Protective effects of melatonin and octreotide against radiation-induced intestinal injury.
OBJECTIVE
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.
Onal
Cem
C
Department of Radiation Oncology, Adana Research and Treatment Centre, Baskent University Medical Faculty, Adana, Turkey. hcemonal@hotmail.com
Kayaselcuk
Fazilet
F
Topkan
Erkan
E
Yavuz
Melek
M
Bacanli
Didem
D
Yavuz
Aydin
A
D000818:Animals; D007410:Intestinal Diseases / Q000517:prevention & control*; D008297:Male; D008550:Melatonin / Q000627:therapeutic use*; D051379:Mice; D015282:Octreotide / Q000627:therapeutic use*; D011832:Radiation Injuries / Q000517:prevention & control*; D011837:Radiation-Protective Agents / Q000627:therapeutic use*; D011897:Random Allocation
D011837:Radiation-Protective Agents; D008550:Melatonin; D015282:Octreotide