A black bean diet reduced the frequency of micronuclei polychromatic erythrocytes in mice simultaneously treated with cyclophosphamide, an indirect acting mutagen.
A black bean diet reduced the frequency of micronuclei (MN) polychromatic erythrocytes (PCE) in mice simultaneously treated with cyclophosphamide (CP), an indirect acting mutagen, according to researchers from the Faculdade de Medicina de Itajubá, Curso de Nutrição, Brazil. The research, published in the December issue of Food and Chemical Toxicology, also showed that peripheral leukocytes showed a statistically significant reduction of DNA damage when mice treated with CP received diets with 1 or 20% black beans.
The researchers designed a study to evaluate the toxicogenetic or protective effect of cooked and dehydrated black beans (Phaseolus vulagris L.) in bone marrow and peripheral blood cells of exposed mice. The frequency of micronuclei detected using the bone marrow erythrocyte micronucleus test and level of DNA lesions detected by the comet assay were chosen as end points reflecting mutagenic and genotoxic damage. Initially, Swiss male mice were fed with a 20% black bean diet in order to detect mutagenic and genotoxic activity.
The researchers found that the diet containing 20% of cooked and dehydrated black beans did not have a mutagenic or cytotoxic effect on mouse bone marrow cells. When the antimutagenicity of black beans was evaluated, significant decreases by 34%, 22% and 33% in the frequency of CP induced MN PCE were observed in mice receiving 1, 10 and 20% diets respectively. Results from a comet assay in blood peripheral leukocytes also showed statistically significant reductions of DNA damage when mice treated with CP received diets with 1 or 20% beans, approximately 59% and 56% reductions, respectively.
'Under the conditions tested herein, mice fed with black bean diets showed a lower incidence of CP-induced DNA damage. This finding emphasises the potential of dietary constituents for human therapies and, also, the applicability of genotoxic evaluation for improving health,' conclude the researchers.
The paper, 'Black bean (Phaseolus vulgaris L.) as a protective agent against DNA damage in mice,' by L. Azevedo, J. C. Gomes, P. C. Stringheta, Á. M. M. C. Gontijo, C. R. Padovani, L. R. Ribeiro and D. M. F Salvadori was published in Food and Chemical Toxicology (2003) 41:1671-1676.
The abstract can be read here.
Contact: L. Azvedo, Faculdade de Medicina de Itajubá, Curso de Nutrição, Rua Cel. Reno Junior, 328, Caixa Postal 25, 37500-000, Itajubá, MG, Brazil.
Email: nutricao@aisi.edu.br