Effects of Pinus pinaster and Pinus koraiensis seed oil supplementation on lipoprotein metabolism in the rat

Abstract

The aim of the present study was to assess the effect of vegetal oils obtained from Pinus pinaster and P. koraiensis seeds on plasma lipoprotein levels and apolipoprotein (apo) gene expression in rats. These oils contain two particular fatty acids of the Δ5-unsaturated polymethylene-interrupted fatty acid (Δ5-UPIFA) family: all-cis-5,9,12-18:3 (pinolenic) and/or all-cis-5,11,14-20:3 (sciadonic) acids. Rats were fed for 28 d a diet containing 5% (w/w) oil supplement. Two control diets were prepared to match the fatty acid composition of P. pinaster or P. koraiensis oils with the exception of Δ5-UPIFA, which were replaced by oleic acid. Pinus pinaster seed oil decreased serum triglycerides by 30% (P<0.02), very low density lipoprotein (VLDL)-triglycerides by 40% (P<0.01), and VLDL-cholesterol by 33% (P<0.03). Pinus koraiensis seed oil decreased serum triglycerides by 16% [not statistically significant (ns)] and VLDL-triglycerides by 21% (ns). Gel permeation chromatography and nondenaturating polyacrylamide gel electrophoresis showed a tendency of high density lipoprotein to shift toward larger particles in pine seed oil-supplemented rats. Finally, P. pinaster seed oil treatment was associated with a small decrease of liver apoC-III (P<0.02) but not in apoE, apoA-I, or apoA-II mRNA levels. The levels of circulating apo were not affected by pine seed oil supplementation. In conclusion, P. pinaster seed oil has a triglyceride-lowering effect in rats, an effect that is due to a reduction in circulating VLDL.