Navegando por Autor "Souza, Thiago"
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Artigo Aqueous leaf extract of Jatropha gossypiifolia L. (Euphorbiaceae) inhibits enzymatic and biological actions of Bothrops jararaca snake venom(Public Library of Science, 2014-08-15) Félix-Silva, Juliana; Souza, Thiago; Menezes, Yamara A. S.; Cabral, Bárbara; Câmara, Rafael Barros Gomes da; Silva-Junior, Arnóbio Antonio da; Rocha, Hugo Alexandre de Oliveira; Rebecchi, Ivanise Marina Moretti; Langassner, Silvana Maria Zucolotto; Fernandes-Pedrosa, Matheus de FreitasSnakebites are a serious public health problem due their high morbi-mortality. The main available specific treatment is the antivenom serum therapy, which has some disadvantages, such as poor neutralization of local effects, risk of immunological reactions, high cost and difficult access in some regions. In this context, the search for alternative therapies is relevant. Therefore, the aim of this study was to evaluate the antiophidic properties of Jatropha gossypiifolia, a medicinal plant used in folk medicine to treat snakebites. The aqueous leaf extract of the plant was prepared by decoction and phytochemical analysis revealed the presence of sugars, alkaloids, flavonoids, tannins, terpenes and/or steroids and proteins. The extract was able to inhibit enzymatic and biologic activities induced by Bothrops jararaca snake venom in vitro and in vivo. The blood incoagulability was efficiently inhibited by the extract by oral route. The hemorrhagic and edematogenic local effects were also inhibited, the former by up to 56% and the latter by 100%, in animals treated with extract by oral and intraperitoneal routes, respectively. The inhibition of myotoxic action of B. jararaca reached almost 100%. According to enzymatic tests performed, it is possible to suggest that the antiophidic activity may be due an inhibitory action upon snake venom metalloproteinases (SVMPs) and/or serine proteinases (SVSPs), including fibrinogenolytic enzymes, clotting factors activators and thrombin like enzymes (SVTLEs), as well upon catalytically inactive phospholipases A2 (Lys49 PLA2). Antiinflammatory activity, at least partially, could also be related to the inhibition of local effects. Additionally, protein precipitating and antioxidant activities may also be important features contributing to the activity presented. In conclusion, the results demonstrate the potential antiophidic activity of J. gossypiifolia extract, including its significant action upon local effects, suggesting that it may be used as a new source of bioactive molecules against bothropic venomTCC Exergoeconomic analysis of a diesel engine(Universidade Federal do Rio Grande do Norte, 2018-12) Barbosa, Arthur Marinho; Cavalcanti, Eduardo; Cavalcanti, Eduardo; Souza, Sandi; Souza, ThiagoThe method of producing power from diesel engines despite being created a long time is still quite used these days, and pollutants formation including their emission are considered one of the major sources of air pollution. This study reports the effects of the engine load on the specific cost per exergy unit of electricity. Experimental results from literature were analyzed, and using this data, combustion model based on the unburned hydrocarbons was developed. Moreover, an energy, exergy and exergoeconomic balance were carried out. Further results will be shown.Artigo In vitro anticoagulant and antioxidant activities of Jatropha gossypiifolia L. (Euphorbiaceae) leaves aiming therapeutical applications(BMC, 2014-10-20) Félix-Silva, Juliana; Souza, Thiago; Câmara, Rafael Barros Gomes da; Cabral, Bárbara; Silva-Júnior, Arnóbio Antônio da; Rebecchi, Ivanise Marina Moretti; Zucolotto, Silvana Maria; Rocha, Hugo Alexandre de Oliveira; Fernandes-Pedrosa, Matheus de FreitasBackground: Jatropha gossypiifolia L. (Euphorbiaceae) is a medicinal plant largely used in folk medicine. Teas from the leaves are popularly used as an antithrombotic agent and the branches are frequently employed as a “thick blood” agent. Considering that the anticoagulant activity associated with antioxidant properties could be beneficial for various cardiovascular diseases, this study’s aim is the evaluation of anticoagulant and antioxidant activities of J. gossypiifolia leaves, seeking new therapeutic purposes for this plant. Methods: The aqueous leaf crude extract (CE) was prepared by decoction and was fractionated by liquid-liquid partition with solvents of increasing polarity. The phytochemical analysis was performed by thin layer chromatography (TLC) and by the spectrophotometric quantification of sugars, proteins and phenolic compounds. The anticoagulant activity was evaluated by prothrombin time (PT) and activated partial thromboplastin time (aPTT) tests. The capacity to act in the fibrinolytic system (fibrinolytic and fibrinogenolytic activities) was also assessed. The antioxidant activity was evaluated by total antioxidant capacity, reducing power, copper chelating activity, iron chelating activity, hydroxyl radical scavenging activity and superoxide radical scavenging assays. The potential toxicity was evaluated using hemolytic assay and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) assay on HEK-293 cells. Results: CE showed significant anticoagulant activity in aPTT test, while no action was observed in PT test, suggesting a preferential action toward the intrinsic and/or common pathway of coagulation. No effect was observed in the fibrinolytic system. Using the aPTT test, it was observed that the residual aqueous (RA) fraction was the most active, being two times more active than CE. RA presented very significant antioxidant activity in all models tested comparable to or even higher than CE. Regarding the safety, CE and RA did not produce significant cytotoxicity in both tests employed. Phytochemical analysis revealed the presence of alkaloids, flavonoids, proteins, tannins, steroids and/or terpenoids and sugars. Conclusions: CE and RA possessed significant anticoagulant and antioxidant activity and absence of cytotoxic effect in vitro, thus showing the potential of the plant, especially RA fraction, as a new source of bioactive molecules for therapeutic purposes, with particular emphasis on the treatment of cardiovascular diseasesTCC Obtenção dos coeficientes de absorção a partir dos parâmetros de linha contidos no banco de dados HITEMP 2010(Universidade Federal do Rio Grande do Norte, 2018-12-11) Hollanda, Luiz Arthur; Maurente, André; Maurente, André; Bernardino, Gabriel; Souza, ThiagoEste trabalho teve como objetivo a obtenção dos coeficientes de absorção do H2O em diferentes temperaturas de 500 K até 2500 K, variando em 50 K, a partir dos parâmetros de linha contidos no banco de dados HITEMP 2010. Utilizou-se o programa JavaHawks para selecionar os parâmetros de cálculo do coeficiente de absorção espectral e da seção-transversal de absorção espectral. Com os dados, foram calculados bancos de dados para o coeficiente de absorção em função do número de onda, também foi feito um gráfico do fluxo de calor divergente radiativo, os resultados foram comparados com o apresentado por Solovjov et al. (2014), e verificou-se que o banco gerado está de acordo com o esperado. Os dados gerados serão utilizados em trabalhos futuros em cálculos linha-por-linha e na determinação de parâmetros para cálculos da transferência de calor por radiação utilizando-se modelos espectrais.