The synthetic triterpenoid RTA-408 limits radiation damage to normal tissue

Results: In the first experiment, 40 rats were divided into the three groups and underwent treatment accordingly. The average flap necrosis was 20% (95% CI, 16-45%) in the radiation control group, 3% (95% CI, 0-11%) in the non-irradiated control, and 3% (95% CI, 0.2-10%) in the radiation group treated with RTA-408. Vascular density was preserved in the treatment group as compared to the radiated control. Nine rats were included in the second experiment, and transcriptome analyses in the treatment group revealed robust activation of antioxidant pathways with induced expression of genes associated with hypoxia and adipogenesis/angiogenesis. Conclusions: Administration of RTA-408 during radiation treatment in a rat model resulted in transcriptome changes which appear to mitigate the toxic effects of radiation, preserving capillary networks and improving flap survival and tissue healing after subsequent surgery. Such reductions in toxicity may have broad implications for functional outcomes and salvage surgery following therapeutic irradiation.