Evaluation of cellular and circulatory antioxidant- and glutathioneassociated enzymes in patients with acute coronary syndrome

Abstract

Destabilization of atherosclerotic plaque in the coronary artery is the result of Oxidative Stress (OS) that damage the myocardial tissues in Acute Coronary Syndrome (ACS). This study investigated the activities of certain circulatory and cellular antioxidant- and glutathione-associated enzymes in ACS patients in comparison to a control group. Standard assay methods were followed to evaluate the activities of Superoxide Dismutase (SOD), catalase, Glutathione-S-transferase (GST), Glutathione Peroxidase (GPx) and Glutathione Reductase (GR). For data analysis, the categorical variables were measured in percentages, and continuous variables were expressed in means and standard deviations. The ACS patients had significantly higher activities of circulatory SOD, GPx and GST compared to the controls (4.36 ± 2.28 U/mL, 49.20 ± 14.12 U/mL and 5.02 ± 3.03 U/mL versus 2.87 ± 1.28 U/mL, 21.53 ± 10.80 U/mL and 3.03 ± 1.99 U/mL, respectively) but their catalase and GR activities were significantly lower. While the catalase activities in the erythrocyte and leukocyte lysates were similar in both groups, the leukocyte SOD activity was significantly lower in patients. A significant positive correlation was found between the GR and catalase activities in patients. The circulatory enzymes SOD, GPx and GST are over-expressed in controlling excessive OS, while the reduced activities of catalase and GR could be the consequence, suggesting therapeutic potentials of using enzymes in reducing OS-mediated endothelial injury in ACS patients.

Keywords: Acute coronary syndrome (ACS), Superoxide dismutase (SOD), Catalase, Glutathione-associated enzymes, Oxidative stress (OS)