Colon-available raspberry polyphenols exhibit anti-cancer effects on in vitro models of colon cancer

Abstract

BackgroundThere is a probable association between consumption of fruit and vegetables and reduced risk of cancer, particularly cancer of the digestive tract. This anti-cancer activity has been attributed in part to anti-oxidants present in these foods. Raspberries in particular are a rich source of the anti-oxidant compounds, such as polyphenols, anthocyanins and ellagitannins.MethodsA "colon-available" raspberry extract (CARE) was prepared that contained phytochemicals surviving a digestion procedure that mimicked the physiochemical conditions of the upper gastrointestinal tract. The polyphenolic-rich extract was assessed for anti-cancer properties in a series of in vitro systems that model important stages of colon carcinogenesis, initiation, promotion and invasion.ResultsThe phytochemical composition of CARE was monitored using liquid chromatography mass spectrometry. The colon-available raspberry extract was reduced in anthocyanins and ellagitannins compared to the original raspberry juice but enriched in other polyphenols and polyphenol breakdown products that were more stable to gastrointestinal digestion. Initiation – CARE caused significant protective effects against DNA damage induced by hydrogen peroxide in HT29 colon cancer cells measured using single cell microgelelectrophoresis. Promotion – CARE significantly decreased the population of HT29 cells in the G1 phase of the cell cycle, effectively reducing the number of cells entering the cell cycle. However, CARE had no effect on epithelial integrity (barrier function) assessed by recording the trans-epithelial resistance (TER) of CACO-2 cell monolayers. Invasion – CARE caused significant inhibition of HT115 colon cancer cell invasion using the matrigel invasion assay.ConclusionThe results indicate that raspberry phytochemicals likely to reach the colon are capable of inhibiting several important stages in colon carcinogenesis in vitro.

Antioxidant and antiproliferative activities of phenolics isolated from fruits of Himalayan yellow raspberry (Rubus ellipticus)

“…It is also possible that differential cytotoxicity could be only elicited at the lower fruit extracts concentrations and the higher fruit concentrations might show cytotoxicity to normal cells. Our observations of high antioxidant and antiproliferative activity of R. ellipticus are in consonance with the previous studies on various species of raspberries, including yellow raspberry, which showed high polyphenol contents and their high antioxidant capacities and antiproliferative activities (Wang and Lin 2000;Ross et al 2007;Coates et al 2007;Weber et al 2008;Gansch et al 2009;Rao and Snyder 2010;Gulcin et al 2011). Significantly higher contents of polyphenols and their antioxidant capacities and anticancer activities observed in the yellow Himalayan raspberry R. ellipticus in the present study were much higher than those reported earlier for yellow raspberry Gansch et al 2009).…”

Assessment of white grape pomace from winemaking as source of bioactive compounds, and its antiproliferative activity

“…Several studies have indicated the anti-cancer potential of polyphenolic compounds, and in particular their ability to inhibit the proliferation of cancer cells via their effects on the cell-cycle and/or apoptosis (Lee et al, 2006;Ramos, Rodríguez-Ramiro, Martín, Goya, & Bravo, 2011;Vu et al, 2012), and have suggested their use as novel dietary chemopreventive agents (Araújo, Gonçalves, & Martel, 2011). For example, the antiproliferative effects of polyphenolic extracts from olive oil (Corona et al, 2007), red wine (Gómez-Alonso et al, 2012), tomato (Saunders, 2009), araçá (Medina et al, 2011), raspberry (Coates et al, 2007) and cranberry (Vu et al, 2012) have been reported. However, to date there are no previous data on the actions of grape pomace extracts, although their potential to protect against oxidative stress has been shown in Caenorhabditis elegans (Jara- Palacios et al, 2013).…”

Synergistic Activity of Plant Based Bioactives in Combating Cancer: An Overview.

“…This anticancer activity has been attributed by the anti-oxidant components of this food. Raspberry extract, bioavailable in colon contains phyto-chemicals surviving the digestion procedure that mimicked the physiochemical conditions of the upper gastro intestinal tract [26]. The polyphenol rich extract is assessed for anticancer properties in a series of in vitro systems that serve as model for important stages of colon carcinogenesis, initiation and invasion.…”