Plasma Total Thiols and Total Thiol/Albumin Ratio in Patients Suffering from Depression

Introduction: Increased oxidative stress has been reported in patients who suffer from depressive disorders. Albumin acts as a target for plasma protein oxidation during oxidative stress. The plasma thiols act as significant in vivo antioxidants. Major SH-groups are found on the surface of albumin molecules. Since depressive disorders are related to oxidative stress. Only a few studies have been done that correlate plasma total thiols with major depressive disorder. The authors intended to draw a relationship between oxidative stress, thiols and major depressive disorder by estimating total plasma thiols and calculating the ratio of thiol/albumin. The study may throw some light in understanding whether the use of anti-oxidant supplements to counter oxidative stress in depressed patients. Aim: The aims was to estimate plasma thiols, albumin and obtain a plasma thiol/albumin ratio in people suffering from depression and compare the levels with the control group. Materials and Methods: This case control study was conducted in Kasturba Medical College, Manipal. Plasma thiols were estimated using Ellman’s method. Plasma albumin levels were estimated using Bromo-cresol green dye binding method. Mann- Whitney U test was used for analysing the data for total thiols and thiol/albumin ratio. A p-value <0.05 was considered significant. Results: The study group was made up of 43 (22 males and 21 females) patients and the control group was made up of 40 (18 males and 22 females) healthy controls. Plasma thiol levels and the plasma total thiol/albumin ratio were significantly elevated (p-value=0.00036) in cases (depression) as compared to that of the controls. Conclusion: Plasma total thiols can be used as an early marker for understanding the risk for major depressive disorders and also be used as a prognostic indicator in the follow up of patients suffering from major depressive disorder who are under treatment.

Ischemia-modified albumin (IMA) and dynamic thiol-disulfide homeostasis in patients with postherpetic neuralgia

Background Ischemia-modified albumin (IMA) is an isotype of albumin that increases under oxidative stress, and plasma thiols are main defense mechanisms against oxidative stress. The objective of this study was to investigate thiol-disulfide homeostasis and serum IMA levels in postherpetic neuralgia (PHN) patients. Methods A total of 29 PHN patients and 30 healthy controls were included in the study. Serum total and native thiol concentrations and serum disulfide concentration were measured using the method described by Erel and Neselioglu. The albumin cobalt binding test was used to measure serum IMA levels. Results Serum IMA levels were 1.21 ± 0.58 AU and 0.75 ± 0.09 AU in the PHN and control groups, respectively (p < 0.001). Serum total thiol concentrations were found to be 421.62 ± 90.28 μmol/L and 598.36 ± 73.63 μmol/L in the PHN and control groups, respectively (p < 0.001). Serum native thiol concentrations were found to be 365.75 ± 92.07 μmol/L and 531.90 ± 72.9 μmol/L in the PHN and control groups, respectively (p < 0.001). Serum disulfide concentrations were found to be 33.23 ± 5.33 μmol/L and 27.93 ± 7.81 μmol/L in the PHN and control groups, respectively (p = 0.003). The native thiol/total thiol ratio was significantly lower, and the disulfide/total thiol and disulfide/native thiol ratios were significantly higher in the PHN group compared to the controls. Conclusions IMA levels are high and dynamic thiol/disulfide homeostasis is disrupted in PHN patients.

N-Acetylcysteine in Handgrip Exercise: Plasma Thiols and Adverse Reactions

N-acetylcysteine (NAC) is a thiol donor with antioxidant properties that has potential use as an ergogenic aid. However, NAC is associated with adverse reactions that limit its use in humans.Purpose:The authors evaluated NAC efficacy as a thiol donor before handgrip exercise, measuring changes in serum cysteine and glutathione status and recording adverse reactions in adult subjects across a range of doses.Methods:Healthy individuals ingested NAC capsules (9 ± 2 or 18 ± 4 mg/kg) or solution (0, 35, 70, or 140 mg/kg). Venous blood samples were collected and subjects answered a questionnaire about adverse reactions.Results:Low doses of NAC (capsules) did not affect plasma cysteine or glutathione or cause adverse reactions. Adverse reactions to NAC solution were predominantly mild and gastrointestinal (GI). Intensity of GI reactions to 140 mg/kg NAC was significantly higher than placebo (in a.u., 0.67 ± 0.16 vs. 0.07 ± 0.04; p < .05). Plasma cysteine concentration increased with NAC dose from 9.3 ± 0.7 μM (placebo) to 65.3 ± 6.7 μM (140 mg/kg); however, there was no difference (p > .05) in plasma cysteine for 70 mg/kg vs. 140 mg/kg. Similar increases were observed for the ratio of cysteine to total cysteine, which was directly related to handgrip exercise performance. Plasma glutathione was elevated and oxidized glutathione diminished (p < .05) with NAC 140 mg/kg vs. placebo.Conclusion:NAC effects on plasma thiols are maximized by oral administration of 70 mg/kg, a dose that does not cause significant adverse reactions.