The protective and therapeutic effects of tea polyphenols on skin

As the main functional component of tea, tea polyphenols have unique protective and therapeutic effects on the skin: anti-aging and wrinkle removing, eliminating brown spots, preventing acne, preventing edema and inflammation, anti allergy, anti-cancer, etc This paper summarizes this Key words: tea polyphenols; skin; protection and treatment of tea polyphenols (TP, the main components are EC, EGC, ECG and EGCG) are the main effective components of tea, accounting for 20% - 30% of the dry weight of tea In recent ten years, the prevention and health care function of tea polyphenols has been a research hotspot in the medical field Many studies have shown that tea polyphenols have remarkable effects on antioxidation, antibacterial, anti radiation, anti-tumor and so on These functions of tea polyphenols give it the effect of protecting and treating skin This paper summarizes the current research results of the health care effect of tea polyphenols on skin 1 Tea polyphenols can prevent skin from aging and wrinkle formation 1 Tea polyphenols can prevent skin from UV damage UV is the main source of skin free radicals Radiation can cause the split of biological molecules and water molecules in the body and produce a large number of free radicals to damage the skin Tea polyphenols can absorb ultraviolet directly The UV with the wavelength of 290-320 nm is the most harmful to the skin, while the UV with the wavelength of 200-330 nm is strongly absorbed by tea polyphenols, so tea polyphenols can directly prevent the UV from damaging the skin Tea polyphenols, known as UV "filters", are the most effective skin protectors affected by UV 1.2 direct scavenging of free radicals by tea polyphenols can directly attack biomolecules or the lipid oxidation products induced by tea polyphenols can further cross link biomolecules and damage the skin Tea polyphenols can prevent the harm of free radicals On the one hand, tea polyphenols can eliminate ROS and directly prevent collagen and other biological macromolecules from being attacked by ROS The results showed that tea polyphenols had a strong scavenging effect on O2 -, Oh, 1O2 and other active oxygen radicals On the other hand, tea polyphenols can eliminate lipid free radicals and block lipid peroxidation EGCG, EGC and ECG can effectively produce lipid peroxidation when the epidermis microsomes are cultured in the silicon phthalocyanine and irradiated with 650 nm light Tea polyphenols can scavenge two kinds of free radicals and become a special free radical scavenger 1.3 at the enzyme and transcription level, tea polyphenols inhibit lipid oxidation and enhance the antioxidant effect by regulating the activity of oxidase and antioxidant enzyme After the green tea extract was injected into the skin of hairless mice, the activities of catalase and glutathione reductase were obviously weakened and had dose effect, but glutathione oxidase and SOD were not affected The research of beung ho showed that tea polyphenols could inhibit the activity of lipoxygenase Tea polyphenols and EGCG also inhibited lipoxygenase and lipid peroxidation in skin mitochondria Tea polyphenols can further prevent lipid oxidation by protecting and inhibiting antioxidant enzymes In addition, tea polyphenols can prevent lipid oxidation at the transcription level EGCG inhibited the binding activity of NF KB and ap-1a, decreased the level of collagenase and mRNA, and inhibited lipid peroxidation Tea polyphenols can inhibit lipid oxidation at the above levels, so as to protect the normal function of skin collagen, lipid and other biological molecules, and delay skin aging and wrinkle formation It is a common symptom that tea polyphenols can inhibit skin spots, pigmentation, red and brown spots There are two reasons for the formation of skin spots: the lasting irradiation of β - UV can increase the melanin in the skin and lead to the tissue change of pigment disorder; the increasing activity of tyrosinase in the skin caused by the long-term lack of glutathione or other reasons can make the tyrosine form dobacone under the action of enzyme, then oxidize to DOPA and form melanin Tea polyphenols can inhibit both of them First of all, tea polyphenols block UV and remove UV induced free radicals, so as to protect the normal function of melanocytes; secondly, tea polyphenols inhibit tyrosinase activity, especially ECG and EGCG The results showed that EGCG had the most protective effect on skin damage induced by UV, IC50 was 3.3 μ g / ml, vitamin E was 16.5 μ g / ml, the relative index of skin erythema in control group and EGCG group was 268 ± 88 and 159 ± 53, respectively It can be seen that the inhibition of tea polyphenols on UV induced erythema is stronger than vitamin E Thirdly, as an effective antioxidant, tea polyphenols can inhibit the oxidation of dopa and prevent pigment formation In addition, the increase of lipid peroxide is related to the occurrence of pigmentation The inhibition of tea polyphenols on lipid oxidation is also beneficial to reduce pigmentation and nourish the skin Tea polyphenols can inhibit inflammation caused by various factors Skin can cause inflammation when exposed to ultraviolet light TP before or 30 minutes after UV irradiation can reduce inflammation of back skin by 70% - 80%, and there is dose effect The increased activity of no synthetase is related to inflammatory response Ahamad et al Showed that TP inhibited the increase of no synthetase caused by TPA in the skin of SENCAR mice and prevented inflammation Oral administration of Oolong tea extract also inhibited carrageenan induced inflammation of the hind paw of rats The author suggested that the anti-inflammatory effect was partly due to the inhibition of the synthesis of prostaglandins by carrageenan Tea polyphenols can also inhibit edema Under UV-B radiation, mouse skin can cause skin edema, destroy antioxidant defense system, and induce the activity of ornithine decarboxylase (ODC) and cyclooxygenase Using 0.2% tea polyphenol as drinking water source for 30 days and then using ultraviolet B radiation (900 MJ / cm2) can significantly protect the skin edema induced by radiation and the damage of skin antioxidant system in SKH-1 hairless mice The results showed that the formation of edema was inhibited by immersing the hind paw of rats in hot oolong tea water solution, and the inhibition rate of 75 × 10-6 tea extract was 60% Tea polyphenol can inhibit the allergic reaction of skin Tea polyphenol can inhibit the allergic reaction of skin caused by various factors First, tea polyphenols inhibit chemical induced allergic reactions Green tea, oolong tea, black tea, ECG, EGC and EGCG can inhibit passive skin hypersensitivity (PCA) IC50 is 149, 185, 153, 162, 80 and 87 mg / kg, respectively The inhibition of EGC and EGCG is stronger than that of tranilast (119mg / kg), which indicates that tea polyphenol has a significant protective effect on type I allergy Tea polyphenols have a good inhibitory effect on allergic reaction of pc-cd (contact dermatitis IV caused by picric chloride) EGCG can inhibit the allergic reaction of pc-cd at the dose of 200 mg / kg The effect of EGCG is 10 times better than that of oral treatment Histamine is one of the causes of allergy Sugiyama et al Used EC, EGC, ECG, EGCG to induce the release of histamine from rat mast cells by compound 48 / 80 The results showed that: 0.1-0.15 Mg / ml of EGC and EGCG can strongly inhibit the release of histamine The inhibition effect of 60% concentration of ECG, EGC and EGCG is two times, eight times and ten times stronger than that of tranilast, the commonly used antiallergic drug The inhibition of tea polyphenols on the release of histamine can prevent the occurrence of allergy Secondly, tea polyphenols inhibit allergic reactions caused by active factors such as antibodies, adrenaline, enzymes, etc In addition to EC, other catechins had significant inhibitory activity The adrenal gland has a good antagonistic effect on histamine, and catechin can promote the activity of adrenal gland and pituitary gland and has an anti-inflammatory effect Calcium ionophore A23187 can stimulate histamine release from leukemic cells EGCG can significantly inhibit this process in a dose-dependent manner It may play a role by increasing the metabolic activity of intracellular Ca + + concentration Tea polyphenols inhibit hyaluronidase activity All tea extracts inhibited hyaluronidase activity and histamine released from peritoneal cells of rats caused by antigens or 48 / 80 compounds The inhibitory effect of bisgallic theaflavin on hyaluronidase was 99.1% In recent years, hyaluronidase has been used as the test object of anti allergic drugs screening in the medical field, so tea polyphenols can be used in anti allergic drugs Japan has applied for a hyaluronidase inhibitor with tea polyphenols as the active ingredient The preparation can be used as cosmetics to prevent allergy and inflammation.