Croton argyrophylloides Muell. Arg. is widely used in Brazilian folk medicine to treat diabetes and venereal diseases. This study examined the acute toxicity and cytotoxicity of the essential oil of C. argyrophylloides (EOCA). In addition, vascular effects of the EOCA have been examined. In mice, an oral acute toxicity test revealed that EOCA could be considered as a non toxic essential oil since it showed a very high LD 50 (9.84 ± 0.01 g/kg). In the brine shrimp (Artemia salina) cytotoxic assay, the LC 50 value of EOCA was 275 [165-534] µg/mL. EOCA (1-1000 µg/mL) relaxed isolated endothelium-intact aortic rings precontracted with phenylephrine with an IC 50 value of 126.7 [89.8-163.7] µg/mL. In rat mesenteric bed preparations precontracted with phenylephrine, EOCA (1-300 µg/mL) also induced a reversible, vasodilator effect with an IC 50 value of 46.0 [33.3-58.7] µg/mL. It is concluded that EOCA is a very interesting agent from the point of view of the possibility of therapeutic application. This is because, whilst showing a very small acute toxicity, EOCA also showed maximal efficacy as a vascular antispasmodic agent with a pharmacological potency similar to that of other Croton species essential oils.

Objective: To investigate the role of angiotensin II/AT 1 receptor signaling and/or cyclooxygenase-2 (COX-2) activation on vascular remodeling and stiffening of the mesenteric resistance arteries (MRA) of ouabain-treated rats.Methods: Ouabain-treated (OUA, 30 mg kg/day for 5 weeks) and vehicle (VEH)-treated Wistar rats were cotreated with losartan (LOS, AT 1 R antagonist), nimesulide (NIM, COX-2 inhibitor) or hydralazine hydrochloride plus hydrochlorothiazide. MRA structure and mechanics were assessed with pressure myography and histology. Picrosirius red staining was used to determine the total collagen content. Western blotting was used to detect the expression of collagen I/III, MMP-2, Src, NFkB, Bax, Bcl-2 and COX-2. Reactive oxygen species (ROS) and plasma angiotensin II levels were measured by fluorescence and ELISA, respectively.Results: Blockade of AT 1 R or inhibition of COX-2 prevented ouabain-induced blood pressure elevation. Plasma angiotensin II level was higher in OUA than in VEH. LOS, but not hydralazine hydrochloride with hydrochlorothiazide, prevented inward hypotrophic remodeling, increased collagen deposition and stiffness, and oxidative stress in OUA MRA. LOS prevented the reduction in the total number of nuclei in the media layer and the Bcl-2 expression induced by OUA in MRA. The higher pSrc/Src ratio, NFkB/IkB ratio, and COX-2 expression in OUA MRA were also prevented by LOS. Likewise, COX-2 inhibition prevented vascular remodeling, mechanical changes, oxidative stress and inflammation in OUA MRA. Conclusion:The results suggest that, regardless of hemodynamic adjustments, the angiotensin II/AT 1 R/pSrc/ ROS/NFkB/COX-2 pathway is involved in the development of MRA inward hypotrophic remodeling and stiffness in ouabain-treated rats.

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Aspectos emocionais e afetivos estão diretamente envolvidos com o processo de ensino e aprendizagem. Sendo assim, a pesquisa objetivou investigar a compreensão de professores da Educação Básica da rede pública de ensino de Iguatu-CE sobre como as emoções dos alunos estão envolvidas no processo de aprendizagem discente. Para tanto, entrevistou-se dez professores de Biologia, sendo avaliado o conteúdo de suas respostas. Os docentes informaram que vários fatores interferem na aprendizagem dos discentes, destacando os relacionados as emoções e as relações familiares dos estudantes. Há diferenças emocionais entre alunos de anos diferentes devido ao processo de amadurecimento dos adolescentes, além de fatores como sono e estresse que interferem negativamente na aprendizagem. Ações que trabalhem o emocional dos estudantes e formações continuadas para professores sobre o assunto supracitado podem ser feitas para melhorar o desempenho dos discentes. Para que a aprendizagem dos estudantes se torne cada vez mais efetiva é importante que o professor esteja atento a todos os fatores importantes no processo de ensino e aprendizagem sejam eles curriculares, pedagógicos e/ou emocionais.