Collagen-EGCG Combination Synergistically Prevents UVB-induced Skin Photoaging in Nude Mice.

Ultraviolet (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 investigated 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 was found that both the solo and combined pretreatments could recover UVB-induced depletion of antioxidative enzymes, including superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), as well as increase of lipid peroxide malondialdehyde (MDA) and inflammatory tumor necrosis factor-α (TNF-α). Meanwhile, the UVB-stimulated skin collagen degradation was attenuated significantly with drug treatments, which was evidenced by expression analysis of matrix metalloproteinase-1 (MMP-1) and hydroxyproline (HYP). Additionally, the mouse skin histology showed that the drug-pretreated groups possessed decreased epidermis thickness and normal collagen fiber structure of the dermis layer. These results demonstrated that EGCG and collagen both can protect the skin against UVB-induced skin photoaging. Synergistically, the combination of them showed the maximum prevention to skin damage, showing its potential in the application of anti-photoaging formulation products. This article is protected by copyright. All rights reserved.