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 gamma-radiation and evaluated at 12, 24, 36 and 48 hours post-irradiation. Whole body irradiation of mice to different doses of gamma-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 gamma-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/FeSO4 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.