Maioli, Marcos A. [UNESP]Alves, Larissa C. [UNESP]Campanini, Andre L. [UNESP]Lima, Michele C. [UNESP]Dorta, Daniel J.Groppo, MiltonCavalheiro, Alberto José [UNESP]Curti, CarlosMingatto, Fábio Erminio [UNESP]2014-05-202014-05-202010-09-01Food Chemistry. Oxford: Elsevier B.V., v. 122, n. 1, p. 203-208, 2010.0308-8146http://hdl.handle.net/11449/26278Plectranthus barbatus Andrews (Lamiaceae) is a popular medicinal plant used to treat gastrointestinal and hepatic ailments. In this work, we assessed the antioxidant activity of the aqueous extract of P. barbatus leaves on Fe(2+)-citrate-mediated membrane lipid peroxidation in isolated rat liver mitochondria, as well in non-mitochondrial systems: DPPH reduction, (center dot)OH scavenging activity, and iron chelation by prevention of formation of the Fe(2+)-bathophenanthroline disulfonic acid (BPS) complex. Within all the tested concentrations (15-75 mu g/ml), P. barbatus extract presented significant free radical-scavenging activity (IC(50) = 35.8 +/- 0.27 mu g/ml in the DPPH: assay and IC(50) = 69.1 +/- 0.73 mu g/ml in the (center dot)OH assay) and chelated iron (IC(50) = 30.4 +/- 3.31 mu g/ml). Over the same concentration range, the plant extract protected mitochondria against Fe(2+)/citrate-mediated swelling and malondialdehyde production, a property that persisted even after simulation of its passage through the digestive tract. These effects could be attributed to the phenolic compounds, nepetoidin - caffeic acid esters, present in the extract. Therefore, P. barbatus extract prevents mitochondrial membrane lipid peroxidation, probably by chelation of iron, revealing potential applicability as a therapeutic source of molecules against diseases involving mitochondrial iron overload. (C) 2010 Elsevier Ltd. All rights reserved.203-208engPlectranthus barbatusMitochondriaReactive oxygen speciesLipid peroxidationAntioxidantIron chelationArtigo10.1016/j.foodchem.2010.02.058WOS:000277702200030Acesso restrito2518006820764120