RESUMO
Strongyloidiasis is a parasitosis that represents a public health problem, in tropical regions. The present study aimed to investigate the anthelmintic effects of several extracts of Argemone mexicana, as well as its main component berberine (Ber) against the third-stage larvae (L3) of Strongyloides venezuelensis in-vitro experiments. Also, the anti-hemolytic activity of the extract, fractions, and Ber were tested in human erythrocytes. A dose-response anthelminthic bioassay demonstrated Ber as the most effective component, followed by methanolic subfraction (Fr3) and finally the crude extract of A. mexicana (Am) showing LC50 response values of 1.6, 19.5, and 92.1 µg/mL, at 96 h respectively. Also, Am, Fr3, and Ber did not produce significant hemolysis against human erythrocytes (p ≤ 0.05). Am and Fr3 showed erythrocyte protection effect capacity at the membrane level (p ≤ 0.05). Furthermore, Ber was found to have an antioxidant activity of 168.18 µg/mL. According to the results, the Fr3 of A. mexicana, and particularly Ber, exhibited potent in-vitro effects against L3 of S. venezuelensis, without hemolytic activity against human erythrocytes and presented good antioxidant capacity. In conclusion, the extracts of A. mexicana and the main component have activity against S. venezuelensis, nevertheless, further studies are required to elucidate the mechanism of action.
Assuntos
Anti-Helmínticos/farmacologia , Argemone/química , Berberina/farmacologia , Extratos Vegetais/farmacologia , Strongyloides/efeitos dos fármacos , Análise de Variância , Animais , Anti-Helmínticos/química , Anti-Helmínticos/uso terapêutico , Berberina/química , Berberina/uso terapêutico , Bioensaio , Relação Dose-Resposta a Droga , Eritrócitos/efeitos dos fármacos , Fezes/parasitologia , Hemólise/efeitos dos fármacos , Humanos , Larva/efeitos dos fármacos , Dose Letal Mediana , Masculino , Extratos Vegetais/química , Extratos Vegetais/uso terapêutico , Folhas de Planta/química , Caules de Planta/química , Ratos , Ratos Wistar , Estrongiloidíase/tratamento farmacológicoRESUMO
A new benzylisoquinoline alkaloid, argemexirine, together with two known protoberberine alkaloids, dl-tetrahydrocoptisine and dihydrocoptisine, have been isolated from the methanolic extract of the whole plant of Argemone mexicana L. The compounds were identified by spectral and chemical evidence. This is the first report of these alkaloids in this plant species.
Assuntos
Alcaloides/química , Argemone/química , Isoquinolinas/química , Alcaloides/isolamento & purificação , Berberina/análogos & derivados , Berberina/química , Isoquinolinas/isolamento & purificação , Espectroscopia de Ressonância Magnética , Metanol , Metilação , Extratos Vegetais/análise , Solventes , Espectrofotometria Infravermelho , Espectrofotometria UltravioletaRESUMO
Spectral and photophysical properties of the alkaloid berberine (B) were studied in solvents with different solvent parameters, using UV/Vis absorption, emission and excitation spectroscopy. The absorption and emission maxima were found to be between 421-431 nm and 514-555 nm, respectively, leading to Stokes' shifts between 4099 and 5735 cm(-1). The fluorescence quantum yields varied between 10(-2)-10(-4), depending on the solvent. Different solvent scales have been used to study the solvatochromism of B. Linear solvation energy relationships (LSER) proposed by Kamlet-Taft suggest that B is a molecule attractive as a probe for solvent polarity and hydrogen bonding properties.
Assuntos
Berberina/química , Solventes/química , Estrutura Molecular , Fotoquímica , Espectrometria de Fluorescência , Espectrofotometria UltravioletaRESUMO
The cytotoxic effects of four alkaloids, berberine, canadine, anonaine, and antioquine were evaluated using three different cell cultures, a primary culture (rat hepatocytes) and two cell lines (HepG2 and HeLa). Our results indicate that berberine, anonaine, and antioquine possess a significant the cytotoxic effect. In contrast, canadine does not possess cytotoxic effect at concentrations tested here. A molecular modeling study indicates that the quaternary nitrogen, the aromatic polycyclic and planar structure of berberine could be the pharmacophoric patron to produce the cytotoxic effect. In parallel our results demonstrated that canadine possess a significant antioxidant activity. Stereoelectronic aspects of this alkaloid were found to be closely related to those displayed by alpha-tocopherol and its water-soluble analogue trolox. The antioxidant activities of canadine, combined with its low-toxic effect, indicated that the potential of this alkaloid as a novel class of antioxidant agent is very interesting and deserves further research.
Assuntos
Antioxidantes/química , Antioxidantes/toxicidade , Berberina/análogos & derivados , Animais , Berberina/química , Berberina/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Glutationa/metabolismo , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Masculino , Modelos Moleculares , Estrutura Molecular , Ratos , Ratos Sprague-DawleyRESUMO
In this work, we report an alternative assay for the determination of the inhibitory effect on monoamine oxidase B (MAO-B) activity of probe compounds. Enzyme MAO-B exhibits fluorescence emissions when it is excited at 412 nm. Using an inexpensive blue LED-like excitation source, we measured the quenching of fluorescence intensity of MAO-B enzyme during the reaction with inhibitors. The applicability of the procedure is demonstrated by assays with l-deprenyl and berberine as inhibitors through the use of fluorescence studies. The IC(50) values of l-deprenyl and berberine were 0.04 and 90 microM, respectively. The K(I) values were 0.020 and 47 microM for l-deprenyl and berberine, respectively. These IC(50) and K(I) values were similar to the values obtained with a standard method. These results demonstrate the feasibility of this method as an alternative to follow the inhibitory effect on MAO-B.
Assuntos
Monoaminoxidase/metabolismo , Espectrometria de Fluorescência/métodos , Animais , Benzilaminas/química , Berberina/química , Berberina/farmacologia , Relação Dose-Resposta a Droga , Cinética , Luz , Camundongos , Mitocôndrias Hepáticas/efeitos dos fármacos , Mitocôndrias Hepáticas/metabolismo , Inibidores da Monoaminoxidase/metabolismo , Selegilina/química , Selegilina/farmacologiaRESUMO
The cytotoxicity of two protoberberine alkaloids: berberine and lincangenine, their 8-hydroxy-7,8-dihydro-derivatives and tetrahydroprotoberberine:thaicanine, was evaluated. The cellular responses through the [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide] (MTT) method were measured in Hela (uterus carcinoma), SVKO3 (ovary carcinoma), Hep-2 (larynx carcinoma), primary culture from mouse embryon, and human fibroblast cells at the concentration: 10-1000 ppm (microg/ml) for 24 h. Berberine showed the highest cytotoxicity among the compounds tested, giving LC50 values for all cell lines at the concentration of 10 ppm. The results indicated that the cytotoxicity was notably decreased by structural changes, i.e. by modulation of the planarity caused by the introduction of hydroxyl group at C-8 and concomitant saturation of double bond between N-C8 in protoberberine molecules. In the case of berberine, the cytotoxic effect changed from 98.8 (berberine) to 39% for 8-hydroxydihydroberberine at the concentration of 100 ppm in Hela cells line. The same effect was observed with lincangenine and 8-OH-lincangenine (cytotoxicities 70 and 25%, respectively, at 1000 ppm in SVKO3 cells). On the other hand, these compounds showed a low selectivity for the different human cancer cell lines tested.