Oxidative stress parameters as biomarkers of risk factor for diabetic foot among the patients with type 2 diabetes

The aim of this study was to determine whether plasma levels of carbonylated proteins, total antioxidant capacity (TAC) and reduced protein thiols could be suitable biomarkers of risk factors for diabetic foot. Individuals with type 2 diabetes with normal protective sensation (normal foot group) vs. loss of protective sensation and/or signs of peripheral arterial disease and/or foot deformities and/or history of ulcers and/or neuropathic fractures and/or amputation (diabetic foot group) were compared. The diabetic foot group showed higher carbonylated protein levels (P = 0.0457) and lower levels of TAC (P = 0.0148) and reduced protein thiols (P = 0.0088), compared with the normal foot group. In general, several other parameters of risk of diabetes complication (blood levels of glycated hemoglobin, glucose and cholesterol, duration of diabetes, body mass index and waist circumference) showed a tendency of higher values in the diabetic foot group. The results suggest that the plasma levels of carbonylated proteins, TAC and reduced protein thiols could furnish information about the risk of diabetic foot, considering that the changes in these biomarkers were associated with the loss of sensitivity and foot ulcerations.

Effectiveness of pranayama on the levels of serum protein thiols and glutathione in breast cancer patients undergoing radiation therapy: A randomized controlled trial.

The effect of Pranayama on the levels of protein thiols and glutathione was studied among breast cancer patients receiving radiation therapy. 160 patients were randomised into experimental and control group using block randomisation. The experimental group received fractionated radiation for five days a week and performed Pranayama (Nadishodhana, Brahmari and Sheethali) for 30 minutes twice daily for five days a week. The control group received only radiation. Blood samples were collected from both the groups at the end of six weeks of radiation therapy and analysed for the levels of serum protein thiols and glutathione. An independent sample ‘t’ test showed a significant difference in the level of serum protein thiols between the two groups (t = 4.43 p 0.001). A Mann- Whitney U test showed a significant difference (z = –3.07 p 0.002) in the level of glutathione as well. These Pranayama techniques improve the antioxidant status of breast cancer patients receiving radiation therapy.

Evaluation of oxidative protein damage in patients with hypercholesterolemia.

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.

Differential Effect of gamma-radiation-induced Heme Oxygenase-1 Activity in Female and Male C57BL/6 Mice

Ionizing radiation produces reactive oxygen species, which exert diverse biological effects on cells and animals. We investigated alterations of heme oxygenase (HO) and non-protein thiols (NPSH), which are known as two major anti-oxidant enzymes, in female and male C57BL/6 mice in the lung, liver, and brain after whole-body gamma-irradiation with 10 Gy (1-7 days) as well as in the lung after whole-thorax gamma-irradiation (WTI) with 12.5 Gy (1-26 weeks). Most significant alteration of HO activity was observed in the liver, which elevated 250% in males. NPSH level in female liver was increased on the 5th-7th days but decreased in males on the 3rd day. In the lung, the elevation of HO activity in both sexes and the pattern of NPSH change were similar to that of the liver. On the other hand, the increase of HO activity on the 16th week and the decrease of NPSH level on the 2nd week were observed only in male lung after WTI. This study shows that the liver is the most sensitive tissue to gamma-irradiation-induced alterations of HO activity in both female and male mice. In addition, there exists significant differential effect of gamma-irradiation on anti-oxidant system in female and male mice.