EXPERIENCE OF USING NON-INVASIVE METHODS IN THE CORRECT AGE-RELATED SKIN CHANGES
Nechiporenko N.M.P.L.
Shupik National Medical Academy of Postgraduate Education
Summary: The aging of human skin may be caused by the passage of time (internal aging - chronoaging) and the cumulative effect of external factors (external aging) such as ultraviolet radiation, which contribute to formation of wrinkles and loss of tissue elasticity. Since both aging processes are associated with phenotypic changes of skin cells the main functional signs of aging occur as a result of structural and compositional disruption of extracellular matrix proteins, loss of interstitial fluid and lipid oxidation.
The article shows an example of non-invasive correction of age-related skin changes by using a nutraceutical vitamin-collagen complex.
Keywords: collagen, elastin, hyaluronic acid, fibroblast, photoaging, chronoaging, vitamin-collagen complex, anti-aging agent.
At a young age, our skin looks fresh, supple and smooth due to the high content of collagen, elastin and hyaluronic acid. However, over the years, the content of these substances is reduced, and it leads to age-related changes, such as: the skin becomes dry, reduced elasticity and flexibility, deterioration of complexion and wrinkles may occur.
Currently, there are two types of skin aging, photoaging (external type associated with UV radiation) and chronoaging (internal type, which is a genetically conditioned process). Each of these types has its own peculiarities. During the age involution the atrophy of subulate, granular and brilliant layer of the epidermis at normal thickness of the stratum corneum and reduction of the ratio of ceramides are observed. This stratum corneum becomes lax and lesser holds a liquid. There is observed a sebum hypoproduction by sebaceous glands. At the same time these glands increase their sizes.
The smooth of basement membrane is observed. The flexibility and elasticity of derma are reduced due to decrease of components of intercellular matrix. In addition to reduced fibrillar proteins, there is a significant reduction of water in the aging skin. This is due to the fact that concentration of hyaluronic acid in the intercellular matrix is decreased.
Depending on the morphological changes of skin, there are conditionally three main periods in human life, such as:
1. Age evolution period (from birth to 20-25 years).
2. Period of some stabilization of age-related changes (from 25-30 to 40-45 years).
During this period, only fibrous structure of the skin is changed. Its elasticity is also reduced.
3. Age involution period (after 40-45 years). Atrophic changes of skin structures become faster and faster.
In photoaging - the stratum corneum becomes callous, thicker and dry. There is observed vascular pattern disorder - telangiectasia; pigmentation, elastosis and other skin changes are appeared.
In spite of this difference in manifestations these types of aging, in essence, have common mechanisms of damage of collagen fibers. If in the chronoaging period the collagen production is reduced by 75% along with the growth of collagen degradation processes, then a single exposure of ultraviolet radiation on the skin up to medium erythema (redness), leads to a temporary decrease of collagen synthesis by 80%. Return to normal standards is approximately in 48-72 hours. If such activity of ultraviolet happens repeatedly, suppression of collagen stays permanently low and changes become irreversible.
The situation, where the signs of photoaging gradually imposed on physiological processes of chronoaging, is a very negative scenario of strengthen and acceleration of aging rate.
For any type of skin aging, the age-related changes are directly associated with dermal fibroblasts, which become flat and rigid (by 60% from 27 to 81 years), in addition, these dermal fibroblasts are cells that have a limited life expectancy (60% of fibroblasts obtained from young donor are able to create a colony in 256 fibroblasts, and in the elderly is only 2%). Increased rigidity affects the rate of migration (transfer) of fibroblasts into the focus of inflammation or injury, and there is also complication of fibroblasts contact with existing collagen of intercellular matrix. It ultimately leads to reduction of its synthetic activity and the viscoelastic properties of organized collagen especially in the zone of papillar dermis. The reduction of antioxidant activity of proteins, involved in antioxidant defense of cells, contributes to reduction of life expectancy greatly. Increased concentration of free radicals causes quick stop of cell division and provokes their premature aging.
Consequently, both quantitative and qualitative compositions of intercellular matrix of the skin are changed with age. It is believed that homeostasis collagen matrix disorder is a distinguishing feature of aging skin which presents both in photoaging and in chronoaging. Every person after 40 loses about 1% of collagen fibers per year, and on average the production of collagen is reduced by 3 times up to 80 years (compared to 18-26 years).
In fact, the name "collagen" is used to refer to 18 proteins, 11 of which contain the dermis. It provides tissues a specific mechanical strength. In addition the collagen influences on the growth, migration, differentiation, secretion and activity of various synthetic cell, also it provides the correct location of all tissue elements and maintains the tissue structure. Thank to collagen fibers the skin has that elasticity which is inherent in young body. Collagen fibrils are constantly renewed and the processes of their synthesis and decay, which is carried out by fibroblasts, are strictly coordinated. But as we get older, this balance is disturbed and the synthesis of new fibers is slowed.
There is observed a defragmentation of collagen, which becomes more rigid with randomly oriented fibrils. There is also the accumulation of debris with creation of crosslinks between collagen, which leads to a damage of its cellular structure. It leads to disturbance of direct contact between collagen fibrils and fibroblast, eliminating its ability to be in a stretched, spindle-shaped state that is a physiologically necessary condition for its normal growth and functioning.
Collagen fibers are strong and flexible but not elastic. Together with elastin, another protein of connective tissue, they form the basis (frame) of the dermis of the skin.
Elastin is presented in a small amount compared to collagen, and its main function is to provide important feature for the skin - reverse deformation (ability to return to its former shape after stretching). In the dermis elastin is also synthesized by fibroblasts, and as a result of fibroblasts cellular aging, the synthesis of elastin is decreased. It leads to skin aging changes. The glycation process, which is the main mechanism of dermis aging – joining the remaining sugar molecules (glucose or fructose) to collagen and protein intracellular matrix (Maillard reaction), leads to accumulation of final products of glycation on collagen and elastin fibers, as a result of which the collagen lattice of dermis loses elasticity and elastic fibers become more resistant for remodeling.
As a result of age-related changes of the skin, there is thinning of the dermis and disturbance of "glycocalyx-fibrillar fibers" ratio, caused by a decrease of the concentration of one of the important components of glycocalyx - glycosaminoglycan with a wide range of biological activity - hyaluronic acid.