Dietary medium-chain triglycerides prevent chemically induced experimental colitis in rats

• Published in: Translational research : the journal of laboratory and clinical medicine Vol. 155; no. 3; pp. 131 - 141
• Main Authors: Kono, Hiroshi, Fujii, Hideki, Ishii, Kenichi, Hosomura, Naohiro, Ogiku, Masahito
• Format: Journal Article
• Language: English
• Published: New York, NY Mosby, Inc 01.03.2010; Elsevier
• Subjects: Animals; Biological and medical sciences; Cells, Cultured; Chemokine CXCL2 - analysis; Colitis - chemically induced; Colitis - prevention & control; Colon - enzymology; Colon - pathology; Endotoxins - blood; General aspects; Interleukin-1beta - genetics; Internal Medicine; Investigative techniques, diagnostic techniques (general aspects); Male; Medical sciences; Mice; Peroxidase - metabolism; Rats; Rats, Wistar; Toll-Like Receptor 4 - analysis; Toll-Like Receptor 4 - genetics; Triglycerides - administration & dosage; Trinitrobenzenesulfonic Acid; Tumor Necrosis Factor-alpha - genetics; IBD; mRNA; MPO; BSA; DMEM; analysis of variance; messenger RNA; ANOVA; FBS; medium-chain triglyceride; RT-PCR; glyceraldehyde-3-phosphate dehydrogenase; TLR; interleukin; reverse-transcription polymerase chain reaction; Toll-like receptor; Dulbecco's modified Eagle medium; IL; myeloperoxidase; TNBS; inflammatory bowel disease; fetal bovine serum; 2,4,6-trinitrobenzene sulphonic acid; TNF-α; MIP; tumor necrosis factor-α; enzyme-linked immunosorbent assay; macrophage inflammatory protein; GAPDH; bovine serum albumin; ELISA; MCT; Nutrition; Rat; Rodentia; Lipids; Medium chain; Experimental study; Triglyceride; Feeding; Medicine; Prevention; Vertebrata; Mammalia; Diet; Animal; Clinical biology; Digestive diseases; Intestinal disease; Colitis
• ISSN: 1931-5244; 1878-1810
• DOI: 10.1016/j.trsl.2009.08.011

The effects of dietary medium-chain triglycerides (MCTs) on experimental colitis induced by 2,4,6-trinitrobenzene sulphonic acid (TNBS) were investigated in rats. Male Wistar rats were given an intracolonic injection of TNBS and were then fed liquid diets containing MCTs or corn oil (AIN93) as controls. Serum and tissue samples were collected 1 week after TNBS enema. The severity of colitis was evaluated pathologically, and tissue myeloperoxidase (MPO) activity was measured. Furthermore, messenger RNA (mRNA) and protein levels for inflammatory cytokines and a chemokine were assessed by reverse-transcription polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. In another set of experiments, the protein expression of Toll-like receptor (TLR)-4 in the colon was measured 1 week after feeding of liquid diets. To investigate the effects of MCTs on macrophages, RAW246.7 macrophages were incubated with media containing albumin conjugated with MCT or linoleic acid, which is the major component of corn oil. Then, the production of tumor necrosis factor-α (TNF-α) was measured. Dietary MCTs blunted significantly the protein levels of TLR-4 in the colon. Furthermore, the expression of TLR-4 was significantly blunted in RAW264.7 cells incubated with MCTs compared with cells incubated with linoleic acid. Induction of interleukin 1β (IL-1β), TNF-α, and macrophage inflammatory protein-2 (MIP-2) in the colon was attenuated by dietary MCT. Furthermore, MPO activities in the colonic tissue were significantly blunted in animals fed the MCT diets compared with those fed the control diets. As a result, dietary MCTs improved chemically induced colitis significantly. MCTs most likely are useful for the therapy of inflammatory bowel disease as an anti-inflammatory immunomodulating nutrient.