Effects of quercetin and beta-carotene supplementation on azoxymethane-induced colon carcinogenesis and inflammatory responses in rats fed with high-fat diet rich in omega-6 fatty acids.

2.50
Hdl Handle:
http://hdl.handle.net/10146/52573
Title:
Effects of quercetin and beta-carotene supplementation on azoxymethane-induced colon carcinogenesis and inflammatory responses in rats fed with high-fat diet rich in omega-6 fatty acids.
Authors:
Choi, Soo-Yeon; Park, Jung Han Yoon; Kim, Jong-Sang; Kim, Mi Kyung; Aruoma, Okezie I.; Sung, Mi-Kyung
Abstract:
Chronic inflammation in gastrointestinal tract has been suggested as a risk factor for tumor formation. The effect of dietary supplementation of quercetin or beta-carotene on colon carcinogenesis and inflammatory response in rats fed with high-fat diet rich in omega-6 fatty acids was assessed. Animals were exposed to two weekly subcutaneous injections of AOM (azoxymethane) at a single dose of 15 mg/kg body weight. A portion of rats from each group was sacrificed at 8 weeks after the last AOM treatment to determine ACF (aberrant crypt foci) formation. Colonic mucosa expression of iNOS (inducible nitric oxide) and COX-2 (cyclooxygenase-2) protein, and blood PGE2 (prostaglandin E2) level were measured. The remaining groups of animals were sacrificed at 33 weeks after the last AOM treatment to examine colon tumor formation. Rats on high-fat diet developed more aberrant crypt foci (P<0.05) compared with those of rats on regular diet. In the same vein, but in contrast to the effect seen with regular diet, the high-fat diet induced a significant up-regulation of iNOS expression. There was no significant change in the extent of COX-2 expression or in the PGE2 levels. Quercetin or beta-carotene supplementation reduced the number of ACF only in animals fed high-fat diet (p<0.05), however, no significant difference in tumor incidence was found. At week 33, the expression of iNOS was reduced by quercetin without a statistical significance, and COX-2 expression was slightly reduced in rats on beta-carotene supplementation. No change in PGE2 levels was observed. Whilst dietary antioxidants are considered as effective suppressors for precancerous lesion formation in colons exposed to high-risk diet, it is clear that elucidating the role of individual antioxidants in colon tumor formation coupled with an understanding of the molecular mechanisms involved would benefit colon cancer prevention strategies.
Citation:
Biofactors 2006, 27 (1-4):137-146
Journal:
BioFactors (Oxford, England)
Issue Date:
2006
URI:
http://hdl.handle.net/10146/52573
PubMed ID:
17012770
Additional Links:
http://iospress.metapress.com/content/fbc5j2djcbxxgwwv/
Type:
Article
Language:
en
Description:
Dietary modulation of cancer & cancer biomarkers. Dietary item or component studied: quercetin; beta-carotene. Outcome studied: aberrant crypt foci in colon; colon tumor incidence; colonic mucosa levels of iNOS and COX-2 proteins and PGE2 levels. Study type: Sprague-Dawley (SD) male rats. Tissue/biological material/sample size: colon; blood. Mode of exposure: dietary. Impact on outcome (including dose-response): Quercetin or beta-carotene supplementation reduced the number of ACF only in animals fed high-fat diet (p<0.05); however, no significant difference in tumor incidence was found; non-significant decrease of iNOS by quercetin; no other effects observed. Keywords - classification:Animals;blood;dietary modulation of cancer & cancer biomarkers;Food;humans;Korea;Quercetin;Rats;Research;
ISSN:
0951-6433
Appears in Collections:
Articles with annotation

Full metadata record

DC FieldValue Language
dc.contributor.authorChoi, Soo-Yeon-
dc.contributor.authorPark, Jung Han Yoon-
dc.contributor.authorKim, Jong-Sang-
dc.contributor.authorKim, Mi Kyung-
dc.contributor.authorAruoma, Okezie I.-
dc.contributor.authorSung, Mi-Kyung-
dc.date.accessioned2009-03-06T10:14:50Z-
dc.date.available2009-03-06T10:14:50Z-
dc.date.issued2006-
dc.identifier.citationBiofactors 2006, 27 (1-4):137-146en
dc.identifier.issn0951-6433-
dc.identifier.pmid17012770-
dc.identifier.urihttp://hdl.handle.net/10146/52573-
dc.descriptionDietary modulation of cancer & cancer biomarkers. Dietary item or component studied: quercetin; beta-carotene. Outcome studied: aberrant crypt foci in colon; colon tumor incidence; colonic mucosa levels of iNOS and COX-2 proteins and PGE2 levels. Study type: Sprague-Dawley (SD) male rats. Tissue/biological material/sample size: colon; blood. Mode of exposure: dietary. Impact on outcome (including dose-response): Quercetin or beta-carotene supplementation reduced the number of ACF only in animals fed high-fat diet (p<0.05); however, no significant difference in tumor incidence was found; non-significant decrease of iNOS by quercetin; no other effects observed. Keywords - classification:Animals;blood;dietary modulation of cancer & cancer biomarkers;Food;humans;Korea;Quercetin;Rats;Research;en
dc.description.abstractChronic inflammation in gastrointestinal tract has been suggested as a risk factor for tumor formation. The effect of dietary supplementation of quercetin or beta-carotene on colon carcinogenesis and inflammatory response in rats fed with high-fat diet rich in omega-6 fatty acids was assessed. Animals were exposed to two weekly subcutaneous injections of AOM (azoxymethane) at a single dose of 15 mg/kg body weight. A portion of rats from each group was sacrificed at 8 weeks after the last AOM treatment to determine ACF (aberrant crypt foci) formation. Colonic mucosa expression of iNOS (inducible nitric oxide) and COX-2 (cyclooxygenase-2) protein, and blood PGE2 (prostaglandin E2) level were measured. The remaining groups of animals were sacrificed at 33 weeks after the last AOM treatment to examine colon tumor formation. Rats on high-fat diet developed more aberrant crypt foci (P<0.05) compared with those of rats on regular diet. In the same vein, but in contrast to the effect seen with regular diet, the high-fat diet induced a significant up-regulation of iNOS expression. There was no significant change in the extent of COX-2 expression or in the PGE2 levels. Quercetin or beta-carotene supplementation reduced the number of ACF only in animals fed high-fat diet (p<0.05), however, no significant difference in tumor incidence was found. At week 33, the expression of iNOS was reduced by quercetin without a statistical significance, and COX-2 expression was slightly reduced in rats on beta-carotene supplementation. No change in PGE2 levels was observed. Whilst dietary antioxidants are considered as effective suppressors for precancerous lesion formation in colons exposed to high-risk diet, it is clear that elucidating the role of individual antioxidants in colon tumor formation coupled with an understanding of the molecular mechanisms involved would benefit colon cancer prevention strategies.en
dc.language.isoenen
dc.relation.urlhttp://iospress.metapress.com/content/fbc5j2djcbxxgwwv/en
dc.subjectiNOSen
dc.subjecthigh-fat dietsen
dc.subjectColon canceren
dc.subjectinflammationen
dc.subjectAntioxidantsen
dc.subjectquercetinen
dc.subjectβ-caroteneen
dc.subjectCOX-2en
dc.subject.meshAnimals-
dc.subject.meshAzoxymethane-
dc.subject.meshCarcinogens-
dc.subject.meshColonic Neoplasms-
dc.subject.meshCyclooxygenase 2-
dc.subject.meshDietary Fats-
dc.subject.meshFatty Acids, Omega-6-
dc.subject.meshMale-
dc.subject.meshModels, Biological-
dc.subject.meshNitric Oxide Synthase Type II-
dc.subject.meshQuercetin-
dc.subject.meshRats-
dc.subject.meshRats, Sprague-Dawley-
dc.subject.meshVitamins-
dc.subject.meshbeta Carotene-
dc.titleEffects of quercetin and beta-carotene supplementation on azoxymethane-induced colon carcinogenesis and inflammatory responses in rats fed with high-fat diet rich in omega-6 fatty acids.en
dc.typeArticleen
dc.identifier.journalBioFactors (Oxford, England)en
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