Omer Akyol

Elevated serum nitric oxide and superoxide dismutase in euthymic bipolar patients: impact of past episodes.

Nitric oxide (NO) has been implicated to play a role in the pathogenesis of many neuropsychiatric disorders. NO level was found high in acute manic inpatients. In this study, we aimed to assess NO level and activity of the antioxidant enzyme, superoxide dismutase (SOD), in euthymic bipolar patients. Twenty-seven patients with bipolar disorder (BD) in euthymic phase, and 20 healthy volunteers were included in this study. A semi-structured form was used to note social, demographic and clinical parameters of the patients. NO level and SOD activity were studied in the serum samples obtained from the patients and controls. The mean serum NO level in BD was significantly higher than in controls. Mean serum SOD activity was found to be elevated in patients with BD compared to controls. Total number of the manic episodes correlated with NO levels, but not with SOD activity. In conclusion, the number of manic episodes is positively associated with NO levels. NO and SOD appear to have a pathophysiological role in BD, especially in Type I euthymic phase, and may be considered an available trait marker for BD.

Current concepts in the pathophysiology of fibromyalgia: the potential role of oxidative stress and nitric oxide

Fibromyalgia (FM) is a common chronic pain syndrome with an unknown etiology. Recent years added new information to our understanding of FM pathophysiology. Researches on genetics, biogenic amines, neurotransmitters, hypothalamic-pituitary-adrenal axis hormones, oxidative stress, and mechanisms of pain modulation, central sensitization, and autonomic functions in FM revealed various abnormalities indicating that multiple factors and mechanisms are involved in the pathogenesis of FM. Oxidative stress and nitric oxide may play an important role in FM pathophysiology, however it is still not clear whether oxidative stress abnormalities documented in FM are the cause or the effect. This should encourage further researches evaluating the potential role of oxidative stress and nitric oxide in the pathophysiology of FM and the efficacy of antioxidant treatments (omega-3 and -6 fatty acids, vitamins and others) in double blind and placebo controlled trials. These future researches will enhance our understanding of the complex pathophysiology of this disorder.

Increased Levels of Nitric Oxide, Cortisol and Adrenomedullin in Patients with Chronic Schizophrenia

Objective: To investigate the levels of serum cortisol, dehydroepiandrosterone sulfate (DHEA-S), nitric oxide (NO) and adrenomedullin (AM) in schizophrenic patients. Subjects and Methods: Sixty-six male patients with chronic schizophrenia and 28 normal male subjects participated in this study. The duration of disease was 145 ± 120 (mean ± SD) months. Serum levels of cortisol and DHEA-S were measured by electrochemiluminescence; plasma nitrite levels as an index of NO were measured with the Griess reaction, while plasma AM concentration was measured by using high-performance liquid chromatography. Results: Patients (12.48 ± 3.2 µg/dl), as compared to controls (10.31 ± 3.1 µg/dl), had higher levels of baseline cortisol (p < 0.05). DHEA-S levels were lower in patients though this did not reach statistical significance (302 ± 156 µg/dl compared to control, 322 ± 96 µg/dl, p > 0.05). The mean levels of plasma AM and NO in the schizophrenic group (44.33 ± 5.07 pmol/l and 36.27 ± 17.6 µmol/l) were significantly higher than the levels in the control group (14.56 ± 4.03 pmol/l and 32.54 ± 7.14 µmol/l; p < 0.001, p < 0.03, respectively). There was a positive association between duration of disease and cortisol/DHEA-S ratio and cortisol level. Conclusion: The data show that schizophrenia is associated with abnormal levels of cortisol, DHEA-S, NO and AM.

Antioxidant properties of propofol and erythropoietin after closed head injury in rats.

Reactive oxygen species play a role during brain injury due to closed head trauma. Enzymatic or nonenzymatic antioxidants may protect brain tissue against oxidative damage. The present study was performed to assess the changes of endogenous indices of oxidative stress in serum from rats subjected to head trauma and whether treatment with propofol and/or erythropoietin (EPO) modifies the levels of endogenous indices of oxidative stress. For these purposes, female Wistar Albino rats were divided into five groups: non-traumatic sham group, trauma performed control, trauma with propofol (i.p.), trauma with EPO (i.p.) and trauma with propofol and EPO performed study groups. At the end of the experimental procedure, blood was taken by cardiac puncture to determine superoxide dismutase (SOD) and xanthine oxidase (XO) activities as well as malondialdehyde (MDA) and nitric oxide (NO) levels in serum. Serum MDA level of control traumatic brain injury (TBI) group was significantly higher than sham operation group (p<0.012). Serum MDA levels in propofol, EPO and propofol+EPO groups were found to be decreased in comparison with control group (p<0.039, p<0.030 and p<0.018, respectively). Serum NO level was found to be increased in TBI group, but difference was not statistically significant when compared to sham-operated group (p=0.092). Propofol, EPO and propofol+EPO administration efficiently reduced serum NO levels to reach sham-operated group (p<0.002, p<0.001 and p<0.015, respectively). These results suggested that acute administration of both propofol and EPO altered the indices of oxidative stress similarly against brain injury due to trauma.

The protective effects of omega − 3 fatty acids against MK-801-induced neurotoxicity in prefrontal cortex of rat

The aims of this study are to investigate the contribution effect of oxidative stress in MK-801-induced experimental psychosis model, and to show that prevention of oxidative stress may improve prognosis. Because oxidative damage has been suggested in the neuropathophysiology of schizophrenia, the possible protecting agents against lipid peroxidation are potential target for the studies in this field. For this purpose, Wistar Albino rats were divided into three groups: the first group was used as control, MK-801 was given to the rats in the second group and MK-801+omega-3 essential fatty acids (EFA) was given to the third group. MK-801 was given intraperitoneally at the dose of 0.5mg/(kgday) once a day for 5 days in experimental psychosis group. In the second group, 0.8g/(kgday), omega-3 FA (eicosapentaenoic acid, 18%, docosahexaenoic acid, 12%) was given to the rats while exposed MK-801. In control group, saline was given intraperitoneally at the same time. After 7 days, rats were killed by decapitation. Prefrontal brain area was removed for histological and biochemical analyses. As a result, malondialdehyde (MDA), as an indicator of lipid peroxidation, protein carbonyl (PC), as an indicator of protein oxidation, nitric oxide (NO) levels and superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) activities as antioxidant enzymes, and xanthine oxidase (XO) and adenosine deaminase (AD) activities as an indicator of DNA oxidation was found to be increased significantly in prefrontal cortex (PFC) of MK-801 group (P<0.0001) compared to control group. In omega-3 FA treated rats, prefrontal tissue MDA, PC and NO levels as well as SOD, GSH-Px, XO, and AD enzyme activities were significantly decreased when compared to MK-801 groups (P<0.0001) whereas catalase (CAT) enzyme activity was not changed. Moreover, in the light of microscopic examination of MK-801 groups, a great number of apoptotic cells were observed. omega-3 FA supplementation decreased the apoptotic cell count in PFC. The results of this study revealed that oxidative stress and apoptotic changes in PFC may play an important role in the pathogenesis of MK-801-induced neuronal toxicity. This experimental study also provides some evidences for the protective effects of omega-3 FA on MK-801-induced changes in PFC of rats.

The potential usage of caffeic acid phenethyl ester (CAPE) against chemotherapy‐induced and radiotherapy‐induced toxicity

Protection of the patients against the side effects of chemotherapy and radiotherapy regimens has attracted increasing interest of clinicians and practitioners. Caffeic acid phenethyl ester (CAPE), which is extracted from the propolis of honeybee hives as an active component, specifically inhibits nuclear factor κB at micromolar concentrations and show ability to stop 5‐lipoxygenase‐catalysed oxygenation of linoleic acid and arachidonic acid. CAPE has antiinflammatory, antiproliferative, antioxidant, cytostatic, antiviral, antibacterial, antifungal and antineoplastic properties. The purpose of this review is to summarize in vivo and in vitro usage of CAPE to prevent the chemotherapy‐induced and radiotherapy‐induced damages and side effects in experimental animals and to develop a new approach for the potential usage of CAPE in clinical trial as a protective agent during chemotherapy and radiotherapy regimens. Copyright

Propofol and erythropoietin antioxidant properties in rat brain injured tissue

So far, several treatment modalities have been attempted to brain protection in cases such as brain trauma, stroke or brain hemorrhage. However, a treatment method that the effect begins immediately and definitely helpful has not been discovered yet. In this study, we aimed to compare the effects of propofol and erythropoietin (Epo) on brain injury caused by oxidative stress and antioxidant properties of these agents after closed head injury (CHI) in rats. For this study, female Wistar Albino rats were divided into five groups: non-traumatic control group, trauma performed group CHI, trauma with propofol (100 mg/kg) intraperitoneally (i.p.), trauma with Epo (5000 U/kg) i.p. and trauma with propofol and Epo performed study groups. Twenty-four hours after CHI, rats were sacrificed and the brains were removed. Superoxide dismutase (SOD), catalase (CAT), xanthine oxidase (XO), nitric oxide (NO), and malondialdehyde (MDA) levels were measured in brain tissue. MDA and NO levels were decreased significantly in Groups Epo, Propofol and Epo+Propofol than Group CHI (p<0.01). XO activity was significantly lower in Group Epo than Group CHI (p<0.05). Epo and propofol decreased oxidative stress by decreasing MDA and NO level in brain tissue after CHI. However, combination of Epo and propofol has no significant beneficial advantage than Epo or propofol alone.

In Vivo and In Vitro Antıneoplastic Actions of Caffeic Acid Phenethyl Ester (CAPE): Therapeutic Perspectives

Cancer prevention and treatment strategies have attracted increasing interest. Caffeic acid phenethyl ester (CAPE), an active component of propolis extract, specifically inhibits NF-κB at μM concentrations and shows ability to stop 5-lipoxygenase-catalyzed oxygenation of linoleic acid and arachidonic acid. Previous studies have demonstrated that CAPE exhibits antioxidant, antiinflammatory, antiproliferative, cytostatic, antiviral, antibacterial, antifungal, and, most improtantly, antineoplastic properties. The primary goal of the present review is to summarize and critically evaluate the current knowledge regarding the anticancer effect of CAPE in different cancer types.

Effect of long-term therapy with sodium valproate on nail and serum trace element status in epileptic children

Antiepileptic drugs could cause changes in the trace element status of the body. Valproic acid (VPA) is a very effective anticonvulsant agent widely used in the management of various forms of epilepsy. Nail trace element content is a reliable index of trace element nutritional status of the body. To determine whether some of the side effects of antiepileptic drugs could be the result of zinc (Zn) depletion within tissues, Zn concentrations as well as copper (Cu) concentrations in nail and serum in 59 children having various types of epilepsy receiving valproate and 31 controls were assessed. Although serum Zn level in epileptic patients was found to be decreased, there was no difference in nail samples when compared to controls. There was a statistically significant increase in nail Cu level in epileptic patients when compared to controls. On the other hand, serum Cu levels were not different between the groups. Although none of our patients showed any symptoms of Cu elevation and Zn depletion, we should pay attention to potential body trace element changes in patients with epilepsy under VPA treatment. In conclusion, our results indicate that serum trace metal homeostasis might be affected by VPA therapy, but not by the convulsive disorder itself.

The protective effect of erdosteine on short-term global brain ischemia/reperfusion injury in rats.

Experimental studies have demonstrated that free radicals play a major role on neuronal injury during ischemia/reperfusion (I/R) in rats. Erdosteine is a thioderivative endowed with mucokinetic, mucolytic and free-radical-scavenging properties. The aim of the present study was to investigate the effect of erdosteine treatment against short-term global brain ischemia/reperfusion injury in rats. The study was carried out on Wistar rats divided into four groups. (i) Control group, (ii) ischemia/reperfusion group, (iii) ischemia/reperfusion+erdosteine group, and (iv) erdosteine group. Superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities as well as thiobarbituric acid reactive substances (TBARSs) and nitric oxide (NO) levels were analysed in erythrocyte and plasma of rats. Plasma NO levels were significantly higher in the ischemia/reperfusion group than the other groups. The activities of SOD and GSH-Px were decreased, while TBARS levels increased in the ischemia/reperfusion group compared to other groups in both plasma and erythrocyte. The erythrocyte CAT activity was higher in erdosteine group and there was a statistically significant increase, when compared with the erdosteine plus ischemia/reperfusion group. By treating the rats with erdosteine, the depletion of endogenous antioxidant enzymes (SOD, CAT, GSH-Px) and increase of TBARS and NO levels were prevented. This study, therefore, suggests that erdosteine reduces parameters of oxidative stress is well supported by the data.