Photoaging Protective Effects of Quercitrin Isolated from ‘Green Ball’ Apple Peel

Premature skin aging, also known as photoaging, refers to the changes in the structure and function of the skin caused by chronic sun exposure. The ultraviolet radiation in sunlight is one of the key factors that cause photoaging. Thus, matrix metalloproteinases (MMPs), transforming growth factor beta-1 (TGFB1), and nuclear factor kappa B (NF-κB) signaling can be an effective therapeutic strategy for ultraviolet B (UVB) exposure. In this study, we used human dermal fibroblast and mouse macrophage cells to identify the mediators of skin photoaging. Quercitrin isolated from ‘Green Ball’ apple peel was treated to UVB-irradiated fibroblast cells and lipopolysaccharide (LPS)-induced macrophages to identify the photoaging prevention effect of quercitrin. Genes that are associated with photoaging were determined by using enzyme-linked immunosorbent assay (ELISA), Western blot, and quantitative polymerase chain reaction (qPCR). Quercitrin increased the collagen biosynthesis in UVB-irradiated fibroblast cells via regulating MMPs, TIMP metallopeptidase inhibitor 1 (TIMP-1), TGFB1, hyaluronan synthase 2 (HAS2), and collagen type I alpha 1 chain (COL1A2). In addition, quercitrin regulated p-65, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2), and its mediators (prostaglandin E2 and nitric oxide), in the NF-κB signaling process, and it inhibited the production of cytokines in LPS-induced macrophages. These results indicate that quercitrin can improve photoaging damaged skin by regulating MMPs, TGFB1, and NF-κB signaling pathway modulators.