Plasma glucose levels of diabetes type 2 patients decreased significantly with Pycnogenol®, compared to placebo. Glycosylated hemoglobin and vasoconstrictive endothelin-1 in the blood were reduced and vaso-relaxant 6-keto prostaglandin f1 alpha was increased with Pycnogenol® but not in placebo. This evidence concerns the gene EDN1 and type 2 diabetes mellitus.