Protective Effects of Antioxidant Chaga Mushroom Decoction on Normal Human Dermal Fibroblasts Exposed to UV-A

Skin cells exposed to ultraviolet (UV) radiation may experience reduced elasticity in skin tissue due to the production of reactive oxygen species (ROS) and the overexpression of collagen type I-degrading enzymes (MMP-1). Beyond preventing UV exposure with sunscreen, components that protect the inner surface of skin tissue may suppress the expression of ROS and their subsequent effects. In this study, the suppression of ROS production from UV-A-irradiated normal human dermal fibroblasts (NHDFs) using Chaga-derived polyphenol decoction (CPD) was examined with confocal laser scanning microscopy. Pretreatment with CPD reduced ROS expression to less than 5% compared to the blank. The evaluation of MMP-1 expression levels induced by ROS production from UV-A-irradiated NHDFs using an ELISA showed that MMP-1 expression in CPD-pretreated NHDFs was suppressed by more than 30% compared to untreated NHDFs. Furthermore, three-dimensional collagen gels containing NHDFs were prepared, and a dynamic mechanical analysis of the elasticity of UV-A-irradiated gels revealed that pretreatment with CPD maintained elasticity at more than five times that of the CPD-untreated gel. These findings suggest that CPD may be promising as a functional food for protecting skin tissue.