linoleic-acid and caffeic-acid-phenethyl-ester

Caffeic acid phenethyl ester (CAPE), a plant polyphenolic concentrated in honeybee propolis, has been found to be biologically active in a variety of pathways. The aim of this study was to determine the antioxidant activity of CAPE using different methods such as total antioxidant activity by the thiocyanate method, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid radicals, 1,1-diphenyl-2-picryl-hydrazyl free radicals, N,N-dimethyl-p-phenylenediamine dihydrochloride radicals and superoxide anion radicals scavenging activities, reducing power and ferrous ions (Fe(2+)) chelating activities. CAPE showed 97.9% inhibition on lipid peroxidation of linoleic acid emulsion. On the other hand, butylated hydroxyanisole, butylated hydroxytoluene, α-tocopherol and trolox indicated an inhibition of 87.3, 97.6, 75.3 and 90.3% on peroxidation in the same system, respectively.

Topics: Antioxidants; Caffeic Acids; Emulsions; Linoleic Acid; Lipid Peroxidation; Phenylethyl Alcohol; Plant Extracts; Polyphenols; Propolis

Caffeic acid phenethyl ester, an active component of propolis extract, inhibits 5-lipoxygenase in the micromolar concentration range. The inhibition is of an uncompetitive type, i.e. the inhibitor binds to the enzyme-substrate complex but not to the free enzyme. Caffeic acid phenethyl ester also exhibits antioxidant properties. At a concentration of 10 microM, it completely blocks production of reactive oxygen species in human neutrophils and the xanthine/xanthine oxidase system.

Topics: Antioxidants; Caffeic Acids; Hordeum; Humans; Kinetics; Linoleic Acid; Linoleic Acids; Lipoxygenase Inhibitors; Luminescent Measurements; Neutrophils; Oxidation-Reduction; Phenylethyl Alcohol; Reactive Oxygen Species; Xanthine; Xanthine Oxidase; Xanthines