The frequency of micronucleated polychromatic (MPCE), normochromatic erythrocytes (MNCE), and polychromatic/normochromatic erythrocyte ratio (PCE/NCE), was studied in the bone marrow of mice orally administered with 0, 200, 225, 250, 275 and 300 mg/kg body weight of hydroalcoholic leaf extract of Aegle marmelos (AME). Treatment of mice with AME, once daily for 5 consecutive days, before exposure to 2 Gy resulted in a significant decline in the frequency of MPCE when compared to the non-drug-treated irradiated control. The greatest reduction in MPCE was observed for 250 mg/kg body weight AME, accompanied by the highest polychromatic erythrocyte to normochromatic erythrocyte ratio, in comparison with the non-drug-treated irradiated control. Therefore, further studies were carried out using this dose of AME, where the animals were administered with 250 mg/kg body weight of AME before exposure to 0, 0.5, 1, 2, 3 and 4 Gy of γ-radiation and evaluated at 12, 24, 36 and 48 hours post-irradiation. Whole body irradiation of mice to different doses of γ-radiation resulted in a dose-dependent increase in the frequency of MPCE at all post-irradiation times. Treatment of 250 mg/kg AME orally (p.o.) before irradiation significantly reduced the frequency of MPCE at all post-treatment times. The frequency of MPCE increased with time, reached a peak level at 24 hours, and declined thereafter. The occurrence of MNCE has also shown a pattern similar to MPCE, except that the MNCE frequency reached a peak level by 48 hours. The AME significantly reduced the frequency of MNCE at all post-irradiation times, when compared to the non-drug-treated irradiated group. Treatment of mice with AME before exposure to different doses of γ-radiation resulted in the inhibition of a radiation-induced decline in the PCE/NCE ratio, when compared with the concurrent irradiated controls. To gain insight into the mechanism of action, AME was tested for its antioxidant effects in cell-free chemical systems using H2O2/FeSO 4 to generate hydroxyl (•OH) radicals, which were measured by a fluorescent probe, 2V, 7V-dichlorofluorescin diacetate (DCFH/DA). Xanthine/xanthine oxidase was used to generate superoxide (O2•-) anion radical, which was measured by a fluorescent probe dihydroethidium (DHE). AME significantly reduced fluorescence in a concentration dependent .manner, indicating its efficacy to scavenge free radicals. Our results demonstrate that one of the mechanism of reduction in the radiation-induced DNA damage in mice bone marrow by AME may be due to scavenging of free radicals and elevation in the antioxidant status, as previously reported.
All Science Journal Classification (ASJC) codes
- Health, Toxicology and Mutagenesis