Flaxseed and its mammalian lignan precursor cause a lengthening or cessation of estrous cycling in rats.
Flaxseed and its mammalian lignan precursor secoisolariciresinol diglycoside (SDG) have been shown to be mammary cancer-protective in rats. Thus, the antiestrogenic effects of flaxseed and SDG were compared with tamoxifen, an antiestrogen, by monitoring rat estrous cycling. Four-week supplementation of a high-fat diet with flaxseed (2.5, 5, or 10%) or SDG (0.75, 1.5 or 3.0 mg/day) produced a dose-related cessation or lengthening (by 18-39%) of estrous cycles in up to 66% of rats. With tamoxifen (1 mg/kg body weight/day), 83% of the animals had irregular cycles or were in persistent diestrus. Flaxseed and SDG were antiestrogenic without gross tissue toxicity.
Orcheson
L J
LJ
Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Ontario, Canada.
Rickard
S E
SE
Seidl
M M
MM
Thompson
L U
LU
D000818:Animals; D002072:Butylene Glycols / Q000494:pharmacology*; D004965:Estrogen Antagonists / Q000494:pharmacology*; D004971:Estrus / Q000187:drug effects*; D005260:Female; D019597:Flax; D017705:Lignans; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley
D002072:Butylene Glycols; D004965:Estrogen Antagonists; D017705:Lignans; C060283:secoisolariciresinol