Evaluation of antibacterial activity of plant extracts on Staphylococcus aureus isolated from bovine mastitis

A resistência bacteriana é responsável perante o fracasso no tratamento de infecções com agentes quimioterápicos. São necessárias novas alternativas para controlar estes micro-organismos. Entre essas alternativas estão plantas utilizadas tradicionalmente na medicina popular. O presente trabalho avaliou a eficiência dos extratos etanólicos e acetonicos de folhas de Cecropia pachystachya e Curatella americana com atividade antibacteriana in vitro em cepas de Staphylococcus aureus isolado de caso de mastite bovina. Os extratos de C. pachystachya e C. americana apresentam MIC de 2,5 mg.mL-1. O composto isolado de C. pachystachya denominado EEB2 apresentou actividade bactericida para uma concentração de 1,25 mg.mL-1. Estes resultados demonstram que os extratos de C. pachystachya e C. americana contém compostos anti-bacterianos.Bacterial drug resistance is responsible for the failure of the treatment of infection using chemotherapeutic agents. Thus, new approaches are necessary for the control of these microorganisms. Included among these alternatives are several plants that are traditionally used in folk medicine. Therefore, the aim of this study was to evaluate the antibacterial activity of the ethanolic and acetone extracts of leaves of Cecropia pachystachya and Curatela americana in vitro against S. aureus bacteria isolates from cases of bovine mastitis. The extracts from C. pachystachya and Curatela americana had a MIC of 2.5 mg.mL-1. The compound isolated from C. pachystachya called EEB2 showed bactericidal activity at a concentration of 1.25 mg.mL-1. These results demonstrate that the extracts of C. pachystachya and C. americana contains antibacterial compounds

Study of the inhibitory activity of plant extracts, flavonoids and derivatives of caffeic acid on Leishmania arginase enzyme (Leishmania) amazonensis

Causada por protozoários do gênero Leishmania, a leishmaniose é uma doença infecciosa que afeta milhões de pessoas em todos os continentes. São grandes os desafios no tratamento da leishmaniose porque os fármacos atualmente disponíveis apresentam alta toxicidade, efeitos colaterais, alto custo e resistência parasitária. Sendo assim, faz-se necessário o desenvolvimento de novas drogas para o tratamento da doença de maneira mais eficiente. A investigação de novas alternativas terapêuticas, novos alvos bioquímicos, em particular a arginase em de Leishmania (L) amazonensis, é considerada um alvo interessante na busca de novos compostos leishmanicidas. A via bioquímica em que está envolvida a arginase é fundamental para a manutenção do ciclo de vida do parasito, sendo responsável pela hidrólise de L-arginina em L-ornitina em mamíferos. Muitos compostos oriundos de produtos naturais tem sido relatados como inibidores da arginase de L. (L.) amazonensis e a presença de grupos hidroxila em suas estruturas mostraram ser importantes na atividade inibidora da enzima. O objetivo desse trabaho estudar a interação bioquímica entre a enzima arginase de L. (L.) amazonensis, extratos vegetais, flavonoides e derivados do ácido cafeico. O extrato acetônico de folhas de Qualea grandiflora apresentou maior capacidade inibitória da arginase (IC50 = 1,7 ± 01 µg/mL) dentre os extratos analisados. Dentre os flavonoides, o composto mais potente foi a taxifolina (IC50 = 1,7 ± 0,2 µM). O verbascosídeo foi o derivado do ácido cafeico com maior potencial de inibição da arginase (IC50 = 0,5 ± 0,2 µM). As estruturas desses compostos podem servir como referência no desenvolvimento de novas drogas para o controle da leishmaniose, que tenham como alvo a arginase.Caused by protozoa of the genus Leishmania, leishmaniosis is an infectious disease that affects millions of people on all continents. The currently available drugs are highly toxic, expensive, have side effects and parasitic resistance and for these reasons there is a need of developing new drugs to more effective treatment of the disease. The research of new therapeutic alternatives, new biochemical targets, in particular the arginase of Leishmania (Leishmania) amazonensis is considered an interesting target in the search for new compounds leishmanicidal. The biochemistry of arginase pathway is essential for the survival of the parasite, is also responsible for hydrolysis of L- arginine to L- ornithine in mammals. Many compounds from natural products has been reported as inhibitors of arginase L. (L.) amazonensis, and the presence of hydroxyl groups in their structures shown to be important for inhibitory activity of the enzyme. This work studies the biochemical interaction between the arginase enzyme, plant extracts, flavonoids and derivatives of caffeic acid. The acetone extract of Qualea grandiflora leaves showed higher inhibitory capacity of arginase (IC50 = 1.7 ± 01 µg/mL) from the analyzed extracts. Among the flavonoids, the most potent compound was taxifolin (IC50 = 1.7 ± 0.2 µM). The verbascosideo was the derivative of caffeic acid with greater potential for arginase inhibition (IC50 = 0.5 ± 0.2 µM) The structures of these compounds can serve as a reference in developing new drugs for the control of leishmaniosis, which target arginase

Phytochemistry

Texto completo. Acesso restrito. p. 71–77The plant Cecropia pachystachya Trécul is widely used in Brazilian ethnomedicine to treat hypertension, asthma, and diabetes. Arginase is an enzyme with levels that are elevated in these disorders, and it is central to Leishmania polyamine biosynthesis. The aims of this study were to evaluate antileishmanial activity and inhibition of the arginase enzyme by C. pachystachya extracts, and to study changes in cellular organization using electron microscopy. The ethanol extract of C. pachystachya was tested on Leishmania (Leishmania) amazonensis promastigote survival/proliferation and arginase activity in vitro. Qualitative ultrastructural analysis was also used to observe changes in cell organization. The major bioactive molecules of the ethanol extract were characterized using liquid chromatography–electrospray ionizationmass spectrometry (LC–ESI-MS). The ethyl acetate fraction of the ethanol extract diminished promastigote axenic growth/survival, inhibited arginase activity, and altered a mitochondrial kinetoplast DNA (K-DNA) array. The bioactive compounds of C. pachystachya were characterized as glucoside flavonoids. Orientin (9) (luteolin-8-C-glucoside) was the main component of the methanol-soluble ethyl acetate fraction obtained from the ethanol extract and is an arginase inhibitor (IC50 15.9 lM). The ethyl acetate fraction was not cytotoxic to splenocytes at a concentration of 200 lg/mL. In conclusion, C. pachystachya contains bioactive compounds that reduce the growth of L. (L.) amazonensis promastigotes, altering mitochondrial K-DNA arrangement and inhibiting arginase.Salvado

Leishmanicidal activity of Cecropia pachystachya flavonoids: arginase inhibition and altered mitochondrial DNA arrangement

Submitted by Ana Maria Fiscina Sampaio ([email protected]) on 2013-10-23T17:55:30Z No. of bitstreams: 1 Cruz, ED Leishmanicidal activity....pdf: 753862 bytes, checksum: c99ee95789e442d656e72a0f4b9edb0c (MD5)Made available in DSpace on 2013-10-23T17:55:30Z (GMT). No. of bitstreams: 1 Cruz, ED Leishmanicidal activity....pdf: 753862 bytes, checksum: c99ee95789e442d656e72a0f4b9edb0c (MD5) Previous issue date: 2013Fundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Laboratório de Biologia Parasitária. Salvador, BA, BrasilUniversidade de São Paulo. Faculdade de Zootecnia e Engenharia de Alimentos. Departamento de Medicina Veterinária. São Paulo, SP, BRasilUniversidade de São Paulo. Faculdade de Medicina de Ribeirão Preto. Departamento de Fisiologia. Ribeirão Preto, SP, BrasilFundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Laboratório de Biologia Parasitária. Salvador, BA, BrasilUniversidade de São Paulo. Faculdade de Zootecnia e Engenharia de Alimentos. Pirassununga, SP, BrazilUniversidade de São Paulo. Faculdade de Zootecnia e Engenharia de Alimentos. Departamento de Medicina Veterinária. São Paulo, SP, BRasilCurso de Farmácia. Unidade de Ensino Superior Ingá. Maringa, SP, BrazilUniversidade Federal da Bahia. Instituto de Química. Departamento de Química Orgânica. Salvador, BA, BrazilFundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Laboratório de Biologia Parasitária. Salvador, BA, BrasilThe plant Cecropia pachystachya Trécul is widely used in Brazilian ethnomedicine to treat hypertension, asthma, and diabetes. Arginase is an enzyme with levels that are elevated in these disorders, and it is central to Leishmania polyamine biosynthesis. The aims of this study were to evaluate antileishmanial activity and inhibition of the arginase enzyme by C. pachystachya extracts, and to study changes in cellular organization using electron microscopy. The ethanol extract of C. pachystachya was tested on Leishmania (Leishmania) amazonensis promastigote survival/proliferation and arginase activity in vitro. Qualitative ultrastructural analysis was also used to observe changes in cell organization. The major bioactive molecules of the ethanol extract were characterized using liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS). The ethyl acetate fraction of the ethanol extract diminished promastigote axenic growth/survival, inhibited arginase activity, and altered a mitochondrial kinetoplast DNA (K-DNA) array. The bioactive compounds of C. pachystachya were characterized as glucoside flavonoids. Orientin (9) (luteolin-8-C-glucoside) was the main component of the methanol-soluble ethyl acetate fraction obtained from the ethanol extract and is an arginase inhibitor (IC50 15.9 µM). The ethyl acetate fraction was not cytotoxic to splenocytes at a concentration of 200 µg/mL. In conclusion, C. pachystachya contains bioactive compounds that reduce the growth of L. (L.) amazonensis promastigotes, altering mitochondrial K-DNA arrangement and inhibiting arginase