Effect of Polyunsaturated Fatty Acids on Homocysteine Metabolism through Regulating the Gene Expressions Involved in Methionine Metabolism

The objective was to investigate the regulatory effect of polyunsaturated fatty acids (PUFAs) on mRNA expression of key genes involved in homocysteine (Hcy) metabolism. Eighty male Sprague Dawley rats were randomly divided into eight groups. The oils were orally administered daily for 8 weeks. Plasma Hcy, phospholipids fatty acids, and mRNA expression were determined. Compared with the control group, plasma Hcy was significantly decreased in the 22:6n-3 and conjugated linoleic acid (CLA) groups; mRNA expression of Mthfr was significantly upregulated in the 22:6n-3, 20:5n-3, and 18:3n-3 groups and downregulated in the 18:2n-6 and stearolic acid (SO) groups. Mat1a was upregulated in the 22:6n-3, 20:5n-3, 18:3n-3, and CLA groups. In addition, Cbs was upregulated in the 22:6n-3, 20:5n-3, 18:3n-3 and CLA groups while downregulated in 18:2n-6 and SO groups. Dietary 22:6n-3 and CLA decrease the plasma concentration of Hcy. mRNA expression of Mthfr, Mat1a, Cbs and Pemt, Gnmt, Mtrr, and Bad is upregulated by n-3 PUFA and downregulated by n-6 PUFA. CLA upregulates mRNA expression of Mat1a and Cbs.