Berry Ellagitannins May Not Be Sufficient for Prevention of Tumors in the Rodent Esophagus

Abstract

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.

Lung cancer inhibitory activity of dietary berries and berry polyphenolics

“…BB contains five distinct anthocyanidins (Dp, Cy, Pt, Pe, and Mv) where as BRB contains almost exclusively Cy and EA. However, the role of the fibers from BB and BRB in tumor inhibitory activity cannot be completely ruled out as fiber fraction from three different berries have been shown to possess chemoprevention activity against esophageal tumorigenesis [6].…”

“…Berries have received great attention lately based on their potential to prevent chemically-induced colon [3] and esophageal [4] cancers in animal models. The initial evidence that berry anthocyanins are chemopreventive in an animal tumor-model was provided by Wang et al [5,6]. This study also demonstrated that the anthocyanin fraction of black raspberries (BRB) was as effective in preventing chemically-induced esophageal tumors in rats as whole BRB powder [6].…”

“…The initial evidence that berry anthocyanins are chemopreventive in an animal tumor-model was provided by Wang et al [5,6]. This study also demonstrated that the anthocyanin fraction of black raspberries (BRB) was as effective in preventing chemically-induced esophageal tumors in rats as whole BRB powder [6]. Our own studies have shown significant inhibition of breast cancer in the rat model by both blueberry (BB) and BRB, indicating that berries are chemopreventive beyond the GI tract [7][8][9].…”

“…1). On the other hand, Wang et al [6] have also reported chemopreventive activity of the fiber fraction of blueberries against the esophageal tumorigenesis. Evidence suggest anthocyanins possess several beneficial attributes such as antioxidant and anti-inflammatory effects, reduce risk of stroke and coronary diseases, and improve cognitive behavior [12].…”

The structure, occurrence and biological activity of ellagitannins: a general review

“…Plants rich in ellagitannins may prevent or delay the lengthy carcinogenesis process ]. Ellagitannins and ellagic acid inhibit cancers of the mouth, esophagus, lung, breast, liver and colon [Aqil et al 2012, González-Sarrías et al 2013a, b, Sakagami et al 2000, Wang et al 2010, 2013.…”