The protective ability of Mediterranean dietary plants against the oxidative damage: The role of radical oxygen species in inflammation and the polyphenol, flavonoid and sterol contents

Ten hydroalcoholic extracts of edible plants from the Calabria region (Italy) were evaluated for their in vitro antioxidant and antiradical properties and in vivo topical anti-inflammatory activity. All the extracts had radical-scavenging and/or antioxidant properties, the most active plants being hawkweed oxtongue and viper's bugloss. The best free radical (DPPH center dot)-scavenging activity was found in hawkweed oxtongue and chicory leaves extracts (IC50 = 25 and 26 mu g/ml, respectively). Hawkweed oxtongue, poppy and viper's bugloss extracts showed the greatest inhibition of linoleic acid oxidation (IC50 = 3 mu g/ml). Viper's bugloss and hawkweed oxtongue extracts had the greatest antioxidant effect on bovine brain peroxidation (IC50 = 11 and 22 mu g/ml). All the extracts also showed an anti-inflammatory effect: 300 mu g/cm(2) provoked oedema reductions ranging from 18% to 43%. Cress was the most active plant. Chicory leaves contained the highest amount of phenolics (190 mg/g) whilst Rush crimps contained the highest amount of flavonoids (32.9 mg/g), followed by hawkweed oxtongue (15.8 mg/g). Cress contained the highest number of sterols. Among them, gamma-sitosterol (12.2%) and ergost-5-en-3-ol (3 beta) (4.5%) were found to be the major constituents. Moreover, three of the identified molecules (stigmasta-5,23-dien-3 beta-ol, stigmasta-5,24(28)-dien-3-ol (3 beta,22E) and 9,19-cyclolanost-24-en-3-ol (3 beta)) were found in this plant only. (c) 2008 Elsevier Ltd. All rights reserved.