Antioxidant Activity of Mart. Stem Bark Fraction in an Iron Overload Model.

Mart., popularly known as "barbatimão", is a plant species traditionally used by topical and oral routes for the treatment of infectious and inflammatory diseases. Considering the well-described antioxidant properties of this species, this study investigated the protective effects of its keto-aqueous extract using an in vitro model of iron overload. Phenolic compounds were quantified and identified by Ultra-Performance Liquid Chromatography coupled with quadrupole Time-Of-Flight Electrospray Ionization Mass Spectrometry () in positive and negative ions mode analysis. Antioxidant activity was analyzed following the iron-chelating-reducing capacity and deoxyribose degradation (2-DR) protection methods. The analysis identified condensed tannins (54.8 mg catechin/g dry fraction (DF), polyphenols (25 mg gallic acid/g DF), and hydrolyzable tannins (28.8 mg tannic acid/g DF). Among the constituents, prodelphinidin, procyanidin, and prorobinetinidine were isolated and identified. The extract significantly protected 2-DR degradation induced by Fe (72% protection) or OH (43% protection). The -phenanthroline test revealed Fe-chelating and Fe-reducing activities of 93% and 84%, respectively. A preliminary toxicological analysis using revealed mortality below 10%, at a concentration of 0.25 mg/mL, indicating low toxicity under the present experimental conditions. In conclusion, the findings of the present study indicate that is a source of antioxidant compounds with the potential to be used in drug development in the context of iron overload disorders, which remains to be further investigated in vivo.