High-level exogenous trans10, cis12 conjugated linoleic acid plays an anti-lipogenesis role in bovine mammary epithelial cells.

Primary bovine mammary epithelial cells (BMECs) were treated by 0, 37.5, 75, 112.5, 150 μmol/L trans10, cis12 conjugated linoleic acid (CLA) to evaluate the effects of different level trans10, cis12 CLA on lipogenesis in BMEC. Addition of 75-150 μmol/L trans10, cis12 CLA reduced significantly the triacylglycerol (TAG) content (P<0.05), but did not have inhibiting action on cell proliferation (P>0.05). Treatment with 150 μmol/L trans10, cis12 CLA for 48 h resulted in a 17.1% reduction (P<0.0001) of medium chain fatty acids (MCFA, C14<C<C16), a 26.5% reduction (P<0.0001) of unsaturated fatty acids (UFA) and a corresponding reduction of the mRNA abundance of acetyl coenzyme A (acetylCoA) carboxylase (ACC) (P=0.046), fatty acid synthase (FAS) (P=0.017) and stearoylCoA desaturase1 (SCD1) (P=0.002). Another finding was that trans10, cis12 CLA elevated expression of diacylglycerol acyltransferase2 (DGAT2) (P=0.020) and long chain acylCoA synthetases (ACSL) (P=0.032). In conclusion, higher trans10, cis12 CLA, not low trans10, cis12 CLA, inhibited milk fat synthesis and changed fatty acid composition by regulating the expression of FAS, ACC, SCD1, DGAT2 and ACSL.