title: Fish oil decreases oxidative DNA damage by enhancing apoptosis in rat colon.
abstract: To determine if dietary fish oil protects against colon cancer by decreasing oxidative DNA damage at the initiation stage of colon tumorigenesis, oxidative DNA damage, proliferation, and apoptosis were assessed by colonic crypt cell position using quantitative immunohistochemical analysis of 8-hydroxydeoxyguanosine (8-OHdG), Ki-67, and TUNEL assay, respectively. Sixty rats were provided one of two diets (corn oil or fish oil) and dextran sodium sulfate (DSS, an inducer of oxidative DNA damage) treatments (no DSS, 3% DSS, or DSS withdrawal). Fish oil feeding resulted in lower 8-OHdG levels (P = 0.038), higher levels of apoptosis (P = 0.035), and a lower cell proliferative index (P = 0.05) compared with corn oil feeding. In the top third of the crypt, fish oil caused an incremental stimulation of apoptosis with increased DNA damage (P = 0.043), whereas there was no such relationship with corn oil. Because polyps and tumors develop from DNA damage that leads to loss of growth and death control, the significant difference in fish oil vs. corn oil on these variables may account, in part, for the observed protective effect of fish oil against oxidatively induced colon cancer.
authors.affiliation: Department of Nutrition and Food Science and the Center for Environmental and Rural Health, Texas A&M University, College Station, TX 77843, USA.
authors.forename: Mee Young
authors.initials: MY
authors.lastname: Hong
authors.forename: Laura K
authors.initials: LK
authors.lastname: Bancroft
authors.forename: Nancy D
authors.initials: ND
authors.lastname: Turner
authors.forename: Laurie A
authors.initials: LA
authors.lastname: Davidson
authors.forename: Mary E
authors.initials: ME
authors.lastname: Murphy
authors.forename: Raymond J
authors.initials: RJ
authors.lastname: Carroll
authors.forename: Robert S
authors.initials: RS
authors.lastname: Chapkin
authors.forename: Joanne R
authors.initials: JR
authors.lastname: Lupton
mesh_terms: D000818:Animals; D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D003106:Colon / Q000166:cytology / Q000187:drug effects; D003110:Colonic Neoplasms / Q000378:metabolism / Q000517:prevention & control*; D004249:DNA Damage / Q000187:drug effects*; D005395:Fish Oils / Q000008:administration & dosage / Q000494:pharmacology*; D007150:Immunohistochemistry; D008297:Male; D018384:Oxidative Stress; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D016588:Anticarcinogenic Agents; D005395:Fish Oils