Natural Products in the Prevention and Treatment of Skin Photoaging: A Review of Mechanisms, Challenges, and Future Perspectives

Increased UV radiation exposure, driven by ongoing ozone layer depletion, has emerged as a critical environmental factor compromising skin integrity. Among its various deleterious effects, photoaging represents a major dermatological concern. To systematically outline the progress in this field, this study first employed bibliometric analysis to review the current research landscape of skin photoaging. The results identified China, South Korea, and the United States as the leading contributors, with keywords such as "antioxidant activity" and "apoptosis" remaining persistent hotspots in recent years. This indicates a shifting research focus towards elucidating oxidative stress mechanisms and developing antioxidant-based intervention strategies. Furthermore, this review summarizes the core biological mechanisms and signaling pathways underlying skin photoaging and provides a systematic elaboration on the multi-target mechanisms by which various natural plant extracts mitigate UV-induced damage. These protective actions involve mitigating oxidative stress, reducing inflammatory responses, facilitating DNA repair, and inhibiting Matrix Metalloproteinase (MMP) activity to prevent collagen breakdown. Additionally, they include modulating hyaluronic acid levels and supporting immune function. The limitations of traditional small molecules and emerging macromolecular compounds in practical applications are also discussed. Despite their potential, natural extracts face challenges such as complex composition, poor stability and bioavailability of active constituents, and a lack of clinical studies. Future research should prioritize investigating multi-component synergistic mechanisms, optimizing extraction and purification techniques, and, crucially, innovating delivery technologies to enhance bioavailability and advance the development and clinical translation of natural products for combating skin photoaging.