Evaluation of some oxidative stress markers in type II diabetes mellitus in Ile-Ife
This study investigated the levels of plasma fasting blood glucose, glycated heamoglobin (HbA1c), and oxidative stress enzyme markers: superoxide dismutase (SOD), catalase, glutathione-S-transferase (GST) in the erythrocyte of type II diabetic patients. This was with a view to knowing the levels of these enzymes in the patients and in healthy subjects. One hundred and fifteen respondents were involved in this study. They comprised sixty five diabetic subjects recruited from the Diabetes Clinic of the Obafemi Awolowo University Teaching Hospital Complex (OAUTHC), Ile-Ife, and fifty healthy controls who volunteered to be part of the study and were members of staff of Obafemi Awolowo University (OAU) and were age and sex matched with test subjects. Ethical approval was obtained from the Ethics and Research Committee of OAUTHC, Ile-Ife. All subjects read and signed the informed consent form. Seven milliliters of venous blood of the patients and controls were collected aseptically. Glycosylated hemoglobin was determined in whole blood using clover HbA1c kit while Plasma fasting blood glucose was determined using Randox kit. The erythrocyte was separated from the plasma by centrifugation at 4000 rpm and washed three times with 250 mM Tris HCl, pH 7.4. The erythrocytes were re-suspended in 1.0 ml of the same buffer and stored at 4°C. The washed erythrocyte was lysed using standard procedure. The hemolysate was centrifuged at 13500 rpm for 30 min. The supernatant was collected and used to assay for the antioxidant enzymes (catalase, superoxide dismutase and glutathione-S-transferase). Significant differences were found when erythrocyte superoxide dismutase, catalase and glutathione-S-transferase specific activities 53.22±2.44, 48.20±2.69, and 1.35±0.09 units/mg protein in diabetic patients were compared with healthy controls 62.54±2.68, 63.22±1.83 and 3.47±0.11 units/mg protein respectively (p< 0.05). When diabetic subjects were grouped into four groups based on the presence of microvascular complications, the specific activity of antioxidant enzymes; superoxide dismutase, glutathione-S-transferase and catalase in diabetic patients with no complications were 59.45±4.94, 51.07±3.59 and 1.52±0.14 units/mg protein. Diabetic patients with one complication had 50.08±4.32, 46.87±6.41 and 1.19±0.13 units/mg protein and diabetic patients with two complications had 46.85±3.66, 47.45±5.58 and 1.0±0.13 units/mg protein respectively. No significant difference was found between these groups (p>0.05). Also when diabetic patients were grouped based on glycemic control, the specific activity of antioxidant enzymes; superoxide dismutase, glutathione-S-transferase and catalase in diabetic patients with poor glycemic control were 73.79±3.01, 51.96±7.38 and 1, 42±0.18 units/mg protein. Patients with fair glycemic control had 45.67±3.07, 45.33±3.84 and 1.28±0.16 units/mg protein while patients with good glycemic control had 55.54±4.12, 52.62±5.29 and 1.39±0.13 units/mg protein respectively. No significant difference was found (p>0.05). This study concluded that the level of erythrocyte antioxidant enzymes activities of Diabetes mellitus patients in Ile-Ife was significantly low.