RESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Senna racemosa (Mill.) H.S. Irwin & Barneby (syn. Cassia racemosa Mill.) is a plant used in traditional Mayamedicinal practices to treat diarrhea. A methanol extract of S. racemosa bark has been shown to have in vitro activity against Giardia intestinalis. No studies of its efficacy and toxicity in in vivo models have been done. The present study objective was to analyze the activity of this methanol extract of S. racemosa bark against Giardia intestinalis trophozoites in experimentally infected mice, and evaluate its toxicological effects in rats. MATERIAL AND METHODS: S. racemosa was collected in Merida, Yucatan, Mexico (21°58'N, 89°36'W) in June 2005. The bark methanol extract was obtained and high performance liquid chromatography (HPLC-DAD) was used to generate a constituent profile. In vivo anti-giardia activity was assayed with an experimental model of G. intestinalis infection in neonatal CD-1 mice. Nine doses ranging from 0.25-15mg extract/kg body weight were tested to determine the dose required to kill 50% of the trophozoites (ED50). An acute toxicity assay was run in which one of four single doses (200, 1000, 2000 and3000mg/kg body weight) was orally administered to adult Wistar rats. Animal weight, death rates, toxic effects and behavioral parameters were observed over a 14-d period. They were then euthanized and a necropsy performed. RESULTS: The S. racemosa bark extract inhibited growth of G. intestinalis (ED50=1.14mg/Kg) in neonatal CD-1 mice. No toxic or lethal effects were observed even at the highest dosage (3000mg/Kg), and neither were signs of toxicity observed in internal organs. The active compounds chrysophanol and physcion were present in the extract at a 1.76 ratio. CONCLUSIONS: The results strongly support traditional use of S. racemosa bark for treatment of diarrhea caused by Giardia intestinalis infection.
Assuntos
Antiprotozoários/farmacologia , Giardia/efeitos dos fármacos , Casca de Planta/química , Extratos Vegetais/farmacologia , Senna/química , Animais , Animais Recém-Nascidos , Antiprotozoários/isolamento & purificação , Antiprotozoários/uso terapêutico , Antiprotozoários/toxicidade , Relação Dose-Resposta a Droga , Giardíase/tratamento farmacológico , Masculino , Metanol/química , Camundongos , Casca de Planta/crescimento & desenvolvimento , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/uso terapêutico , Extratos Vegetais/toxicidade , Ratos Wistar , Senna/crescimento & desenvolvimento , Testes de Toxicidade AgudaRESUMO
The plant Aeschynomene fascicularis (Fabaceae) has been used in Mayan traditional medicine in the Yucatan peninsula. However, the compounds present in the plant responsible for its curative properties have not yet been investigated. Aeschynomene fascicularis root bark was extracted with 100% methanol to obtain a crude extract. The methanol extract was partitioned successively with solvents with increasing polarity to obtain the corresponding hexane (Hx), dichloromethane (DCM) and ethyl acetate fractions (EtOAc), as well as a residual water-alcoholic fraction. These fractions were tested for their cytotoxic activities using an MTT assay against Hep-2 cancer cell lines. The Hx fraction led to the isolation of spinochalcone C (1), spinochalcone A (2), isocordoin (3) and secundiflorol G (4). Their structures were identified based on spectroscopic evidence and chemical properties. All compounds were subjected to cytotoxicity and antiproliferative assays against a panel of seven cell lines, including one normal-type cell line. Spinochalcone A (2) exhibited cytotoxic activity against DU-145 cell line and antiproliferative activity against the KB cell line. Secundiflorol G (4) showed strong cytotoxic activity towards KB and Hep-2 cell lines. In addition, isocordoin (3) showed moderate activity on KB, Hep-2 and DU-145 cell lines. The active Compounds 2, 3 and 4 are potential therapeutic entities against cancer.