Chemoprevention by white currant is mediated by the reduction of nuclear β-catenin and NF-κB levels in Min mice adenomas

Abstract

Background Berries are a good natural source of phenolic compounds and many berries or their compounds have been shown to be chemopreventive. White currant is an interesting berry, as it contains low levels of dominant berry phenolics such as ellagic acid, anthocyanins and other flavonoids. Aims of the study To study if white currant is chemopreventive in an experimental model for intestinal tumorigenesis and further study the effects on β-catenin and NF-κB signaling pathways. Methods Multiple intestinal neoplasia (Min) mice were fed an AIN-93G based control diet or a diet containing 10% freeze dried white currant (Ribes x pallidum) for 10 weeks. Cell signaling parameters were analysed from intestinal adenomas and surrounding mucosa by Western blotting and immunohistochemistry. Results The white currant diet reduced the number of adenomas from 81 (min–max 47–114) to 51 (36–84) in the total small intestine of Min mice (P < 0.02). Most of the adenomas develop in the distal part of the small intestine, and in this area white currant reduced the number from 49 to 29.5 (P < 0.01) and also the size of the adenomas from 0.88 mm to 0.70 mm (P < 0.02). In the colon white currant increased the number of adenomas (0.3 ± 0.6 vs. 0.8 ± 0.6, mean ± SD, P < 0.05), but did not affect the size. White currant reduced nuclear β-catenin and NF-κB protein levels in the adenomas (P < 0.05 and P < 0.02, respectively). They were correlated with the size of adenomas (P < 0.01). Conclusions This study shows that white currant is effective in preventing cancer initiation and progression in the Min mouse. Whether the positive effects are due to its special phenolic composition needs to be studied in more detail.