UVB-Protective Effects and Its Mechanisms of Vitis amurensis Rupr. Methanol Extract in Human Primary Dermal Fibroblasts

Abstract

Cumulative exposure of the skin to ultraviolet light causes skin photoaging by breaking down the extracellular matrix (ECM), degrading Type I procollagen (COL1A1), and enhancing the proinflammatory cytokine levels in the skin. The extract of the herb Vitis amurensis Rupr. (VA) was traditionally used therapeutically owing to its antitumor and antimicrobial activities; however, its UV-protective effect on skin remains unclear. This study was aimed to explore the photoprotective effect of VA in human dermal fibroblast (HDF) and elucidated the underlying molecular pathway. We quantified the total phenolic/flavonoid content and evaluated the free radical scavenging, antiwrinkling, and anti-inflammatory effects of the VA extract at nontoxic concentrations in UVB-irradiated HDFs. We found that the VA extract scavenged free radicals and cellular reactive oxygen species (ROS), downregulated matrix metalloproteinases-1 (MMP-1) expression, restored Type I procollagen expression at the gene and protein levels, and reduced the proinflammatory cytokine IL-6 expression. Mechanistically, VA primarily downregulated the ERK and JNK pathways to regulate MMP-1 expression and activated the Smad pathway by suppressing the ERK pathway for COL1A1 synthesis. Moreover, we identified ε-viniferin as the major ingredient in the VA extract and that it exerted Type I procollagen expression-promoting activity, indicating its role as the effective compound in the VA extract. These findings suggest that VA is a photoprotective biomaterial that can be used in the cosmetics industry.