Sesame seed and its lignans produce marked enhancement of vitamin E activity in rats fed a low alpha-tocopherol diet.

Three series of experiments demonstrated that sesame seed and its lignans cause significant elevation of alpha-tocopherol content in rats. In Experiment 1, 20% sesame seed (with a negligible amount of alpha-tocopherol) supplementing 10 (low), 50 (normal), or 250 (high) mg/kg alpha-tocopherol diets (protein and fat concentrations in diets were adjusted to 200 and 110 g/kg, respectively) all caused a significant increase of alpha-tocopherol in the blood and tissue of rats. In Experiment 2, groups of rats were fed five different diets: a vitamin E-free control diet, a low alpha-tocopherol diet, and three low alpha-tocopherol diets supplemented with 5, 10, and 15% sesame seed. Changes in lipid peroxides in liver, red blood cell hemolysis, and pyruvate kinase activity, as indices of vitamin E deficiency, were examined. These indices were high in the low alpha-tocopherol diet, whereas supplementation with even 5% sesame seed suppressed these indices completely and caused a significant increase of alpha-tocopherol content in the plasma and liver. In Experiment 3, two diets containing sesame lignan (sesaminol or sesamin) and low alpha-tocopherol were tested. Results in both of the sesame lignan-fed groups were comparable to those observed in the sesame seed-fed groups as shown in Experiment 2. These experiments indicate that sesame seed lignans enhance vitamin E activity in rats fed a low alpha-tocopherol diet and cause a marked increase in alpha-tocopherol concentration in the blood and tissue of rats fed an alpha-tocopherol-containing diet with sesame seed or its lignans.