14 research outputs found
Calagualine inhibits nuclear transcription factors-ÎșB activated by various inflammatory and tumor promoting agents
Grape seed proanthocyanidins extract promotes bone formation in rat's mandibular condyle
Effect of grape seed proanthocyanidins extract on alteration of mechanical properties of metaphysis tibia bone in rats fed a low-calcium diet
Chemical constituents from the Paraguayan medicinal plant, Eupatorium macrocephalum Less.
Anti-Inflammatory Activity of Thymol: Inhibitory Effect on the Release of Human Neutrophil Elastase
Effect of two phenanthrene alkaloids on angiotensin II-induced leukocyteâendothelial cell interactions in vivo
1. The present study has evaluated the effect of two phenanthrene alkaloids, uvariopsine and stephenanthrine, on angiotensin II (Ang-II)-induced leukocyteâendothelial cell interactions in vivo and the mechanisms involved in their activity. Intravital microscopy within the rat mesenteric microcirculation was used. 2. A 60 min superfusion with 1 nM Ang-II induced a significant increase in the leukocyteâendothelial cell interactions that were completely inhibited by 1 ÎŒM uvariopsine cosuperfusion. A lower dose of 0.1 ÎŒM significantly reduced Ang-II-induced leukocyte adhesion by 75%. 3. When Ang-II was cosuperfused with 1 and 0.1 ÎŒM stephenanthrine, Ang-II-induced leukocyte responses were significantly diminished. A lower dose of 0.01 ÎŒM only affected Ang-II-induced leukocyte adhesion. 4. Both alkaloids inhibited Ang-II-induced endothelial P-selectin upregulation and the generation of reactive oxygen species (ROS) in endothelial cells stimulated with Ang-II, in fMLP-stimulated human neutrophils (PMNs) and in the hypoxanthineâxanthine oxidase system. However, cyclic AMP levels in PMNs stimulated with fMLP were not affected. 5. Uvariopsine and stephenanthrine inhibited PAF-induced elevations in intracellular calcium levels in PMNs (IC(50) values: 15.1 and 6.1 ÎŒM respectively) and blocked the binding of [(3)H]PAF to these leukocytes. They also reduced PAF-induced increases in intracellular levels of superoxide anion and hydrogen peroxide. 6. In conclusion, stephenanthrine and uvariopsine are potent inhibitors of Ang-II-induced leukocyte accumulation in vivo. This effect appears to be mediated through ROS scavenging activity and blockade of PAF receptor. Thus, they have potential therapeutic interest for the control of leukocyte recruitment that occurs in cardiovascular disease states in which Ang-II is involved