Effects of a flaxseed mixture and plant oils rich in alpha-linolenic acid on the adenoma formation in multiple intestinal neoplasia (Min) mice.
Flaxseed is a dietary source of possible chemopreventive compounds such as lignans and alpha-linolenic acid (ALA). To study the effects of a flaxseed mixture on adenoma formation in multiple intestinal neoplasia mice, the mice were fed a diet containing 2.7 % flaxseed, 4.5 % fibre and 3.7 % ALA. To elucidate the effect of oils of the mixture we also composed a diet without flaxseed but with the same oil composition. The median number of adenomas in the small intestine was fifty-four for the control group, and thirty-seven (P=0.023) and forty-two (P=0.095) for flaxseed and oil groups, respectively. Compared with controls (1.2 mm), the adenoma size was smaller in the flaxseed (0.9 mm; P=0.002) and oil (1.0 mm; P=0.012) groups. Both diets changed the proportions of n-3 and n-6 fatty acids in the colonic mucosa. Membrane beta-catenin and protein kinase C (PKC)-zeta levels were reduced in the adenoma v. mucosa (P<0.05), and an inverse association was found between the membrane PKC-zeta in the mucosa and the adenoma number (r -0.460, P=0.008, n 32). Only the flaxseed diet increased lignan levels in the caecum (P=0.002) and in plasma (P=0.002) but they were not associated with tumour formation. The results suggest that the preventive effect of flaxseed on colon carcinogenesis may be due to the oil part of flaxseed, and the loss of beta-catenin and PKC-zeta from the membranes of the mucosal tissue may play a permissive role in intestinal tumour development.
Oikarinen
Seija I
SI
Department of Applied Chemistry and Microbiology (Nutrition), PO Box 66, FIN-00014 University of Helsinki, Finland. seija.oikarinen@helsinki.fi
Pajari
Anne-Maria
AM
Salminen
Irma
I
Heinonen
Satu-Maarit
SM
Adlercreutz
Herman
H
Mutanen
Marja
M
D000199:Actins / Q000032:analysis; D000236:Adenoma / Q000378:metabolism / Q000517:prevention & control*; D000818:Animals; D015153:Blotting, Western / Q000379:methods; D003106:Colon / Q000737:chemistry; D051546:Cyclooxygenase 2 / Q000032:analysis; D005227:Fatty Acids / Q000032:analysis; D019597:Flax; D007413:Intestinal Mucosa / Q000737:chemistry; D007414:Intestinal Neoplasms / Q000378:metabolism / Q000517:prevention & control*; D017705:Lignans / Q000378:metabolism; D008043:Linseed Oil / Q000378:metabolism; D051379:Mice; D008817:Mice, Mutant Strains; D023421:Models, Animal; D009378:Neoplasms, Multiple Primary / Q000378:metabolism / Q000517:prevention & control*; D010938:Plant Oils / Q000008:administration & dosage*; D011493:Protein Kinase C / Q000032:analysis; D015430:Weight Gain; D017962:alpha-Linolenic Acid / Q000008:administration & dosage*; D051176:beta Catenin / Q000032:analysis
D000199:Actins; D005227:Fatty Acids; D017705:Lignans; D010938:Plant Oils; D051176:beta Catenin; D017962:alpha-Linolenic Acid; D008043:Linseed Oil; D051546:Cyclooxygenase 2; D011493:Protein Kinase C