curcumin mitigates radiation-induced lung pneumonitis and fibrosis in rats

Radiation-induced lung injury is one of the most prominent factors that interfere with chest cancer radiotherapy, and poses a great threat to patients exposed to total body irradiation. upregulation of pro-oxidant enzymes is one of the main mechanisms through which the late effects of ionizing radiation on lung injury can be exerted. interleukin (il)-4 and il-13 are two important cytokines that have been proposed to be involved in this process. through stimulation of dual oxidase 1 and 2 (duox 1 & 2), they induce chronic oxidative stress in irradiated tissues. in this study, we evaluated the effects of curcumin treatment on the regulation of il-4 and il-13, duox1 & 2 genes as well as the pathological changes developed by this treatment. twenty male wistar rats were divided into four groups: radiation only; curcumin only; radiation +curcumin; and control group with neither pharmacotherapy nor radiation. curcumin was administered for 4 and 6 consecutive days before and after irradiation, respectively. also, the chest area was irradiated with 15 gy using a cobalt-60 gamma rays source. all rats were sacrificed 67 days after irradiation, followed by the assessment of the levels of il-4 and il-13; the expression of il- 4 receptor-a1 (il4ra1), il13ra2, duox1 and duox2, and finally the histopathological changes were evaluated. radiation led to the increased level of il-4, while the level of il-13 showed no change. qpcr results showed the upregulation of il4ra1, duox1 and duox2 following lung irradiation. histopathological evaluation also showed a remarkable increase in pneumonitis and fibrosis. treatment with curcumin downregulated the expression of il-4, il4ra1, duox1 & 2. furthermore, it could mitigate pneumonitis and fibrosis following lung irradiation. the late effects of radiation- induced lung injury may be due to the upregulation of duox1 & 2 genes. curcumin, through modulation of these genes, may contribute to the protection against ionizing radiation.