Abstract: Stannous chloride (SnCl2) is employed as a reducing agent to obtain Technetium-99m-labelled radiopharmaceuticals in nuclear medicine kits, being inject endogenously in humans. Toxic effects of. these kits were not studied, thus making it important to evaluate their impact in humans. The use of natural extracts as medicines is growing around the world. The chayotte (Sechium edule) is a subtropical vegetable with potent diuretic action. It is used in folk medicine due its hypotensor effect. In this study, plasmid deoxyribonucleic acid (DNA) was exposed to chayotte extracts (macerated) (0.1g mL-1) in presence of stannous chloride (SnCl2). Samples of the plasmid DNA were analyzed through agarose gel electrophoresis. The results show that the chayotte extract was capable of damaging the DNA in the presence and in the absent of SnCl2.