Role of pomegranate and citrus fruit juices in colon cancer prevention

Table 1 In vitro summary of action against colon cancer by fruit juices and their components

Juice and its components	Cell line tested	Observation/result	Ref.
Whole/crude pomegranate juice	HT-29 human colon cancer cells	Inhibition of NFκB activation, AKT activity and COX-2 expression	[18,19]
		Inhibition of COX-2 expression leading to the prevention of initiation and progression of colon cancer	[24]
Ellagitannins of pomegranate juice	Caco-2 cells	Apoptosis of Caco-2 cells through the mitochondrial pathway	[16]
Punicalagin of pomegranate juice	HT-29 colon cancer cells	Down regulation of the anti-apoptotic Bc1-XL protein was achieved with 30 μmol/L ellagic acid and 100 μmol/L punicalaginInduction of intrinsic pathway of apoptosis in colon cancer cells	[25]
Urolithins A and C of pomegranate juice	HT-29 human colon cancer cells	Inhibition of 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced CYP1-mediated ethoxyresorufin-O-deethylase activityIC50 values range: 56.7-74.8 μmol/LInduction of apoptosis in a time- and dose-dependent manner	[15]
Naringenin of citrus juice	HT-29 colon cancer cells	Inhibition of cell proliferation at doses greater than 0.71 mmol/L demonstrated using colorimetric assay	[36]
Limonoids of citrus juice	Human colon cancer cell lines	Induction of apoptosis and cytotoxic effects in MCF-7 and SKOV-3 cells at high concentrations	[37]
Flavonoids of citrus juice		Cell cycle blockade in G0/G1 phase
Tangeritin	Human colorectal carcinoma-COLO 205 cells	Reduced levels of cyclins (A, D1 and E)Decreased phosphorylation of RbIncreased production of cyclin-dependent kinase inhibitors, p53, p21, p27	[38]
Luteolin		Inhibition of growth of colon cancer cells	[39]
Nobiletin		Inhibition of growth of colon cancer cells

NFκB: Nuclear factor-kappa B; AKT: Protein kinase B; COX-2: Cyclooxygenase 2; CYP: Cytochrome P450; MCF: Human breast cancer cell line; SKOV-3: Human colorectal cancer cell line.

Table 2 In vivo summary of action against colon cancer by fruit juices and their components

Juice and its components	Animal model used	Observation/result	Ref.
Whole/crude pomegranate juice	Male F-344 rats	Histopathological studies of azoxymethane-induced rat colonSignificant decrease in number of large cryptic fociIncrease in feed intake and weight gainProtective effects against cancer cachexiaThree times higher activity of GSTAnti oxidative actions by scavenging free radicals	[29]
	Mice	Inhibition of JNK1/2 activity, p38, ERK1/2 and COX-2 expression	[30]
Apigenin of citrus juice	Azoxymethane-induced CF-1 mice	Reduced ODC activity and ACF numbersReduced tumor formation	[39]
Mixture of apigenin and epigallocathechin-gallate	Patients with colorectal neoplasia	Suppressed colon neoplasia recurrence rates	[41]
Hesperitin of citrus juice	DMH-treated male Wistar rats	Reduced number of ACF at a dose of 20 mg/kg	[40]
Nobiletin of citrus juice	Azoxymethane-treated male F344 rats	Decreased PGE2 production in ratsChemo-preventive agents at the promotion stage of colon carcinogenesis	[43]
Naringenin of citrus juice	Azoxymethane-injected Sprague Dawley rats	Reduced levels of COX-2 and iNOSDecrease in proliferation of colon cancer cells	[45,46]

GST: Glutathione S transferase; JNK: c-Jun N-terminal kinase; COX-2: Cyclooxygenase2; ODC: Ornithine decarboxylase; ACF: Aberrant crypt foci; PGE2: Prostaglandin E2; iNOS: Inducible nitric oxide synthase; DMH: 1,2-dimethylhydrazine.