Bilal Aytaç

Serum glutathione peroxidase, xanthine oxidase, and superoxide dismutase activities and malondialdehyde levels in patients with Parkinson's disease.

Parkinson’s disease (PD) is a progressive neurodegenerative disorder characterized by loss of dopaminergic (DA) neurons in the substantia nigra pars compacta (SNpc). Oxidative stress has been hypothesized to play a major role in the development of PD in various studies. This study assessed to investigate oxidative and anti-oxidative status in PD patients. We evaluated oxidant/antioxidant status by measuring serum malondialdehyde (MDA) levels, xanthine oxidase (XO) activities, and activities of antioxidant enzymes, namely, glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD). The study included 29 patients with PD and 32 healthy subjects as controls. Comparison of oxidative parameters in the patient and control groups revealed significantly higher GSH-Px and XO activities in the patient group. Serum MDA and SOD activities in PD patients were not significantly different from the controls. MDA was negatively correlated with duration of the PD and positively with age of onset. There was a negative correlation between SOD and Hoehn and Yahr (H&Y) stage. According to these results, we suggest that oxidative stress may contribute to the development of PD.

Hepatic oxidant/antioxidant status in cholesterol‐fed rabbits: Effects of garlic extract

Aim:  The investigation of oxidant/antioxidant status in hepatic tissues from cholesterol‐fed rabbits and the establishment of possible protective effects of aqueous garlic extract on cholesterol‐induced hepatic steatosis.

Decreased antioxidant status in migraine patients with brain white matter hyperintensities.

Migraine patients have an increased risk to develop deep white matter hyperintensities (WMH) than the general population. Oxidative stress is believed to play a role in the pathogenesis of migraine. The present study was undertaken to assess oxidant/antioxidant balance of migraineurs with and without WMH. We hypothesized that increased oxidative stress and decreased antioxidant response may play a role in the pathophysiology of WMH in migraineurs. The study included 32 patients in the migraine group and 17 age- and sex-matched healthy subjects without headache in the control group. The migraine group comprised 18 with WMH and 14 without WMH. We evaluated oxidative status with malondialdehyde (MDA) and to determine the activities of antioxidant enzymes: superoxide dismutase, glutathione peroxidase and catalase (CAT) in serum of migraineurs and controls. Comparison of the patient and control groups for oxidative parameters revealed significantly lower level of CAT and higher level of MDA in the patient group. Two-way comparison for CAT and MDA of the migraine with and without WMH and the controls revealed that CAT serum level significantly decreased in migraine patients with WMH than migraine patients without WMH and controls. In this preliminary study, we demonstrated that the levels of CAT were decreased in migraine patients with WMH compared to patients without WMH and controls. These findings suggest that decreased antioxidant response may play a role in the pathophysiology of WMH in migraineurs. Besides, our results encourage the new treatment and follow-up options based on antioxidant systems.

Serum oxidant and antioxidant status of patients with chronic tension-type headache: possible effects of medical treatment

Tension-type headache (TTH) is one of the most common and costly primary types of headache in clinical practice, with an unknown etiology. This study assessed to investigate oxidative and antioxidative status in patients with chronic tension-type headache (CTTH), and to evaluate possible effect of medical treatment. The study included 41 CTTH patients and 19 age- and sex-matched healthy subjects without headache as controls. The CTTH group comprised 20 patients receiving treatment and 21 untreated patients. We evaluated oxidant/antioxidant status by measuring serum malondialdehyde (MDA) levels and activities of antioxidant enzymes, namely glutathione peroxidase (GSH-Px) and catalase (CAT). Comparison of oxidative parameters in the patient and control groups revealed significantly lower CAT activities and higher MDA level and GSH-Px activities in the patient group. In the CTTH group, serum CAT activities were found to be significantly decreased in patient groups, while serum MDA levels and GSH-Px activities were found to be higher in the untreated CTTH patients. These findings suggest that oxidative stress is increased in the patients with CTTH, and medical treatment abolishes the stress in part. It has been concluded that antioxidant support might be helpful for the patients with CTTH to prevent oxidant stress and peroxidation damages further.

Oxidative and nitrosative stress in serum of patients with Parkinson’s disease

Parkinson’s disease (PD) is one of the common neurodegenerative disorders. Oxidative stress is considered as a contributing factor to the development of PD. The present study aims to investigate serum oxidative stress status in patients with PD. Oxidative stress was assessed by measuring serum nitric oxide levels, lipid hydroperoxide concentrations, and nitric oxide synthase activity. In addition, total serum antioxidant capacity (TAC) was evaluated using the serum 2,2-Diphenyl-1-picryl-hydrazyl (DPPH) free-radical scavenging method in 32 patient with Parkinson’s disease and 32 control subjects. Our results indicated that serum nitric oxide and lipid hydroperoxide levels were significantly lower in patients with PD than controls. Moreover, nitric oxide levels were found to be negatively correlated with Unified Parkinson’s Disease Rating Scale (UPDRS). However, no statistical difference was observed in total serum antioxidant capacities and nitric oxide synthase activities between patients and controls. The present study indicates that although antioxidant capacity was not changed, lipid hydroperoxide (LPO) level was found decreased. This might show pre-oxidative process in these patients. In addition, decreased nitric oxide (NO) level and negative correlation observed between NO level and disease rating scale implicated a role for NO in the disease process.