title: Moderate doses of conjugated linoleic acid isomers mix contribute to lowering body fat content maintaining insulin sensitivity and a noninflammatory pattern in adipose tissue in mice.
abstract: Conjugated linoleic acid (CLA) modulates body composition, especially by reducing adipose tissue. However, despite the increasing knowledge about CLA's beneficial effects on obesity management, the mechanism of action is not yet fully understood. Furthermore, in some human studies fat loss is accompanied by impairment in insulin sensitivity, especially when using the trans-10,cis-12 isomer. The aim of this work was to study the effects of moderate doses of CLA on body fat deposition, cytokine profile and inflammatory markers in mice. Mice were orally treated with a mixture of CLA isomers, cis-9,trans-11 and trans-10,cis-12 (50:50), for 35 days with doses of CLA1 (0.15 g CLA/kg body weight) and CLA2 (0.5 g CLA/kg body weight). CLA had discrete effects on body weight but caused a clear reduction in fat mass (retroperitoneal and mesenteric as the most sensitive depots), although no other tissue weights were affected. Glucose and insulin were not altered by CLA treatment, and maintenance of glucose homeostasis was observed even under insulin overload. The study of gene expression (Emr1, MCP-1, IL-6, TNFalpha, PPARgamma2 and iNOS) either in adipocytes and/or in the stromal vascular fraction indicated that CLA does not lead to the infiltration of macrophages in adipose tissue or to the induction of expression of pro-inflammatory cytokines. The use of a mixture of both isomers, as well as moderate doses of CLA, is able to induce a reduction of fat gain without an impairment of adipose tissue function while preserving insulin sensitivity.
authors.affiliation: Laboratorio de Biología Molecular, Nutrición y Biotecnología, University of the Balearic Islands and CIBER de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), E-07122, Palma de Mallorca, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: Parra
authors.forename: Francisca
authors.initials: F
authors.lastname: Serra
authors.forename: Andreu
authors.initials: A
authors.lastname: Palou
mesh_terms: D052438:Adipocytes, White / Q000187:drug effects / Q000378:metabolism; D000273:Adipose Tissue / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D019440:Anti-Obesity Agents / Q000008:administration & dosage / Q000494:pharmacology*; D001823:Body Composition / Q000187:drug effects*; D004032:Diet; D004305:Dose-Response Relationship, Drug; D005786:Gene Expression Regulation / Q000187:drug effects; D018836:Inflammation Mediators / Q000378:metabolism*; D007333:Insulin Resistance; D044243:Linoleic Acids, Conjugated / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009929:Organ Size / Q000187:drug effects; D010936:Plant Extracts / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D011897:Random Allocation; D012450:Safflower Oil / Q000737:chemistry; D015430:Weight Gain / Q000187:drug effects
chemical_list: D019440:Anti-Obesity Agents; D018836:Inflammation Mediators; D044243:Linoleic Acids, Conjugated; D010936:Plant Extracts; D012333:RNA, Messenger; D012450:Safflower Oil