Chemoprotective Effects of Flaxseed Lignans Enterodiol and Enterolactone in Non-transformed Colonocytes

Previous epidemiological studies have shown that colon cancer incidence is correlated to diet and estrogen status. Phytoestrogens are molecules with similar structures to estrogen that occur naturally in plants. There is in vitro and in vivo evidence that phytoestrogens in the diet can inhibit carcinogenesis. The phytoestrogenic mammalian lignans enterolactone (EL) and enterodiol (ED) in flaxseed have been shown to be effective in decreasing tumor incidence in carcinogenic models, but there is little data regarding their effects in non-malignant cells. The following studies used a nontransformed cell line of young adult mouse colonocytes (YAMC) to determine the protective effects of ED and EL in chemoprevention. Our results demonstrate that low levels of EL (1μM) and ED (5μM) are effective at significantly reducing cell growth and increasing apoptosis. These treatments also regulated transcription via significant differences in gene levels related to apoptosis and cell cycle progression. The data collected demonstrate some of the physiological effects of EL and ED on the cellular and molecular level. These changes may contribute to the overall effect of prevention of colon cancer carcinogenesis seen with flaxseed consumption