Chemopreventive Effect of Dietary d-α-Tocopheryl Succinate Supplementation on Precancer Colon Aberrant Crypt Formation and Vitamin E Analogue Levels in Young and Old Rats

Abstract

: This study examined the effects of dietary d-α tocopheryl succinate (αTS) in female rats, 20 mo (OLD) or 2 mo (YNG) of age, on azoxymethane (AOM)-induced colonic aberrant crypt foci (ACF) and tissue distribution of d-α-tocopherol (-αT), d-γ-tocopherol (γT), and -αTS. Rats were fed a commercial rodent chow supplemented with or without 1 (YNG) or 2 (OLD) g -αTS/kg diet for 1 week prior to ip administration of AOM to induce colon ACF. The animals were sacrificed after 49 days of exposure. The results showed that OLD rats had significantly fewer ACF than YNG animals, and the percent body fat and serum triglycerides were significantly higher in the OLD group compared with the YNG. However, only OLD animals receiving -αTS had significantly reduced numbers of larger ACF and significantly higher levels of colonic -αT, γT, and -αTS. These data support previous studies demonstrating that dietary -αTS administration is protective against intestinal cancer. Also, this is the first study to show that -αTS accumulates in most tissues following dietary exposure. We hypothesize that increased colon accumulation of fat-soluble vitamin E compounds and subsequent chemoprevention may be related to greater percent body fat and serum triglycerides in OLD animals receiving dietary TS.