title: Cloudy apple juice is more effective than apple polyphenols and an apple juice derived cloud fraction in a rat model of colon carcinogenesis.
abstract: As recently shown, a cloudy apple juice (CloA) was effective to modulate colon cancer associated parameters in rats treated with 1,2-dimethylhydrazine (DMH). To identify the bioactive substance classes in CloA, we fractionated CloA to yield a total polyphenol (PF) and a cloud (CF) fraction consisting of proteins, fatty acids, polyphenols, and cell wall polysaccharides. Rats received water (control (Cont)) or CloA, PF, and CF separate or combined (PF-CF) ad libitum for 7 weeks starting one week before the first DMH-injection. As determined by comet assay, the DMH-induced genotoxicity in colonocytes of controls (Cont/DMH: 7.7 +/- 0.5%) was significantly reduced by CloA (3.3 +/- 0.3%) but not by any of the fractions. The crypt cell proliferation induced by DMH (Cont/NaCl: 7.5 +/- 0.6%; Cont/DMH: 14.9 +/- 0.8%) was significantly decreased by CloA (9.4 +/- 0.4%), PF (12.4 +/- 0.7%), CF (11.6 +/- 0.4%), and PF-CF (12.4 +/- 0.6%). Although not statistically significant, CloA tended to reduce the number of large aberrant crypt foci (ACF) (Cont/DMH: 19.0 +/- 3.7; CloA/DMH: 12.3 +/- 1.9), while none of the fractions affected ACFs. Neither CloA nor the fractions changed mRNAs of colonic cyclooxygenases (COX-1, COX-2), glutathione-associated enzymes (GST-M2, gamma-GCS, GST-P), the splenocyte CD4/CD8 ratio, natural killer cell activity, and plasma antioxidant status. These results demonstrate that CloA had a higher cancer-preventive potential than the fractions and further, besides PF, identified CF as an additional bioactive fraction of CloA.
authors.affiliation: Institute of Nutritional Physiology, Federal Research Centre for Nutrition and Food, Haid-und-Neu-Strasse 9, 76131 Karlsruhe, Germany. stephan.barth@bfel.de
authors.forename: Stephan W
authors.initials: SW
authors.lastname: Barth
authors.forename: Christine
authors.initials: C
authors.lastname: Faehndrich
authors.forename: Achim
authors.initials: A
authors.lastname: Bub
authors.forename: Bernhard
authors.initials: B
authors.lastname: Watzl
authors.forename: Frank
authors.initials: F
authors.lastname: Will
authors.forename: Helmut
authors.initials: H
authors.lastname: Dietrich
authors.forename: Gerhard
authors.initials: G
authors.lastname: Rechkemmer
authors.forename: Karlis
authors.initials: K
authors.lastname: Briviba
mesh_terms: D019813:1,2-Dimethylhydrazine; D000818:Animals; D001628:Beverages / Q000032:analysis*; D003110:Colonic Neoplasms / Q000139:chemically induced / Q000473:pathology / Q000517:prevention & control*; D005419:Flavonoids / Q000008:administration & dosage* / Q000032:analysis*; D005638:Fruit / Q000737:chemistry*; D008297:Male; D027845:Malus / Q000737:chemistry*; D010636:Phenols / Q000008:administration & dosage* / Q000032:analysis*; D059808:Polyphenols; D051381:Rats; D011916:Rats, Inbred F344
chemical_list: D005419:Flavonoids; D010636:Phenols; D059808:Polyphenols; D019813:1,2-Dimethylhydrazine