function of the skin in the pathogenesis of some dermatoses // Contemporary problems dermatovenerology, immunology and medical cosmetology. 2009, No. 2. S. 87-90.
- Kalyuzhnaya L. D. Atopic dermatitis and dry skin // Clinical immunology. Allergology. Infectology. 2009, No. 1. S. 27-18.
- Tkachenko S., Hernandez E. Aquaporins in the regulation of skin water balance // Cosmetics and Medicine. 2011, No. 2. S. 26-33.
- Myadlets O.D., Adaskevich V.P. Morphofunctional dermatology. M .: Medlit, 2006.752 p.
- Margolina A.A., Hernandez E.I., Zaykina O.E. New cosmetology. M., 2002.208 p.
- Yu.N. Koshevenko Human skin. T. 2.M .: Medicine, 2008.754 p.
- Yu.N. Koshevenko Human skin. T. 1.M .: Medicine, 2006, 360 p.
- Modern external therapy for dermatoses (with elements of physiotherapy) / Under. edited by N.G. Korotkiy. Tver: "Provincial Medicine", 2001.528 p.
- Cork M. J., Robinson D. A., Vasilopoulos Y. et al. New perspectives on epidermal barrier dysfunction in atopic dermatitis: gene-environment interactions // J Allergy Clin Immunol. 2006; 118 (1): 3-21.
- Dobrev H. Scientific Researches of the Union of Scientists // Series D. Medicine, Pharmacy and Stomatology. 2002; 1: 107-10. Plovdiv.
- Norlen L., Nicander I., Lundh Rozell B. et al. Inter- and intra-individual differences in human stratum corneum lipid content related to physical parameters of skin barrier function in vivo // J Invest Dermatol. 1999; 112 (1): 72-77.
- Roh M., Han M., Kim D., Chung K. Sebum Output as a Factor Contributing to the Size of Facial Pores // Br J Dermatol. 2006; 155 (5): 890-894.
- Arabiyskaya E.R., Sokolovsky E.V. Dry skin. Causes of occurrence. Correction principles // Journal of Dermatovenereology and Cosmetology. 2002, No. 1. P. 23-25.
- Hernandez E.I. Moisturizing the skin. M .: Firm Klavel LLC, School of Cosmetic Chemists LLC, 2007. 32 p.
Yu.A. Gallyamova,Doctor of Medical Sciences, Professor
O. A. Barinova
RMAPO, Moscow
What is a lipid layer and why is it needed?
The outermost layer of the epidermis (skin) is called the stratum corneum. It got this name due to the shape of its cells - they have thorns like horns. These cells have no nuclei, but there is a protein called keratin and nothing else. The stratum corneum protects our skin from the effects of the external environment and does not allow the water of our body to freely evaporate into space, that is, it saves us from dehydration. The surface of the stratum corneum is covered with a water-lipid mantle or a lipid layer (barrier). Violation of this barrier by cosmetics and the environment leads to increased sensitivity, dryness and tightness, itching, allergies and flaking of the skin.
The lipid layer is a mixture of sebum, sweat and exfoliating particles of the stratum corneum. It may seem that this is terribly unhygienic muck, but in fact, it is a very necessary thing for the health of our skin, and indeed the whole organism.
The lipid composition of the stratum corneum has nothing to do with sebum - neither in origin, nor in composition, nor in structure. Sebum is formed in the cells of the sebaceous glands. Stratum corneum lipids are synthesized in keratinocytes as they mature.
Lipids (fats) of the protective layer are organized in stacked bilayers. These bilayers do not allow substances from the outside to penetrate the skin, but they allow oxygen to pass through.
Now a little history-biology.
Our ancestors, well, sooooo distant, lived in the water. Their skin separated the external water from the internal one. When they crawled out (or were they thrown out by a wave?) On land, a mechanism was needed that separates the internal water and the gaseous environment of the air. This is the role that the lipid layer of the skin has taken on. The composition of the lipid layer is unique to the human body - it exists only on the skin. The ph of our lipid layer is in the range of 4, 5-5, 5. This important indicator, because a change in Ph to the lower or higher side destroys the lipid layer. Any cosmetics, or rather emulsifiers, which are part of their composition, also partially destroy the lipid layer.
It turns out that by washing our face, using creams and cosmetics, we harm our skin?
Yes and no. Yes, because any interference with natural processes affects our body in an unpredictable way. No, because we do not live in a natural habitat and must adapt to its conditions. Our task in the process of skin care is to make sure that there are more advantages from care than disadvantages.
First, let's look at cleansers and their effect on the lipid layer.
Cleansers.
Solid soap.
Worst possible option. Its Ph is shifted to the alkaline side, that is, more than 7. It actively removes not only dirt, but also the lipid layer itself, from which the skin becomes dry and defenseless against the attack of bacteria and viruses. The natural protection of the skin from the sun's rays decreases, and the likelihood of the appearance of age spots increases.
Liquid soap , it is also a hydrophilic cleaner or a hydrophilic emulsion. Synthetic detergent, which includes petroleum products, oils, fats. Due to the presence of free fatty acids in it and the absence of alkali, it has less irritating effect on the skin. Hydrophilic cleaners are composed of water and oily phases to dissolve and remove different types pollution. The Ph of such a product is 5, 5, and corresponds to the Ph of the skin. Almost all hydrophilic cleaners contain SLS (sodium laurel sulfate), which is quite aggressive on the skin to remove oil. Only expensive cosmetic companies produce cleansing emulsions without SLS.
Sometimes SLES (sodium loret sulfate) is used, this is when another ester chain has been added to the SLS. Products containing SLES foam well and are less aggressive to the skin.
Hydrophilic emulsions with the addition of free fatty acids, this is what is sold with the label "Moisture - 25%". The problem is that hydration is actually out of the question. Such products simply leave a protective film on the skin instead of a washed off lipid layer to prevent water evaporation.
What to do? Don't wash your face?
You will have to wash, because in the conditions of the city, the "periodic table" that settles on our skin per day destroys the lipid barrier faster than any soap.
However, I never tire of repeating, washing - washing - strife. The most thorough washing for oily skin requires the use of soap with salicylic acid - it has an antiseptic effect, exfoliates dead cells of the stratum corneum and dries out the inflamed areas. Morning wash for oily skin without significant problems, includes the use of lotion for oily skin and water. Or just lotion.
For normal skin, the washing emulsion is used only in the most thorough washing. In the morning and just before bed, it is sufficient to wipe the skin with an alcohol-free lotion.
For dry skin - use milk when washing thoroughly, and lotions that do not contain alcohol in the morning and before bedtime.
What else is on the shelves besides soap?
Foaming Soap Cream
- designed to care problem skin... As well as shaving foam, it is based on stearic soap. Usually substances that have an anti-inflammatory effect are added there.
Foam for washing.
Remember, the more transparent the consistency of the foam, the more aggressive it is. Foam for dry skin cannot be transparent!
Gel without soap.
Typically, its base is glycerin, and it is intended for dry and sensitive skin.
Cleansing milk, cream, cream.
Use only on normal to dry skin. There is no "milk for oily skin" whatever the manufacturers write there. Cosmetic milk, cream, etc. include mineral oil in their composition. Don't be fooled. There are no minerals in this oil. It is an oil product that leaves on the skin the same film that remains on the surface of the ocean after a tanker accident. It kills all living things, because it blocks the access of oxygen.
Don't be alarmed. Mineral oil perfectly removes any dirt. But it must be very thoroughly washed off. Milk that is not completely washed off on oily skin will interfere with normal excretory processes and quickly lead to the formation of comedones and acne.
But for dry skin, this is an excellent cleanser, without aggressive components that destroy the lipid layer, but you still need to thoroughly rinse off the milk.
Lotions.
The higher the alcohol content of the lotion, the more oily skin it is intended for. Lotion for dry skin should not contain alcohol at all. And if you have normal skin then try to use a lotion that does not contain alcohol.
Many lotions are based on propylene glycol and glycerin. Glycerin has one unpleasant property; when the air humidity is above 65%, it draws water out of the skin. Therefore, at high humidity, we replace lotions with glycerin ... with ordinary milk diluted with mineral water. All sorts of horrors are also told about propylene glycol, but I will not dwell on them in detail, because cosmetics without this solvent are very expensive. If you are strongly against propylene glycol, then it is better to use home remedies for washing.
Tonics and eau de toilette.
They are not cleansers. Their task is to restore the Ph of the skin and / or to have any specific effect. For oily skin - antiseptic and anti-inflammatory, for normal and dry skin - soothing or toning.
Very good for lipid preservation if your remedies include:
- instead of propylene glycol - silicones - cyclomethicone, simethicone and dimethicone.
- instead of mineral oil - vegetable oils(jojoba, avocado, mycademia) and vegetable wax.
- instead of SLS and SLES - proteins of milk, soy, algae and the latest achievement - phospholipids, which are related to skin lipids.
We will be careful in choosing the means to cleanse the skin and preserve the lipid layer.
I recommend to people with dry, sensitive skin from the Swiss brand Methode Cholley, it contains all the components that restore the lipid barrier of the skin and eliminate the feeling of tightness and sensitivity of the skin!
Sometimes, when our skin is experiencing problems, it seems to us that we need some kind of special and very expensive cream to restore its normal state. But this article is about how, knowing the elementary laws of nature and human physiology, you can create a simple, inexpensive and unique recipe that can completely restore the skin and give it a moisturized, smooth and healthy look.
We always expect a miracle from each new announced cream of famous brands, and this expectation comes down to one thing - we need smooth, fresh and healthy skin. But even those people who do not have obvious skin diseases can hardly claim that their skin condition is always perfect. We are "tormented" by dryness, peeling, redness, or obvious dullness - "fatigue" of the skin.
At the heart of all these problems lies damage to the lipid barrier of the skin , and, accordingly, the solution to all these problems will be to restore the lipid barrier of the skin.))) Let's figure it out.
What is the lipid barrier?
To explain in very simple terms, this is the uppermost part of our skin, which we observe every day, and which consists of flat scales (bricks, "dead" keratinocytes that have completely passed their entire life cycle from the basal skin layer to the uppermost stratum corneum), glued together by fat cells (lipids). You can imagine this for yourself in the form of bricks glued together with cement, and forming a strong, waterproof wall.
Why should the stratum corneum be waterproof and why are lipids needed?
Our skin is a rather complex and "wise" organ. At its very "bottom" there is a hypodermis, consisting of adipose tissue, which accumulates and retains the moisture contained in the tissues of the body. Slightly higher and closer to the surface - the dermis begins, which has special cells that absorb moisture from the hypodermis, like sponges, and this moisture goes unhindered further upward into the epidermis, right up to the stratum corneum itself. And just the stratum corneum (corneocytes glued together with fatty lipids) is the last layer and at the same time a barrier for the further release of moisture to the outside, i.e. her fumes.
Accordingly, if something happens to the lipid "cement" and it becomes thinner or even destroyed (for example, due to exposure of the skin to alkali in the form of soap), water, which is an integral part of healthy, dense and radiant skin, evaporates through loose loose scales stratum corneum, and we have the following visible problems on the face:
Apparent dehydration of the skin
flabbiness
decreased skin elasticity (sagging)
peeling
dryness
fine wrinkle network
And also, through the broken lipid barrier, various substances (bacteria, toxins, etc.) can penetrate into the skin, which can cause its irritation, such as:
Eczema
dermatitis
acne
The lipid layer (“cement”) consists of free fatty acids (mainly oleic and linoleic), ceramides (up to 50% in the skin) and cholesterol.
How can the barrier function of the skin be disrupted?
Yes, very easy.
For example, washing your face frequently with hot water and soap, or special means for washing, with the addition of surfactants.
Or with the help of various aggressive environmental factors that cause peroxidation of these very lipids of the skin (summer sun exposure, solarium use, immune reactions).
Or because of the impaired production of lipids by the body as a result of physical stress.
What is important for us to know.
Lipid barrier easy and very fast is restored from the outside, by means of well-formulated cosmetics.
Free fatty acids can be replaced with plant triglycerides (scientifically proven) , which is extremely important for the restoration of the disturbed lipid barrier in oily and inflamed skin.
And now, we propose to prepare you the following simple and inexpensive cream to restore a healthy and blooming appearance of the skin after summer vacations, hard and nervous working days, and simply - to restore the beauty of the skin after various kinds of inflammation. There is no age limit.
We have prepared two recipes: for oily skin (and with acne) and for normal to dry skin.
Sources of fatty acids - vegetable triglycerides and vegetable oils, rich in oleic and linoleic acids, sources of ceramides - "Ceramide Complex", and a source of cholesterol - natural lanolin. Plus, each recipe is sure to add Natural Moisturizing Factor ingredients to restore transepidermal moisture loss in the skin.
Revitalizing cream-serum for oily and acne-prone skin (50 ml).
Phase 1 (bold)
Phase 2 (water)
Phase 3 (active)
- 3 ml
- 2.5 ml
- 30 drops
Cooking.
In a water bath in different refractory cups, heat Phase 1 and Phase 2 until the components of Phase 1 (oils and emulsifiers) are completely melted and become a single homogeneous oily liquid.
Mix both phases in one piece and start beating with a mixer until an emulsion forms, and continue beating for a short time (5 - 10 minutes).
When the emulsion has cooled slightly, add the Phase 3 components (assets) to it in turn and continue whisking for a few more minutes. Transfer the emulsion to a cosmetic jar and chill the cream in the refrigerator.
With the help of such a cream, you can easily restore the damaged lipid barrier of the skin and compensate for the loss of moisture that was caused by insufficient skin care during the summer holidays. In just a few days, it will already be noticeable how the skin will become smooth, elastic, perfectly moisturized, and therefore blooming and healthy.
Advice! In the cream, if desired, you can add. It will be an additional moisturizing-soothing active for the skin, and a pleasant subtle and soothing aroma for your sense of smell and comfort, because essential oils- this is the main healing agent in aromatherapy, and we combine aromatherapy and natural cosmetology with pleasure and great benefit in our recipes for beautiful and youthful skin.
Molecules of phospholipids and glycolipids are amphiphilic, that is, the hydrocarbon radicals of fatty acids and sphingosine are hydrophobic, and the other part of the molecule formed from carbohydrates, the phosphoric acid residue with choline, serine, ethanolamine attached to it, is hydrophilic. As a result, in the aqueous medium, the hydrophobic regions of the phospholipid molecule are displaced from the aqueous medium and interact with each other, and the hydrophilic regions are in contact with water, resulting in the formation of a double lipid layer of cell membranes (Figure 9.1.). This double membrane layer is permeated with protein molecules - microtubules. Oligosaccharides are attached to the outside of the membrane. The amount of protein and carbohydrates in different membranes is not the same. Membrane proteins can perform structural functions, can be enzymes, carry out transmembrane transport of nutrients, and can perform various regulatory functions. Membranes always exist as closed structures (see Figure 9.1). The lipid bilayer is self-assembling. This ability of membranes is used to create artificial lipid vesicles - liposomes.
Liposomes are widely used as capsules for the delivery of various drugs, antigens, enzymes to various organs and tissues, since lipid capsules are able to penetrate cell membranes. This allows drugs to be directed exactly to the target in the affected organ.
Figure 9.1. Diagram of a cell membrane from a lipid bilayer. The hydrophobic regions of the lipid molecule are attracted to each other; hydrophilic regions of the molecule are on the outside. Protein molecules permeate the lipid bilayer.
Lipid metabolism
In the body, neutral fats are found in 2 forms: storage fat and protoplasmic fat.
The protoplasmic fat contains phospholipids and lipoproteins. They are involved in the formation of the structural components of cells. The membranes of cells, mitochondria and microsomes are composed of lipoproteins and regulate the permeability of certain substances. The amount of protoplasmic fat is stable and does not change with fasting or obesity.
Reserve (reserve) fat - it contains triacylglycerols of fatty acids - is found in the subcutaneous fatty tissue and in the fat depots of internal organs.
The function of reserve fat is that it is a reserve source of energy available for use during fasting; it is an insulating material against cold and mechanical injuries.
It is also important that lipids, when decaying, release not only energy, but also a significant amount of water:
When 1 gram of protein is oxidized, 0.4 g is released; carbohydrates - 0.5 g; lipids - 1 g of water. This property of lipids is of great importance for animals living in the desert (camels).
Digestion of lipids in the gastrointestinal tract
In the oral cavity, lipids are only mechanically processed. There is a small amount of lipase in the stomach, which hydrolyzes fats. Low activity of lipase of gastric juice is associated with the acidic reaction of the contents of the stomach. In addition, lipase can only affect emulsified fats; there are no conditions in the stomach for the formation of fat emulsions. Only in children and monogastric animals does gastric acid lipase play an important role in lipid digestion.
The intestine is the main site for the digestion of lipids. In the duodenum, lipids are affected by liver bile and pancreatic juice, while the intestinal contents (chyme) are neutralized. Fats are emulsified by bile acids. Bile contains: cholic acid, deoxycholic (3.12 dihydroxycholanic), chenodeoxycholic (3.7 dihydroxycholanic) acids, sodium salts of paired bile acids: glycocholic, glycodeoxycholic, taurocholic, taurodeoxycholic. They are composed of two components: cholic and deoxycholic acids, as well as glycine and taurine.
deoxycholic acid chenodeoxycholic acid
glycocholic acid
taurocholic acid
Bile salts emulsify fats well. This increases the area of contact of enzymes with fats and increases the effect of the enzyme. Insufficient synthesis of bile acids or delayed intake disrupts the effectiveness of enzymes. Fats are usually absorbed after hydrolysis, but some of the finely emulsified fats are absorbed through the intestinal wall and pass into the lymph without hydrolysis.
Esterases break the ester bond in fats between the alcohol group and the carboxyl group of carboxylic acids and inorganic acids (lipase, phosphatase).
Under the action of lipase, fats are hydrolyzed into glycerol and higher fatty acids. Lipase activity is increased by the action of bile, i.e. bile directly activates lipase. In addition, the activity of lipase is increased by Ca ++ ions due to the fact that Ca ++ ions form insoluble salts (soaps) with the liberated fatty acids and prevent their suppressive effect on lipase activity.
Under the action of lipase, the ether bonds at the α and α 1 (side) carbon atoms of glycerol are initially hydrolyzed, then at the β-carbon atom:
Under the action of lipase, up to 40% of triacylglycerides are broken down to glycerol and fatty acids, 50-55% is hydrolyzed to 2-monoacylglycerols and 3-10% is not hydrolyzed and absorbed as triacylglycerols.
The sterides of the feed are broken down by the enzyme cholesterol esterase to cholesterol and higher fatty acids. Phosphatides are hydrolyzed under the influence of phospholipases A, A 2, C and D. Each enzyme acts on a specific ester bond of the lipid. The points of application of phospholipases are shown in the diagram:
Phospholipases of the pancreas, tissue phospholipases are produced in the form of enzymes and are activated by trypsin. Phospholipase A 2 of snake venom catalyzes the elimination of unsaturated fatty acid at position 2 of phosphoglycerides. In this case, lysolecithins with hemolytic action are formed.
phosphotidylcholine lysolecithin
Therefore, when this poison enters the bloodstream, severe hemolysis occurs. In the intestine, this danger is eliminated by the action of phospholipase A1, which rapidly inactivates lysophosphatide as a result of the cleavage of a saturated fatty acid residue from it, converting it into inactive glycerophosphocholine.
Lysolecithins in low concentrations stimulate the differentiation of lymphoid cells, the activity of protein kinase C, and enhance cell proliferation.
Colamine phosphatides and serine phosphatides are cleaved by phospholipase A to lysocolamine phosphatides, lysoserine phosphatides, which are further cleaved by phospholipase A 2 . Phospholipases C and D hydrolyze choline bonds; colamine and serine with phosphoric acid and the phosphoric acid residue with glycerol.
Lipid absorption occurs in the small intestine. Fatty acids with a chain length of less than 10 carbon atoms are absorbed in unesterified form. For absorption, the presence of emulsifying substances is necessary - bile acids and bile.
Resynthesis of fat characteristic of a given organism occurs in the intestinal wall. The concentration of lipids in the blood is high within 3-5 hours after ingestion. Chylomicrons- small particles of fat, formed after absorption in the intestinal wall, are lipoproteins surrounded by phospholipids and a protein membrane, inside they contain molecules of fat and bile acids. They enter the liver, where lipids undergo an intermediate exchange, and bile acids pass into the gallbladder and then back into the intestines (see Figure 9.3 on page 192). As a result of this circulation, a small amount of bile acids is lost. It is believed that a molecule of bile acid makes 4 circuits per day.
