Dynamic Thiol/Disulphide Homeostasis in Patients With Fibromyalgia

Changes in Dynamic Thiol/Disulfide Homeostasis, and Substance P, B-Endorphin and α-Tocopherol Concentrations in the Spinal Cord of Chronically Lame Dairy Cows

Initial lameness inflammation leads to chronic lameness and development of chronic pain due to the release of pro-inflammatory mediators such as reactive oxygen species (ROS), which are implicated in the transition from acute to chronic pain, and free radical scavengers countering thiol, substance P (SP), and β-endorphin (BE). The present study aimed to evaluate the dynamic thiol-disulfide homeostasis, α-tocopherol concentrations and SP and BE concentrations in the spinal cord of chronically lame dairy cows. Ten lame and 10 non-lame cows with a parity range of 2-6 were selected for the study. Lame cows had a history of up to 3 months of lameness. Spinal cord samples were obtained from the L2 to L4 lumbar vertebrae aspect of each animal. A thiol-disulfide homeostasis assay was performed using absorbance, and the α-tocopherol concentration was determined by HPLC. SP and BE concentrations were measured using ELISA kits. The results indicated that SP and BE were significantly higher in the spinal cord of lame cows. In contrast, disulfide levels and α-tocopherol concentrations were significantly lower in the spinal cord of lame cows. In conclusion, disulfide levels and α-tocopherol concentrations indicated a defective antioxidant response in cows with chronic lameness. The results of SP and BE concentrations suggested chronic pain and a defective endogenous analgesic response.

Thiol-disulfide homeostasis: an integrated approach with biochemical and clinical aspects

Dynamic thiol-disulfide homeostasis (TDH) is a new area has begun to attract more scrutiny. Dynamic TDH is reversal of thiol oxidation in proteins and represents the status of thiols (-SH) and disulfides (-S-S-). Organic compounds containing the sulfhydryl group is called thiol, composed of sulfur and hydrogen atoms. Disulfides are the most important class of dynamic, redox responsive covalent bonds build in between two thiol groups. For many years, thiol levels were analyzed by several methods. During last years, measurements of disulfide levels have been analyzed by a novel automated method, developed by Erel and Neselioglu. In this method, addition to thiol (termed as native thiol) levels, disulfide levels were also measured and sum of native thiol and disulfide levels were termed as total thiol. Therefore, TDH was begun to be understood in organism. In healthy humans, TDH is maintained within a certain range. Dysregulated dynamic TDH has been implicated several disorders with unknown etiology. A growing body of evidence has demonstrated that the thiol-disulfide homeostasis is involved in variety diseases, such as diabetes mellitus, hypertension, nonsmall cell lung cancer, familial Mediterranean fever (FMF), inflammatory bowel diseases, occupational diseases, gestational diabetes mellitus and preeclampsia. These results may elucidate some pathogenic mechanism or may be a predictor indicating diagnostic clue, prognostic marker or therapeutic sign. In conclusion, protection of the thiol-disulfide homeostasis is of great importance for the human being. Evidence achieved so far has proposed that thiol-disulfide homeostasis is an important issue needs to elucidate wholly.

Dynamic thiol and disulphide homoeostasis in fibromyalgia

INTRODUCTION

Thiol and disulphide levels are biomarkers that provide useful information about oxidative stress and antioxidant capacity, showing a different homoeostasis in inflammatory and proliferative diseases. We aimed to clarify the possible aetiology of this disease by using thiol and disulphide levels in patients with fibromyalgia, the basis of which has not yet been clearly elucidated.

MATERIAL AND METHODS

A total of 156 individuals: 86 patients with fibromyalgia and 70 age-matched controls were included in this prospective non-randomised case-control study. Demographic characteristics including smoking status, body mass index (BMI), the duration of complaints, and pain levels were carefully recorded. Dynamic thiol-disulphide homoeostasis in blood samples was determined by an automatic-spectrophotometric method. The Mann-Whitney U and Student's t-test were used to determine the differences between the groups.

RESULTS

Sex, BMI, and smoking status were similar between the groups (p = 0.62, p = 0.09, and p = 0.64, respectively). While native thiol levels were found to be high in patients with fibromyalgia (p = 0.018), disulphide levels and the rates of disulphide/native thiol and disulphide/total thiol were significantly low (p = 0.049, p = 0.007, and p = 0.007, respectively). Correlation analysis showed no significant relationship between thiol-disulphide levels and duration of complaints or pain level.

CONCLUSIONS

Thiol-disulphide balance in fibromyalgia was found to be similar to benign proliferative diseases, suggesting that the underlying mechanism is more likely to be of proliferative pattern rather than inflammatory. Additionally, fibromyalgia is not directly associated with increase in oxidative stress. The molecular mechanisms need to be elucidated.

Assessment of Serum Ischemia-modified albumin, Prolidase and Thiol-Disulphide Levels in Subjects With Breast Cancer

Background: Oxidative damage is of great importance for patients with breast cancer. Thus, studies were performed to identify the relationship between breast cancer and oxidative stress biomarkers.

Objectives: In this study, our aim was to find out the oxidative and antioxidant status, serum thiol-disulphide levels in subjects with breast cancer.

Methods: This study was conducted between March and June 2018 with 82 control subjects (aged between 32-67 years) and 127 breast cancer patients (aged between 27-66 years) (p=0.058) in Selcuk University Faculty of Medicine, Konya, Turkey. Serum myeloperoxidase (MPO), catalase, prolidase were analyzed with kinetic spectrophotometric and thiol-disulphide, ischemia-modified albumin (IMA), ceruloplasmin were detected by colorimetric methods.

Results: Serum levels of catalase [199.3 (16.4-489.9) vs 81.6 (18.2-322.9) (kU/L)], MPO [124±28 vs 101±31 U/L], disulphide [25 (11-61) vs 18 (2-41) µmol/L], IMA [0.66 (0.31-3.30) vs 0.62 (0.19-1.31) absorbance unit (ABSU)] and prolidase levels [2217±538 vs 1456±401 U/L] were higher in patients than control subjects (For all p<0.001 except for IMA p=0.031). Native thiol [342±60 vs 391±52 µmol/L] and total thiol levels [396±56 vs 430±52 µmol/L] were lower in patients compared with the control group (For all p<0.001).

Conclusions: Levels of serum thiol/disulphide and prolidase might be reliable indicators for determining oxidative status in certain patient populations.