ABSTRACT
Snake toxins, such as phospholipases A2 and proteases, are used as research tools to evaluate biological activities and to understand physiopathological processes of natural compounds better. In the present study, the phenolic compounds catechin and epicatechin were incubated with snake venoms to evaluate their inhibition against different substrates. Catechin and epicatechin exerted inhibitions between 20% and 95% on the activity of phospholipases A2 present in the venom of Bothrops alternatus. In the hemolytic activity, catechin exerted inhibitions between 20% and 25% in all proportions evaluated on the B. jararacussu venom, whereas epicatechin inhibited 20% of the venom activity. Coagulation induced by B. atrox and B. jararacussu venoms was significantly inhibited by catechin and epicatechin, where the time for coagulation was two to three times higher after previous incubation of the venoms with the compounds. The most significant inhibitions for the proteolytic activity on casein were 17% and 27%, respectively, by both compounds. Catechin inhibited serine protease activity induced by B. atrox venom by 64% and epicatechin by 65%. Regarding B. atrox-induced thrombolysis, catechin exerted 40% inhibition and epicatechin around 30%. The fibrinogen proteolysis was completely inhibited by catechin acting on the B. atrox venom in the proportion of 1:1 and by epicatechin on B. jararacussu venom. Catechin and epicatechin showed promising inhibitory action on proteases and phospholipases A2 . Therefore, these compounds can be explored as an adjuvant for serum therapy or pharmaceutical purposes, once they act on homologous enzymes that are present in humans.