The effect of conjugated linoleic acid (CLA) on insulin resistance (IR) was isomer specific. In the present study, we induced IR Chang liver cells by incubating cells with 100nmol/L insulin for 24h. Then the effect of trans10, cis12-conjugated linoleic acid (t10, c12-CLA) and cis9, trans11-conjugated linoleic acid (c9, t11-CLA) on IR cells were studied. 1μmol/L, 2μmol/L, 5μmol/L and 10μmol/L t10, c12-CLA, but not c9, t11-CLA were found to enhance glucose consumption of IR cells in a dose-dependent way. 2μmol/L t10, c12-CLA for 12h incubation significantly improved glucose consumption of IR cells and increased phospho-protein kinase B (p-PKB/p-Akt) protein level. The enhancement of glucose consumption of IR cells by t10, c12-CLA and the level of p-Akt was strongly inhibited by phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002, indicating that PI3K/Akt insulin signaling pathway may be involved in the beneficial effect of t10, c12-CLA on alleviating IR. PRACTICAL APPLICATION: The intake of dairy foods has been shown to be relevant with type 2 diabetes in various conditions. A potential group of biologically active compounds that attracted lots of attention these years to explain this effect might be CLA. However, the potential effect of CLA on diabetes is isomer-specific, thus, the study performed on pure CLA isomer is important to make the issue clearly. In the current study, we focused on the effect of pure t10, c12-CLA and c9, t11-CLA on IR, key characteristics of type 2 diabetes. The results show that t10, c12-CLA, rather than c9, t11-CLA improved the glucose uptake and utilization, suggesting a beneficial effect of t10, c12-CLA on alleviating type 2 diabetes. This conclusion may be of help in the research and development of functional food and pharmaceuticals rich in t10, c12-CLA for the therapy of IR and type 2 diabetes. © 2011 Wiley Periodicals, Inc.
10.1111/j.1745-4514.2010.00485.x
Journal article
Journal of Food Biochemistry
01/12/2011
35
1593 - 1602