Headache in children and dynamic thiol/disulfide balance evaluation with a new method

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.

Is ischemia associated with the formation of White matter lesions in migraine?

OBJECTIVE

White matter lesions (WMLs) are more common in migraine patients than in the normal population. Ischemia/hypoxia and oxidative stress are considered to play a role in WMLs formation. This study aimed to investigate ischemia-modified albumin (IMA), ferroxidase and thiol/disulfide homeostasis in migraineurs with and without WMLs.

PATIENTS AND METHODS

Sixty-two migraineurs with WML, 59 migraineurs without WML and 61 controls were included in the study. All participants underwent brain MRI. WMLs was evaluated according to the Fazekas scale. IMA, ferroxidase, total thiol, native thiol and disulfide measurements were carried out in all participants.

RESULTS

The IMA levels were higher in the migraine groups compared to the control group (p < 0.001) and in the WML group compared to non-WML (p < 0.001). The total and native thiol levels were higher in the non-WML group compared to the control and WML groups (p < 0.001 for both). The disulfide levels were similar between the control and non-WML groups, but they were significantly lower in the WML group compared to the control and non-WML groups. There was no significant difference between the groups in terms of the ferroxidase levels (p = 0.092). The thiol/disulfide, IMA and ferroxidase levels were not significantly correlated with the frequency and duration of attacks, severity of pain and disability due to migraine.

CONCLUSION

Increased serum IMA levels in migraineurs point to the role of ischemia/hypoxia, and increased total thiol and decreased disulfide levels indicate an oxidant/antioxidant imbalance in migraine. Ischemia/hypoxia may play a role in WMLs formation in migraine.

Relationship between thiol-disulphide homeostasis and visual evoked potentials in patients with multiple sclerosis

PURPOSE

To examine the thiol-disulphide homeostasis during an optic neuritis episode in patients with multiple sclerosis and the relationship between this homeostasis and P100 wave latency.

MATERIALS AND METHOD

Visual evoked potential reviews of multiple sclerosis patients who presented with an optic neuritis episode were conducted and P100 latencies were measured. Peripheral blood samples were collected from all patients. Native thiol and total thiol concentrations were measured with the automated method that was recently developed. Their amount of disulphide bonds, disulphide/native thiol, disulphide/total thiol and native thiol/total thiol ratios were calculated. The relationship between P100 latency and thiol-disulphide homeostasis was investigated.

RESULTS

A significant positive correlation was determined between the disulphide/native thiol ratio and both mean P100 latency and maximum P100 latency (p = 0.021, r = 0.136; p = 0.030, r = 0.177, respectively).

DISCUSSION

As the balance of the plasma dominated by antioxidants moves towards the oxidant side, in other words as a higher rate of thiol is oxidised from the thiol pool, P100 latency is extended. N-acetylcysteine and alpha lipoic acid as well as thiol supplements can improve the thiol-disulphide balance, reinforce antioxidant defence and it can help in slowing down the demyelinating damage.

Vitamin D supplementation does not improve plasma thiol/disulfide homeostasis

BACKGROUND

Impairment of thiol/disulfide homeostasis, as well as vitamin D deficiency, are responsible for the pathophysiology of many acute and chronic diseases. This study examined the relationship between thiol/disulfide homeostasis and vitamin D level and supplementation.

METHODS

A total of 203 healthy children were included in the study. The participants were divided into four groups according to 25-hydroxyvitamin D (25(OH)D) level: group 1, severe deficiency (<10 ng/mL); group 2, deficiency (10-20 ng/mL); group 3, insufficiency (20-30 ng/mL); and group 4, sufficiency (≥30 ng/mL). Furthermore, group 5 was defined as being on vitamin D supplementation.

RESULT

Native thiol was lower in group 5 than in groups 2-4 (P = 0.003). Disulfide was higher in groups 1, 4 and 5 than groups 2 and 3 (P < 0.001). Total thiol was lower in group 5 than in group 4 (P = 0.032). The ratio of native thiol/total thiol was lower in groups 1 and 5 compared with groups 2 and 3, and in group 4 compared with group 3 (P < 0.001). The ratios of disulfide/total thiol and disulfide/native thiol were higher in groups 1 and 5 than in groups 2 and 3 whereas only the disulfide/total thiol ratio was higher in group 4 than in group 3 (P < 0.001).

CONCLUSIONS

In healthy children, severe deficiency of vitamin D causes impairment of thiol/disulfide homeostasis and increases protein oxidation, which cannot be reversed by external vitamin D supplementation.