Chemopreventive effect of apple and berry fruits against colon cancer

Table 1 In vitro and in vivo effects of apple extracts against colon cancer

Apple juice and itsComponents	Models(cell line/animal)	Observation/result	Ref.
Apple extracts	HT29 and LT97 colon adenoma cell line	SCFA increased 1.5 fold in fermented samples	[19]
		SCFA stimulates apoptosis, differentiation and growth arrest
Composite mixture of apple extracts	HT29 cells	PKC activity was decreased by 50% after 24 h exposure of 403 mg/mL	[17]
		Upstream signaling elements targeted after longer duration of exposure
Polyphenolic mixtures from cider, table apples and apple pomace; Phenolics such as phlorizin, rutin, quercetin and phloretin	Caco-2 cells and HT29 colonic cell lines	Reduced oxidative damage	[14]
		Reduced the presence of butyl hydroperoxide-induced ROS
	Caco-2 cells	Induction of p450 1A1 expression and inhibition of catalytic activity of the enzyme
Anthocyanidin-rich fraction of apple juice	HT29 and MCF-7 breast cancer cell line	Significant dose reduction in HT29 cells and not in MCF-7 cells	[15]
		MCF-7 cells are less responsive to extract exposure
Procyanidins of apple juice (polymeric polyphenols)	SW620 adenocarcinoma-derived metastatic cells of colon cancer	Dose-dependent inhibition of cell growth	[16]
		50% of inhibition at 45 mg/mL and total inhibition at 70 mg/mL
		Downregulation of signaling pathway such as cell proliferation and differentiation, PKC and enzymes involved in polyamine biosynthesis and stimulation of catabolism
		Increased number of apoptotic cells and interruption in cell cycle
Apple phytochemicals	Rats injected with azoxymethane	Reduction in preneoplastic lesions and 50% fewer aberrant crypts
Apple juice extract; Synthetic mixture, isolated components	HT29 cells	Decreased growth rate efficiently for 24, 48 and 72 h	[18]
		Increased the expression of genes which include phase-2 enzymes, including glutathone-s-transferases and sulfotransferases, which are involved in chemoprevention
		Growth rate inhibition was less efficient comparatively
		Lesser effectiveness than either mixture
Two preparation methods of apple juice: clear and cloudy (higher content of pectin and procyanidin)	Rat model (induced with 1,2-dimethylhydrazine)	Protection from dimethylhydrazine-induced genotoxic damage	[20]
		Important markers were reduced including decreased number of large aberrant crypt foci in the distal colon, reduced DNA damage and reduced hyper-proliferation
Polyphenolic-rich extracts	Rat model (induced with 1,2-dimethylhydrazine)	Juice fractions were found to be more effective in protecting from damage compared to isolated fractions	[21]

PKC: Protein kinase C; ROS: Reactive oxygen species; SCFA: Short-chain fatty acids.