Comparative study of antioxidant potential of curcumin and its degradation products-vanillin, ferulic acid and dehydrozingerone

Curcumin is one of the most intensively studied biologically active antioxidants during the last decade. Its chemical instability and rapid degradation at physiological conditions (pH ? 7) was stated as the most important limitation for its potential applications. Numerous approaches have been undertaken to overcome the problem with the bioavailability of curcumin, including the use of such adjuvants as piperine, liposomes, system of nanoparticles, phospholipid complexes and design of new structural analogs of curcumin. On the other hand, degradation of a compound does not necessarily lead to loss of its activity. Whether and how the degradation and oxidation pathways contribute to the biological and antioxidant activities of curcumin has also been discussed. The aim of this study was to compare the antioxidant activity of curcumin with those of its degradation products (ferulic acid, vanillin and dehydrozingerone), when added in binary and ternary mixtures. Lipid autoxidation was used for assessing the chain-breaking antioxidant efficiency and reactivity of the phenols. The results obtained showed much stronger activity of curcumin than that of all the individual compounds and their binary and triple mixtures.