37 research outputs found
Trypanocidal Activity Of Brazilian Plants Against Epimastigote Forms From Y And Bolivia Strains Of Trypanosoma Cruzi
Chagas disease is one of the main public health problems in Latin America. Since the available treatments for this disease are not effective in providing cure, the screening of potential antiprotozoal agents is essential, mainly of those obtained from natural sources. This study aimed to provide an evaluation of the trypanocidal activity of 92 ethanol extracts from species belonging to the families Annonaceae, Apiaceae, Cucurbitaceae, Lamiaceae, Lauraceae, Moraceae, Nyctaginaceae, and Verbenaceae against the Y and Bolivia strains of Trypanosoma cruzi. Additionally, cytotoxic activity on LLCMK2 fibroblasts was evaluated. Both the trypanocidal activity and cytotoxicity were evaluated using the MTT method, in the following concentrations: 500, 350, 250, and 100 μg/mL. Benznidazole was used for positive control. The best results among the 92 samples evaluated were obtained with ethanol extracts of Ocotea paranapiacabensis (Am93) and Aegiphila lhotzkiana (Am160). Am93 showed trypanocidal activity against epimastigote forms of the Bolivia strain and was moderately toxic to LLCMK2 cells, its Selectivity Index (SI) being 14.56, while Am160 showed moderate trypanocidal activity against the Bolivia strain and moderate toxicicity, its SI being equal to 1.15. The screening of Brazilian plants has indicated the potential effect of ethanol extracts obtained from Ocotea paranapiacabensis and Aegiphila lhotzkiana against Chagas disease.223528533Bastos, J.K., Albuquerque, S., Silva, M.L.A., Evaluation of the trypanocidal activity of lignans isolated from the leaves of Zanthoxylum naranjillo (1999) Planta Med, 65, pp. 1-4Batista Jr., J.M., Lopes, A.A., Ambrósio, D.L., Regasini, L.O., Kato, M.J., Bolzani, V.S., Cicarelli, R.M., Furlan, M., Natural chromenes and chromene derivatives as potencial antitrypanosomal agents (2008) Biol Pharm Bull, 31, pp. 538-540Botsaris, A., Plants used traditionally to treat malaria in Brazil: The archives of Flora Medicinal (2007) J Ethnobiol Ethnomed, 1, p. 18Buainain, A., Giazzi, J.F., Belda Neto, F.M., Martini, A.S., Rosa, J.A., Pozetti, G.L., Estudo da atividade de extratos vegetais sobre o desenvolvimento de Trypanosoma cruzi em meio líquido de Warren (1992) Rev Cien Farm, 14, pp. 93-102Cabral, M.M., Barbosa-Filho, J.M., Maia, G.L., Chaves, M.C., Braga, M.V., de Souza, W., Neolignans from plants in northeastern Brazil (Lauraceae) with activity against (2010) Trypanosoma Cruzi. Exp Parasitol, 124, pp. 319-324Costa-Lotufo, L.V., Silveira, E.R., Barros, M.C., Lima, M.A., de Moraes, M.E., de Moraes, M.O., Pessoa, C., Antiproliferative effects of abietane diterpenes from aegiphilla lhotzkyana (2004) Planta Med, 70, pp. 180-182Cotinguiba, F., Regasini, L.O., Bolzani, V.S., Debonsi, H.M., Passerini, D.O., Cicarelli, R.M.B., Kato, M.J., Furlan, M., Piperamides and their derivatives as potential antitrypanosomal agents (2009) Med Chem Res, 18, pp. 703-711Coura, J.R., Castro, S.L., A critical review on Chagas disease chemotherapy (2002) Mem I Oswaldo Cruz, 97, pp. 3-24Coura, J.R., Present situation and new strategies for Chagas disease chemotherapy: A proposal (2009) Mem I Oswaldo Cruz, 104, pp. 549-554Fernandes, O., Souto, R.P., Castro, J.A., Pereira, J.B., Fernandes, N.C., Junqueira, A.C., Naiff, R.D., Coura, J.R., Brazilian isolates of Trypanosoma cruzi from humans and triatomines classified into two lineages using mini-exon and ribosomal RNA sequences (1998) Am J Trop Med Hyg, 58, pp. 807-811Fournet, A., Ferreira, M.E., Rojas de Arias, A., Guy, I., Guinaudeau, H., Heinzen, H., Phytochemical and antiprotozoal activity of (2007) Ocotea Lancifolia. Fitoterapia, 78, pp. 382-384Lopes, A.A., López, S.N., Regasini, L.O., Batista, J.M., Ambrósio, D.L., Kato, M.J., da Silva, B.V., Furlan, M., In vitro activity of compounds isolated from Piper crassinervium against Trypanosoma cruzi (2008) Nat Prod Res, 22, pp. 1040-1046Macedo, A.M., Oliveira, R.P., Pena, S.D.J., Chagas disease: Role of parasite genetic variation in pathogenesis (2002) Exp Mol Med, 4, pp. 1-16Muelas-Serrano, S., Nogal-Ruiz, J.J., Gómez-Barrio, A., Setting of a colorimetric method to determine the viability of Trypanosoma cruzi epimastigotes (2000) Parasitol Res, 86, pp. 999-1002Nwaka, S., Ridley, R.G., Virtual drug discovery and development for neglected diseases through publicprivate partnerships (2003) Nat Rev Drug Discov, 2, pp. 919-928Osorio, E., Arango, G.J., Jiménez, N., Alzate, F., Ruiz, G., Gutiérrez, D., Paco, M.A., Robledo, S., Antiprotozoal and cytotoxic activities in vitro of Colombian Annonaceae (2007) J Ethnopharmacol, 111, pp. 630-635Regasini, L.O., Cotinguiba, F., Passerini, G.D., Bolzani, V.S., Cicarelli, R.M.B., Kato, M.J., Furlan, M., Trypanocidal activity of Piper arboreum and Piper tuberculatum (Piperaceae) (2009) Rev Bras Farmacog, 19, pp. 199-203Saraiva, J., Vega, C., Rolon, M., da Silva, R., Silva, M.L., Donate, P.M., Bastos, J.K., de Albuquerque, S., In vitro and in vivo activity of lignan lactones derivatives against Trypanosoma cruzi (2007) Parasitol Res, 100, pp. 791-795Tibayrenc, M., Ayala, F.J., The clonal theory of parasitic protozoa: 12 years on (2002) Trends Parasitol, 18, pp. 405-410(2010), http://www.who.int/mediacentre/factsheets/fs340/en/index.html, World Health Organization 2010, accessed in Au
Radiative Cooling in MHD Models of the Quiet Sun Convection Zone and Corona
We present a series of numerical simulations of the quiet Sun plasma threaded
by magnetic fields that extend from the upper convection zone into the low
corona. We discuss an efficient, simplified approximation to the physics of
optically thick radiative transport through the surface layers, and investigate
the effects of convective turbulence on the magnetic structure of the Sun's
atmosphere in an initially unipolar (open field) region. We find that the net
Poynting flux below the surface is on average directed toward the interior,
while in the photosphere and chromosphere the net flow of electromagnetic
energy is outward into the solar corona. Overturning convective motions between
these layers driven by rapid radiative cooling appears to be the source of
energy for the oppositely directed fluxes of electromagnetic energy.Comment: 20 pages, 5 figures, Solar Physics, in pres
Solar Ultraviolet Bursts
The term “ultraviolet (UV) burst” is introduced to describe small, intense, transient brightenings in ultraviolet images of solar active regions. We inventorize their properties and provide a definition based on image sequences in transition-region lines. Coronal signatures are rare, and most bursts are associated with small-scale, canceling opposite-polarity fields in the photosphere that occur in emerging flux regions, moving magnetic features in sunspot moats, and sunspot light bridges. We also compare UV bursts with similar transition-region phenomena found previously in solar ultraviolet spectrometry and with similar phenomena at optical wavelengths, in particular Ellerman bombs. Akin to the latter, UV bursts are probably small-scale magnetic reconnection events occurring in the low atmosphere, at photospheric and/or chromospheric heights. Their intense emission in lines with optically thin formation gives unique diagnostic opportunities for studying the physics of magnetic reconnection in the low solar atmosphere. This paper is a review report from an International Space Science Institute team that met in 2016–2017
Phenology, caudex growth and age estimation of Cyathea corcovadensis (Raddi) Domin (Cyatheaceae) in a subtropical forest in southern Brazil
Obese obstructive sleep apnea patients with tonsil hypertrophy submitted to tonsillectomy
Crescimento do cáudice e fenologia de Dicksonia sellowiana Hook. (Dicksoniaceae) no sul do Brasil
Plasma lipid profiles discriminate bacterial from viral infection in febrile children
Fever is the most common reason that children present to Emergency Departments. Clinical signs and symptoms suggestive of bacterial infection ar
Avaliação de atividade fungitóxica e isolamento de aloaromadendrano - 4α, 10 β - diol em Hypericum cordatum
Hypericum cordatum é uma espécie do cerrado que foi selecionada em triagem de plantas com atividade fungitóxica. O objetivo do presente trabalho foi isolar e identificar compostos com atividade antifúngica em extratos de folhas em diclorometano. O pó das folhas das plantas foi submetido à extração exaustiva com éter de petróleo e diclorometano. O extrato em diclorometano, e as frações ativas, foram submetidos à fracionamentos biomonitorados em coluna de Sephadex LH-20, respectivamente, com os eluentes clorofórmio:metanol (1:1) e com um gradiente de hexano:diclorometano (1:4); diclorometano:acetona (3:2 e 1:4), metanol, e água. As frações que mostraram atividade foram submetidas à cromatografia em camada delgada preparativa de sílica gel GF254, sendo que o material de maior massa foi analisado em CLAE semipreparativa. A fração ativa foi analisada por RMN de ¹H, tendo sido identificado o aloaromadendrano - 4α -10β - diol como componente principal da fração. Conclui-se, portanto, que este é um dos compostos responsáveis pela atividade fungitóxica de Hypericum cordatum