Protective Effects of Antioxidant Mix Pre-Treatment Against Visible Light-Induced Damage in Dark Skin Phototype

Visible light (VL) accounts for approximately 50% of the solar radiation reaching Earth's surface and has emerged as a major contributor to skin photoaging and pigmentation disorders, particularly in individuals with darker Fitzpatrick skin phototypes. Increasing evidence suggests that VL exposure induces oxidative stress, inflammation, and melanogenesis by generating reactive oxygen species. In this study, we investigated the protective effects of a topical antioxidant formulation (AOX Mix) containing 15% ascorbic acid, 0.5% ferulic acid, and 1% tocopherol against VL exposure in ex vivo skin biopsies from donors with Fitzpatrick skin phototypes IV-V. To preserve physiological tissue tension and closely replicate in vivo skin responses, human skin explants were maintained using the TenSkin™ culture system. Samples were pretreated with AOX Mix for 30 min, then exposed to VL for 8 h, and collected on Days 2 and 7 for histological and molecular analyses. Our results demonstrated that prolonged exposure to VL disrupted redox homeostasis and induced structural alterations in skin explants, accompanied by increased markers of oxidative stress and pigmentation. In contrast, pre-treatment with AOX Mix significantly attenuated these effects, preserving tissue architecture and reducing molecular indicators of photodamage. In addition, we observed the co-localization of 4-hydroxynonenal and collagen type I, suggesting that oxidative post-translational modification of collagen may contribute to its loss. These findings suggest that antioxidant-based interventions, such as AOX Mix, may be a promising strategy for protecting dark skin against VL exposure.