RESUMO
The radioprotective effects of vitamin C and famotidine were investigated using the micronucleus test for anticlastogenic and cell proliferation activity. Various doses of vitamin C and famotidine were administered intraperitoneally 2 h before 2Gy gamma irradiation to NMRI adult male mice. Frequency of micronuclei in 1000 PCEs [MnPCEs] were scored for each sample. Cell proliferation ratio [PCE/PCE+NCE] was also calculated. Data were statistically evaluated using one-way ANOVA and Tukey's HSD test. The results indicated that gamma irradiation alone caused a significant increase in the MnPCEs and reduced the cell proliferation ratio. Administration of various doses of famotidine and vitamin C before gamma irradiation reduced MnPCEs and therefore clastogenic effects of radiation. Famotidine didn't change cell proliferation compared to the irradiation group but vitamin C significantly improved and increased cell proliferation to the control group's level. The dose reduction factor [DRF] calculated, shows a DRF=2 for famotidine and a DRF=1.7 for vitamin C which is indicative of a high radioprotective property of these compounds. The way in which these compounds reduced the clastogenic effects of radiation might be via antioxidant property and free radical scavenging mechanism