Antioxidant Activity, Phenolic Content, and Peroxide Value of Essential Oil and Extracts of Some Medicinal and Aromatic Plants Used as Condiments and Herbal Teas in Turkey

Mehmet Musa Özcan,Özcan Erel,Emine Etöz Herken 한국식품영양과학회 2009 Journal of medicinal food Vol.12 No.1

The antioxidant activity, total peroxide values, and total phenol contents of several medicinal and aromatic plant essential oil and extracts from Turkey were examined. Total phenolic contents were determined using a spectrophotometric technique and calculated as gallic acid equivalents. Total antioxidant activity of essential oil and extracts varied from 0.6853 to 1.3113 and 0.3189 to 0.6119 μmol of Trolox equivalents/g, respectively. The total phenolic content of essential oil ranged from 0.0871 to 0.5919 mg of gallic acid/g dry weight. However, the total phenolic contents of extracts were found to be higher compared with those of essential oils. The amount of total peroxide values of oils varied from 7.31 (pickling herb) to 58.23 (bitter fennel flower) μmol of H2O2/g. As a result, it is shown that medicinal plant derivatives such as extract and essential oils can be useful as a potential source of total phenol, peroxide, and antioxidant capacity for protection of processed foods.

Thiol/Disulfide Homeostasis in Bipolar and Unipolar Depression

Gamze Erzin,Güven Özkaya,Canan Topçuoğlu,Rabia Nazik Yüksel,Özcan Erel,Emine Feyza Yurt,Erol Göka,Sinan Gülöksüz 대한정신약물학회 2020 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.18 No.3

Objective: Bipolar disorder and unipolar depressive disorder are complex phenotypes. There appear to be phenotypical, mechanistic, and therapeutic differences between bipolar depression (BD) and unipolar depression (UD). There is a need for understanding the underlying biological variation between these clinical entities. The role of oxidative processes underlying bipolar disorder and depression has been demonstrated. Thiol-disulfide homeostasis (TDH) is a recent oxidative stress marker. In this study, we aimed to inspect patients with bipolar depression and unipolar depression in terms of thiol-disulfide balance and to compare them with healthy controls. Methods: Patients admitted to the outpatient clinic of Ankara Numune Training and Research Hospital and diagnosed either as a depressive episode with bipolar disorder (n = 37) or unipolar depression (n = 24) according to DSM-5 criteria, along with healthy controls (HC) (n = 50), were included in the study. Native thiol, total thiol, and disulfide levels were compared across the groups. Results: In comparison to HC, both BD and UD groups had higher disulfide levels, disulfide/native thiol ratio, and disulfide/total thiol ratio. No significant differences between BD and UD were detected in terms of disulfide level, disulfide/ native thiol ratio, and disulfide/total thiol ratio. Conclusion: Increased levels of disulfide, native thiol, and disulfide/total thiol ratios compared to healthy controls in both UD and BD groups may be indicative of the presence of oxidative damage in these two clinical conditions. To clarify the role of oxidative stress in the pathophysiology of depressive disorders and investigate TDH, longitudinal studies in patients with medication-free UD and BD are required.

Oxidative Stress and Inflammatory Biomarkers in People with Methamphetamine Use Disorder

Çetin Turan,Güliz Şenormancı,Salim Neşelioğlu,Yasemin Budak,Özcan Erel,Ömer Şenormancı 대한정신약물학회 2023 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.21 No.3

Objective: This study aimed to investigate the blood serum levels of biomarkers specifying oxidative stress status and systemic inflammation between people using methamphetamine (METH) and the control group (CG). Serum thiol/disulfide balance and ischemia-modified albumin levels were studied to determine oxidative stress, and serum interleukin-6 (IL-6) levels and complete blood count (CBC) were to assess inflammation. Methods: Fifty patients with METH use disorder (MUD) and 36 CG participants were included in the study. Two tubes of venous blood samples were taken to measure oxidative stress, serum thiol/disulfide balance, ischemia-modified albumin, and IL-6 levels between groups. The correlation of parameters measuring oxidative stress and inflammation between groups with sociodemographic data was investigated. Results: In this study, serum total thiol, free thiol levels, disulfide/native thiol percentage ratios, and serum ischemia-modified albumin levels of the patients were statistically significantly higher than the healthy controls. No difference was observed between the groups in serum disulfide levels and serum IL-6 levels. Considering the regression analysis, only the duration of substance use was a statistically significant factor in explaining serum IL-6 levels. The parameters showing inflammation in the CBC were significantly higher in the patients than in the CG. Conclusion: CBC can be used to evaluate systemic inflammation in patients with MUD. Parameters measuring thiol/disulfide homeostasis and ischemia-modified albumin can be, also, used to assess oxidative stress.

Thiol-disulphide Homeostasis in Patients with Schizophrenia: The Potential Biomarkers of Oxidative Stress in Acute Exacerbation of Schizophrenia

Şükrü Alperen Korkmaz,Semra Ulusoy Kaymak,Salim Neşelioğlu,Özcan Erel 대한정신약물학회 2024 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.22 No.1

Objective: Recent evidence suggests that oxidative stress contributes to the pathophysiology of schizophrenia. This study aimed to compare thiol-disulphide homeostasis in acute and stable phases of schizophrenia for the first time. Methods: Among the patients with schizophrenia, 61 in the acute-phase and 61 in the stable phase of their illness were enrolled in the study. Native thiol (NT), total thiol (TT), disulphide (SS), disulphide/native thiol, disulphide/total thiol, and native thiol/total thiol for thiol-disulphide homeostasis were compared between the groups. The Brief Psychiatric Rating Scale (BPRS), Scale for the Assessment of Positive/Negative Symptoms (SAPS/SANS), Clinical Global Impression- Severity Scale (CGI-S), Barnes Akathisia Rating Scale, and Simpson-Angus Scale were used to assess symptoms. Results: After controlling for age, sex, body mass index, and smoking status there were significant differences in NT, TT, SS/NT, SS/TT, and NT/TT, but not SS. Thiol/disulphide homeostasis has shifted in favour of the oxidative side in patients with acute-phase compared to that in stable schizophrenia. BPRS, SAPS, and CGI-S scores were significantly correlated with all six thiol-disulphide parameters, but not SANS, when controlling for age and sex. Significant receiver operating characteristic (ROC) curves were obtained for all thiol-disulphide homeostasis parameters. Discriminant analysis was found to be statistically significant in discriminating between groups. Conclusion: These results show that oxidative status increases thiol-disulphide homeostasis in patients with acute-phase schizophrenia compared to those with stable schizophrenia. These findings suggest that thiol-disulphide parameters can be used as biomarkers for the acute exacerbation of schizophrenia.

Thiol Disulfide Homeostasis in Schizophrenic Patients Using Atypical Antipsychotic Drugs

Halef Okan Dogan,Etem Erdal Ersan,Hüseyin Aydin,Serpil Erdoğan,Serpil Erşan,Murat Alişik,Sevtap Bakir,Özcan Erel,Derya Koç 대한정신약물학회 2018 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.16 No.1

Objective: Schizophrenia is a severe, debilitating mental disorder characterized by behavioral abnormalities. Although several studies have investigated the role of oxidative stress and the effects of antipsychotic drugs on oxidative markers in schizophrenia, adequate information is not available on these issues. The aim of this study is to determine the changes in oxidative status and thiol disulfide homeostasis in schizophrenic patients using atypical antipsychotic drugs. Methods: Thirteen schizophrenic patients using atypical antipsychotic drugs and 30 healthy controls were included this study. The concentrations of total oxidant status (TOS), total antioxidant status (TAS), native thiol, total thiol, and disulfide levels were determined in the study population. Results: The TAS (p=0.001), total thiol, and native thiol levels (p<0.001) were higher in the patients compared to the controls, whereas the TOS and disulfide levels were lower in the patients than in the controls (p<0.001). Conclusion: These results may suggest that atypical antipsychotic drugs have a useful therapeutic effect by reducing oxidative stress via the inhibition of the formation of disulfide bonds. The study population number was one of the limitations of this study. Therefore, further studies are needed to establish the association between thiol disulfide homeostasis in schizophrenic patients using atypical antipsychotic drugs