Preventive And Curative Effect Of Tea Polyphenols And Tea Pigments On Skin Photoaging Of Mice Induced By Ultraviolet Irradiation

Objective: An animal model of skin photoaging was made to study the preventive and curative effect of tea polyphenols and tea pigments on skin photoaging of mice induced by UV irradiation. Try to find out the dose-dependent manner of tea polyphenols or tea pigments, which one is better and the mechanism of antioxidative effect.Method: One hundred and ten female mice were randomly divided into eleven groups: blank^group, deionized water administered by gavage or topoically (control group), tea polyphenols and tea pigments with different dose. They were administered by gavage or topically. Total antioxidative ability(T-AOC), superoxidedismutase(SOD) and lipid peroxidation products------malondialdehyde(MDA) in themurine skin were examined with colorimetry. The morphologic alteration of elastic fibers of dermis was observed by using Light microscope. Using a nested PCR method to detect mitochondrial DNA mutagenesis.Result: The animal model of photoaging was made successfully. The levels of T-AOC, SOD of tea polyphenols or tea pigments administered by gavage groups at high dose, and 5% tea polyphenols or tea pigments administered topically groups were higher than that of control group(P<0.05), the content of MDA was lower than that of control group(P<0.05). Both tea polyphenols and tea pigments could ameliorate the levels of biochemical index in a dose-dependent manner. Few broken, convolute, amorphous elastic fibers were observed in the groups treated with tea polyphenols and tea pigments, and some wavy elastic fibers were also observed. The mtDNA deletion mutagenesis in the groups treated with tea polyphenols and tea pigments occurred less frequently than that of control group.Conclusion: In the present study both tea polyphenols and tea pigments administered by gavage or topically could significantly enhance the level of T-AOC and SOD, and reduce the content of MDA, and ameliorate lesions of elastic fibers of dermis. Preventive and curative effects of tea polyphenols and tea pigments on skin photoaging of mice were dose dependent. Tea polyphenols and tea pigments could remission mtDNA deletion mutagenesis of murine skin. These suggested that tea pigments and tea polyphenols had similar preventive and curative effects on skin photoaging of mice induced by UV irradiation.