Protective effects of cimetidine against oxidative stress induced by low-dose irradiation

Objective To study the protective effects of cimetidine against oxidative stress in rats induced by cumulative low-dose irradiation. Methods Sixty SD rats were randomly divided into 6 groups (10 each): normal control group, model control group, lentinan group [89mg/(kg•d)] and 3 dose groups of cimetidine. After oral administration, all the rats were exposed to γ-ray irradiation 8 hours/day for 12 days, and sacr if iced on the 13th day. The activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and the content of malondialdehyde (MDA) in serum, liver, thymus and spleen were determined. By using the superoxide anion radical system, hydroxyl radical system, H2O2 radical system, oxidation system of linoleic acid induced by alkane radical system and diphenylpicryl hydrazinyl radical (DPPH) radical system, the antioxidation activities of cimetidine were detected. R esults The activities of SOD in liver and thymus decreased significantly, the GPx activit y in ser um, liver and spleen decreased significantly and MDA level in ser um, liver and spleen increased significantly after 0.3Gy cumulative ionizing radiation. Cimetidine enhanced the activities of antioxidant enzymes in serum and organs, and reduced the MDA level. In a certain concentration range, cimetidine had different scavenging effects onto these radical systems, and showed good per for mance in hydroxyl radical. Conclusion Cimetidine can effectively ameliorate the oxidative stress from low-dose cumulative irradiation by scavenging free radicals, increase the activity of antioxidant enzymes and reduce the content of lipid peroxidation products, thus presents a potential radio protective effect. DOI: 10.11855/j.issn.0577-7402.2017.02.07