Protective effect of Alstonia scholaris against radiation-induced clastogenic and biochemical alterations in mice.

We studied the radioprotective effect of Alstonia scholaris bark extract (ASE) on cytogenetic alterations in the form of chromosomal aberrations and micronuclei induction in bone marrow. For this purpose, one group of male Swiss albino mice was exposed to 2.5 Gy gamma radiation to serve as the irradiated control, while the other group received ASE (100 mg/kg bwt/d) orally for 5 consecutive days 30 min before irradiation to serve as the experimental group. Results indicated that dicentrics and chromosomal exchanges were increased at 12 h post-exposure in both groups, followed by a gradual decline and then disappearance by d 15 and 7, respectively. However, the occurrence of chromatid breaks and acentric fragments was also maximum at 12 h, and later decreased without attaining the normal value, even up to the last necropsy interval. The percentage of such aberrations was significantly less in the ASE-pretreated irradiated animals. The incidence of chromosome breaks and centric rings kept increasing up to d 1, but then declined gradually and reached zero beginning at d 7; they were significantly lower in the ASE-treated irradiated group at the early intervals. A significant decrease in glutathione (GSH) and an increase in lipid peroxidation were observed after radiation exposure in untreated controls, whereas ASE-pretreated irradiated animals exhibited a significant increase in GSH and a decrease in lipid peroxidation; however, the values remained below normal. The results from the present study suggest that ASE pretreatment provides protection against radiation-induced chromosomal damage and micronuclei induction in the bone marrow of mice.