Antioxidant properties of oregano (Origanum vulgare) leaf extracts

We tested the antioxidant properties of both aqueous and methanolic extracts of oregano (origanum vulgare). They proved to be effective in the inhibition of all phases of the peroxidative process: first neutralizing free radicals (superoxide anion, hydroxyl radical and 1,1-diphenyl-2-picrylhydrazyl radical), then blocking peroxidation catalysis by iron (through iron-chelating and iron-oxidizing properties), and finally through interruption of lipid-radical chain reactions (chain-breaking activity). Their anti-glycosylation activity was also effective. The glycosylation of lipoproteins is directly related to their peroxidation. The amount of extract used in our experiments was obtained from 0.1-1 mg of dried leaves, amounts far less than those normally used in the Mediterranean diet.