title: Partial replacement of ω-6 fatty acids with medium-chain triglycerides, but not olive oil, improves colon cytokine response and damage in experimental colitis.
abstract: BACKGROUND
  Soybean oil is rich in ω-6 fatty acids, which are associated with higher incidence and more severe cases of inflammatory bowel diseases. The authors evaluated whether partial replacement of soybean oil by medium-chain triglycerides (MCTs) or olive oil influenced the incidence and severity of experimental ulcerative colitis by using different parenteral lipid emulsions (LEs).
  
  
  METHODS
  Wistar rats (n = 40) were randomized to receive parenteral infusion of the following LE: 100% soybean oil (SO), 50% MCT mixed with 50% soybean oil (MCT/SO), 80% olive oil mixed with 20% soybean oil (OO/SO), or saline (CC). After 72 hours of infusion, acetic acid experimental colitis was induced. After 24 hours, colon histology and cytokine expression were analyzed.
  
  
  RESULTS
  SO was not significantly associated with overall tissue damage. MCT/SO was not associated with necrosis (P < .005), whereas OO/SO had higher frequencies of ulcer and necrosis (P < .005). SO was associated with increased expression of interferon-γ (P = .005) and OO/SO with increased interleukin (IL)-6 and decreased tumor necrosis factor-α expression (P < .05). MCT/SO appeared to decrease IL-1 (P < .05) and increase IL-4 (P < .001) expression.
  
  
  CONCLUSIONS
  Parenteral SO with high concentration of ω-6 fatty acids was not associated with greater tissue damage in experimental colitis. SO partial replacement with MCT/SO decreased the frequency of histological necrosis and favorably modulated cytokine expression in the colon; however, replacement with OO/SO had unfavorable effects.
authors.affiliation: University of São Paulo, School of Medicine (FMUSP), Department of Gastroenterology, Digestive Surgery Division-LIM 35, São Paulo, Brazil.
authors.forename: Pedro L
authors.initials: PL
authors.lastname: Bertevello
authors.forename: Leticia
authors.initials: L
authors.lastname: De Nardi
authors.forename: Raquel S
authors.initials: RS
authors.lastname: Torrinhas
authors.forename: Angela F
authors.initials: AF
authors.lastname: Logullo
authors.forename: Dan L
authors.initials: DL
authors.lastname: Waitzberg
mesh_terms: D000818:Animals; D003093:Colitis, Ulcerative / Q000188:drug therapy* / Q000473:pathology; D003106:Colon / Q000187:drug effects* / Q000378:metabolism* / Q000473:pathology; D004655:Emulsions; D043371:Fatty Acids, Omega-6 / Q000008:administration & dosage*; D007375:Interleukin-1 / Q000378:metabolism; D015847:Interleukin-4 / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D008297:Male; D000069463:Olive Oil; D010938:Plant Oils / Q000008:administration & dosage*; D051381:Rats; D017208:Rats, Wistar; D013024:Soybean Oil / Q000008:administration & dosage; D014280:Triglycerides / Q000008:administration & dosage*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D004655:Emulsions; D043371:Fatty Acids, Omega-6; D007375:Interleukin-1; D015850:Interleukin-6; D000069463:Olive Oil; D010938:Plant Oils; D014280:Triglycerides; D014409:Tumor Necrosis Factor-alpha; D015847:Interleukin-4; D013024:Soybean Oil