Bauhinia monandra (pata-de-vaca, pulse) is originated from Asia and widely spread in the world; leaf infusions are used as hipoglicemiant by folk medicine. Also, a highly purified leaf lectin has been obtained from B. monandra (BmoLL). Confirmation of efficacy and toxicity assays concerning new phytotherapics are necessary to be done prior to commercialization. The aim of this work was the evaluation of genotoxic potential from saline leaf extract (E) and BmoLL on DNA. In vitro analyses were done with plasmidial DNA to verify if these compounds were able to generate DNA strand breaks. In addition, treatment with exonuclease III was performed to detect abasic sites. E (1.1; 3.3; 9.9; 29.7; 89.1 µg/µL) and BmoLL (0.164; 0.493; 1.478; 4.4; 13.3; 39.9; 119.7; 359.2 ng/µL) were incubated with 1 µg of plasmidial DNA for 1 h at 37°C. Conformational alterations were analyzed by agarose gel electrophoresis where Form I corresponded to supercoiled DNA migrating faster than Form II (circular DNA). Form III (linear DNA) migrated between forms I and II. The presence of abasic sites was determined after exposition of plasmidial DNA to derivatives of B. monandra; exonuclease III was incubated for 30 min at 37ºC before eletrophoretical analysis. Results showed that E, but not BmoLL, was able to induce phosphodiester breaks. However, concerning abasic sites, E (all concentrations) and lectin (39.9; 119.7; 359.2 ng/µL) generated breaks on DNA. Results suggest that E has a greater genotoxic potential than BmoLL. This lectin could be, in the future, part of a new formulation for diabetes treatment. Other tests, like Ames assay will be performed to better characterize the mutagenic potential of these natural products.