The coming of age of vitamin E

Abstract

In man's nature there are several periods which they call ages; infant, child, adolescent. youth, man, elderly man, old man; an infant is up to seven years, the cut,ting of teeth; a boy up to the beginning of puberty, fourteen years; an adolescent, up to the appearance of down on the chin at 21 years; youth, to the end of development. at 28 years; man, up to 49 years; elderlv, up to 56 years, and after this, an old man." Hippocrates By Hippocrates' standards, vitamin E (tu-t.ocophero1 J has achieved "old man" status since it. was originally discovered nearly seven decades ago (1 ). However, in the field of human clinical nutrition, vitamin E is an infant who has only begun "cutting its t.eeth" over the past decade; previously it was considered by most as a "vitamin looking for a disease'' ( 2 ) . Originallv described as a factor that prevented fetal resorption in the laboratory rat (l), the nutritional role of vitamin E expanded when Evans and Burr (3) reported in 1928 a paralysis in t,he suckling offspring of vitamin E-deficient mother rats. This new neurological role for vit,amin E was further substantiated by reports of "nutritional encephalomalacia" in the chick (4) and "nutrit,ional muscular dystrophy" in guinea pigs and rats (5) fed vitamin E-deficient diets. In 1936, Evans et, al. (6) isolated from wheat. germ an alcohol having the biological activity of vitamin E and proposed the term "tocopherol," derived from theGreek "tokos" (offspring) and "pherein" (to bear). Finally, in the 1950's, the antioxidant properties of vitamin E became evident (7,8), and it,s interrelationship t.o the trace mineral, selenium, a component, of the antioxidant enzyme glutathione peroxidase (9, lo), also was discovered. Thus, by 1960 it was well established that vitamin E functioned as a lipid-soluble antioxidant in animals and was essential for the development and maintenance of reproduction and neurological function. Although vitamin E is currently being studied in relation to a number of human diseases and metabolic processes, one area of recent interest and investigation in human nutrition has been the identification of vitamin E malabsorption and deficiency during pathological disorders causing nialabsorption of dietary fat. To this end, in this issue of Hepatology, Muiioz and coworkers ( 11 ) have carefully examined intestinal absorption of vitamin E in pat.ients with primary biliary cirrhosis (PHC) and vitamin E

d-alpha-tocopherol inhibits collagen alpha 1(I) gene expression in cultured human fibroblasts. Modulation of constitutive collagen gene expression by lipid peroxidation.

“…Presumably, by inhibiting lipid peroxidation and thus the formation of reactive aldehydes, such as MDA and 4-HNE, d-a-tocopherol inhibits adduct formation. Presently, no other biologically important function has been ascribed to d-atocopherol distinct from its role as an antioxidant (46). d-aTocopherol may alter the expression or function of putative trans-acting factors or modify the transport ofthese DNA binding proteins into the nucleus.…”

Assessment of hepatic vitamin E status in adult patients with liver disease

“…[3][4][5] Although vitamin E plasma Toc/TL ratio would predict hepatic vitamin E status. therapy is used to prevent neurological injury caused byTo test these hypotheses, we measured a-tocopherol concenvitamin E deficiency in patients with serious liver distrations in liver biopsy specimens, RBCs, and plasma and eases, 1,6,7 it is controversial whether vitamin E therapy clinisimultaneously determined concentrations of the three major lipid fractions in sera and liver tissues.Abbreviations: RBC, red blood cell; FL, fatty liver; CPH, chronic persistent hepatitis; …”

“…Because vitamin E-deficient red blood cells (RBCs) hospitalized for biliary tract surgery, 13 with chronic persisare fragile (as a result of hydrogen peroxidation), 7 RBCs are tent hepatitis, 9 with chronic aggressive hepatitis, 10 with considered a peripheral target tissue for vitamin E. RBC aacute hepatitis, 10 with cirrhosis, 7 with both cirrhosis and tocopherol has been assumed to be a reliable indicator of hepatic cell carcinoma, and 8 with fatty liver). Hepatic, erythvitamin E status in biomembranes.…”

“…The ratios of a-TL ratio) has also been used as a clinical index of plasma tocopherol to total lipid concentrations (Toc/TL ratios) in vitamin E status. 7,[10][11][12] However, to our knowledge, no pubplasma and liver were calculated. In both comparison patients lished reports compare hepatic a-tocopherol concentrations and patients with chronic persistent hepatitis and fatty liver, with RBC a-tocopherol concentrations or plasma Toc/TL rahepatic a-tocopherol concentrations were strongly correlated tios in adult patients with liver disease.…”

“…To test these hypotheses, we measured a-tocopherol concenvitamin E deficiency in patients with serious liver distrations in liver biopsy specimens, RBCs, and plasma and eases, 1,6,7 it is controversial whether vitamin E therapy clinisimultaneously determined concentrations of the three major lipid fractions in sera and liver tissues.…”