Dietary alpha-Tocopherol Decreases alpha-Tocotrienol but Not gamma-Tocotrienol Concentration in Rats. Ikeda S, Tohyama T, Yoshimura H, Hamamura K, Abe K, Yamashita K Department of Food and Nutrition, Sugiyama Jogakuen University, Chikusa-ku, Nagoya, Japan and. Eisai Co. Ltd., Bunkyo-ku, Tokyo, Japan. We previously showed that alpha- and gamma-tocotrienols accumulate in adipose tissue and skin but not in plasma or other tissues of rats fed a tocotrienol-rich fraction extracted from palm oil containing alpha-tocopherol and alpha- and gamma-tocotrienols. To clarify the nature of tocotrienol metabolism, we studied the distribution of alpha- or gamma-tocotrienol in rats fed alpha- or gamma-tocotrienol without alpha-tocopherol, and the effect of alpha-tocopherol on their distribution. Wistar rats (4-wk-old) were fed a diet with 50 mg alpha-tocotrienol/kg alone or with 50 mg alpha-tocopherol/kg in expt. 1, and a diet with 50 mg gamma-tocotrienol/kg alone or with 50 mg alpha-tocopherol/kg in expt. 2, for 8 wk. alpha-Tocotrienol was detected in various tissues and plasma of the rats fed alpha-tocotrienol alone, and the alpha-tocotrienol concentrations in those tissues and plasma decreased (P < 0.05) by the dietary alpha-tocopherol in the rats fed alpha-tocotrienol with alpha-tocopherol. However, gamma-tocotrienol preferentially accumulated in the adipose tissue and skin of the rats fed gamma-tocotrienol alone, and the dietary alpha-tocopherol failed either to decrease (P >/= 0.05) gamma-tocotrienol concentrations in the adipose tissue and skin or to increase (P >/= 0.05) in the urinary excretion of 2,7,8-trimethyl-2(2'-carboxymethyl)-6-hydroxycroman, a metabolite of gamma-tocotrienol, in the rats fed gamma-tocotrienol with alpha-tocopherol. These data suggest that alpha-tocopherol enhances the alpha-tocotrienol metabolism but not the gamma-tocotrienol metabolism in rats. J Nutr 2003 Feb;133(2):428-34 Nutrition & Cancer, 1999 Sorry we did not get better citation info Euro J Cancer Prevention, 12/04 Lipids, 5/98 Remember we are NOT Doctors and have NO medical training. This site is like an Encylopedia - there are many pages, many links on many topics. Support our work with any size DONATION - see left side of any page - for how to donate. You can help raise awareness of CAM.