Sesamin (a compound from sesame oil) increases tocopherol levels in rats fed ad libitum

Six groups of rats were fed diets low, but adequate, in alpha-tocopherol but high in gamma-tocopherol. The six diets differed only in their contents (0, 0.25, 0.5, 1.0, 2.0, and 4.0 g/kg, respectively) of sesamin, a lignan from sesame oil. After four weeks of ad libitum feeding, the rats were sacrificed and the concentrations of alpha- and gamma-tocopherols were measured in the plasma, livers, and lungs. Sesamin-feeding increased gamma-tocopherol and gamma-/alpha-tocopherol ratios in the plasma (P < 0.05), liver (P < 0.001), and lungs (P < 0.001). The increase was non-significant for alpha-tocopherol. Thus, sesamin appears to spare gamma-tocopherol in rat plasma and tissues, and this effect persists in the presence of alpha-tocopherol, a known competitor to gamma-tocopherol. This suggests that the bioavailability of gamma-tocopherol is enhanced in phenol-containing diets as compared with purified diets.