An Investigation of Oxidative Stress and Thiol/Disulphide Homeostasis in Graves' Disease

Changes in biomarkers of the redox status in whole blood and red blood cell lysates in canine hypothyroidism

Hypothyroidism is the most commonly diagnosed endocrine disease in dogs. The objective of this study was to evaluate the changes in the redox status in canine hypothyroidism using whole blood (WB) and red blood cell (RBCs) lysates. For this purpose, a panel of five antioxidants and five oxidants biomarkers was measured in WB and RBCs lysates of 30 dogs with hypothyroidism, 26 dogs with non-thyroidal illnesses and 15 healthy dogs. The antioxidants measured were cupric reducing antioxidant capacity (CUPRAC), ferric reducing ability of plasma (FRAP), Trolox equivalent antioxidant capacity (TEAC), thiol and paraoxonase type-1 (PON-1). Oxidants measured include the total oxidant status (TOS), peroxide-activity (POX-Act), reactive oxygen-derived metabolites (d-ROMs), advanced oxidation protein products (AOPP) and thiobarbituric acid reactive substances (TBARS). WB showed a significant decrease of the antioxidants CUPRAC, TEAC and thiol, and also an increase in TBARS and a decrease in AOPP in dogs with hypothyroidism compared to healthy dogs. Meanwhile, RBCs lysates showed a significant increase in FRAP and PON-1 in dogs with hypothyroidism. The changes in the redox biomarkers in this study show that WB in canine hypothyroidism had a higher number of changes in biomarkers of the redox status than RBCs lysates, making it a promising sample type for the evaluation of the redox status in this disease. In addition, WB is easier and simpler to process than RBCs lysates and unlike serum, it does not have any hemolysis interference.

Melatonin-Attenuated Oxidative Stress in High-Risk Pregnant Women Receiving Enoxaparin and Aspirin

Objective

In pregnancy, reducing inflammation and oxidative stress is important. Administration of melatonin during pregnancy can improve reproductive performance by improving the placental antioxidant system and inflammatory response. This investigation was carried out to evaluate the beneficial impact of melatonin on the oxidative stress state among high-risk pregnant women receiving enoxaparin and aspirin.

Methods

In this double-blind, placebo-controlled trial, 40 pregnant women, aged 15-45 years at 6 weeks of pregnancy, were randomly selected and divided into intervention and control groups. The control group received prophylaxis enoxaparin and aspirin once daily between 6 and 16 weeks of pregnancy. The intervention group was taken enoxaparin and aspirin for 9 weeks and melatonin once daily from the sixth week of pregnancy to delivery time. Blood samples were taken to measure some oxidative stress biomarkers including total antioxidant capacity (TAC), malondialdehyde (MDA), total thiol (T-SH), protein carbonyl (PCO), and nitric oxide (NO). The level of high-sensitivity C-reactive protein (hs-CRP) was also determined.

Results

TAC and T-SH levels increased significantly in the intervention group in comparison with the control group. Melatonin administration compared to the control group led to a significantly decreased level of NO and an insignificant hs-CRP level.

Conclusion

Melatonin supplementation in high-risk pregnancy had favorable effects on TAC, T-SH, NO, and hs-CRP levels, improved antioxidant activity, and reduced inflammation. More studies are needed in different pregnancy conditions along with the measurement of different biomarkers.

Correlation of Metabolic Syndrome with Redox Homeostasis Biomarkers: Evidence from High-Fat Diet Model in Wistar Rats

Metabolic Syndrome (MetS) is an extremely complex disease. A non-balanced diet such as high-fat diet (HFD) induces metabolic dysfunction that could modify redox homeostasis. We here aimed at exploring redox homeostasis in male Wistar rats, following 8 weeks of HFD, correlating the eventual modification of selected biomarkers that could be associated with the clinical manifestations of MetS. Therefore, we selected parameters relative to both the glucose tolerance and lipid altered metabolism, but also oxidative pattern. We assessed some biomarkers of oxidative stress i.e., thiols balance, lipid peroxidation and antioxidant barriers, via the use of specific biochemical assays, individuating eventual cross correlation with parameters relative to MetS through a Principal Component Analysis (PCA). The present study shows that 8 weeks of HFD induce MetS in rats, altering glucose and lipid homeostasis and increasing visceral adipose tissue, but also impairing the physiological antioxidant responses that could not counteract the oxidative stress condition. Crucially, cross-correlation analysis suggested that the assessment of specific oxidative stress parameters reported here can provide information comparable to the more widely acquired biomarkers of Mets such as glucose tolerance. Lastly, hepatic steatosis in association with the oxidative stress condition was also highlighted by histological analysis. This research will elucidate the fundamental impact of these oxidative stress parameters on MetS induced in the HFD rat model, tracing paths for developing prevention approaches.

A New Biomarker in The Distinction Between Stable Coronary Artery Disease and Acute Coronary Syndrome:Thiols

Backraund; Thiols are important elements for oxidation reactions and under oxidative stress. The aim of this study was to determine thiole levels, an antioxidative marker in CAD patients with stable and acute coronary syndrome. Methods; 210 of the patients included in the study were diagnosed with acute coronary syndrome (ACS), 205 consisted of patients with stable angina pectoris (SAP). Thiol groups levels and thiol/disulphide homeostasis was measured by spectrophotometrically. Results: Native thiol and total thiol levels, disulfide/natural thiol and disulfide/total thiol ratios were decreased in the ACS groups compared to the SAP groups Conclusions: Thiol levels and thiol / disulfide ratios can be used as markers to evaluate acute coronary syndrome.

Proptosis is associated with thiol-disulfide in patients with Graves' ophthalmopathy

Objective

Graves' ophthalmopathy (GO) is a vision-threatening finding observed in approximately half of Graves' disease patients. The pathophysiology of GO is unclear, and one of the suspected factors is oxidative stress. In our study, we compared the relationship between proptosis and SH-SS in patients diagnosed with GO.

Methods

In this prospective study, 40 recently diagnosed Graves' disease patients with proptosis, 40 recently diagnosed Graves' disease patients without GO and 30 healthy individuals with similar demographic characteristics were included. Serum thiol-disulfide (SH-SS) measurements were performed. Eye examinations were performed by a single ophthalmologist to check for the presence of GO, and proptosis values were recorded with a Hertel exophthalmometer.

Results

Total SH values were lower in the group with proptosis than in the other groups (p < 0.05). Total and native SH values were lower in patients without proptosis than in the control group (p < 0.05). Total SH, native SH and SS levels were independently associated with proptosis (p < 0.05). According to this analysis, it was found that increasing SS and decreasing total and native SH levels increased the probability of proptosis by 24.4%, 32.7% and 32.4%, respectively.

Conclusion

A decrease in SH, which is a natural antioxidant that protects the body against oxidative stress, and an increase in SS are important signs of oxidative damage. Proptosis and SH-SS are closely related in GO. This may help us detect GO and proptosis in Graves' patients. It can also assist in developing new options for preventing and treating GO.

Total thiol can contribute to differentiating prostate cancer from BPH: Prostate Thiol Index as a new player

To assess the distinctiveness of serum native thiol (NT), total thiol (TT) and disulfide (SS) levels in PCa patients, we created a new parameter, prostate thiol index (PTI) [tPSA (TTxPVxAge) ^-1/2 ]. We determined the performance of the PTI on PCa diagnosis. A total of 107 male patients (PCa:65; BPH:42) who were separated according to their Gleason scores, ISUP grades and EAU risk groups and 20 healthy subjects were included. The performances of the tests were determined. The PCa and BPH groups had lower NT and TT levels and higher SS levels than the control group. PCa patients had higher PTI, tPSA, fPSA, PSAD levels, lower fPSA%, PV and PSA-AV levels than BPH patients. TT, PTI, tPSA, fPSA, fPSA%, PSA-AV, PSAD and PV had significant diagnostic performances. PTI had the highest AUC value and accuracy, PSA-AV had the highest specificity, and fPSA had the lowest sensitivity. The performance of the PTI was the best in distinguishing PCa from BPH. PTI, tPSA and PSAD positively and PSA-AV negatively correlated with ISUP grades and EAU groups. TT can contribute to the discrimination of PCa from BPH and PTI may decrease unnecessary biopsies in clinical practice.

Thiol/disulfide homeostasis impaired in patients with primary Sjögren's syndrome

Background

Primary Sjögren's syndrome (pSS) is a disease associated with the overexpression of proinflammatory cytokines, and oxidative stress is one of the factors responsible for its etiopathogenesis. This study aimed to investigate the thiol/disulphide homeostasis in pSS patients.

Methods

The study included 68 pSS patients and 69 healthy controls. Thiol/disulphide homeostasis (total thiol, native thiol, and disulphide levels) was measured using the automatic spectrophotometric method developed by Erel and Neselioglu, and the results of the 2 groups were compared.

Results

The gender and age distributions of the pSS and control groups were similar (P = 0.988 and P = 0.065). Total thiol and native thiol levels were lower in the pSS group than in the control group (470.08 ± 33.65 µmol/L vs. 528.21 ± 44.99 µmol/L, P < 0.001, and 439.14 ± 30.67 µmol/L vs. 497.56 ± 46.70 µmol/L, P < 0.001, respectively). There were no differences in disulphide levels between groups [17.00 (range 0.70-217.0) µmol/L vs. 14.95 (range 2.10-40.10) µmol/L, P = 0.195].

Conclusions

It was concluded that the thiol/disulphide balance shifted towards disulphide in patients with pSS.

Oxidative stress as a key feature of autoimmune thyroiditis: an update

INTRODUCTION

Oxidative stress has been proposed as one of the factors concurring in the pathophysiology of autoimmune thyroid diseases. Reactive oxygen species are the main expression of oxidative stress in biological systems, and their production can overcome antioxidant defenses ultimately leading to cell damage, apoptosis, and death. The present review was aimed at describing the state of the art of the relationships between oxidative stress and autoimmune thyroiditis. The most used biomarkers of oxidative stress and their correlation with thyroid function are reported.

EVIDENCE ACQUISITION

We conducted a search of the literature in the English language starting from 2000, using the following search terms: "Hashimoto thyroiditis," "autoimmune thyroiditis," "hypothyroidism," "hyperthyroidism," "oxidative stress," "oxidants," "antioxidant," "advanced glycation end products." Both clinical studies and animal models were evaluated.

EVIDENCE SYNTHESIS

Data form clinical studies clearly indicate that the balance between oxidants and antioxidants is shifted towards the oxidative side in patients with autoimmune thyroiditis, suggesting that oxidative stress may be a key event in the pathophysiology of the disease, irrespective of thyroid function. Studies in animal models, such as the NOD.H2h4 mouse, confirm that thyroidal accumulation of ROS plays a role in the initiation and progression of autoimmune thyroiditis.

CONCLUSIONS

Oxidant/antioxidant imbalance represent a key feature of thyroid autoimmunity. Oxidative stress parameters could be used as biochemical markers of chronic inflammation, to better predict the disease evolution along its natural history. Dietary habits and antioxidant supplements may provide protection from autoimmunity, opening new perspectives in the development of more tailored therapies.