Dietary sesame lignans decrease lipid peroxidation in rats fed docosahexaenoic acid.

We have previously reported that dietary sesamin and sesaminol, major lignans of sesame seed, elevate the alpha-tocopherol concentration and decrease the thiobarbituric acid reactive substance (TBARS) concentration in the plasma and liver of rats. In this study, the effects of dietary sesamin and sesaminol on the lipid peroxidation in the plasma and tissues of rats fed docosahexaenoic acid (DHA, 22:6 n-3) were examined. Male Wistar rats (4-wk-old) were divided into the following six experimental groups: control group, fed a basal diet: sesamin group, fed a diet with sesamin (2 g/kg); sesaminol group, fed a diet with sesaminol (2 g/kg); DHA group, fed a diet containing DHA (5 g/kg); DHA + sesamin group, fed a diet containing DHA with sesamin; and DHA + sesaminol group, fed a diet containing DHA with sesaminol. Each diet contained either 0.01 or 0.05 g D-alpha-tocopherol/kg, and the rats were fed the respective experimental diet for 5 wk. The dietary DHA elevated the TBARS concentration and also increased the red blood-cell hemolysis induced by the dialuric acid. The dietary sesamin and sesaminol lowered the TBARS concentrations and decreased the red blood hemolysis. The dietary sesamin and sesaminol elevated the alpha-tocopherol concentrations in the plasma, liver, and brain of the rats fed a diet with or without DHA. These results suggest that dietary sesame lignans decrease lipid peroxidation as a result of elevating the alpha-tocopherol concentration in rats fed DHA.