Exploring Cellular and Molecular Mechanisms Involved in UV-inducedSkin Photo-aging

The skin is especially vulnerable to aging, with ultraviolet (UV)-exposed areas like the face, neck, and hands showing changes more quickly than protected regions. This study explored how UV light drives skin photoaging at the cellular and molecular levels, and assessed how naturally derived compounds might help counter these effects. Through a systematic review of Web of Science and PubMed, preclinical and clinical studies met the inclusion criteria. The analysis focused on measurable outcomes, including wrinkle depth, pigmentation, skin hydration, and collagen content. Results suggest that certain polyphenols, flavonoids, and carotenoids can reduce wrinkle depth by up to 23%, boost hydration by 15-20%, and increase collagen density by 12-18% within 8-12 weeks of use. These benefits appear to stem from multiple mechanisms, including inhibiting matrix metalloproteinases, neutralizing reactive oxygen species, and activating TGF-β signaling. Overall, natural compounds show strong potential in protecting against UV-induced skin aging, but further well-designed clinical trials are needed to address formulation stability, bioavailability, long-term safety, and lasting effectiveness.