The radioprotective effect of hydroalcholic Zataria multiflora (Avishan-e shirazi) extract was investigated against genotoxicity induced by γ irradiation in human lymphocytes. Peripheral blood samples were collected from human volunteers and incubated with Z. multiflora extract at different concentrations (5, 10, and 50 μg/mL) for 1 hour. At each dose point, the whole blood was exposed in vitro to 150 cGy of cobalt-60 γ irradiation, and then the lymphocytes were cultured with mitogenic stimulation to determine number of the micronuclei in cytokinesis-blocked binucleated cells. The treatment of lymphocytes with extract showed a significant decrease in the incidence of micronuclei binucleated cells, compared with similarly irradiated lymphocytes without extract against γ irradiation. The maximum protection and decrease in frequency of micronuclei was observed at 50 μg/mL of Zataria extract by 32% reduction. High-performance liquid chromatography analysis of extract showed that it contains high amounts of thymol. Zataria extract exhibited concentration-dependent radical-scavenging activity on 1,1-diphenyl-2-picryl hydrazyl free radicals. These data have an important application for the protection of human lymphocyte from the genetic damage and side-effects induced by γ irradiation in personnel exposed to radiation.

Background:131-radioiodine has been widely used as an effective radionuclide for treatment of patients with thyroid diseases. The purpose of the present study is to investigate the radioprotective effects of curcumin as a natural product that protects against the genotoxic effects of 131I in human cultured lymphocytes.Materials and Methods:Whole blood samples from human volunteers were incubated with curcumin at doses of 5, 10, and 50 μg/mL. After 1-hour incubation, the lymphocytes were incubated with 131I (100 μCi/1.5 ml) for 2 hours. The lymphocyte cultures were then mitogenically stimulated to allow for evaluation of the number of micronuclei in cytokinesis-blocked binucleated cells.Results:Incubation of lymphocytes with 131I at dose 100 μCi/1.5 mL induced genotoxicity shown by increase in micronuclei frequency in human lymphocytes. Curcumin at 5, 10, and 50 μg/mL doses significantly reduced the micronuclei frequency. Maximal protective effects and greatest decrease in micronuclei frequency were observed when whole blood was incubated with 50 μg/mL dose of curcumin with 52%.Conclusion:This study has important implications for patients undergoing 131I therapy. Our results indicate a protective role for curcumin against the genetic damage and side effects induced by 131I administration.

131-radioiodine has been widely used as an effective radionuclide for treatment of patients with thyroid diseases. The purpose of this study was to investigate the genotoxic effects of iodine-131 in human cultured lymphocytes. Whole blood samples from human volunteers were incubated with iodine-131 (10, 50, 100 µCi/1.5ml) for 2 h. The lymphocytes were mitogenically stimulated to allow for evaluation of the number of micronuclei in cytokinesis-blocked binucleated cells. At the dose 100 µCi, iodine-131 induced genotoxicity by an 8.5 fold increase in the frequency of micronuclei in human lymphocytes compared with the control group.

The purpose of this study was to investigate the radioprotective effects of resveratrol as a natural product that protects against genotoxic actions of (131)I in cultured human lymphocytes. Whole-blood samples from human volunteers were treated with resveratrol at doses of 0.5, 1, 5, and 50 μg/mL for 1 h, after which the lymphocytes were incubated with (131)I (100 μCi/1.5 mL) for 2 h. The lymphocyte cultures were then mitogenically stimulated to enable evaluation of the number of micronuclei in cytokinesis-blocked binucleated cells. Incubation of lymphocytes with (131)I induced genotoxicity, which was reflected by an increase in micronuclei frequency. At the doses tested, resveratrol significantly reduced micronuclei frequency. Maximal protective effects occurred at a dose of 1 μg/mL, with total micronuclei values being reduced by 65 % compared to controls. In conclusion, our results indicate protective effects of resveratrol at low doses against genetic damage and adverse effects induced by (131)I administration.