Mammalian lignans inhibit the growth of estrogen-independent human colon tumor cells.
OBJECTIVE
The mammalian lignans enterolactone (EL) and enterodiol (ED) derived from precursors in foods, particularly flaxseed, have been shown to reduce the mammary tumor growth due to their antiestrogenic properties. Our objective was to investigate whether lignans have growth inhibitory effects against colon tumor cells and whether these effects are mediated through their antiestrogenic activity.


METHODS
Four human colon tumor cell lines (LS174T, Caco-2, HCT-15, T-84) were incubated with various levels of EL, ED or 17 beta-estradiol for 8 to 10 days. Cell proliferation was measured by the BrdU method.


RESULTS
At 100 microM concentration, both lignans significantly reduced the proliferation of all cell lines. EL was more than twice as effective as ED at this concentration. The growth was not affected by the presence of 17 beta-estradiol implying that these cells are not estrogen-sensitive.


CONCLUSIONS
Lignans are growth inhibitors of colon tumor cells and they may act through mechanism(s) other than antiestrogenic activity.
Department of Nutritional Sciences, University of Toronto, Ont., Canada.
M K
MK
Sung
M
M
Lautens
L U
LU
Thompson
D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D002455:Cell Division / Q000187:drug effects*; D003110:Colonic Neoplasms / Q000473:pathology*; D004958:Estradiol / Q000494:pharmacology*; D004967:Estrogens / Q000494:pharmacology*; D006801:Humans; D007700:Kinetics; D017705:Lignans / Q000494:pharmacology*; D008322:Mammals; D014407:Tumor Cells, Cultured
D004967:Estrogens; D017705:Lignans; D004958:Estradiol; C029498:2,3-bis(3'-hydroxybenzyl)butane-1,4-diol; D015107:4-Butyrolactone; C029497:2,3-bis(3'-hydroxybenzyl)butyrolactone