title: Modulation of colonic inflammation in Mdr1a(-/-) mice by green tea polyphenols and their effects on the colon transcriptome and proteome.
abstract: Animal models are an important tool to understand the complex pathogenesis of inflammatory bowel diseases (IBDs). This study tested the anti-inflammatory potential of a green tea extract rich in polyphenols (GrTP) in the colon of the multidrug resistance targeted mutation (Mdr1a(-/-)) mouse model of IBD. Insights into mechanisms responsible for this reduction in inflammation were gained using transcriptome and proteome analyses. Mice were randomly assigned to an AIN-76A (control) or GrTP-enriched diet. At 21 or 24 weeks of age, a colonic histological injury score was determined for each mouse, colon mRNA transcript levels were assessed using microarrays, and colon protein expression was measured using two-dimensional gel electrophoresis and liquid chromatography-mass spectrometry protein identification. Mean colonic histological injury score of GrTP-fed Mdr1a(-/-) mice was significantly lower compared to those fed the control diet. Microarray and proteomics analyses showed reduced abundance of transcripts and proteins associated with immune and inflammatory response and fibrinogenesis pathways, and increased abundance of those associated with xenobiotic metabolism pathways in response to GrTP, suggesting that its anti-inflammatory activity is mediated by multiple molecular pathways. Peroxisome proliferator-activated receptor-α and signal transducer and activator of transcription 1 appear to be two key molecules which regulate these effects. These results support the view that dietary intake of polyphenols derived from green tea can ameliorate intestinal inflammation in the colon of a mouse model of IBD, and are in agreement with studies suggesting that consumption of green tea may reduce IBD symptoms and therefore play a part in an overall IBD treatment regimen.
authors: Food Nutrition and Health Team, Food and Bio-based Products Group, Palmerston North 4442, New Zealand. Electronic address: matthew.barnett@agresearch.co.nz.
authors: Matthew P G
authors: MP
authors: Barnett
authors: Janine M
authors: JM
authors: Cooney
authors: Yvonne E M
authors: YE
authors: Dommels
authors: Katia
authors: K
authors: Nones
authors: Diane T
authors: DT
authors: Brewster
authors: Zaneta
authors: Z
authors: Park
authors: Christine A
authors: CA
authors: Butts
authors: Warren C
authors: WC
authors: McNabb
authors: William A
authors: WA
authors: Laing
authors: Nicole C
authors: NC
authors: Roy
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B / Q000172:deficiency*; D000818:Animals; D003092:Colitis / Q000473:pathology / Q000517:prevention & control*; D003106:Colon / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D015212:Inflammatory Bowel Diseases / Q000517:prevention & control; D008297:Male; D051379:Mice; D023421:Models, Animal; D047493:PPAR alpha / Q000502:physiology; D059808:Polyphenols / Q000494:pharmacology*; D020543:Proteome; D050794:STAT1 Transcription Factor / Q000502:physiology; D013662:Tea / Q000737:chemistry; D059467:Transcriptome
chemical_list: D018435:ATP Binding Cassette Transporter, Subfamily B; D047493:PPAR alpha; D059808:Polyphenols; D020543:Proteome; D050794:STAT1 Transcription Factor; D013662:Tea; C095122:multidrug resistance protein 3
keywords: Epigallocatechin gallate (EGCG); Gene expression; Inflammatory bowel diseases; Protein expression