Exploration of the protective effects of ginkgo biloba extract against <scp>UVA</scp> ‐induced skin Photoaging in mice

Abstract Ultraviolet A (UVA) intensity in daily life is a significant risk factor for skin photoaging. Ginkgo biloba extract (GBE), a plant‐derived natural extract widely used in clinical practice, has been reported to reduce oxidative damage under various pathological conditions, including diabetes, ischemic injury, and neurodegeneration. These findings suggest that GBE may also protect the skin against UVA‐induced oxidative damage and photoaging. In this study, a UVA‐induced photoaging model was established by applying 1% 8‐methoxypsoralen (8‐MOP) to the dorsal skin of mice two hours before each UVA exposure to enhance photosensitivity. The mice were then exposed to UVA radiation for seven consecutive days with a cumulative dose of 110 J/cm 2 , while GBE was administered orally (100 mg/kg/day) prior to and during UVA irradiation. Skin oxidative stress markers, collagen degradation, and plasma inflammatory cytokines (TNF‐α, IL‐1β, COX‐2, IL‐6) were analyzed, and Western blotting was used to assess MAPK pathway activation (ERK, JNK, p38), NF‐κB nuclear translocation, and the expression of c‐Jun, c‐Fos, and matrix metalloproteinases (MMP‐1, MMP‐3, MMP‐9). UVA/8‐MOP exposure significantly enhanced oxidative stress, inflammatory responses, and MMP expression, activating MAPK and NF‐κB pathways, whereas GBE treatment markedly alleviated these effects and preserved collagen structure. These findings suggest that GBE exerts protective potential against UVA/8‐MOP‐induced skin photoaging by mitigating oxidative stress, enhancing endogenous defense mechanisms, reducing free radical damage to biomolecules such as DNA and proteins, and suppressing inflammation, supporting its possible application as a therapeutic candidate for anti‐photoaging interventions.