Abstract
Asperglaucide (ASP) is an aurantiamide, an effective constituent of purslane (Portulaca oleracea L.), a safe to eat greenery. Effects of ASP on endothelial function, endothelial nitric oxide synthase (eNOS) expression, vascular fluidity, renal and vascular reactive oxygen, and nitrogen species (ROS/RNS) production was examined in the two-kidney one-clip (2 K-1C) rat model of renovascular arterial hypertension. ASP toxicity, dose dependent eNOS gene expression and protein levels were also analyzed in human umbilical vein endothelial cells (HUVEC). The 2 K-1C model of hypertension was created via surgery and mean blood pressure (MBP) was measured by tail-cuff method during four weeks of ASP treatment. Erythrocyte deformability was monitored by rotational ektacytometry, while vascular constrictor and dilator responses were determined in organ baths. eNOS gene expression and protein levels were assessed in thoracic aorta and HUVEC. MBP was significantly decreased in hypertensive rats treated with ASP. Endothelium dependent vascular dilator and constrictor responses were also considerably improved following ASP treatment. There was a notable increase in red blood cell deformability in hypertensive rats treated with ASP as compared to hypertensive rats alone. A significant increase was observed in eNOS gene expression and protein levels in both normotensive and hypertensive rats treated with ASP. Treatment of HUVEC with 3 µM ASP notably increased eNOS mRNA and protein levels. In conclusion, ASP lowered blood pressure, improved endothelium-mediated relaxation, decreased renovascular ROS/RNS production in hypertensive rats. ASP also increased eNOS protein expression in aorta and HUVEC at nontoxic doses. ASP may have future potential as an anti-hypertensive agent.