Effects of vitamin E treatment in cholestatic children

Vitamin E and neurodegeneration

Alpha-tocopherol (vitamin E) is a plant-derived antioxidant that is essential for human health. Studies with humans and with animal models of vitamin E deficiency established the critical roles of the vitamin in protecting the central nervous system, and especially the cerebellum, from oxidative damage and motor coordination deficits. We review here the established roles of vitamin E in protecting cerebellar functions, as well as emerging data demonstrating the critical roles of alpha-tocopherol in preserving learning, memory and emotive responses. We also discuss the importance of vitamin E adequacy in seemingly unrelated neurological disorders.

Standard treatment of alpha-tocopherol in Alagille patients with severe cholestasis is insufficient

Alpha-tocopherol (alpha-T) is the most effective lipid-soluble antioxidant present in cells. We investigated the efficacy of alpha-T supplements for preventing lipid peroxidation in patients with Alagille syndrome, according to the severity of cholestasis. Patients were assigned to two groups on the basis of plasma bilirubin concentration (group I, bilirubin <100 microM; group II, bilirubin >100 microM). alpha-T concentrations were determined in plasma, in isolated lipoproteins, and in red blood cell membranes. In both groups of patients, alpha-T concentrations in plasma were similar to those in control subjects, but the distribution of alpha-T in lipoproteins was affected by the abnormal lipoprotein pattern in these patients. The efficacy of alpha-T was estimated by determining the amount of hydroperoxide produced from phosphatidylcholine and phosphatidylethanolamine (PE) molecular species owing to oxidative stress induced by lipoxygenase treatment. The concentrations of phosphatidylcholine molecular species and its corresponding hydroperoxides were significantly higher in both groups of patients. In group I, alpha-T and PE molecular species concentrations were similar to those in control subjects, but PE hydroperoxide concentrations were higher than those in the control subjects. In group II, alpha-T concentration was significantly lower and the concentrations of some PE molecular species and all PE hydroperoxides were lower than those in the control subjects. In conclusion, erythrocyte membrane alpha-T concentration was significantly lower only in patients with severe jaundice, despite alpha-T supplementation, raising the question as to whether the usual treatment was appropriate in this group.

Fatty acid content in lymphocytes from children with syndromic paucity of interlobular bile ducts, Alagille syndrome

Fatty acid (FA) concentrations were studied in lymphocytes isolated from children with syndromic paucity of interlobular bile ducts (PILBD), Alagille syndrome. The aim of this study was to assess whether the specific FA changes previously observed in fibroblast cultures from such patients were also present in other tissues. Lymphocyte FA, obtained both from controls and patients were studied under two experimental conditions, either after separation of the mononuclear cells or after 48 hours of culture. Freshly isolated lymphocytes from patients presented few FA changes compared to the controls. However, when patient lymphocytes were placed in culture medium for 48 hours, FA changes were amplified compared to those observed in controls; the decrease in the sum of saturated and n-6 polyunsaturated FA of total lipids was significant only in patients, and the n-3 FA of phospholipids was strikingly increased in patients (p < or = 0.001), compared to controls. These results are related to those previously observed in fibroblast cultures and suggest that placing cells in culture could reveal a pre-existing cellular abnormality in patients with PILBD.