Document Type : Original Article
Department of Medical Physics, School of Medicine-International Campus, Iran University of Medical Sciences, Tehran, Iran
Department of Lab Sciences, School of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran
Department of Medical Biotechnology, School of Advanced Technology, Tehran University of Medical Sciences, Tehran, Iran
4Department of Radiotherapy, Hospital of Shohada Tajrish, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Critical macromolecules such as DNA maybe damaged by free radicals that are generated from the interaction of ionizing radiation with biological systems. Melatonin and vitamin C have been shown to be direct free radical scavengers. The aim of this study was to investigate the in vivo/in vitro radioprotective effects of melatonin and vitamin C separately and combined against genotoxicity induced by 6 MV x-ray irradiation in human cultured blood lymphocytes.
Materials and Methods
In this experimental study, fifteen volunteers were divided into three groups of melatonin, vitamin C and melatonin plus vitamin C treatment. Peripheral blood samples were collected from each group before, and 1, 2 and 3 hours after melatonin and vitamin C administration (separately and combined). The blood samples were then irradiated with 200 cGy of 6 MV x-ray. In order to characterize chromosomal aberrations, the lymphocyte samples were cultured with mitogenic stimulus on cytokinesisblocked binucleated cells.
The samples collected 1hour after melatonin and vitamin C (separately and combined) ingestion exhibited a significant decrease in the incidence of micronuclei compared with their control group (P < 0.05). The maximum synergic protection and reduction in frequency of micronuclei (57%) was observed 1 hour after vitamin C and melatonin administration combined.
We conclude that simultaneous administration of melatonin and vitamin C as radioprotector substances before irradiation may reduce genotoxicity caused by x-ray irradiation.