Wild blueberry (Vaccinium angustifolium) consumption affects the composition and structure of glycosaminoglycans in Sprague-Dawley rat aorta.

摘要

Among fruit and vegetables, blueberries are one of the richest sources of antioxidants, which may provide protection against coronary heart disease and stroke. Glycosaminoglycans (GAG) are functionally and structurally important carbohydrate components of the aorta; they interact with various compounds e.g. lipoproteins and are affected in the development of atherosclerosis. In this study, effects of a diet rich in blueberries on the content and structure of aortic GAG were investigated in Sprague-Dawley rats. The rats were fed on control or a blueberry-rich feeds for 13 wk. At the end of the feeding period, rats were anaesthetized and their thoracic aortas were removed. Papain digestion, alkaline borohydride treatment and anion-exchange chromatography were used to isolate aortic tissue GAG. Treatment of the fractions with specific lyases and cellulose acetate electrophoresis indicated the presence of 3 GAG populations: hyaluronan (HA); heparan sulfate (HS); and galactosaminoglycans (GalAG). Enzymic degradation followed by high-performance capillary electrophoresis was used to determine disaccharide composition. In the aortas of rats fed on blueberry feeds, content of GAs was 13% higher than in control fed rats; this difference was attributed to a higher content of GalAG (67%). Among the sulfated disaccharides, overall concn. of oversulfated disaccharides in both HS and GalAG populations were lower in the aortas of blueberry fed rats than in control fed rats. Results indicate, for the first time, that diets rich in blueberries produce structural alterations in rat aortic tissue GAG. It is suggested that these changes may affect cellular signal transduction pathways and may have major consequences for the biological function of GAG molecules within the vascular environment.