The effectiveness of an aqueous extract of Caryocar brasiliense (Caryocaraceae) Camb pulp, popularly known in Brazil as pequi, against clastogenicity induced by cyclophosphamide and bleomycin was evaluated using an in vivo mouse bone marrow cell micronuclei test, an in vitro Chinese hamster ovary cell (CHO-K1) chromosome aberration test and an in vitro antioxidant assay based on the oxidative damage to 2-deoxy-D-ribose (2-DR) induced by hydroxyl radicals ( • OH) generated by the reaction between ascorbic acid and (Fe III)-EDTA. In mouse bone marrow cells the extract showed a protective effect against micronuclei induced by cyclophosphamide and bleomycin but did not interfere with polychromatic bone marrow erythrocyte proliferation, except when the mice had been treated with the highest dose of cyclophosphamide. When CHO-K1 cells were pretreated by adding 0.01, 0.05 or 0.1 mL of extract per mL of cell culture medium 24 or 48 h before bleomycin or cyclophosphamide there was a protective effect against chromosome breaks and a significant decrease in the mitotic index (a measure of cytotoxicity) of the CHO-K1 cells. The extract also had a protective effect against oxidative hydroxyl radical damage to 2-DR. This study suggests that C. brasiliense pulp aqueous extract has anticlastogenic potential, possibly due to its antioxidative properties.

An evaluation of the genotoxicity of domestic sewage was carried out in a municipal wastewater treatment plant. The study was carried out using Allium cepa root tip cells through cytological parameters such as aberrant cells in anaphase-telophase and the mitotic index, and the fish species Oreochromis niloticus and Tilapia rendalli, through the index of micronuclei in peripheral erythrocytes. In the Allium test, each of the four stages of the wasterwater treatment routine was analyzed, i.e., crude sewage, primary effluent, secondary effluent, and tertiary effluent. O. niloticus and T. rendalli specimens were maintained in an aquarium continuously receiving the final effluent, in an open system, before being discharged into Lake Paranoá. For micronuclei analysis, blood samples were drawn after 7, 21, 60, 102 and 142 days, respectively, in controlled conditions. The numbers of aberrant cells found in the Allium test did not differ among the four stages tested, nor when compared with the control. At all stages, the most concentrated sample was more toxic than the respective diluted samples, as demonstrated by the decreased mitotic index. Different sampling of the same group of fish revealed no increase in the micronuclei frequency, regardless of the period of exposure. A correlation between long-term exposure and micronuclei induction was not found either