Antioxidant effect of Turmeric and saffron on the oxidation of hepatocytes, LDL and non-enzymatic glycation of hemoglobin

ABSTRACT

Free radicals especially reactive oxygen species are known as important factors, which by damage to biomolecules like DNA, proteins, membrane, enzymes and lipids produce pathological disorders. Lipid peroxidation of LDL particles and membranes of hepatocytes may be involved in the process of atherosclerosis and liver dysfunction respectively. Also non-enzymatic glycosylation of proteins is involved in the complication of diabetic patients. Due to oxidant/antioxidant imbalance, destructive effects of free radicals may appear over time. Therefore, an investigation about the antioxidant effects of some popular spices including curcuma longa and crocus sativus zeylanicum on three oxidative systems [LDL oxidation, oxidation of cell membranes of liver hepatocytes and non-enzymatic gly cation of hemoglobin] was done. Total extracts of the above-mentioned plants were obtained. Hepatocyte membranes of rat liver were selected as a sensitive system to peroxidation and in the vicinity of tert-butyl hydroperoxide [TBH] [1.5mM] as an oxidant agent, the amount of malondialdehyde [MDA] was measured in the presence and absence of plant extract as a lipid peroxidation marker. Also released Alanine Aspartate Aminofransterase [AST] was measured as a cell membrane damage marker due to peroxidation. Glycosylation changes of hemoglobin and LDL oxidation were evaluated in the presence and absence of extracts. The results showed that curcuma at a concentration of 10microg/ml inhibited MDA formation by 28.8% and AST released by 25.53%. Curcuma at a concentration of Ijug/ml inhibited hemoglobin glycosylation by 25.85%. It has a dose dependent effect at all concentration. Also the plant showed the most antioxidant effect on LDL oxidation at the concentration of microg/ml. Crocus at applied doses has no definite inhibitory effect on MDA and AST formation, [results not shown] but crocus has a minimal inhibitory effect on hemoglobin glycosylation and LDL oxidation. This study showed that curcuma at applied doses has an inhibitory effect on all three oxidative systems in mentioned diseases and probably would be important for prevention of atherosclerosis, diabetes and liver dysfunction. Crocus at the used concentration had not any effect on these oxidative systems