Chondroitin sulfate and the skin

1. Chondroitin sulfate and the skin
2. Skin conditions

Chondroitin sulfate and the skin

Skin is the primary tissue that both protects us and makes us look good. Water is essential so that connective tissue such as the skin can fully perform its functions. What makes our skin look young and fresh is corium (the inner skin), which is about 75% collagen tissue; the rest is elastic tissues, fibroblast cells (which make and secrete collagen proteins) and proteoglycan, which mostly consists of chondroitin sulfate and fills the gaps between them. With age, as the water content in our corium decreases, the number of wrinkles and amount of sagging in the skin will increase in direct proportion. This happens because the ability of the inter-cellular substance inside the corium to retain water decreases, causing degeneration in the collagen tissue. The main underlying reason is that less chondroitin sulfate and other acidic polysaccharides are synthesized inside fibroblasts.

One more reason we can think of is increased oxygen free-radical production (which increases with age). These oxygen free radicals possess a much stronger oxidative effect than normal oxygen and therefore can chop large collagen, chondroitin sulfate, and hyaluronic acid molecules into smaller segments. Because of that, the number of large mucopolysaccharide molecules decreases and skin ageing progresses. Managing the functions of the inter-cellar substance, where the key role is played by chondroitin sulfate, go far beyond water and ions. Vitamins, hormones, and, according to the latest studies, even some enzymes that have great importance for skin health can all be temporarily stored by the inter-cellar substance.

Collagen, the protein component in the connective tissue.

Besides chondroitin sulfate and other mucopolysaccharides, there is another important connective tissue component—collagen protein. Collagen accounts for 25-30% of all proteins in mammals, and it is the main component of their skin. Proteins are basically amino acid molecules chained together, and collagen is comprised of counter-clockwise twined amino acid molecule links that are twined clockwise by three. This structure makes collagen tissue very resilient: collagen tissue with a diameter of 1 millimeter is strong enough to pull a 10-kg load. For example, the Achilles tendon, which is almost completely made of collagen, can have a tensile load of 200 kg in an average human, and for a horse, it is about four tons. Collagen’s structure is very reminiscent of hair braids, which makes it a rare example in the natural world. To make this braid structure, one-third of all amino acids must be glycine (the smallest amino acid), and the remaining two-thirds are the amino acids that, similarly to glycine, are small and have a low nutrition value. Another substance essential for collagen production is vitamin C. If there is a shortage of vitamin C, the collagen produced becomes defective, and it can also cause scurvy. The main function of collagen as an extracellular structure is to support cells physically. Compared to collagen’s “hard” task of serving as a container, the role of chondroitin sulfate in proteoglycan is “soft”; it gives instructions on what materials should be stored inside the collagen storage house. If there is a decrease in chondroitin sulfate, the “managing” ability over collagen weakens, and the risk of connective tissue problems rises.

Collagen types and distribution
Type	Form	Distribution	Sugar content
Type I	Tissue	Skin, tendons, bones, fascia	Low
Type II	Tissue	Cartilage, nucleus pulposus, notochord, vitreous body	High
Type III	Tissue	Fetal skin, uterus, blood vessels	Almost none
Type IV	Reticular	Kidney glomerular basement membrane, crystalline lens (of the eye)	High
Type V	No tissue form	Contained in small amounts in wide areas of human body	High

On the other hand, when there is enough chondroitin sulfate and other mucopolysaccharides, both the collagen framework and the cells within and around it perform their functions correctly. There are five types of collagen, all of which have different characteristics and distribution areas.

Skin structure

Skin is the outermost layer that covers and protects our whole body. An average human’s gross area of skin is said to be about 1.6 meters (which corresponds to about eight newspaper pages), and the average skin thickness is said to be about two millimeters. Skin’s average total weight is about four kilograms per adult person, which, if you think of it as an organ, makes it the largest and heaviest of all human organs. Above all, skin is essential to how we look; as they say, “beauty is but skin deep.” If we look at how the skin is structured, on the surface, there is the horny layer that peels off on a daily basis. These cells are produced by the basal layer, which is below the epidermal layer. When a basal layer cell divides, two cells appear: one will remain a second-generation basal layer cell, and the other will become a spinous layer cell. A spinous layer cell is called this because its long branches resemble spines. These cells produce the keratin tissue in cells and make them stronger. Cell division goes on in the basal layer continuously, so older cells, as if they are on an elevator, go up to a higher layer and become granular layer cells. When they rise even higher, their nuclei vanish, and they become horny layer cells, denucleated cells where all production activity terminates and the life cycle ends. The Langerhans cells should also be mentioned. These cells are, in a sense, cell “police,” identifying and eating foreign bodies and microorganisms that might have entered the epidermis. At the border of the epidermis and the corium are melanocytes. These are the pigment-producing cells that use the tyrosine amino acid to produce the black pigment melanin, which in turn is transferred to the spinous layer cells. The color of the skin is determined by how much melanin is present. An interesting fact is that skin color is different in people of different races not because there are more or fewer melanocytes depending on a race but because the melanocytes’ work intensity differs.

The corium (the inner skin). Below the epidermal layer and before the subcutaneous layer begins, there is a special tissue called the corium. This layer is almost 70% collagen, 1-2% elastic fiber, and almost 1% proteoglycan, and it includes various types of cells, including fibroblasts, lymphocytes, histiocytes, etc. This formation is a typical connective tissue. Every component has a corresponding function: collagen fiber makes the skin durable, elastic fiber is needed for skin elasticity, fibroblasts are the factories that produce these fibers, and other mucopolysaccharides, lymphocytes, and histocytes perform the immune function and are needed when there is a foreign intrusion or some local emergency. Although they are present in small amounts, chondroitin sulfate, hyaluronic acid, and other mucopolysaccharides within proteoglycan play an invaluable role: by attracting water, they make this system work.

Skin functionality
1) Protective	Physical protection. Protects the internal body parts from external factors and prevents them from flowing out. Skin protects against UV radiation and microorganisms. Skin hair also serves a protective function. Chemical protection. Skin secretes sebum (contains squalene, neutral fat, and wax), which serves as a protective membrane. Immunological protection. This function is carried out by macrophages (histocytes), T-lymphocytes, and B-lymphocytes.
2) Body temperature control	70% of all heat produced in the body metabolically is released through skin (the remaining 30% is released with breathing). Body temperature is also controlled with sweat secreted from perspiratory glands.
3) Tactility (sense of touch)	Due to special nerve endings distributed throughout the skin, we have a sense of touch. Through it, we can feel pleasure, pressure, pain, temperature, etc.
4) Breathing	Skin breathing corresponds to about 1/200 of lung breathing.

Skin conditions

Wrinkles

Skin wrinkles happen when sulcus cutis (skin grooves) that were already present in the skin become deeper. This is a type of aging symptom that reveals itself when water and fat content decreases and the skin became more prone to dryness, which causes cells to shrink and makes the skin grooves bigger and deeper. The decrease in proteoglycan’s water-retaining ability, which impedes the passage of water and ions and therefore lowers cell metabolic activity, is thought to be the main factor causing wrinkles. In turn, this is most likely caused by aging of the fibroblasts themselves and external factors such as increase in the production of free radicals and other harmful substances because of UV radiation. Wrinkles at the corners of the eyes are the most noticeable because this area is where the keratin layer is the thinnest.

Itching

Itching can be caused by multiple factors, including some that have no relationship to the skin itself. For example, there can be a phantom itching feeling that will stimulate some particular centers of the central nervous system. What creates the sense of itching is sensory (pain) nerve endings, especially those distributed in the upper part of the papillary layer. When these nerve centers are stimulated moderately and continuously, we feel itching, but when the same nerve endings are stimulated more intensely, we feel pain. There are multiple substances that can cause itching, e.g. papain, plasmin, proteolytic enzymes, bile salt, compounds such as prostaglandin, etc. When we are bitten by a mosquito, the itching is caused by an enzyme-like substance that prevents blood from coagulating. Nettle rash (hives), etc., cause itching because edemas (which appear subcutaneously due to an allergic reaction) stimulate the sensory nerve endings. Edemas appear because histamine and other toxins, causing an allergic reaction, increase the blood vessel permeability of the area and blood plasma can enter the tissue and cause swelling. Blood plasma is almost entirely water, so applying chondroitin sulfate, which is known for its water-adjusting function, should yield positive results.

Stains and freckles

Stains

Brown stains that appear on skin are often called liver spots because people used to think they are caused mainly by liver problems. Some of these stains are known to increase in summer and disappear in winter, which suggests that they can be caused by UV radiation, which stimulates melanocytes. In addition, these skin stains are known to increase during pregnancy, which suggests that they can also be caused by hormonal disorders.

Freckles

Freckles, like stains, can appear in areas such as the face, shoulders, hands, back, etc., and while they are small, it is difficult to tell the difference between the two. There is often a genetic predisposition for freckles, and it is said that moderate freckles are caused by dominant genes, but more intense freckles can be caused by autosomal recessive inheritance (genes). Whether we go to the seaside in the summer or skiing in the mountains in the winter, our skin is always ready to produce some extra melanin to shut out unwelcome UV radiation. After we return from our vacation and the UV radiation levels go down, the extra melanin in our skin will also decrease naturally. Chondroitin sulfate is thought to be effective in calming down the excited melanocytes and normalizing the melanin production levels.