RESUMEN

The enhancement of cholinergic functions via acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibition is considered a valuable therapeutic strategy for the treatment of Alzheimer's disease. This study aimed to evaluate the in vitro effect of ZINC390718, previously filtered using computational approaches, on both cholinesterases and to characterize, using a molecular dynamics (MD) simulation, the possible binding mode of this compound inside the cholinesterase enzymes. The in vitro cytotoxicity effect was also investigated using a primary astrocyte-enriched glial cell culture. ZINC390718 presented in vitro dual inhibitory activity against AChE at a high micromolar range (IC50 = 543.8 µM) and against BuChE (IC50 = 241.1 µM) in a concentration-dependent manner, with greater activity against BuChE. The MD simulation revealed that ZINC390718 performed important hydrophobic and H-bond interactions with the catalytic residue sites on both targets. The residues that promoted the hydrophobic interactions and H-bonding in the AChE target were Leu67, Trp86, Phe123, Tyr124, Ser293, Phe295, and Tyr341, and on the BuChE target, they were Asp70, Tyr332, Tyr128, Ile442, Trp82, and Glu197. The cytotoxic effect of Z390718, evaluated via cell viability, showed that the molecule has low in vitro toxicity. The in vitro and in silico results indicate that ZINC390718 can be used as chemotype for the optimization and identification of new dual cholinesterase inhibitors.

RESUMEN

The dual inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) is considered as an important strategy for the treatment of Alzheimer's disease. In this study, we applied the bioguided fractionations of Ocotea daphinifolia ethyl acetate active extract to furnish a fraction with high inhibitory activity for AChE and BuChE (82% and 92%, respectively). High-performance liquid chromatography semipreparative purification of this fraction provided two new natural products: 1-ß-D-galactopyranosyl-glycerol-2,3-heptanedionate, (1) whose complete chemical structural elucidation was made with spectrometric analysis (MS, 1D, and 2D NMR) and its minor derivative 1-ß-D-gulopyranosyl-glycerol-2,3-heptanedionate; (2) which could be characterized by 2D 1 H-13 C heteronuclear single-quantum correlation spectra analysis. Investigation of the intermolecular interactions with cholinesterases was carried out by molecular docking studies, and results suggested that both compounds are capable to interact with the catalytic site of both enzymes. Compounds 1 and 2 interact with residues of catalytic domains and the peripheral anionic binding site of AChE and BuChE. The results are comparable to those achieved with rivastigmine and galantamine. Thus, this study provides evidence for consideration of the glycosylglycerol from O. daphnifolia as new valuable dual cholinesterases inhibitor.

Asunto(s)

Enfermedad de Alzheimer , Ocotea , Inhibidores de la Colinesterasa/química , Butirilcolinesterasa/química , Simulación del Acoplamiento Molecular , Acetilcolinesterasa/metabolismo , Ocotea/metabolismo , Glicerol , Espectroscopía de Resonancia Magnética

RESUMEN

INTRODUCTION: Lauraceae alkaloids are a structurally diverse class of plant specialised secondary metabolites that play an important role in modern pharmacotherapy, being useful as well as model compounds for the development of synthetic analogues. However, alkaloids characterisation is challenging due to low concentrations, the complexity of plant extracts, and long processes for accurate structural determinations. OBJECTIVE: The use of high-performance thin layer chromatography coupled with desorption electrospray ionisation multistage mass spectrometry (HPTLC DESI-MSn ) as a fast tool to identify alkaloids present in Ocotea spixiana extract and evaluate the extract's acaricide activity. METHODS: Ocotea spixiana twigs were extracted by conventional liquid-liquid partitioning. HPTLC analysis of the ethyl acetate extract was performed to separate isobaric alkaloids prior to DESI-MSn analysis, performed from MS3 up to MS7 . The extract's acaricide activity against Rhipicephalus microplus was evaluated by in vitro (larval immersion test) and in silico tests. RESULTS: HPTLC-DESI-MSn analysis was performed to identify a total of 13 aporphine and four benzylisoquinoline-type alkaloids reported for the first time in O. spixiana. In vitro evaluation of the extract and the alkaloid boldine showed significant activity against R. microplus larvae. It was established in silico that boldine had important intermolecular interactions with R. microplus acetylcholinesterase enzyme. CONCLUSION: The present study demonstrated that HPTLC-DESI-MSn is a useful analytical tool to identify isoquinoline alkaloids in plant extracts. The acaricide activity of the O. spixiana ethyl acetate extract can be correlated to the presence of alkaloids.

Asunto(s)

Acaricidas , Alcaloides , Aporfinas , Bencilisoquinolinas , Ocotea , Acaricidas/farmacología , Alcaloides/farmacología , Aporfinas/farmacología , Extractos Vegetales/farmacología , Espectrometría de Masas en Tándem

RESUMEN

Astrocytic tumour cells derived from human (GL-15) and rat (C6) gliomas, as well as non-tumoural astrocytic cells, were exposed to the saponin-rich fraction (SF) from Agave sisalana waste and the cytotoxic effects were evaluated. Cytotoxicity assays revealed a reduction of cell viability that was more intensive in glioma than in non-tumoural cells. The SF induced morphological changes in C6 cells. They were characterised by cytoplasmic vacuole formation associated with increase in the formation of acidic lysosomes. The SF was subjected to purification on Sephadex LH-20, which characterised three probable steroidal saponins (sisalins) by electrospray ionisation mass spectrometry multistage (ESI-MSn). Sisalins from sisal may be responsible for the cytotoxicity, which involves cytoplasmatic vacuole formation and selective action for glioma cells.

Asunto(s)

Agave/química , Antineoplásicos Fitogénicos/farmacología , Astrocitos/efectos de los fármacos , Saponinas/química , Saponinas/farmacología , Animales , Antineoplásicos Fitogénicos/química , Astrocitos/patología , Línea Celular Tumoral , Chlorocebus aethiops , Citoplasma/efectos de los fármacos , Citoplasma/patología , Glioma/patología , Humanos , Estructura Molecular , Extractos Vegetales/química , Ratas , Saponinas/análisis , Espectrometría de Masa por Ionización de Electrospray/métodos , Espectrometría de Masas en Tándem , Vacuolas/efectos de los fármacos , Vacuolas/patología , Células Vero

RESUMEN

AbstractThe species Marcetia taxifolia (A. St.-Hil.) DC., Melastomataceae, which is endemic of the rupestrian fields of northeastern Brazil, contains a significant amount of flavonoids. In this work, the potential of the ethanolic extract of M. taxifolia as the active principle in a sunscreen photoprotection (UV-A and UV-B) formulation was investigated. The Liquid Chromatography High Performance-Diode Array Detector quantification (quercetin), total flavonoid content, antioxidant activity through 2.2-diphenyl-1- picrylhydrazil method, photoprotective activity against UV-B and UV-A radiation in vitro (spectrophotometric method) and potential for eye irritation using the methodology of the hen egg test-chorioallantoic membrane were performed in the extract. After that, the formulations were prepared using different concentrations of active ethanolic extract (5, 10, 20 and 30%) and the evaluation of the sun protection factor was carried out using the same methodology used for the crude extract. The crude extract showed UV-A photoprotection and low eye irritation in the hen egg test-chorioallantoic membrane test. All formulations containing M. taxifolia extract had ≥ 6 sun protection factor. Its shows the possibility to use this extracts as a sunscreen in pharmaceutical preparations.

RESUMEN

This study describes the in vitro anthelmintic activity of aqueous extracts (AE), ethyl acetate extracts (EE), flavonoid fractions (FF) and saponin fractions (SF) obtained from sisal waste (Agave sisalana) against gastrointestinal nematodes of goats. The activity of these extracts was evaluated by performing inhibition of egg hatch (EHA) and larval migration (LMI) assays. The EC(50) results of the EHA corresponded to 4.7, 0.1 and 0.05 mg/mL for EE, EA and FF, respectively. The SF fraction showed no ovicidal activity. The percent efficacies that were observed for the LMI were 50.3, 33.2 and 64.1% for the AE, EE and SF, respectively. The FF fraction did not show activity against the larvae. The analysis of the FF fraction indicates the presence of a homoisoflavonoid. This report suggests that the A. sisalana has activity in vitro against gastrointestinal nematodes of goats. This effect is likely related to the presence of homoisoflavonoid and saponin compounds, which have different actions for specific stages of nematode development.

Asunto(s)

Agave/química , Antihelmínticos/farmacología , Enfermedades de las Cabras/tratamiento farmacológico , Nematodos/efectos de los fármacos , Infecciones por Nematodos/veterinaria , Extractos Vegetales/farmacología , Animales , Antihelmínticos/química , Antihelmínticos/aislamiento & purificación , Femenino , Flavonoides/aislamiento & purificación , Enfermedades Gastrointestinales/tratamiento farmacológico , Enfermedades Gastrointestinales/parasitología , Enfermedades Gastrointestinales/veterinaria , Enfermedades de las Cabras/parasitología , Cabras , Larva/efectos de los fármacos , Nematodos/aislamiento & purificación , Infecciones por Nematodos/tratamiento farmacológico , Infecciones por Nematodos/parasitología , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación , Saponinas/aislamiento & purificación

RESUMEN

Active compounds from Agave sisalana with antiparasitic action against gastrointestinal nematodes (GINs) could be an alternative to diversify the range of parasite management methods in the livestock sector. The objective of this study was to evaluate the in vitro action of A. sisalana extract on the development of sheep and goat GINs. The extract, obtained from shredded sisal leaves, was utilized at various concentrations in the egg hatch test (EHT), larval development test (LDT), larval feeding inhibition test (LFIT) and adult motility test (AMT). The LC(50) and LC(95) in the EHT were 6.90 and 24.79 mg/mL, in the LDT were 0.041 and 0.067 mg/mL and in the LFIT were 0.053 and 0.24 mg/mL, respectively, showing a dose-dependent relationship. The development and feeding inhibition on L(1) were both 100% at a dose of 0.12 mg/mL. In the AMT there was 100% inhibition at 75 mg/mL after 24h of exposure. The extract of A. sisalana therefore demonstrated significant action on L(1) at 0.12 mg/mL. So, if part of the A. sisalana extract passes through the animal's gastrointestinal system, this material can have a significant effect on the parasites in the feces. This is an interesting approach because it can drastically reduce the pasture contamination as well as the infection of herds.

Asunto(s)

Agave/química , Enfermedades Gastrointestinales/veterinaria , Enfermedades de las Cabras/tratamiento farmacológico , Infecciones por Nematodos/veterinaria , Extractos Vegetales/farmacología , Enfermedades de las Ovejas/tratamiento farmacológico , Albendazol/farmacología , Albendazol/uso terapéutico , Animales , Antihelmínticos/farmacología , Antihelmínticos/uso terapéutico , Relación Dosis-Respuesta a Droga , Enfermedades Gastrointestinales/tratamiento farmacológico , Enfermedades Gastrointestinales/parasitología , Enfermedades de las Cabras/parasitología , Cabras , Larva/efectos de los fármacos , Larva/fisiología , Nematodos/efectos de los fármacos , Nematodos/crecimiento & desarrollo , Nematodos/fisiología , Infecciones por Nematodos/tratamiento farmacológico , Infecciones por Nematodos/parasitología , Óvulo/efectos de los fármacos , Óvulo/fisiología , Extractos Vegetales/uso terapéutico , Ovinos , Enfermedades de las Ovejas/parasitología

RESUMEN

It was evaluated the anthelmintic activity of Agave sisalana (sisal) juice against gastrointestinal nematodes and its potential toxic effects in goats. In vitro tests showed more than 95% reduction in larval counts of the genus Haemonchus spp. at concentrations between 86.5 and 146.3 mg.mL–1. In vivo the percent reduction of larvae of the fourth (L4) and fifth (L5) stages of Haemonchus, Oesophagostomum and Trichostrongylus was less than 95% in groups GI and GII, and between 80 and 90% in group GIII. A. sisalana juice at the concentrations tested in vitro was effective against gastrointestinal nematodes in goats; however, its anthelmintic efficacy was reduced when administered to animals.(AU)

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Foi avaliada a atividade anti-helmíntica do suco de Agave sisalana (sisal) contra nematódeos gastrintestinais e possíveis efeitos tóxicos em caprinos. Nos testes in vitro, encontrou-se redução superior a 95% na contagem de larvas do gênero Haemonchus spp. nas concentrações entre 86,5 e 146,3 mg.mL–1. In vivo, o percentual de redução de larvas de quarto (L4) e quinto (L5) estágios de Haemonchus, Oesophagostomum e Trichostrongylus foi inferior a 95% para o GI e GII, e entre 80 e 90% para o GIII. O suco de A. sisalana nas concentrações testadas in vitro foi efetivo contra nematódeos gastrintestinais de caprinos, apresentando, no entanto, reduzida eficácia anti-helmíntica quando administrado nos animais. (AU)

Asunto(s)

Antihelmínticos , Agave , Cabras/parasitología , Nematodos

RESUMEN

Phitotherapy has been frequently utilized in parasitism control for numerous animal species. The aim of this experiment was to evaluate the in vitro effects of aqueous extracts of Mentha piperita L. and Chenopodium ambrosioides L. leaves in larvae cultures of gastrointestinal nematodes of goats. Six different concentrations of M. piperita extracts (196; 150.7; 115.9; 89.1; 68.5 e 52.7 mg/mL) and C. ambrosioides extracts (110,6; 85; 65,3; 50,2; 38,6 e 29,6 mg/mL) were used for the treatment of larvae cultures, in triple assays. Distilled water and doramectin were used in larvae cultures as negative and positive controls, respectively. The results revealed a reduction of more than 95% of the infective larvae when M. piperita extracts were used in the concentrations of 115.9 and 196 mg/mL, and C. ambrosioides extract in the concentration of 110.6 mg/mL, supporting the effect of these extracts in the in vitro treatment of gastrointestinal nematodes of goats.

Asunto(s)

Chenopodium ambrosioides , Tracto Gastrointestinal/parasitología , Cabras/parasitología , Mentha piperita , Nematodos/efectos de los fármacos , Extractos Vegetales/farmacología , Hojas de la Planta , Animales , Larva/efectos de los fármacos , Agua

RESUMEN

A aflatoxina M1 (AFM1) é um produto da biotransformação da aflatoxina B1, a qual é excretada no leite de animais que ingerem alimentos contaminados. Os objetivos deste trabalho foram otimizar o método por cromatografia em camada delgada (CCD) para análise de AFM1 em leite de cabra e avaliar sua ocorrência no Estado da Bahia. Foram coletadas 100 amostras de leite em cinco propriedades, localizadas na região do Recôncavo Baiano, durante o período de novembro de 2000 a agosto de 2002. A AFM1 foi determinada no leite por meio de método de CCD conforme Sabino et al. (1989) modificado com a utilização de acetato de chumbo na fase de purificação para promover a precipitação de proteínas do substrato, possibilitando a visualização da AFM1 na placa cromatográfica. Os limites de detecção e quantificação obtidos pela técnica modificada foram de 0,2 e 0,5μg/L, respectivamente, com percentual de recuperação de 89,6% e coeficiente de variação igual a zero. Estes resultados revelaram que esta metodologia mostrou-se eficiente para a determinação de AFM1 em leite caprino. Em todas as amostras analisadas não foi detectada a presença de AFM1, demonstrando a boa qualidade deste produto quanto à contaminação por esta toxina

Asunto(s)

Aflatoxina M1 , Cabras , Cromatografía en Capa Delgada/métodos , Leche , Contaminación de Alimentos

RESUMEN

Este estudo teve como objetivo avaliar a contaminação por aflatoxinas (B1,B2,G1 e G2) em amostras de amendoim comercializadas em alguns municípios do estado da Bahia. Foram analisadas 100 amostras, sendo 33 de amendoim e 67 de produtos a base de amendoim. A coleta das amostras foi realizada aleatoriamente em diferentes estabelecimentos comerciais da cidade de Salvador (75 amostras) e em municípios do estado da Bahia (25 amostras) durante o período de janeiro a outubro de 2002. A extração foi realizada com acetonitrila:água (84:16, v/v), e a quantificação das aflatoxinas procedida pelo método de Cromatografia Líquida de Alta Eficiência (CLAE), empregando detecção por fluorescência. Das 31 amostras de amendoim analisadas, 29 (93,55 por cento) foram positivas, sendo que 17 (54,84 por cento), apresentaram teor de contaminação por B1 + B2 + G1+G2 superior a 20 ug/kg. Para as 69 amostras de derivados de amendoim, apenas 6 (8,7 por cento) apresentaram contaminação por aflatoxinas B1+B2+G1+G2 superior ao limite. Os resultados ainda revelaram que 20(80 por cento) do total de amostras coletadas nos municípios do Estado (25) e 38 (50,7 por cento) das 75 amostras procedentes de Salvador foram positivas. Os resultados ressaltam a necessidade de um controle eficaz dos níveis de aflatoxinas destes produtos na região

Asunto(s)

Arachis , Aflatoxinas , Contaminación de Alimentos/análisis , Cromatografía Liquida/métodos