Protective effects of melatonin and octreotide against radiation-induced intestinal injury

Abstract

Purpose: To compare the protective effects of the potent antioxidants, melatonin and octreotide, against radiation-induced intestinal injury.

Methods: A total of 42 male 3-month-old Swiss albino mice (40 ± 10 g) were matched according to body weight and randomly assigned to one of six groups: control; radiation treatment (RT) only; melatonin only (15 mg/kg, i.p.); melatonin + RT; octreotide only (50 μg/kg i.p.); and octreotide + RT. Intestinal damage was induced by exposure to a single whole-body radiation dose of 8 Gy. All mice tolerated the experimental interventions, and no deaths were observed.

Results: Irradiation induced architectural disorganization, including inflammatory mononuclear cell infiltration, villitis, and desquamation with eosinophilic necrosis, and diminished mucosal thickness, crypt height, and villous height. In the melatonin + RT and octreotide + RT groups, the villous pattern was well preserved; desquamation at villous tips and edema was prominent, but necrosis was absent. The radiation-induced decrease in mucosal thickness was significantly reduced by pretreatment with melatonin (p < 0.001) or octreotide (p = 0.01), although the protective effect was significantly greater for melatonin (p = 0.04). Pretreatment with melatonin also preserved villous height (p = 0.009) and crypt height (p = 0.03); although a similar trend was observed for pre-irradiation octreotide, the differences were not significant.

Conclusions: Melatonin and octreotide potently protected against radiation-induced intestinal injury in mice, but melatonin was significantly more effective in preserving the histological structure of the intestines, a finding that warrants confirmation in clinical studies.