The Effects of Cis-9, Trans-11 and Trans-10, Cis-12 Conjugated Linoleic Acids on delta4-desaturation in HepG2 Cells

Abstract

The objective of this study was to determine the effects of cis-9, trans-11 and trans-10, cis-12 CLA on the delta4-desaturation process in HepG2 cells. Experiments were conducted in which HepG2 cells were incubated with 25 micromol/L of those fatty acids and the concentrations of (n-6) and (n-3) polyunsaturated fatty acids in phosphatidyl choline and phosphatidyl ethanolamine were determined. In the presence of eicosapentaenoic acid, cells treated with trans-10, cis-12 CLA had a lower ratio of docosahexaenoic acid [22:6 (n-3)], the product of delta4-desaturation, to docosapentaenoic acid [22:5 (n-3)], the substrate of delta4-desaturation in both phospholipids, than control cells or cells treated with cis-9, trans-11 CLA (p < 0.05). This suggests that trans-10, cis-12 CLA suppresses the delta4-desaturation process in HepG2 cells.

Trans-10,cis-12-CLA-Caused Lipodystrophy Is Associated with Profound Changes of Fatty Acid Profiles of Liver, White Adipose Tissue and Erythrocytes in Mice: Possible Link to Tissue-Specific Alterations of Fatty Acid Desaturation

“…4 ) did not seem to result mainly from a shift of the percentages due to an increase of the MUFA fraction. More likely, an active sup- pression of desaturation occurred, since t 10, c 12-CLA has been shown to reduce the ⌬ 6 and ⌬ 5 desaturation ratios in HepG2 cells [55,56] . Due to the fact that only marginal amounts of C20: 4(n-6) were detectable in the liver lipids of the CLA-mix diet group, the observation that coadministration of arachidonic acid to a CLA-mix diet averts the development of fatty livers in mice [57] is of outstanding interest.…”