Abstract
The present study evaluates antihyperglycemic activity of fractionated Pycnogenol® and its ability to improve endothelial dysfunction in diabetic animals. The aim of this study was to isolate from Pycnogenol® mixture its active compounds and compare their efficacy on observed parameters. Pycnogenol® mixture was fractioned by re-extracting with petroleum ether, chloroform, ethyl acetate and butanol, subsequently. Pycnogenol® mixture and fractions (butanolic, water, ethyl acetate) were administered during 6 weeks to diabetic rats. Blood glucose levels were assessed from the arterio-venous blood at the beginning of experiment and at the end of experiment. Endothelial dysfunction was evaluated as the contractile responses to phenylephrine and acetylcholine. The amount of collagen I and III was assessed from thoracic aorta after picrosirius red staining. For the confirmation of the changes on molecular level, we determinated endothelial NO synthase (eNOS) and heat shock protein 90 (Hsp90) expression from left ventricle. Overall, the result suggest, that fractions are not so effective on observed parameters as Pycnogenol® mixture itself, indicating synergistic effect of the plant constituents.