Dehydrodieugenol B and hexane extract from Endlicheria paniculata regulate inflammation, angiogenesis, and collagen deposition induced by a murine sponge model.

The present study reports the evaluation of hexane extract from Endlicheria paniculata and its main metabolite dehydrodieugenol B in the inflammatory response induced by a murine implant sponge model. As a result, a reduction in the inflammatory markers (myeloperoxidase and N-acetyl-ß-D-glucosaminidase) and number of mast cells were observed in comparison to the control group. All doses were also able to reduce angiogenic parameters evaluated in fibrovascular tissue. In implants treated with dehydrodieugenol B a reduction in total collagen deposition and types I and III collagen fibers were observed, while an increased in total collagen deposition and types I and III collagen fibers were observed in the treatment with hexane extract. Docking studies into cyclooxygenase-2 active site revealed that the dehydrodieugenol B had binding modes and energies comparable with celecoxib, diclofenac and ibuprofen. Therefore, dehydrodieugenol B was able to alter key components of chronic inflammation, resulting in a reduced inflammatory response and also presenting antifibrogenic and antiangiogenic effects. However, treatment with hexane extract resulted in a reduced inflammatory response with antiangiogenic effects, but caused fibrogenic effects.

Purification and characterization of tenerplasminin-1, a serine peptidase inhibitor with antiplasmin activity from the coral snake (Micrurus tener tener) venom.

A plasmin inhibitor, named tenerplasminin-1 (TP1), was isolated from Micrurus tener tener (Mtt) venom. It showed a molecular mass of 6542Da, similarly to Kunitz-type serine peptidase inhibitors. The amidolytic activity of plasmin (0.5nM) on synthetic substrate S-2251 was inhibited by 91% following the incubation with TP1 (1nM). Aprotinin (2nM) used as the positive control of inhibition, reduced the plasmin amidolytic activity by 71%. Plasmin fibrinolytic activity (0.05nM) was inhibited by 67% following incubation with TP1 (0.1nM). The degradation of fibrinogen chains induced by plasmin, trypsin or elastase was inhibited by TP1 at a 1:2, 1:4 and 1:20 enzyme:inhibitor ratio, respectively. On the other hand, the proteolytic activity of crude Mtt venom on fibrinogen chains, previously attributed to metallopeptidases, was not abolished by TP1. The tPA-clot lysis assay showed that TP1 (0.2nM) acts like aprotinin (0.4nM) inducing a delay in lysis time and lysis rate which may be associated with the inhibition of plasmin generated from the endogenous plasminogen activation. TP1 is the first serine protease plasmin-like inhibitor isolated from Mtt snake venom which has been characterized in relation to its mechanism of action, formation of a plasmin:TP1 complex and therapeutic potential as anti-fibrinolytic agent, a biological characteristic of great interest in the field of biomedical research. They could be used to regulate the fibrinolytic system in pathologies such as metastatic cancer, parasitic infections, hemophilia and other hemorrhagic syndromes, in which an intense fibrinolytic activity is observed.

Inhibitors of melanogenesis in B16 melanoma 4A5 cells from flower buds of Lawsonia inermis (Henna).

The methanolic extract of Lawsonia inermis L. (henna) showed significant inhibitory activity toward melanogenesis in B16 melanoma 4A5 cells. Among the constituents isolated from the methanolic extract, luteolin, quercetin, and (±)-eriodictyol showed stronger inhibitory activity than the reference compound, arbutin. Several structure-activity relationships of the flavonoids were suggested, and OGlc

Deficient antithrombin III activity and enhanced fibrinolysis in patients with liver disease: evidence against a cause-effect relationship.

To investigate the pathogenesis of fibrinolysis in liver disease, antithrombin III (AT III) activity, prothrombin fragment (F1 + 2) and d-dimer (D-DI) were measured in 50 patients with liver disease and in 17 healthy controls. Moreover, 4 patients with cirrhosis were randomly assigned to receive either an intravenous infusion of AT III (at two different dosages) or placebo, with a crossover design. Increased levels of D-DI were detected in patients with cirrhosis and hepatocellular carcinoma in comparison both with control subjects and with patients with acute hepatitis or mild chronic liver disease. An inverse correlation was observed between AT III and D-DI (r = -0.755, P < 0.001, simple linear regression), while no correlation was found between D-DI or AT III and F1 + 2. The correlation of the deficiency of AT III activity by infusion of human AT III did not result in any significant change (P0.10, analysis of variance for repeated measures) of the plasma concentration of either D-DI or F1 + 2, in comparison to placebo. Thus, advanced forms of chronic liver disease, but not acute hepatitis and mild forms of chronic liver disease, are associated with increased plasma concentrations of markers of fibrinolysis, which are inversely correlated with AT III activity. However, the correction of the deficient AT III activity does not affect the plasma concentration of either D-DI or F1 + 2, thence not supporting the hypothesis that enhanced fibrinolysis in advanced liver disease is the result of low-grade disseminated intravascular coagulation.

Low molecular weight fibrinolytic inhibitor from Guerin epithelioma.

Antifibrinolytic activity of the extract from Guerin epithelioma, a highly metastatic tumour implanted to rats, was determined by fibrinolytic and zymographic methods. The extract exhibits antifibrinolytic activity which is thermostable (60-100 degrees C) and pH-stable (pH 2.7-12). It contains a fibrinolytic inhibitor, with Mr about 7000, with antiplasmin properties, bound to lys-Sepharose and heparin-Sepharose. The molecular weight, physicochemical properties and antiplasmin action of the epithelioma inhibitor prove its identity with the low molecular weight antifibrinolytic factor appearing in the plasma of rats during the development of this tumour.

An inhibitor of plasminogen activator in rabbit endothelial cells.

The antifibrinolytic activity of cytosols obtained from cultured rabbit endothelial cells was studied to determine whether it resulted from the presence of an antiplasmin or an antiactivator. These cytosol preparations inhibited the fibrinolytic activity initiated by some plasminogen activators (e.g. urokinase, rabbit endothelial cell activator), but not others (e.g. activators associated with bovine endothelial cells and Rous sarcoma virus-infected chick embryo fibroblasts), suggesting that inhibition occurred at the level of plasmin formation, not plasmin activity. The fibrinolytic activity of plasmin itself was unaffected by concentrations of cytosol that completely blocked urokinase-mediated fibrinolysis consistent with this conclusion. In addition, the ability of urokinase to cleave 125I-plasminogen into its characteristic activation fragments was inhibited by cytosol in a dose-dependent manner. When urokinase was analyzed by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate, two peaks of activity were detected, corresponding to Mr = 55,000 and 32,000. Urokinase preincubated with cytosol and analyzed in a similar manner demonstrated no activity in any portion of the gel, suggesting that its ability to function as a plasminogen activator was irreversibly lost following its interaction with cytosol. These results indicate that the antifibrinolytic activity of rabbit endothelial cells results from the presence of a molecule or molecules with antiactivator activity. The cellular location and unusual degree of specificity distinguish the endothelial cell inhibitor(s) from antifibrinolytic agents observed in other cells and in plasma and platelets.