ABSTRACT
Erythrina speciosa Andrews, Fabaceae, is used in the South of Brazil as sedative and tranquilizers. In this study, behavioral effects of aqueous (AE) and dichloromethane (DCM) extracts of E. speciosa leaves were evaluated in male mice, as well as their lethal dose 50 percent (LD50). The extracts were administered by gavage in doses ranging from 50 to 400 mg/kg 1 h before the behavioral tests. AE decreased ambulation (50, 100 and 400 mg/kg) and rearing (50 and 400 mg/kg) in the open-field but did not influence elevated plus maze, rotarod and pentobarbital-induced sleep tests. No behavioral effects were observed after DCM administration. LD50 for both extracts were higher than 2000 mg/kg. The results showed that AE and DCM extracts of E. speciosa leaves do not produce anxiolytic effect in the elevated plus maze nor seems to depress the Central Nervous System. However, since serotonergic mechanisms may be involved in the pharmacological action of Erythrina plants and the elevated plus maze test is not adequate to evaluate serotonergic drugs, our results do not invalidate the use of this plant in folk medicine but suggest that the mechanism involved in a possible central action of Erythrina needs to be clarified.
Erythrina speciosa Andrews, Fabaceae, é usada na região Sul do Brasil como sedativa e tranquilizante. Neste estudo, uma possível ação central do extrato aquoso (EA) e fração diclorometano (DCM) das folhas da E. speciosa foi avaliada em camundongos machos submetidos a testes comportamentais 1 h após o tratamento (gavage). Também foi avaliada a dose letal 50 por cento (DL50) como indicativa da toxicidade aguda desta planta. O EA diminuiu a locomoção (50, 100 e 400 mg/kg) e o levantar (50 e 400 mg/kg) no teste de campo aberto mas não alterou nenhum dos comportamentos avaliados nos testes de labirinto em cruz elevado, rotarod e sono induzido. A DCM não alterou nenhum dos comportamentos avaliados. A DL50 de ambos os extratos foi estimada como sendo >2000 mg/kg. Os resultados sugerem ausência de efeito ansiolítico e depressor do Sistema Nervoso Central das folhas de E. speciosa. Entretanto, como mecanismos serotonérgicos podem estar envolvidos na ação farmacológica de plantas do gênero Erythrina e o teste de labirinto em cruz elevado não é adequado para avaliar o efeito de drogas serotonérgicas, nossos resultados não invalidam o uso desta planta na medicina popular, mas apontam a necessidade de se investigar o mecanismo de ação envolvido no possível efeito central de plantas do gênero Erythrina.
ABSTRACT
Extract of Vernonia condensata (Asteraceae = Compositae) leaves has different uses in Brazilian folk medicine, which includes analgesic and antiinflamatory agent. The aim of this study was to apply a modified simplex-centroid mixture design to evaluate the best extractor system for the antinociceptive activity, evaluated by writhing test. Different solvents (acetone, dichloromethane, ethanol and ethyl acetate) as well as their binary, ternary and quaternary mixtures were used. For comparison, aqueous extract was also evaluated. LD50 was estimated and qualitative phytochemical screening, conducted. The extracts with antinociceptive activity were: aqueous, acetone, dicloromethane (DCM), ethanol (ETOH), acetone-DCM, acetone-ETOH, acetone-ethyl acetate, ETOH-ethyl acetate, acetone-DCM-ethyl acetate, acetone-ETOH-ethyl acetate and DCM-ETOH-ethyl acetate. The higher margin of safety (LD50/ED50) was for acetone > acetone-ETOH-ethyl acetate > aqueous > ETOH = acetone-ETOH > DCM > acetone-ethyl acetate > DCM-ETOH-ethyl acetate > acetone-DCM > acetone-DCM-ethyl acetate. Phytochemical screening showed that all the extracts contained alkaloids, phenolic compounds, flavonoids, tannins and saponins. In conclusion, the extractor system influences both the pharmacological activity and acute toxicity of leaves from V. condensata. Acetone and the ternary mixture, acetone-ETOH-ethyl acetate extracts showed higher margin of safety than aqueous extract.
ABSTRACT
The aim of this study was to verify if the principal components method of analysis could be employed to characterize commercial powdermainly starch used in pudding preparation, identifying and reducing the most important factors. The multivariate analysis was applied to data regarding composition and functional properties which were taken from twelve samples totaling fourteen variables. The data were analyzed using a personal computer system ARTHUR. Seven variables (starch, fracturability, firmness, adhesiviness, cohesiveness, elasticity, total solids) of greater correlation and higher absolute values that were characteristic of the two principal components selected after the first examination. A second analysis which used only selected variables maintained the initial behaviour confirming the possibility of reducing variables without important loss of information. The application of the multivariate analysis using the principal components method for the study of commercial puddings proved to be efficient in the classification based on sample similarity, besides selecting and reducing variables to more outstanding factors