Antioxidant/prooxidant effects of alpha-tocopherol, quercetin and isorhamnetin on linoleic acid peroxidation induced by Cu(II) and H2O2

Bakir T., Sonmezoglu I. , Imer F., Apak R.

INTERNATIONAL JOURNAL OF FOOD SCIENCES AND NUTRITION, vol.65, no.2, pp.226-234, 2014 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 65 Issue: 2
  • Publication Date: 2014
  • Doi Number: 10.3109/09637486.2013.845654
  • Journal Indexes: Science Citation Index Expanded, Scopus
  • Page Numbers: pp.226-234


The peroxidation of linoleic acid (LA) in the presence of copper(II) (Cu(II)) ions alone and with alpha-tocopherol (alpha-TocH) was investigated in aerated and incubated emulsions at 37 degrees C and pH 7. Additionally, the effects of quercetin (QR) and its O-methylated derivative, isorhamnetin (IR), as potential antioxidant protectors were studied in the (Cu(II) + TocH)-induced LA peroxidation system. Cu(II)-induced LA peroxidation followed pseudo-first-order kinetics with respect to primary (hydroperoxides) and secondary (aldehydes- and ketones-like) oxidation products, which were determined by ferric thiocyanate and thiobarbituric acid-reactive substances methods, respectively. As opposed to the concentration-dependent (at 0.6 and 10.0 mu M) prooxidative action of alpha-TocH in the absence of QR and IR, the latter two compounds showed antioxidant effect over TocH. The peroxidation of LA in the presence of Cu(II)-H2O2 combination alone and with TocH, QR and IR were also investigated in aerated and incubated emulsions, where the latter three compounds exhibited antioxidant effects.