Melatonin a Promising Candidate for DNA Double-Stranded Breaks Reduction in Patients Undergoing Abdomen-Pelvis Computed Tomography Examinations.

BACKGROUND AND OBJECTIVE: Cancer incidence is 24% greater in children and young adults exposed to Computed Tomography (CT) scans than those unexposed. Non-repair of ionizing radiation-induced DNA double-Strand Breaks (DSBs) can initiate carcinogenesis. In the present study, we aimed to investigate the radioprotective potential of melatonin against DSBs in peripheral blood lymphocytes of patients undergoing the abdomen-pelvis CT examinations. METHODS: This double-blind, placebo-controlled clinical trial was conducted on thirty patients. These patients were divided into two groups; group one (control) patients who have undergone the CT examination received a single oral dose of placebo, while in group two, patients received a single oral dose of 100mg melatonin. In both groups, blood samples were collected 5-10min before and 30 minutes after the CT examination. The lymphocytes from these samples were isolated and DSBs were analyzed using gammaH2AX immunofluorescence microscopy. RESULTS: Compared to the control group, the use of melatonin 1h before the CT examination caused a significant reduction in gammaH2AX-foci, indicating a reduction in DSBs. In addition, no side effect was observed in patients following 100mg melatonin administration. CONCLUSION: For the first time, this study has shown that melatonin has protective effects against radiation-induced genotoxicity in peripheral blood lymphocytes of patients undergoing abdomen-pelvis CT examinations. Therefore, melatonin can be considered as a promising candidate for reducing DSBs in patients undergoing the abdomen-pelvis CT examinations.