Singlet oxygen effect on lipid oxidation in the presence and absence ofsynthetic/natural antioxidants, using sheep erythrocyte hemoglobin

Photooxidation of lipids is an undesirable chemical process in which essential fatty acids areconverted into peroxides with singlet oxygen (۱O۲), which causes oxidative spoilage of meatproducts [۱-۳]. Erythrocytes are used as a model for lipid oxidation because residual blood canenhance lipid oxidation upon hemolysis and release of hemoglobin [۳]. This study aims atinvestigation of ۱O۲ effect on lipid oxidation in erythrocyte model and oleic acid. In this study,hydroalcoholic extracts of Turmeric (Curcuma longa L.) and Cumin (Cuminum cyminum L.)were used as natural antioxidants. Butyl hydroxytoluene (BHT) was used as a syntheticantioxidant and sodium azide (NaN۳) was applied as a well-known singlet oxygen scavenger.The generation or inhibition of ۱O۲ and peroxide products in the sheep blood erythrocyte andoleic acid in the presence of Rose Bengal photosensitizer, light and various antioxidants wereobtained by ۱H NMR spectroscopy, UV-Vis spectroscopy, TBARS assay and iodometrictitration. The antioxidant results showed that NaN۳,turmeric, cumin, and BHT were able toprevent the photooxidation of lipids into peroxide products in sheep erythrocyte model, ۱۰۰%,۷۰.۹۳%, ۶۲.۲۶%, and ۵۱.۹۲%, respectively. Meanwhile, these inhibition values in thephotocatalytic conversion of oleic acid to peroxide products were obtained as ۱۰۰%, ۷۱.۱۰%,۴۶.۶۳% and ۲۴.۰۸%, respectively. These results declared that the two methods have a positivecorrelation for invistigation of lipids and fatty acids phootooxidation.

کلیدواژه ها:

Hemoglobin ، lipid oxidation ، singlet oxygen ، antioxidants