Rutin from Buckwheat Flowers and Leaves Exerts Protective Effect on Vascular Damage Stimulated by High Glucose In Vivo and In Vitro

Protective effect of rutin from buckwheat flowers and leaves (RBFL) was performed on vascular injury induced by high glucose stimulation. Two models were used in the experiment. In the first model, streptozotocin (STZ) was used to induce type diabetes and establish vascular injury in vivo. In the second model, thoracic aorta of normal rat was incubated in high glucose solution to establish vascular injury in vitro. The fasting blood glucose (FBG) and body weight were measured. Endothelium-dependent and non-endothelium-dependent vasodilation induced by acetylcholine (Ach) and nitroprusside (SNP) were detected, respectively. The level of reactive oxygen species (ROS), nitric oxide (NO), superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), and nitricoxide synthase (NOS) in serum were assayed. The protein expressions of inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) on thoracic aorta were also detected. RBFL could decrease PEG and ROS level, increase the NO, SOD and NOS level in serum, but had no influence on the GSH-PX activity. RBFL could improve the endothelium-dependent vasodilation induced by acetylcholine in a dose-dependent manner. RBFL has no obviously effect on non-endothelium-dependent vasodilation induced by nitroprusside. RBFL could increase the eNOS expression and decrease the iNOS expression of thoracic aorta. These findings suggest that RBFL could improve the endothelium-dependent vasodilation of thoracic aorta in high glucose injury or diabetes and the mechanism may be related to promote the NO synthesis of endothelial cells.