Glutathione and Related Antioxidant Capacities But Not Vitamin B-6 Had Significant Association with Severity of Liver Dysfunction in Liver Cirrhotic Patients

Abstract

Abstract Objectives Liver cirrhosis is often associated with increased oxidative stress and decreased antioxidant capacities. Vitamin B-6 and glutathione (GSH) are antioxidant nutrients. Inadequate vitamin B-6 status may indirectly limit GSH synthesis and further affect the antioxidant capacities. The purpose of this study was to assess whether individual or the combination of vitamin B-6 and GSH supplementation had effects on antioxidant capacities and clinical outcomes in patients with liver cirrhosis. Methods This was a double-blind randomized clinical trial and a follow-up study. 61 liver cirrhotic patients were randomly assigned to placebo, vitamin B-6 (50 mg pyridoxine/d), GSH (500 mg/d) or B-6 + GSH groups for 12 weeks. After the end of supplementation, 61 patients were followed until the end of the study. Baseline and 12 weeks of fasting blood samples were drawn to measure levels of plasma GSH, oxidized GSH (GSSG), trolox equivalent antioxidant capacity (TEAC), activities of glutathione S-transferase (GSH-St), glutathione peroxidase (GSH-Px), glutathione reductase (GSH-Rd), superoxide dismutase (SOD) and catalase. The severity of liver dysfunction (Child-Turcotte-Pugh score) was evaluated at baseline, 12 weeks after baseline, and the end of the follow-up time. Results The median follow-up time was 984 d, 21 patients were lost of follow-up during follow-up period. After 12 weeks of supplementation, neither vitamin B-6 nor GSH supplementation had effects on indicators of oxidative stress and antioxidant capacities. However, high levels of GSH, GSH/GSSG ratio, and GSH-St activity at baseline (week 0) but not at week 12 had significant effect on low Child-Turcotte-Pugh scores at week 0, week12 and the end of follow-up in all patients after adjusting for potential confounders. Conclusions Although GSH supplementation had no significant effect on reducing oxidative stress and increase antioxidant capacities, the decreased glutathione and its related enzyme activity should be considered by clinicians in the treatment of liver cirrhotic patients. Funding Sources This study was funded by a grant from the Ministry of Science and Technology, Taiwan (MOST 104–2320-B-040–009-MY3) and Taichung Veterans General Hospital, Taiwan (TCVGH-1084601C).