Protective effects of soluble fiber from undaria pinnatifida on vascular endothelium in mice

The objective of this study was to investigate the protective effect of soluble fiber extracted from Undaria pinnatifida (UP) on vascular endothelium and the mechanisms involved. The experiments were performed in aorta and plasma from C57BL/6J control and apolipoprotein E deficient (ApoE‐ / ‐) mice treated or not with UP soluble fiber (5 or 10%) for 8 weeks. UP soluble fiber treatment improved endothelium‐dependent vasorelaxation, increased the maximal relaxation value, and decreased the half‐maximum effective concentration concomitantly with a decrease in asymmetric dimethylarginine (ADMA) and malondialdehyde plasma concentrations, and increase in the expression as well as activity of dimethylarginine dimethylaminohydrolase II in ApoE‐ / ‐ mice. Treatment with UP soluble fiber also significantly decreased reactive oxygen species production in mice aorta. The present results suggest that the protective effect of UP soluble fiber on vascular endothelium may be associated with a decrease in ADMA level in mice. PRACTICAL APPLICATIONS: Soluble fiber have complex beneficial effects on cardiovascular system such as lowering serum cholesterol, inhibiting lipid peroxidation, reducing blood pressure, increasing insulin sensitivity, modulating plasma glucose, improving homocysteine levels, protecting against intima‐media thickness progression of the common carotid arteries, and decreasing the serum levels of markers of inflammation. The present work reports that the protective effect of Undaria pinnatifida soluble fiber on vascular endothelium may be associated with a decrease in ADMA level. It complements previous work. This is important because the mechanism responsible for the protective effect of fiber on endothelial function is defined. Furthermore, it provides information for the consumer about the potential effects of fiber and Undaria pinnatifida.