Antioxidant activity of clove oil - A powerful antioxidant source

The number of methods to measure the antioxidants in botanicals, foods, nutraceuticals and other dietary supplements has increased considerably in the last decade. Clove oil is obtained by distillation of the flowers, stems and leaves of the clove tree. In the present paper, clove oil was evaluated by employing various in vitro antioxidant assay such as alpha,alpha-diphenyl-beta-picryl-hydrazyl free radical (DPPH center dot) scavenging, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging activity, total antioxidant activity determination by ferric thiocyanate, total reducing ability determination by Fe3+-Fe2+ transformation method, superoxide anion radical scavenging by riboflavin/methionine/illuminate system, hydrogen peroxide scavenging and ferrous ions (Fe2+) chelating activities. Clove oil inhibited 97.3% lipid peroxidation of linoleic acid emulsion at 15 mu g/mL concentration. However, under the same conditions, the standard antioxidant compounds such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), alpha-tocopherol and trolox demonstrated inhibition of 95.4, 99.7, 84.6 and 95.6% on peroxidation of linoleic acid emulsion at 45 mu g/mL concentration, respectively. In addition, clove oil had an effective DPPH center dot scavenging, ABTS(center dot+) scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, ferric ions (Fe3+) reducing power and ferrous ions (Fe2+) chelating activities. Also, these various antioxidant activities were compared to BHA, BHT, alpha-tocopherol and trolox as reference antioxidant compounds. (C) 2010 King Saud University. Production and hosting by Elsevier B. V. All rights reserved.