Collagen‐EGCG Combination Synergistically Prevents UVB‐Induced Skin Photoaging in Nude Mice

Abstract

AbstractUltraviolet (UV) radiation is a major cause of skin photoaging through generating excessive oxidative stress and inflammation. One of the strategies is to use photo‐chemoprotectors, such as natural products with antioxidant and anti‐inflammatory properties, to protect the skin from photo damage. The present study investigates the photoprotective potentials of topical administration of unhydrolyzed collagen, epigallocatechin gallate (EGCG), and their combination against ultraviolet B (UVB)‐induced photoaging in nude mice. It is found that both the solo and combined pretreatments could recover UVB‐induced depletion of antioxidative enzymes, including superoxide dismutase and glutathione peroxidase (GSH‐Px), as well as an increase of lipid peroxide malondialdehyde and inflammatory tumor necrosis factor‐α. Meanwhile, the UVB‐stimulated skin collagen degradation is attenuated significantly with drug treatments, which is evidenced by expression analysis of matrix metalloproteinase‐1 and hydroxyproline. Additionally, the mouse skin histology shows that the drug‐pretreated groups possess decreased epidermis thickness and normal collagen fiber structure of the dermis layer. These results demonstrate that both EGCG and collagen can protect the skin against UVB‐induced skin photoaging. Synergistically, the combination of them shows the maximum prevention to skin damage, showing its potential in the application of anti‐photoaging formulation products.