Topical Application of the Synthetic Triterpenoid RTA 408 Protects Mice from Radiation-Induced Dermatitis

The study evaluated the protective effects of RTA 408, a synthetic triterpenoid, against radiation-induced dermatitis in mice. Mice were irradiated and treated with varying concentrations of RTA 408, which significantly reduced dermatitis severity in a dose-dependent manner. The highest concentration (1.0%) led to normal skin appearance, substantial hair regrowth, and alleviation of skin ulcers by day 40. These effects were linked to increased expression of antioxidative Nrf2 target genes and decreased expression of proinflammatory NF-κB target genes, suggesting RTA 408 as a promising therapy for radiation-induced dermatitis.