Evaluation of Oxidative Protein Damage in Patients with Hypercholesterolemia
Hypercholesterolemia, Protein thiols, Reactive oxygen species, LDL cholesterol.
Keywords:
Hypercholesterolemia, Protein thiols, Reactive oxygen species, LDL cholesterolAbstract
Background: Hypercholesterolemia is highly prevalent in Indian population and known to contribute towards increased mortality and morbidity related to cardiovascular and cerebrovascular disorders. An antioxidant defence system consisting of enzymatic and non-enzymatic compounds prevents oxidative damage of lipoproteins in the plasma. When the activity of this system decreases or the reactive oxygen species (ROS) production increases, oxidative stress may occur.The –SH group (reduced thiols) bound to proteins (protein thiols) play a major role in maintaining the antioxidant status of the body. Protein thiols acts as major extracellular antioxidant, they react with reactive oxygen species (ROS) and prevent LDL oxidation. Such thiols have been studied in different disease conditions and found to be decreased compared to healthy control samples. Reduced concentration of protein thiol found to have positive correlation with increase serum level of LDL cholesterol. In the current work we have measured the level of serum protein thiols along with lipid profile in newly diagnosed hyperlipidemic patients and we tried to establish the relationship between serum protein thiols and lipid profile parameters. Objective: To study the level of protein thiols as a potent antioxidant in patient with an increased level of cholesterol. Materials: After obtaining prior consent, blood (2 ml) was taken using aseptic precautions from hypercholesterolemic patients (n = 25) and age and sex matched healthy controls (n = 25) in plain vacutainers. Serum protein thiols were measured by spectrophotometric method using 5, 5′ dithio-bis (2-nitrobenzoic acid) (DTNB). Triglyceride levels were measured by Cobas 6000 using a GPO Trinder method and HDL levels by Cobas 6000 using a direct- homogenous method. LDL levels were calculated. Results: There was a significant decrease in the levels of protein thiols p< 0.001 in hypercholesterolemic patients when compared to healthy controls and a corresponding correlatable increase in the level of LDL cholesterol due to oxidative damage. Conclusion: There may be a role for protein thiols as a biomarker in pathophysiology of cardiovascular and cerebrovascular disorders in patients with hyperlipidemia.
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