FORMATION OF REACTIVE OXYGEN INTERMEDIATES MIGHT BE INVOLVED IN THE TRYPANOCIDAL ACTIVITY OF GALLIC ACID

We investigated the mechanism of the trypanocidal activity of gallic a cid (GA), GA-induced trypanocidal activity was significantly reduced b y pretreatment with superoxide dismutase (SOD) and/or catalase. The ES R technique with 5,5-dimethyl-1-pyrroline N-oxide (DMPO) as a spin tra pping agent revealed that a DMPO-OH adduct was detected in culture med ium containing GA. The intensity of ESR signals of the DMPO-OH adduct was increased in a time dependent manner. SOD also inhibited the forma tion of GA-induced DMPO-OH adducts, Furthermore, GA enhanced DNA singl e-strand breaks induced by Fenton reagent. These results suggest the p ossibility that GA acts as a pro-oxidant for trypanocidal activity.