Impact of glutathione and vitamin B‐6 in cirrhosis patients

Vitamin B‐6 and glutathione (GSH) are antioxidant nutrients, and inadequate vitamin B‐6 may indirectly limit glutathione synthesis and further affect the antioxidant capacities. Since liver cirrhosis is often associated with increased oxidative stress and decreased antioxidant capacities, we conducted a double‐blind randomized controlled trial to assess the antioxidative effect of vitamin B‐6, GSH, or vitamin B‐6/GSH combined supplementation in cirrhotic patients. We followed patients after the end of supplementation to evaluate the association of vitamin B‐6 and GSH with disease severity. In total, 61 liver cirrhosis 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, the condition of patient’s disease severity was followed until the end of the study. Neither vitamin B‐6 nor GSH supplementation had significant effects on indicators of oxidative stress and antioxidant capacities. The median follow‐up time was 984 d, and 21 patients were lost to follow‐up. High levels of GSH, a high GSH/oxidized GSH ratio, and high GSH‐St activity at baseline (Week 0) had a significant effect on low Child–Turcotte–Pugh scores at Week 0, the end of supplementation (Week 12), and the end of follow‐up in all patients after adjusting for potential confounders. Although the decreased GSH and its related enzyme activity were associated with the severity of liver cirrhosis, vitamin B‐6 and GSH supplementation had no significant effect on reducing oxidative stress and increasing antioxidant capacities.