RESUMO
El objetivo del presente trabajo fue la evaluación preclínica y el estudio de estabilidad de extractos a partir del follaje de Momordica charantia Lin. Se obtuvieron extractos acuoso e hidroalcohólico para los cuales se establecieron las especificaciones de calidad mediante la evaluación de tres lotes y se estudió su estabilidad por el método de vida de estante durante 12 meses. A los extractos se le evaluó el potencial genotóxico mediante ensayos de micronúcleos en médula ósea de ratón y aberraciones cromosómicas en linfocitos de sangre periférica. La actividad hipoglicemiante oral fue evaluada en animales con hiperglicemia temporal inducida por carga de glucosa. Como resultados se establecieron las especificaciones de calidad de los extractos acuoso e hidroalcohólico, los mismos mostraron estabilidad por 6 meses para el extracto acuoso y 12 meses para el extracto hidroalcohólico. No mostraron efecto genotóxico en los ensayos evaluados y mostraron efecto hipoglicemiante oral a la dosis de 450 mg/kg.
The objective of this investigation was the preclinical evaluation and the stability study of the Momordica charantia Linn hydroalcoholic and aqueous leaf extracts. The hydroalcoholic and aqueous extracts were obtained and the quality specifications were determined by evaluating three lots. The stability of the extracts was evaluated for 12 months. The genotoxic potential of the extracts was evaluated by mouse bone marrow micronucleus test and chromosome aberration test. The hypoglycemic effect was determined by oral glucose tolerance test. As results, the quality specifications were established and the aqueous extract was stable for 6 months and the hydroalcoholic extract for 12 months. A genotoxic effect was not observed in both extracts and the hypoglycemic effect was observed at the oral dose of 450 mg/kg of body weight.
Assuntos
Extratos Vegetais/análise , Reatividade-Estabilidade , Momordica charantia/anatomia & histologia , Genotoxicidade/análise , Hipoglicemiantes/farmacologiaRESUMO
The reducing activity on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, z.rad;OH radical scavenging potential, in vitro inhibition of lipid peroxidation and modulation of mutagenicity induced by ter-butyl hydroperoxide (TBH) in Escherichia coli were sequentially screened in 45 species of plants used with medicinal purposes in Cuba, in a search for antioxidant agents which protect DNA against oxidative stress.Five species, e.g. Tamarindus indica L., Lippia alba L., Pimenta dioica (L.) Merr, Rheedia aristata Griseb. and Curcuma longa L. displayed IC(50)<30 micro g/ml in the DPPH radical reduction assay and IC(50)<32 micro g/ml in lipid peroxidation inhibition testing. Pimenta dioica and Curcuma longa L. showed also a 20% inhibition of the in vitro induced z.rad;OH attack to deoxyglucose. Further antimutagenesis assay in Escherichia coli IC 188 evidenced that only Pimenta dioica prevents DNA damage by TBH to the test bacteria. A role of antioxidant enzymes is presumed in this case, as judged by a different response in the isogenic Escherichia coli IC 203 deficient in catalase and alkyl hydroperoxide reductase and the discrete inhibition of oxidative mutagenesis also observed when pre-treatment of the extract was assayed. Eugenol, the main constituent of the essential oil of Pimenta dioica, also inhibited oxidative mutagenesis by TBH in Escherichia coli, at concentrations ranging from 150 to 400 micro g/plate.
Assuntos
Antimutagênicos/farmacologia , Antioxidantes/farmacologia , Plantas Medicinais/química , Compostos de Bifenilo , Cuba , Dano ao DNA , Escherichia coli/efeitos dos fármacos , Escherichia coli/metabolismo , Sequestradores de Radicais Livres/farmacologia , Radicais Livres/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Medicina Tradicional , Picratos/farmacologia , Extratos Vegetais/farmacologia , Estruturas Vegetais/químicaRESUMO
The mutagenic potential of a crude extract of Parthenium hysterophorus L. was assessed in the Salmonella/microsome (Ames) assay and the mouse bone marrow micronucleus test. Results in the bacterial mutagenicity assay were negative for the five strains employed, e.g. TA 1535, TA1537, TA 98, TA 100 and TA 102, while cytotoxicity was evident in all cases at 5000 microg per plate, the highest concentration assayed. A decrease in toxicity was observed with exogenous mammalian metabolic activation (S9) or glutathione (5 micromol per plate). When mutagenicity was monitored after column chromatography fractionation of the crude, fraction 1 was mutagenic in strain TA 98 (+S9). Besides, cytotoxicity was found in fraction 5, where parthenin was eluted. The micronucleus test was negative in mice upon oral administration, at doses up to 96 mg of crude per kg. Bone marrow toxicity was not observed. The crude extract exhibited some in vitro pro-oxidant activity. It also inhibited lipid peroxidation (IC(50)=4.1 microg/ml) but failed to act as .OH scavenger.