No 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.

Prilocaine (PRL) is a common local anesthetic. Despite the successful use of regional anesthesia for intraocular surgery, there are associated side effects that may affect the retina in case of accidental intravitreal injection. This study examined the signal transduction pathways activated by PRL toxicity and determined the protective role of nitric oxide synthase‐2 (NOS2) inhibition in cultured human‐derived retinal pigment epithelial cells (ARPE‐19). Toxicity analysis was performed using the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl tetrazolium bromide assay to detect the toxic dose of PRL and protective effectiveness of asperglaucide (ASP), an NOS2 inhibitor. Nuclear factor kappa B p65 (NF‐κB p65), phosphorylated NF‐κB p65, phospho‐protein kinase B (AKT), NOS2, nitrotyrosine, and cleaved caspase‐3 protein levels were evaluated by immunofluorescence staining and/or western blot analysis. Interleukin‐6 (IL‐6) and nitrated protein levels were quantified using an immunoassay, whereas caspase‐3 activity and nitrite/nitrate levels were measured using a fluorometric method. A significant increase in NF‐κB p65, and phosphorylated NF‐κB p65 and AKT levels due to PRL toxicity was observed. Similarly, IL‐6, NOS2, nitrite/nitrate, and nitrotyrosine levels were significantly higher in PRL‐treated cells than in control cells. Application of ASP to PRL‐treated cells reduced NF‐κB p65, and phosphorylated NF‐κB p65 and AKT to basal levels. IL‐6, NOS2, nitrite/nitrate, and nitrotyrosine levels also considerably decreased following ASP treatment in cells experiencing PRL‐induced toxicity. Moreover, the caspase‐3‐dependent apoptotic pathway was not activated. Our results indicate that ASP could ameliorate PRL‐induced activation of NF‐κB p65 that led to inflammation in cultured ARPE‐19 cells.