Protective role of rosmarinic acid against radiation-induced dermatitis: focus on oxidative stress and inflammation

BACKGROUND: This study investigated the potential protective role of rosmarinic acid (RA) against oxidative stress, inflammation, and fibrosis induced by ionizing radiation in an experimental rat model. METHODS: A total of 42 male Sprague-Dawley rats were randomly divided into seven groups (n = 6): G0, G1(14), G1(28), G2(14), G2(28), G3(14), and G3(28). While the G1 groups were exposed to radiation without treatment, the G2 groups received intraperitoneal saline, and the G3 groups were administered 20 mg/kg RA intraperitoneally. Skin tissue samples were collected on days 14 and 28 for histopathological, immunofluorescence, and biochemical analyses. Statistical evaluation was performed via SPSS software. RESULTS: Histological evaluation revealed intact skin morphology in the G0 group, whereas the G1 and G2 groups exhibited structural disorganization, epidermal and dermal loss, and hyperplasia. Mast cell infiltration and inflammatory activity were significantly increased, accompanied by reduced vascularization. In contrast, the morphological damage in the G3 group was ameliorated. Immunofluorescence analysis revealed elevated TGFβ-1 and 8-OHdG expression in G1 and G2, which was markedly reduced in G3. Similarly, the levels of biochemical markers of oxidative stress and inflammation were greater in the G1 and G2 groups but lower in the RA-treated groups. CONCLUSIONS: Rosmarinic acid administration mitigated radiation-induced oxidative damage, inflammatory responses, and fibrotic changes in skin tissue. These findings suggest that RA exerts protective effects against radiation-induced skin injury through modulation of oxidative stress and inflammation in this experimental model.