The modifying effect of β-carotene on gamma radiation-induced elevation of oxidative reactions and genotoxicity in male rats

Abstract

The aim of the present work was to evaluate the modulatory role of β-carotene on the radiation-induced changes in certain biochemical and cytogenetic parameters. β-Carotene was given by gavage at a dose of 5 mg/kg body weight for 7 consecutive days before whole body gamma irradiation with 7 Gy (single dose). The levels of β-carotene in plasma, thiobarbituric acid-reactive substances (TBARS) in plasma and liver, the activities of superoxide dismutase (SOD) and catalase in blood and liver were the selected parameters. Furthermore, the frequency of micronuclei (MN) of polychromatic erythrocytes (PCEs), normochromatic erythrocytes (NCEs), the ratio of PCEs/NCEs and the mitotic index (MI) of bone marrow cells were also evaluated. The biochemical and cytogenetic determinations were carried out 1, 24, and 72 h after radiation exposure. The results obtained revealed that administration of β-carotene pre-irradiation significantly inhibited the decrease in plasma β-carotene, significantly reduced the levels of TBARS in plasma and liver. Significant protection of the radiation-induced changes in the activities of SOD and catalase was also recorded in the blood and liver of β-carotene-treated and -irradiated rats. β-Carotene resulted in significant inhibition in the frequency of radiation-induced MN, as well as in the ratio of PCEs/NCEs and the MI of bone marrow cells. These results suggest that β-carotene as a natural product with its antioxidant capacity and capability of quenching singlet oxygen, could play a modulatory role against the cellular damage affected by free radicals induced by whole body irradiation.