Green tea extract EGCG, also known as tea tannin and tea tannin; is a generic term for a class of polyhydroxyphenolic compounds contained in tea.
1. Whitening effect of green tea extract
The color of the skin is mainly determined by the melanin content. The melanin production mechanism is generally considered to be tyrosine-catalyzed synthesis in melanosomes in melanocytes. Currently used are V E, V C , superoxide dismutase S O D , kojic acid and plant extracts, all of which have a whitening effect.
2. The convergence of tea polyphenols
Polyphenols and proteins are combined by hydrophobic bonds and nitrogen bonds. In daily chemistry, they are said to have astringency because they cause human skin to converge. The most direct reason why people use plant polyphenols in cosmetics is their astringency. This property allows the polyphenol-containing cosmetic to have good adhesion to the skin under water-proof conditions, and can shrink the coarse pores, so that the loose skin converges and tightens to reduce wrinkles, thereby giving the skin a delicate appearance. .
3. The moisturizing effect of tea polyphenols
Moisturizers are used to keep the skin delicate and lubricious. It is necessary to use a water-retaining substance that can be combined with water on the surface of the skin to moisturize the stratum corneum, delay and prevent moisture evaporation in the skin. This substance is called a moisturizer. Tea polyphenols are a natural product with a moisturizing effect. Because of their polyhydric alcohol structure, they can absorb moisture in the air. The moisturizing of tea polyphenols also lies in the inhibitory activity of hyaluronidase. Thereby achieving a true physiological deep moisturizing effect in skin care products.
4. Tea polyphenols
Proper sun exposure is a necessary condition for maintaining human health. However, after exposure to the sun and long-term exposure, ultraviolet rays can cause burning and redness of the skin and even rash and dermatitis. There are also skin tumors and other conditions. Excessive sun exposure is also a major external cause of skin aging. Therefore, sunscreens have become an important class of products in cosmetics. Sunscreens can be roughly divided into physical ultraviolet shielding agents and chemical ultraviolet absorbents. Generally, organic sunscreens belong to the latter. A variety of sunscreen agents have been developed, such as nitrogen benzoic acid, salicylic acid lipids, p-methyl cinnamic acid esters, benzophenones and derivatives thereof. Most of these sunscreens are oil-soluble compounds, some of which are locally irritating to the skin. It is therefore important to screen water-soluble sunscreens with UV absorption from natural products. Tea polyphenols belong to such a class of compounds. Polyphenols are a natural product that is strongly absorbed in the ultraviolet light region and are not toxic to humans. Polyphenols extracted from plants such as tea polyphenol persimmon tannins have been confirmed. Through the combination of several polyphenols and flavonoids, the absorption of ultraviolet light region can be used to obtain a broad-spectrum sunscreen natural ultraviolet absorber, which can reduce the formation of skin melanin and prevent skin aging.
5. Anti-wrinkle effect of tea polyphenols
Skin aging is manifested in skin elasticity, slack, roughness, wrinkles, age spots and other phenomena. Physiologically, it mainly involves two types of reactions such as cross-linking and degradation of skin proteins and connective tissues. Reactive oxygen free radicals are a major factor in cross-linking. Antioxidants act to eliminate wrinkles by eliminating free radicals. Citrate fatty acid esters significantly inhibit wrinkle formation. If added with witch hazel or paeonol extract, the anti-wrinkle effect is enhanced. Tea polyphenols have inhibitory effects on collagenase and elastase, which can prevent the content of elastin from declining or denaturation, and maintain skin elasticity and wrinkle resistance.
6. Other health effects of tea on the skin
Tea polyphenols have a variety of pharmacological activities and physiological activities, such as polyphenols convergence, hemostasis, antibacterial, anti-inflammatory, anti-metastatic and other properties, can be used as an external agent to treat a variety of skin inflammation and accelerate wound healing.