Thrombin inhibitory activity of some polyphenolic compounds

Thrombin, also known as an active plasma coagulation factor II, belongs to the family of serine proteases and plays a crucial role in blood coagulation process. The process of thrombin generation is the central event of the hemostatic process and regulates blood coagulant activity. For this reason, thrombin inhibition is key to successful novel antithrombotic pharmacotherapy. The aim of our present study was to examine the effects of the well-known polyphenolic compounds on the activity of thrombin, by characterization of its interaction with selected polyphenols using different biochemical methods and biosensor BIAcore analyses. Only six compounds, cyanidin, quercetin, silybin, cyanin, (+)-catechin and (−)-epicatechin, of all examined in this study polyphenols caused the inhibition of thrombin amidolytic activity. But only three of the six compounds (cyanidin, quercetin and silybin) changed thrombin proteolytic activity. BIAcore analyses demonstrated that cyanidin and quercetin caused a strong response in the interaction with immobilized thrombin, while cyanin and (−)-epicatechin induced a low response. Lineweaver–Burk curves show that used polyphenol aglycones act as competitive thrombin inhibitors. Our results suggest that polyphenolic compounds might be potential structural bases and source to find and project nature-based, safe, orally bioavailable direct thrombin inhibitors.This work was supported by Grant 545/485 and Grant 506/810 from the University of Lodz

Bolsa Família: um survey sobre os efeitos do programa de transferência de renda condicionada do Brasil

Revisam-se pesquisas sobre efeitos do Programa Bolsa Família. Há quatro evidências frequentes. A primeira é que o programa tem focalização relativamente boa, mas que pode ainda ser melhorada. A segunda é o efeito positivo sobre a aquisição (consumo) de alimentos – sem conclusões sobre a qualidade da dieta. A terceira diz respeito ao estimulo às crianças a participarem da escola (matrícula, frequência e progressão), embora pouco se saiba sobre os efeitos na aprendizagem. A ausência de efeitos sobre a fecundidade das mulheres caracteriza a quarta conclusão robusta que se pode tirar da literatura, ainda que mais estudos devam ser realizados. Em outras dimensões, as evidências não formam consenso sobre direção dos efeitos.This paper surveys the literature about the effects of Bolsa Familia Program. We found four main results. The first is that the program is relatively well targeted, but it can still be improved.The second is the positive effect on the acquisition (consumption) of food, but there is no conclusions about the quality of the diet. The third is that the program encourages children to attend school (enrollment, attendance and progression). However, little is known about the effects on learning. The absence of effects on the fecundity of the women characterizes the fourth conclusion that can be drawn from the literature, although more studies must be carried out on this topic. In other dimensions, the evidence does not form consensus on the direction of effects

Resveratrol, a Natural Phenolic Compound May Reduce Carbonylation Proteins Induced by Peroxynitrite in Blood Platelets

Abstract. Resveratrol (3,4 ,5-trihydroxystilbene) has a very broad range of biological properties, including antiplatelet and antioxidative activity. We investigated in vitro the effect of resveratrol on carbonylation of proteins (indicators of oxidative stress) in blood platelets treated with peroxynitrite (ONOO − ), a strong biological oxidant and inflammatory mediator. We observed that carbonylation of proteins induced by ONOO − (0.1 mmol/l), in the presence of resveratrol (0.25-0.1 mmol/l) is reduced. Resveratrol may scavenge ONOO − , and may be useful in the prevention of ONOO − -related diseases, such as inflammatory and cardiovascular diseases

Peroxynitrite a strong biological oxidant

As demonstrated in recent years, one of the major factors of oxidative stress, generated in the circulatory system, in both acute and chronic pathological conditions, is peroxynitrite (ONOO –) [4]. Peroxynitrite is a strong biological oxidant and nitrating compound, generated in vivo from a rapid reaction of two relatively less reactive, but commonly found, of free radicals: nitrogen monoxide (NO ) and superoxide (O2–) [8]. This reaction occurs spontaneously and is not catalyzed by any enzyme. A fundamental reaction of ONOO – in biological systems is its fast reaction with carbon dioxide (k = 5,7 ź 104 M–1 s–1) and yields a short-lived intermediate, nitrosoperoxycarbonate (ONOOCO 2 –), which homolyzes leads to the formation of carbonate (CO 3–) and nitrogen dioxide (NO 2) radicals (yield ~35%) [29, 30] (Fig. 1), which are one-electron oxidants. ONOO – is responsible for oxidative modifications in a wide variety of biomolecules and is capable to induce of nitrative changes in sulfur and aromatic amino acids, especially 3-nitrotyrosine and dityrosine formation [17] (Fig. 2). This article describes the formation, reactivity and biological action of peroxynitrite

Major regional-scale production of O₃ and secondary organic aerosol in remote Amazon regions from the dynamics and photochemistry of urban and forest emissions

The Amazon rainforest suffers increasing pressure from anthropogenic activities. A key aspect not fully understood is how anthropogenic atmospheric emissions within the basin interact with biogenic emissions and impact the forest’s atmosphere and biosphere. We combine a high-resolution atmospheric chemical transport model with an improved emissions inventory and in-situ measurements to investigate a surprisingly high concentration of ozone (O3) and secondary organic aerosol (SOA) 150–200 km downwind of Manaus city in an otherwise pristine forested region. We show that atmospheric dynamics and photochemistry determine a gross production of secondary pollutants seen in the simulation. After sunrise, the erosion of the nocturnal boundary layer mixes natural forest emissions, rich in biogenic volatile organic compounds, with a lofted pollution layer transported overnight, rich in nitrogen oxides and formaldehyde. As a result, O3 and SOA concentrations greater than ∼47 ppbv and 1.8 μg m–3, respectively, were found, with maximum concentrations occurring at 2 pm LT, 150–200 km downwind of Manaus city. These high concentrations affect a large primary forested area of about 11,250 km2. These oxidative areas are under a NOx-limited regime so that changes in NOx emissions from Manaus have a significant impact on O3 and SOA production