Berry ellagitannins may not be sufficient for prevention of tumors in the rodent esophagus.
Biodirected fractionation is used to identify the active inhibitory constituents in berries for esophageal cancer in rats. The present study was undertaken to determine if ellagitannins contribute to the chemopreventive activity of an alcohol/water-insoluble (residue) fraction of berries. Rats consumed diets containing residue fractions of three berry types, that is, black raspberries (BRBs), strawberries (STRWs), and blueberries (BBs), that differ in their content of ellagitannins in the order BRB > STRW > BB. Animals were fed residue diets beginning 2 weeks before treatment with the esophageal carcinogen N-nitrosomethylbenzylamine (NMBA) and throughout the 30-week bioassay. Residue fractions from all three berry types were about equally effective in reducing NMBA tumorigenesis in the rat esophagus irrespective of their ellagitannin content (0.01-0.62 g/kg of diet). These results suggest that the ellagitannins may not be responsible for the chemopreventive effects of the alcohol/water-insoluble fraction of berries.
Wang
Li-Shu
LS
The Ohio State University Comprehensive Cancer Center, Columbus, Ohio 43240, USA.
Hecht
Stephen
S
Carmella
Steven
S
Seguin
Claire
C
Rocha
Claudio
C
Yu
Nanxiong
N
Stoner
Kristen
K
Chiu
Steven
S
Stoner
Gary
G
D000818:Animals; D029798:Blueberry Plants / Q000737:chemistry*; D004195:Disease Models, Animal; D004938:Esophageal Neoplasms / Q000188:drug therapy / Q000517:prevention & control*; D005638:Fruit / Q000737:chemistry*; D006801:Humans; D047348:Hydrolyzable Tannins / Q000008:administration & dosage*; D008297:Male; D010936:Plant Extracts / Q000008:administration & dosage*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D027824:Rosaceae / Q000737:chemistry*
D047348:Hydrolyzable Tannins; D010936:Plant Extracts