Navegando por Assunto "Leishmanicida"

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Acesso aberto (Open Access)
Estudos farmacognósticos, fitoquímicos e atividade antileishmania de espécies Geissospermum (Apocynaceae)
(Universidade Federal do Pará, 2016-11-07) SILVA, João Victor da Silva e; MARINHO, Andrey Moacir do Rosario; http://lattes.cnpq.br/2511998363000599; DOLABELA, Maria Fâni; http://lattes.cnpq.br/0458080121943649
This study aimed to perform pharmacognostic and phytochemical studies, and assess antileishmanial activity and cytotoxicity of Geissospermum vellosii Allemão and Geissospermum sericeum Miers. The pharmacognostic study was carried out as described in the Brazilian Pharmacopoeia, 2010. The ethanol extracts (GVEE and GSEE) were obtained by exhaustive maceration with ethanol (96 ° GL), followed by concentration in rotaevaporator. The ethanol extract was fractionated using two methods: extraction under reflux (fractions of different polarities) and acid-base partition (neutral and alkaloid fractions). The alkaloid fractions (GVAF and GSAF) were fractionated on a chromatographic column with Sephadex LH-20 gel, and the resulting subfractions were analyzed on TLC, and reveled through Dragendorff reagent and ultraviolet (365 nm). The F6GVAF and F6GSAF subfractions, with alkaloids detected and good yield, were subjected to semi-preparative HPLC-DAD, and spectrophotometric methods. For evaluating the antileishmanial activity, promastigote forms of Leishmania amazonensis at a concentration of 5 x 106 parasites/100μL were treated with the samples at different concentrations for 24, 48 and 72h. The analysis was done adding [3- (4,5-dimethylthiazol-2-yl) -2,5- diphenyltetrazolium bromide (MTT) to the samples in an ELISA reader at 490 nm. Cytotoxicity was assessed through cell viability assay with MTT in differentiated THP- 1 cells and HepG2. As a selection criteria, the selectivity index (IS) was calculated as the ratio between the cytotoxic concentration 50% in cell lines, and the inhibitory concentration 50% found for protozoa, considering as promising values ≥ 10. The plant powder was classified as thick (G. vellosii), and very thick (G. sericeum), low density, with pH 4.94 (G. vellosii) and 6.47 (G. sericeum), negative to saponins, with ash and moisture within the parameters established by the Brazilian Pharmacopoeia V. In the phytochemical study, we suggest the isolation of an indole alkaloid (F3F6FAGV) and a β-carbolinic (flavopereirine) from both species. The fractionation of GVEE and GSEE resulted in more cytotoxic subfractions, but the exposure time and refractionation reduced this effect. In the antipromatigota assay, all samples were active, and the fractionation increased the activity. The flavopereirine presented time-dependent activity greater than amphotericin B. However, the flavopereirine in association with indole alkaloid and/or amphotericin B reduced the selectivity of this metabolite. The extracts fractionation increases the selectivity index, and the selectivity of flavopereirin is high (SI = 4893.3). Therefore, the isolation of flavopereirine contributes to reduce cytotoxicity and increase selectivity, showing itself as a promising antileishmanial agent.
Acesso aberto (Open Access)
Estudos farmacognósticos, fitoquímicos e biológicos de Annona glabra L. (Annonaceae)
(Universidade Federal do Pará, 2016-05-12) BRÍGIDO, Heliton Patrick Cordovil; MARINHO, Moacir do Rosario Marinho; http://lattes.cnpq.br/2511998363000599; DOLABELA, Maria Fâni; http://lattes.cnpq.br/0458080121943649
In this study, the Annona glabra underwent pharmacognostic, phytochemicals and biological studies (leishmanicide and antimicrobial activity). In pharmacognostic studies, we used the methods described in Brazilian Pharmacopoeia V ed. (2010). The ethanolic extract (EE) was obtained by maceration of the powder batch of shells with ethanol. The extract was fractionated by liquid-liquid partition with hexane and 10% aqueous methanol resulting in hexane (HF), and methanol (MF) fractions. The MF was submitted to Sephadex column. This procedure resulted in 46 fractions that were analyzed in thin layer chromatography and revealed with sulfuric acid, Dragendorff, and ultraviolet (360 nm) being assembled into 5 groups according to their chromatographic profiles. Group 3 was purified by column chromatography on a preparative scale yielding the G3-1 sample. EE, MF, HF, Group 2 and G3-1 were analyzed by HPLC-DAD. The G3-1 sample was analysed by mass spectrometry and nuclear magnetic resonance (NMR). To evaluate the antimicrobial activity, methods of agar diffusion (Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa) and microdilution (MIC) were used. The EE and its fractions were subjected to leishmanicide activity test (Leishmania amazonensis). The powder was classified as coarse and low-density, with ash and moisture contents within the parameters established by the Brazilian Pharmacopoeia. In HPLC-DAD, the main peaks of EE and its fractions were presented in UV absorption spectrum of 240 nm to 280 nm, and 300 nm to 400 nm suggestive respectively Band II (Ring A), and band I (ring B ) of flavonoid. The G3-1 chemical structure was identified as flavonoid rutin. In the agar diffusion test, we observed the formation of halos in EE and MF only in Staphylococcus aureus plates. In the microdilution assay, the EE and FM showed MIC> 1000 mg / mL, considered inactive. In antileishman test, the EE showed IC50> 200 / ml. The MF and HF also showed IC50> 200 / ml; however, they inhibited the growth of promastigotes respectively in 20% and 33.7%. The subtractions and G3-1 Group 2 showed IC50> 200 / ml, but the concentration of 200 / ml inhibited the parasite growth by approximately 45%. The EE, fractions, and subfractions were inactive against L. amazonensis amastigotes. However, the HF concentrations of 250 and 125 g / ml inhibited infection in 39.1% and 18.7%. In short, EE and its fractions were shown to be inactive in the antimicrobial and leishmanicide trials, but fractionation contributed to increase activity suggesting that active substances must be at low levels in extract and its fractions.