Evaluation of the mutagenic effect of the iodinated contrast medium Urografina® 292 using the micronucleus test in mouse bone marrow cells.

Contrast media (CM) are frequently used in diagnostic radiology and in radiotherapy as a diagnostic tool and in treatment planning. Previous studies have demonstrated that these compounds induce chromosomal aberrations. This study evaluates the mutagenic effects induced by the contrast medium Urografina® 292 (meglumine amidotrizoate and sodium-ionic dimmer) in bone marrow cells (BMC) of mice in vivo. Micronuclei assay was performed in BMC of CF-1 mice injected with CM 1.5 and 3.0 mL/kg intravenous doses and 1.0, 2.0, 3.0 mL/kg intraperitoneal doses. The animals were beheaded 24 h after treatment by cervical dislocation, and femur BMC from each animal were used in the micronucleus test. The group treated with the highest intravenous injection of Urografina® 292 (3.0 mL/kg) presented an increase in the frequency of micronucleated polychromatic erythrocytes (MNPCEs) in relation at the control group (P<0.05). The results obtained after intraperitoneal administration of CM showed that all doses (1.0 mL/kg, 2.0 mL/kg and 3.0 mL/kg) increased the frequency of MNPCEs, being significantly different from the negative control (P< 0.01). The present results suggest that iodinated contrast media Urografina® 292 may cause a significant increase of cytogenetic damage in bone marrow cells of mice.

Influence of Mikania laevigata Extract over the Genotoxicity Induced by Alkylating Agents.

Medicinal plants are still widely used worldwide; yet for some species, little or no information is available concerning their biological activity, specially their genotoxic and antimutagenic potential. Mikania laevigata (Asteraceae) is a native plant from South America, and its extracts are largely used to treat respiratory complaints. The aim of the present work was then to evaluate, in vivo, the potential biological activity of M. laevigata on the genotoxicity induced by methyl methanesulfonate (MMS) and cyclophosphamide (CP), using the comet assay. Male CF1 mice were divided into groups of 5-6 animals, received by gavage 0.1 mL/10 g body wt of water, Mikania laevigata extract (MLE), MMS, and CP. Results showed that treatment with 200 mg/kg of the MLE previously to MMS and CP administration, respectively, reduced the damage index (DI) in 52% and 60%, when compared to DI at 24 h. Pretreatment also reduced the damage frequency (DF) in 56% (MMS) and 58% (CP), compared to DF at 24 h. MLE administration has been shown to protect mouse DNA from damage induced by alkylating agents; this corroborates to the biological activities of M. laevigata and points towards the need of plant compounds isolation to proceed with further studies.