Dragon's blood may have radioprotective effects in radiation-induced rat brain injury

Dragon's blood is a bright red resin obtained from Dracaena cochinchinensis. It is a traditional medicinal that is used for wound healing and to stop bleeding. Its main biological activity appears to be from phenolic compounds found in Dragon's blood. In this study, the radioprotective effects of Dragon's blood were examined after whole brain irradiation of rats with either 100 MeV/u Carbon ¹²C⁶⁺ heavy ions or ⁶⁰Co γ-rays. The amounts of radiation-induced oxidative stress, inflammatory cytokines and apoptosis in irradiated rat brains were compared with and without Dragon's blood treatment. Compared to the "irradiation only" control group, the Dragon's blood treatment group significantly decreased malondialdehyde and hydrogen peroxide levels, and increased superoxide dismutase activity and glutathione levels induced by oxidative stress in radiation exposed rats (P < 0.05). Dragon's blood also significantly reduced radiation-induced inflammatory cytokines of tumor necrosis factor-α, interferon-γ and interleukin-6 levels (P < 0.05) and inhibited hippocampal neuronal apoptosis in ⁶⁰Co γ-ray irradiated rats. Furthermore, Dragon's blood significantly increased expression of brain-derived neurophic factor and inhibited the expression of pro-apoptotic caspase 3 (P < 0.050.01). Finally, Dragon's blood significantly inhibited expression of the AP-1 transcription factor family members c-fos and c-jun proteins (P < 0.050.01). The results obtained here suggest that Dragon's blood has radioprotective properties in rat brains after both heavy ions and ⁶⁰Co γ-ray exposure.