Age changes of the contents of glycosaminoglycans in the skin of women

Researches are carried out in laboratory of NPP Zhespar-Bios

Proteoglycans (PG) are one of the basic components of an intercellular matrix. It is the high-molecular aggregates consisting of subunits of glycosaminoglycans and protein cortex, joint by a trisaccaride part. They provide mechanical and barrier properties of tissues, their turgor, participate in an exchange of water and salts, carry out series of other important functions. Thus the main function load is put on glycosaminoglycans (GAG) with the high charge, functioning on the ion-exchange mechanism and the representing linear polymers containing repeatedly replicating disaccharide fragment, submitted by hexuronic acid and a hexosamine, paired about glycoside connections. Now evolve three basic classes of GAG, containing hexuronic acids - not sulfated hyaluronic acid both sulfated chondroitin and heparansulfates.

In the complexion the morphological and physiological changes with the years are marked, allowing to assume presence of changes in the contents (GAG) is glycosaminoglycans. So, the degree of hydration decreases, flabbiness, paste-like states are observed, the elasticity and mechanical strength of the skin drop.

By series of authors in due time it has been shown, that average values of the contents in the skin of some classes of GAG faces of young age have less, than at the last in advanced age. In the available modern literature we have not found the argued data on causal dependence between age and concentration of GAG in the skin. In our opinion, for comprehension of mechanisms of ageing not the smaller attention is deserved with an estimation of age changes of the contents in the skin of protein and nucleic acids.

In a modern cosmetology enough great volume of data of the empirical character has collected, allowing to offer fixed technologies of improvement of a condition of the skin, however does not cause doubts necessity of carrying out of basic researches for their natural-science substantiation.

In connection with, the purpose of the present research studying function dependence between age and the contents in the skin of women was stated is glycosaminoglycans, protein and DNA.

Technique. Investigated 50 samples of the skin (cadaverine tissues) women in the age of from 15 till 90 years. Samples in weight of 0,5-1,0 g preserved ethanol in system: Glycerin in the ratio 1:1, stored at +40С. Before carrying out of researches samples subjected to basic hydrolysis 2М NaOH within 1 hour at 60°С, neutralized and determined the general protein on Louri. As the standard for construction of the calibration curve used human seralbumin after basic hydrolysis, which was carried out in the same conditions, as experimental samples. Further carried out gel-filtration on sefadeks G-25 for separation of biopolmers which were subjected to anion-exchange chromatography on DEAE-cellulose. A fractionating manufactured distilled water and solutions of sodium chloride of a growing molarity (0,15; 0,5; 2,0). In aqueous and 0,15 M of fraction with the help of spectrum-photometric method determined DNA, in 0,5 M and 2,0 M fractions - glycosaminoglycans on a method of Dishe. Statistical processing of the obtained data made with the help of software package STATISTICA 6.0 for Windows.

Results and their discussion. Summary results on the basic surveyed groups are submitted in table 1. According to the classifications which are accepted in gerontology and age psychology, we have conditionally enough distributed the data on age gradation: 40-50 (maturity), 50-60 years (crisis of a maturity), 60-70 years (advanced age), 70-80 years (early old age) and 80-90 years (late old age). In Table 1 besides the contents of protein, GAG, DNA, factors DNA/PROTEIN, GAG/protein and GAG/DNA are listed.

Table 1

Biochemical indexes of the skin of woman’s above forty years

Picture 4

The quantity of GAG in the skin of women above forty years old

Mg/g of tissue

Age, years

From the data submitted in table 1, follows, that with the years the contents of GAG in the skin authentically decreases with 178,91 ±39,54 up to 44,72+27,19, that is in 4,0 times. The level of protein and DNA in the skin with the years statistically authentically did not change.

Comparison of average values of the contents of GAG (per g of tissue) on the Student's t-test has revealed six significant differences between all age groups (Table 2).

Matrix of values of probabilities (Р) of statistical differences of average values of the contents of GAG (per mg of tissue) in age groups by Student's t-test

Table 2

Note: filling indicates statistically authentic differences between average values

At use as an index of factor of GAG/protein the quantity of statistically authentic differences of average values was essentially decreased (up to two) and they were less strong (Table 3), that, apparently, is caused by a variation of a level of protein in samples. Similar results are obtained at statistical processing factors of GAG/DNA (Table 4): only statistically significant two differences medium at level Р<0,05. Apparently, as well as in case of factor of GAG/protein, the cause of reduction of differences between groups was the variation of a level of DNA in tissues.

Table 3

Matrix of values of probabilities (Р) of statistical differences of average values of the contents of GAG (on mg of protein) in age groups on the Student's t-test

Note: filling indicates statistically authentic differences between average values

Matrix of values of probabilities (Р) of statistical differences of average values of the contents of GAG (on mkg of DNA) in age groups on the Student's t-test

Table 4

Note: filling indicates statistically significant differences.

Correlation analysis between the investigated variables has shown presence of strong negative correlation connection between age and a level of GAG. Correlations were absent between age, protein and DNA. Introduction in correlation analysis of factors of GAG/DNA and GAG/protein decreased force of correlation connections up to medium and moderate according to Table 5.

Table 5

Matrix of intercorrelations between indexes of age, the contents it is glycosaminoglycans, protein, DNA, factors of GAG/protein and GAG/DNA in the skin of women

Also in Table 5 "technical" correlation between GAG and containing GAG in the factors, caused by correlation of GAG-GAG, peer 1,0 are listed. The same cause causes authentic "technical" correlation between protein and factor containing its, and also between DNA and its factor.

For the proof of influence of age on a level was glycosaminoglycans in the skin of women us dispersion analysis (one-factor), confirmed at a high level the importance (Р<0,001) this dependence (Table 6) is carried out.

Results of dispersion analysis (one-factor) influence of age on the contents of GAG in the skin of women

Table 6

For the proof of significant influence of age on the contents of GAG we carried out the factor analysis (Table 7).

Factor analysis of biochemical and age indexes of the skin of women

Table 7

Note: bold font indicates correlation between the factor and a variable big 0,6

Factor-1 significantly correlated with the years, glycosaminoglycans and the indexes including GAG, and did not correlate with protein and DNA. Factor-2 has been connected to protein, and factor-3 - with DNA. Thus, it is possible to ascertain presence not simply statistical, but function connection between age and the contents it is glycosaminoglycans in the skin of women. Obtained results also testify to absence of statistical connections between factors that has allowed us to apply the methodical approach of orthogonal rotation of factors under the program Varimax improving efficiency of the analysis (Table 8).

Results of rotation of factors (varimax) of biochemical and age indexes of the skin of women

Table 8

Note: bold font indicates correlation between the factor and a variable big 0,6

Rotation of factors has revealed intensifying statistical connections between them and the variables ascertained by the traditional factor analysis. So, correlation between factor-1 and GAG has increased on an absolute value with 0,892 up to 0,952, factor-2 and protein - with 0,798 up to 0,953, factor-3 from DNA - with 0,819 up to 0,994. The obtained data with high degree of reliance enable to establish interdependence between age and the contents is glycosaminoglycans in the skin of women.

Picture 5.

GAG

Line of regression of dependent variable (GAG) on a predictor (age).

For the description of dependence of the contents of GAG from age we carried out the regression analysis which results are listed in picture 5, allowed with high degree of reliance (р <0,00001) to characterize the equation of regression of dependence of a level of GAG from age in the skin of women.

The carried out researches enabled make a conclusion, that indexes of the contents in the skin of protein and DNA are stable enough and do not change with the years. At the same time, it is possible to ascertain with a high level of reliability, which with the years in the skin of women the level decreases is glycosaminoglycans according to the listed equation of linear regression.

The revealed laws, in our opinion, are of interest for a medical gerontology regarding the analysis of conformity of passport age biological, and also for a cosmetology as objective criterion of application of the technologies improving a turgor, an elasticity and appearance of skin surfaces.

The primary goal of all manipulations of the cosmetician is conservation, and at the best increase of GAG in the skin. It gives substantial effect of rejuvenation of the skin both externally, and is function.

Rejuvenating effect of cosmetic line of Plazan.

Work is executed in laboratory NPP Zhespar-Bios and Center of cosmetic correction Eklan of the Russian Academy of sciences

Fig. 6

Changes of quantity of protein, nucleic acids also it is glycosaminoglycans in the skin of lower eyelids under influence of cosmetics PLAZAN

Fig. 7

Changes of spectrum it of glycosaminoglycans of the skin of lower eyelids under influence of cosmetics PLAZAN

We carried out experiment according to influence of collagen masks Plazan and creams with hyaluronic acid (a cream around of eyes) on composition of the skin of lower eyelids. To the patient before operation of a blepharoplasty carried out processing the left eyelid under the scheme - 5 procedures with a placental collagen mask (napkin) Plazan in 1-2 days and daily three times day applied a cream around of eyes during 14 days. Right eyelid served as the control and any processings was not carried out. After an excision of the skin of eyelids during operation of a blepharoplasty, samples investigated on quantity in them of protein, nucleic acids, is glycosaminoglycan integrally and separately sulfated and not sulfated by GAG. Results of experiment are listed in picture 6.

As we see, two week use of cosmetics Plazan in a combination to collagen masks results in substantial growth of protein in the skin (on 31%), nucleic acids on 21% and cooperative GAG on 3%. Externally, the increase of protein has resulted in rising an elasticity of the skin. The increase of nucleic acids testifies to rising ability of the skin to regeneration and updating of cellular structures. But the most interesting data are obtained at research is glycosaminoglycan. Their total has increased insignificantly, all by 3%, but research by separate kinds (7) has shown picture, that the specified procedures of care of the skin a result in increase of hyaluronic acid at 7%, and quantity sulfated by GAG has decreased on 2%.

Similar redistribution of a spectrum of GAG testifies to increase of hydration of the skin and as a result - its rejuvenation, equivalent 2,5 years. The given researches have convincingly shown: use of cosmetics Plazan containing increased quantity of placental hyaluronic acid, results in positive changes of biochemical components of the skin that gives effect of appreciable rejuvenation.

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