ANTIOXIDANT/PROOXIDANT EFFECTS OF GARLIC ON LINOLEIC ACID PEROXIDATION INDUCED BY COPPER(II)

Authors : Temelkan Bakır, İnci Sönmezoğlu, Reşat Apak

Pages : 36-38

View : 5 | Download : 4

Publication Date : 2015-01-30

Article Type : Other Papers

Abstract :Antioxidant compounds in food have proven health-protecting effects. Garlic insert ignore into journalissuearticles values(Allium sativum); has been cultivated since ancient times and used as a spice and condiment for many centuries. Garlic contains polyphenol and sulphur compounds, which are responsible for its antioxidant activity. In this study the peroxidation of linoleic acid insert ignore into journalissuearticles values(LA); in the presence of copper insert ignore into journalissuearticles values(II); [Cuinsert ignore into journalissuearticles values(II);] ions alone and with garlic extract was investigated in aerated and incubated emulsions at 37oC and pH 7. Cuinsert ignore into journalissuearticles values(II);-induced LA peroxidation followed pesudo-first order kinetics with respect to primary insert ignore into journalissuearticles values(hydroperoxides); and secondary insert ignore into journalissuearticles values(aldehydes- and ketones-like); oxidation products, which were determined by ferric thiocyanate insert ignore into journalissuearticles values(FeIII-SCN); and thiobarbituric acidreactive substances insert ignore into journalissuearticles values(TBARS); methods, respectively [1]. In accordance with theoretical expectations [2], garlic extract showed a distinct dose-dependent antioxidant effect on inhibition of LA peroxidation with respect to hydroperoxide formation, as measured by FeIIISCN colorimetry. Surprisingly, TBARS results were contradictory to this finding, possibly showing the prooxidative effect of garlic extract on secondary product formation during peroxidation. This unexpected result may stem from the generation of reactive sulfur species insert ignore into journalissuearticles values(RSS); from garlic extract under the Cuinsert ignore into journalissuearticles values(II);-induced oxidizing conditions of the TBARS assay, enhancing insert ignore into journalissuearticles values(rather than retarding); sulfhydryl and LA oxidation in model systems of lipid oxidation which is better expressed in secondary product formation [3].
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