1．Keep the water
Hyaluronic Acid guarantees the water function in the skin organization is one of its most important physiological functions, Its theory guarantees water number Above 500ml/g, contracts in the organization in the knot the reality to guarantee the water number approximately.HA when high density, its long molecular chain interweaves mutually the lattice, adds it with the water hydrogen bond union, thus plays very strongly guarantees the water role.HA outside the butcher in the matrix main function is The maintenance moisture content, with other sulphating mucopolysaccharide and the collogen, the elastic egg waits in vain the fibrous protein, composes together including outside the massive moisture content butcher the porodine matrix, becomes the cell metabolism the material interchange medium.This kind of watery porodine matrix, causes the skin to be pliable but hard to break, the rich elasticity, the sufficient moisture content causes the flesh smoothly delicate.When skin moist feeling vanishing, appears the wrinkle, some people thought is which causes as a result of the HA reduction.Along with the age growth, in the skin the HA content reduces, the skin organization cell and the intercellular space moisture content reduces, the space which by HA the intercellular space which primarily composes the porodine matrix fills to reduce, causes the cell arrangement to be close, the collogen dehydration hardens, causes the skin to be rough, loses the elasticity.Therefore the moisture content regarding the skin health is very important. Guarantees Shui Baoshi always is the skin care puts on make-up skin care cosmetics) one of most main research topics, also is one of skin appliances main functions.

2．Maintenance extracellular spatial
Matrix ingredients and so on HA and sulfuric acid chondroitin, sulfuric acid skin element and contain the massive moisture contents, form the butcher outer space together, is advantageous in the nutrients supply and metabolism waste emissions, the epidermal cell migration, the immune cell (the Langge rarely Si cell and the lymph thin in dermis difference .

3.Large ion merit
On the HA member chain each double sugar unit has a negative charge (one C00ˉ), enable it to have the similar ionic exchange medicinal preparation function, around the adjustment cell the positive ion flowing and the density .

4. Prticipation keratin cell change process
HA in cuticular layer close participation keratin cell multiplication, to outer layer migration and differentiation and so on, adjustment entire change process, but its itself metabolism hormone, growth factor and cell activator (cytokinin) equisignal member regulative [6,7].Regards the xanthognic acid (retinoic acid) and the epidermis grows because of �? epidermal growth factor, EGF) may stimulate HA the biosynthesis, increases in the skin the HA content, but the hydrogenation may then pine's function opposite.Therefore, from the cosmetology and the protection skin angle, the skin surface should little use the adrenal cortex hormone class medicine as far as possible .

5. Aceptor unions affects
A and epidermal cell surface CD44 acceptor union, promotion epidermal cell normal differentiation.The CD44 acceptor is the epidermis normal growth and the split up symbol, when the skin has the squamose cell cancer, the keratin cell split up stop, falls off with the CD44 acceptor reduction and HA from the cell surface concerns.HA is the cell survival signal material, it with the keratin cell surface acceptor union, has one kind of stimulation, can slow down to the cutin cell differentiation which finally withers perishes .

6. Emination free radicals affect
Hyaluronic Acid active oxygen soap in the epidermis which in the sunlight the ultraviolet radiation produces, by the base, protects the skin to exempt its evil, is called the highly effective free radical the street sweeper”.The oxygen free radical may cause the lipin peroxidation, the destruction cell membrane, the killing cell, and pigmentation concerns with skin.HA and the oxygen free radical has the response, the free radical is eliminated, HA is degraded.Therefore HA also has guards against exposes to the sun the function.