Abstract
Roupala montana Aubl. (Proteaceae) is a typical savannah species and native to tropical South America that has a moderate mortality for adult forms of Schistossoma mansoni. Because this species has been little studied, the aim of this investigation was to evaluate the influence of R. montana extract on DNA damage induced by methyl methanesulfonate (MMS) in peripheral blood cells and liver of Swiss mice using the micronucleus and comet assay, respectively. R. montana dichloromethane extract was prepared from a stock solution (0.5 mg/mL) in 5% dimethyl sulfoxide in water. Animals received a single dose of different concentrations of R. montana (5, 10 and 20 mg/kg body weight) by gavage (0.5 mL/animal). For antigenotoxicity assessment, different concentrations of R. montana were administered simultaneously with MMS diluted in water (40 mg/kg, intraperitoneally; 0.3 mL/animal). Peripheral blood and hepatocyte samples were obtained 48 and 24 h after treatment, respectively. Results showed that R. montana administered alone indicated the absence of genotoxicity in the mouse micronucleus or comet assay. On the other hand, administration of different doses of R. montana concomitantly with MMS led to a significant reduction in frequency of micronucleated polychromatic erythrocytes and DNA damage, when compared to the group treated only with MMS. Further, for the micronucleus assay, the gradual increase of R. montana concentration led to a proportional increase in the reduction of genotoxicity induced by MMS, indicating a dose-response relationship.
Acknowledgements
The authors also thank Valéria M.M. Gimenez from Centro Universitário Claretiano, Batatais, São Paulo, Brazil, and Milton Groppo Junior from Faculdade de Filosofia, Ciências e Letras, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil, for collection and identification of the material and Márcio Luis Andrade e Silva for permitting the use of the HPLC apparatus (FAPESP; grant no.: 2005/01550-8).