Antioxidant potential of wild plant foods

Abstract

Oxidative stress has been implicated in the ageing process and in several chronic diseases such as diabetes, cancer, and cardiovascular diseases. Endogenous antioxidant defenses, including enzymes and nonenzymatic compounds, try to combat the oxidative stress created by the disequilibrium between the production of reactive oxygen and nitrogen species and the antioxidant defense system. Natural matrices such as food plants could help the exogenous defense antioxidant system in the mentioned process. Within this perspective, Mediterranean regions contribute significantly owing to their richness in species and habitats. This chapter details and compares the antioxidant activities of different edible parts of selected wild species in the Mediterranean regions, which were traditionally gathered and consumed as food and snacks. Thirty-three species from 16 families of flowering plants were studied. Asteraceae (daisy family), Polygonaceae (sorrel family), Rosaceae (dog-rose family), and Lamiaceae (mint family) are the most representative, as 70 % of the reviewed species are taxonomically included in such botanical families. Experimental research on these species is mainly focused on aerial plant pieces, for instance basal and other leaves, midribs, young stems, shoots, and inflorescences, as these plant parts are the most used and available. Given the complexity of antioxidant measurement assays, the following methods have been selected to give an idea of the antioxidant properties of different wild plant foods from the Mediterranean area: reducing power (Folin–Ciocalteu and ferricyanide/Prussian blue assays), 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity, and lipid peroxidation inhibition (β-carotene/linoleate assay and thiobarbituric acid reactive species assay).