Background: In many studies, chemicals and natural materials were tested to reduce the harmful effects of radiation. prepared from bone marrow cells and stained in May-Granwald and Giemsa. Finally, the cells were counted with microscope, frequencies of polychromatic erythrocyte (PCE), normochoromatic erythrocyte (NCE) and their micronuclated cell were recorded. PCE / PCE + NCE were calculated. Results: There were significant differences of MNPCE/1000PCE, MNNCE/1000NCE and PCE/PCE+NCE among different groups with similar radiation doses (p0.01). Moreover, there were significant differences of MNPCE/1000PCE and PCE/PCE+NCE among different doses of radiation (p0.01). While considering MNNCE/1000NCE, there were no significant variations among silimar organizations with rays dosage (p?0.05). Summary: Dental administration of Famotidine, supplement Cimetidine and C demonstrate reliable and similar radioprotective results. Additionally, the protecting effect of solitary usage of these medicines was like the mixture form. Therefore, the oral usage of mixture, 48 hours after irradiation cannot induce even more radioprotective impact. strong course=”kwd-title” Keywords: Micronuclei , Rays , Radioprotection , Cimetidine , Supplement C , Famotidine Intro People could be subjected to undesirable rays during medical rays or methods incidents in medication, radioterrorism or industry. Rays causes cells cytotoxic and clastogenic problems , by Etomoxir supplier energy transfer from rays to macromolecules such as for example DNA, protein and lipid membranes . Free of charge radical Proliferation potential clients to cell death by damaging or breaking chemical substance bonds in DNA . The harmful ramifications of ionizing rays in natural systems could be a primary discussion between radi? ation and target macromolecules, or indirect due to the products released during the interaction between radiation and water. Hydroxyl radical is the most destructive type of water radiolysis product . Oxygen free radicals are more destructive and responsible for about 50% of the overall damages caused by free radicals, especially DNA failures [5,6]. Radiation shielding reduces ionizing radiation damages . Micronuclei test is one of the cytogenetic methods for the evaluation of radioprotective compounds . It is an important indicator of protective effects of radioprotective drugs and ionizing radiation damages . This test is a reliable method for assessing the clastogenic effects of materials in both in vitro and in vivo [9,10]. In order to prevent damage to human, besides rules set by international organizations, chemicals and natural materials were tested to reduce the harmful effects of radiation. Radioprotective agents are synthetic substances or natural basic products that are instantly administrated before irradiation to lessen injuries due to ionizing rays . A perfect radioprotector should offer significant safety against the consequences of rays, an acceptable path of administration, oral preferably, consumed and distributed through the entire body quickly, accesable and cheap readily, steady allowing easy managing chemically, storage space in surrounding temperatures and Rabbit Polyclonal to MAPK1/3 (phospho-Tyr205/222) appropriate for the wide variety of additional medicines which employees or individuals make use of. Additionally, it will need to have anacceptable toxicity and protecting time-window impact [11,12]. There’s a continuing deagerness in the recognition and the advancement of non-toxic and effective radioprotectants that may reduce the aftereffect of ionizing rays . Supplement C or ascorbic acidity is among the greatest defenses against the consequences of cell harming free radicals, proven to possess radioprotective Etomoxir supplier results [14-17] significantly. Also, the radioprotective aftereffect of supplement C on the inner Etomoxir supplier and external rays and an array of DRF have already been reported [15,18-20]. Administration of supplement C ahead of irradiation stops micronuclei [14,21] and apoptosis . Radiation induced wounds improved with administration of vitamin C . It can lead to the repair of DNA failure and improved cell survival . and the reduction of DNA damage in normal cells . Cimetidine and Famotidine are antagonists of histamine typeII receptors used clinically for treating peptic ulcers, have been reported to be radioprotective due to its radical scavenging ability [25,26] and stimulation of the immunosystem [27,28]. Famotidine prevents DNA damage , apoptosis [22,30] and the formation of micronuclei . Besides, the inhibition of gastric acid secretion induced by histamine is a powerful hydroxyl radical sweeper . These drugs with a dose-dependent effect prevent the production Etomoxir supplier of O2- and H2O2 in neutrophils . According to previous studies and given the importance of following a diet of radioprotective drugs, this study investigated and compared radioprotective effects of combination and single oral administration of vitamin C, Cimetidine and Famotidine at micronuclei test. Material and Methods Experimental Animals Seven or six week male NMRI mice (Pasture Institute, Amol, Iran) were housed five per cage (for one week) in climate-controlled, circadian rhythm-adjusted rooms, and they were allowed free access to.