title: Salicylate modulates oxidative stress in the rat colon: a proteomic approach.
abstract: The dietary phenolic compound, salicylic acid, decreases oxidative stress and pro-inflammatory and potentially neo-plastic prostaglandins with a concomitant increase in glutathione peroxidase activity. Salicylic acid, a dietary plant-based phenolic compound and also the main metabolite of aspirin, may contribute to the colon protective effects of plant-based diets. Oxidative stress is a characteristic of pre-cancerous and cancerous colon and inflammatory bowel diseases (IBD) that increase colon cancer risk. The mechanism(s) whereby salicylic acid modulates potentially pro-cancerous activity associated with oxidative stress is further investigated here using a proteomic approach. A rat model of oxidative stress was supplemented with salicylic acid (1 mg/kg diet, mean plasma levels 310+/-32 micromol/l). Soluble colon protein extracts were subjected to 2D PAGE. Salicylic acid modulated proteins, identified using MALDI-TOF and LC/MS/MS, are involved in protein folding, transport, redox, energy metabolism and cytoskeletal regulation. A partial least squares (PLS) analysis approach was used to assist biological interpretation of the altered protein profiles via their associations between previously published biochemical measurements of oxidative stress, prostaglandin levels and increased glutathione peroxidase activity. Early detection of altered homeostasis in colon may assist in identifying pre-pathological features preceding colon tumorigenesis and contribute to an understanding of epidemiological evidence supporting a protective effect of plant-based diets.
authors.affiliation: Gut Health Division, Rowett Research Institute, Greenburn Road, Bucksburn, Aberdeen, AB21 9SB Scotland, UK. jed@rri.sari.ac.uk
authors.forename: Janice E
authors.initials: JE
authors.lastname: Drew
authors.forename: Sara
authors.initials: S
authors.lastname: Padidar
authors.forename: Graham
authors.initials: G
authors.lastname: Horgan
authors.forename: Garry G
authors.initials: GG
authors.lastname: Duthie
authors.forename: Wendy R
authors.initials: WR
authors.lastname: Russell
authors.forename: Martin
authors.initials: M
authors.lastname: Reid
authors.forename: Gary
authors.initials: G
authors.lastname: Duncan
authors.forename: Garry J
authors.initials: GJ
authors.lastname: Rucklidge
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003106:Colon / Q000187:drug effects* / Q000378:metabolism; D004563:Electrochemistry; D015180:Electrophoresis, Gel, Two-Dimensional; D018384:Oxidative Stress / Q000187:drug effects*; D020543:Proteome; D051381:Rats; D020156:Salicylic Acid / Q000494:pharmacology*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D020543:Proteome; D020156:Salicylic Acid