title: Effect of long-term dietary supplementation of high-gamma-linolenic canola oil versus borage oil on growth, hematology, serum biochemistry, and N-6 fatty acid metabolism in rats.
abstract: Dietary supplementation of a high-gamma-linolenic acid canola oil (HGCO) containing approximately 36% (w/w) of gamma-linolenic acid (GLA, 18:3n-6) from the seeds of a genetically transformed canola strain, was assessed for its long-term biological effects. Growing Sprague-Dawley rats (n = 30) were fed a purified AIN93G diet containing 5, 10, or 15% (w/w) of HGCO as the fat source. For comparison, a separate group of rats (n = 10) was given the diet containing 15% (w/w) of borage oil (BO), which contained 22% (w/w) of GLA. After 12 weeks of feeding, the growth, relative organ weights, hematology, and serum biochemistry were found to be similar among rats fed the 5, 10, and 15% HGCO diets. The GLA levels in plasma and liver phospholipids (PL) were also similar. However, the levels of GLA in peripheral tissues (muscle PL and adipose triacylglycerols) were significantly higher in rats fed the 10 and 15% HGCO diets than those fed the 5% HGCO diet. When the above biologic parameters were compared between the 15% HGCO and 15% BO dietary groups, there were no significant differences except for lower final body weights and higher tissue levels of GLA, dihomo-gamma-linolenic acid (20:3n-6) and arachidonic acid (20:4n-6) in the 15% HGCO dietary group as compared with the 15% BO dietary group. This is due to a higher GLA content and possibly a more favorable stereospecific distribution of GLA in HGCO. Overall, long-term (12-week) feeding with diets containing up to 15% HGCO resulted in no adverse effects on growth, organ weight, hematology and serum biochemistry as compared to the diet containing 15% BO, suggesting that HGCO may be a safe alternative source of GLA.
authors.affiliation: Strategic Research and Development, Ross Products Division, Abbott Laboratories, Columbus, Ohio 43219, USA.
authors.forename: Jim-Wen
authors.initials: JW
authors.lastname: Liu
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: DeMichele
authors.forename: John
authors.initials: J
authors.lastname: Palombo
authors.forename: Lu-Te
authors.initials: LT
authors.lastname: Chuang
authors.forename: Christine
authors.initials: C
authors.lastname: Hastilow
authors.forename: Emil
authors.initials: E
authors.lastname: Bobik
authors.forename: Yung-Sheng
authors.initials: YS
authors.lastname: Huang
mesh_terms: D000273:Adipose Tissue; D000818:Animals; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage*; D005229:Fatty Acids, Monounsaturated / Q000008:administration & dosage* / Q000737:chemistry; D043371:Fatty Acids, Omega-6 / Q000378:metabolism*; D006400:Hematocrit; D007958:Leukocyte Count; D008055:Lipids / Q000032:analysis / Q000097:blood; D008099:Liver / Q000033:anatomy & histology / Q000737:chemistry; D008297:Male; D009929:Organ Size; D010938:Plant Oils / Q000008:administration & dosage*; D000074262:Rapeseed Oil; D051381:Rats; D017207:Rats, Sprague-Dawley; D015430:Weight Gain; D017965:gamma-Linolenic Acid / Q000008:administration & dosage*
chemical_list: D004042:Dietary Fats, Unsaturated; D005229:Fatty Acids, Monounsaturated; D043371:Fatty Acids, Omega-6; D008055:Lipids; D010938:Plant Oils; D000074262:Rapeseed Oil; D017965:gamma-Linolenic Acid; C079363:borage oil