High‐level exogenous trans 10, cis 12 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 trans 10, cis 12 conjugated linoleic acid ( CLA ) to evaluate the effects of different level trans 10, cis 12 CLA on lipogenesis in BMEC . Addition of 75–150 μmol/L trans 10, cis 12 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 trans 10, cis 12 CLA for 48 h resulted in a 17.1% reduction ( P  < 0.0001) of medium chain fatty acids ( MCFA , C 14 < C < C 16), 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 ( SCD 1 ) ( P  = 0.002). Another finding was that trans 10, cis 12 CLA elevated expression of diacylglycerol acyltransferase2 ( DGAT 2 ) ( P  = 0.020) and long chain acylCoA synthetases ( ACSL ) ( P  = 0.032). In conclusion, higher trans 10, cis 12 CLA , not low trans 10, cis 12 CLA , inhibited milk fat synthesis and changed fatty acid composition by regulating the expression of FAS , ACC , SCD 1, DGAT 2 and ACSL .