Rosa rugosa Root Extract as a Functional Food Ingredient, Mitigating UVB-Induced Skin Aging Through MAPK/AP-1 and AGE-RAGE Pathway Modulation

Rosa rugosa root extract (RR-r) has been used in East Asian medicine to treat metabolic disorders, including diabetes and alcohol-induced liver toxicity. Although RR-r has been demonstrated to exhibit anti-inflammatory and antioxidant properties, further research is required to elucidate its protective effects against ultraviolet B (UVB)-induced skin photoaging. In this study, high-performance liquid chromatography was used to identify rutin as the major indicator compound of RR-r. The photoprotective activity of RR-r was evaluated using a mouse model of UVB-induced skin damage. Mice were orally administered RR-r (100 or 200 mg/kg) for 8 weeks during UVB irradiation. RR-r significantly alleviated UVB-induced wrinkle formation, epidermal thickening, and collagen fiber degradation. The assessment of skin morphology and hydration was conducted through the use of histological staining (H&E and Masson's trichrome), wrinkle and moisture analysis, and enzyme-linked immunosorbent assay quantification of hyaluronic acid. Western blotting revealed that RR-r increased pro-collagen type I, tissue inhibitor of metalloproteinases 1, hyaluronan, collagen-1 while reducing the matrix metalloproteinase family, hyaluronidase 1 and hyaluronidase 2. A further mechanistic analysis revealed that RR-r inhibited UVB-induced phosphorylation of mitogen-activated protein kinase pathway components and downstream activator protein-1 factors. Furthermore, RR-r significantly suppressed UVB-induced accumulation of advanced glycation end products (AGEs) and expression of their receptor, RAGE. Collectively, these findings demonstrate that oral RR-r effectively protects against UVB-induced photoaging by regulating wrinkle-related proteins, enhancing skin hydration, and modulating MAPK/AP-1 and AGE-RAGE signaling. Thus, RR-r may represent a promising natural candidate for skin anti-aging interventions.