Pinolenic acid is a polyunsaturated fatty acid found in Korean pine (Pinus orientalis) and maritime pine (Pinus pinaster) seed oils. Both oils have been found to have lipid-lowering properties. A diet containing maritime pine seed oil (MPSO) lowered high-density lipoprotein and ApoA1 levels in transgenic mice expressing human ApoA1. MPSO was found to diminish cholesterol efflux in vitro. Korean pine seed oil supplements may help in obesity by reduction of appetite. People taking this oil had an increase in the satiety hormones CCK and GLP-1 and a reduced desire to eat. The activity of the oil is attributed to pinolenic acid. Pinolenic acid is not converted to arachidonic acid metabolically and can reduce arachidonic acid levels in the phosphatidylinositol fraction of HepG2 cells from 15.9% to 7.0%. Pinolenic acid ethyl ester is a neutral, more lipophilic form of the free acid.