Resveratrol Treats UVB-Induced Photoaging by Anti-MMP Expression, through Anti-Inflammatory, Antioxidant, and Antiapoptotic Properties, and Treats Photoaging by Upregulating VEGF-B Expression

UVB exposure is one of the primary factors responsible for the development of photoaging, and the aim of this study was to investigate the mechanism involved in the photoprotective properties of resveratrol (RES) in UVB-induced photoaging. Photoaging models of Hacat cells and ICR mice were established by UVB irradiation. The effect of RES on cell viability was then assessed using the MTT assay. The effect of RES on reactive oxygen species (ROS) production was detected through a fluorescent probe assay. The effect of RES on oxidized glutathione (GSSH) content, and superoxide dismutase (SOD) activity in photoaging Hacat cells, were measured separately, using kits. An enzyme-linked immunosorbent assay (ELISA) was used to measure the effect of RES on IL-6 secretion. The effect of VEGF-B on RES photoprotection was examined through the RT-qPCR method, after silencing VEGF-B through siRNA transfection. For animal experiments, the relative water content of the skin of ICR mice was determined using the Corneometer CM825 skin moisture tester. Starting from the third week of the study, the back skin of photoaging ICR mice was photographed weekly using the TIVI700 camera, and the depth of skin wrinkles in photoaging ICR mice was also analyzed. The thickness of the epidermis in photoaging ICR mice was assessed by the hematoxylin-eosin (HE) staining method. The content of collagen fibers in the skin dermis of photoaging ICR mice was measured by the Masson trichrome staining method. The content of collagen III in the dermis of the skin in photoaging ICR mice was measured through immunohistochemistry (IHC) techniques. The effect of RES on the mRNA expression levels of MMP-1, MMP-9, HO-1, GPX-4, IL-6, TNF-alpha, VEGF-B, caspase9, and caspase3 in photoaging Hacat cells, and that of MMP-3, Nrf2, HO-1, NQO1, SOD1, GPX-4, caspase9, caspase3, and IL-6 in the skin of photoaging ICR mice, was measured by RT-qPCR. The effects of RES on caspase3, Nrf2 (intranuclear), COX-2, P-ERK1/2, ERK1/2, P-P38MAPK, and P38MAPK in photoaging Hacat cells, and on MMP-9, caspase3, COX-2, P-JNK, P-ERK1/2, and P-P38MAPK protein expression in the skin of photoaging ICR mice, were assayed by the WB method. The results of this study, therefore, show that RES has a protective effect against UVB-induced photoaging in both Hacat cells and ICR mice. Its mechanism of action may include reducing the expression of MMPs and the secretion of collagen and inflammatory factors by inhibiting the ROS-mediated MAPK and COX-2 signaling pathways, balancing oxidative stress in the skin of Hacat cells and ICR mice by promoting the Nrf2 signaling pathway, inducing antiapoptotic effects by inhibiting caspase activation, and exerting antioxidant and antiapoptotic effects by targeting the VEGF-B, demonstrating its photoprotective effects against UVB irradiation-induced photoaging.