| dc.description.abstract | Uranium is a highly radioactive heavy metal with isotopes that decay on the geological time scale. Uranium is known to induce chromosomal damages and oxidative stress. In the present study, we investigated the protective role of Ginkgo biloba (GB) leaf extract on uranyl acetate (U-235)-induced toxicity in Swiss albino mice. For this purpose, we performed the chromosome aberration (CA) test and mouse-erythrocyte micronucleus (Mus-EMN) assay in the erythrocyte, bone marrow and exfoliated buccal mucosa cells. Blood malondialdehyde (MDA) and glutathione (GSH) levels were also determined. The animals were randomly divided into six groups, each consisting of six animals. They were treated with 5 mg/kg b.wt uranium by oral gavage for 5 days. GB extract (50 and 150 mg/kg b.wt) was administered by oral gavage at 48 h, 24 h, and 15 min before uranium application. As a result, uranium-only treated mice presented higher frequency of CAs, micronuclei (MN) and abnormal metaphases (AM) when compared to the controls. These mice also displayed lower mean mitotic index (MI) than the controls. Moreover, there was a significant increase (P<0.05) in MDA levels, but a significant decrease (P<0.05) in GSH levels, when compared to the controls. Pretreatment of mice with GB significantly decreased the MN frequency in the erythrocyte cells. Similarly, the number of abnormal metaphases (AM) and the frequency of CAs, such as break, acentric, fragment, gap and ring, were fairly decreased and the value of MI was increased. In addition, the frequency of MN in the erythrocytes was greater than those in the exfoliated cells of buccal mucosa. Moreover, GB supplementation caused a dose-dependent amelioration in the oxidative stress. These findings suggested that GB leaf extract has a protective effect against uranium-induced genotoxicity and oxidative stress in albino mice, due to its antioxidant properties. | en_US |
