Oxidative stress induced protein carbonylation and lipid peroxydation in experimental animals

Abstract

Background and Aim: Oxidative stress is an imbalance of pro-oxidant/antioxidant homeostasis which occurs in organisms because of various exogenous and endogenous factors. One of those is big amounts of metals such as aluminium or iron which we used to induce oxidative stress. The main aim was to measure the level of this process in mice liver and brain. Materials and Methods: Oxidative stress level was measured by detecting protein carbonylation and lipid peroxydation using protein carbonyl groups and malondialdehyde (MDA) as biomarkers. First, mice liver or brain homogenate was prepared. Protein level in homogenate which should be less than 10 mg/ml was measured using Warburg-Christian method. The homogenate was treated in the following ways: in the first group of samples AlCl3 was added, in the second group – FeCl3 to induce oxidative stress. Remaining samples were made as control groups: control and control incubated. For detecting protein carbonyl groups 2,4-dinitrophenylhydrazine was added to homogenate, which leaded to formation of stable dinitrophenyl hydrazone product. This then was detected using a method of spectrophotometric quantification of the acid hydrazones at 370 nm. For detecting MDA, the reaction with thiobarbituric acid was made and MDA concentration was evaluated using spectophotometric method at 540 nm. Results: MDA level in mice liver samples with AlCl3 was the same as in control incubated and it was 2 times higher than in control (p<0.05). Highest level of MDA was found in samples treated with FeCl3 which was 33 times higher comparing with control (p<0.05). Similar results were found while comparing MDA level in mice brain samples. In those with FeCl3 MDA level was 24 times higher than in control (p<0.05). There were no statistically significant results comparing protein carbonyl level in mice liver and brain. Conclusions: Results have shown that aluminium ions have no higher effect on homo