Mitochondria could be an important target for ultraviolet radiation (UVR)-induced skin damage. Therefore, protecting mitochondria using mitochondria-targeted antioxidants may protect skin from UV-induced photodamage. In the present study, UVR-induced skin damage model was developed by irradiating male Wistar rats with UVB at a dose of 120 mJ/cm2, twice a week for a period of 5 weeks. Mito-TEMPO was administered intraperitoneally (0.1 mg/kg b.w.) twice a week for 5 weeks. After 5 weeks of treatment period, animals were sacrificed and the dorsal skin tissues were collected. Physical examinations of the skin for analyzing wrinkle formation and epidermal thickening were carried out. Skin tissues were used for the evaluation of histopathological changes, mitochondrial dysfunction analysis, and mitochondrial membrane potential. Physical and histological examination showed that mito-TEMPO protected from the damaging effect of UVB radiation. A significant increase in mitochondrial reactive oxygen species (mtROS) generation with a concomitant increase in mitochondrial lipid peroxidation (mtLPO) was observed in UV-irradiated groups. UV-induced generation of mtROS and mtLPO formation was effectively reduced by mito-TEMPO. Mito-TEMPO pre-treatment improved mitochondrial complex II activity, which was significantly reduced in the UV-irradiated group. The results suggested that mito-TEMPO effectively protected skin tissue against UV-induced oxidative stress and damage.
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