RESUMEN
In our attempt to isolate the pharmacologically active ingredients in the aqueous extracts of Mareya micrantha, we have selected the contractions of the longitudinal muscle of the isolated guinea-pig ileum preparation as a pharmacological marker to monitor retention of pharmacological activity during the chromatographic separation. The aqueous extracts of Mareya micrantha elicited concentration-dependent contractions of the preparation. The maximum response elicited by the aqueous extracts was 50% of the maximum response elicited by the maximum dose of acetylcholine (ACh), 10(-7) M. Mepenzolate (10(-8)-10(-5) M), a specific muscarinic receptor antagonist, similarly antagonized contractions elicited by the aqueous extracts suggesting that the cholinergic ingredient(s) in the extract are acting at the muscarinic receptors of the preparation. Fraction 2-4, which was separated from the aqueous extracts by Sephadex gel chromatography, dose-dependently elicited contractions of the preparation. The maximum response was 80% of the maximum response elicited by the maximum dose of ACh suggesting that separation has enhanced the cholinergic activity of the content in the extract.
Asunto(s)
Colinérgicos/aislamiento & purificación , Músculo Liso/efectos de los fármacos , Extractos Vegetales/farmacología , Acetilcolina/farmacología , Animales , Bencilatos/farmacología , Fraccionamiento Químico , Colinérgicos/farmacología , Relación Dosis-Respuesta a Droga , Cobayas , Íleon/efectos de los fármacos , Íleon/metabolismo , Técnicas In Vitro , Masculino , Muscarina/farmacología , Antagonistas Muscarínicos , Contracción Muscular/efectos de los fármacos , Parasimpatolíticos/farmacología , Fisostigmina/farmacología , Piperidinas/farmacología , Extractos Vegetales/química , Agua/químicaRESUMEN
Aqueous extracts of Mareya micrantha are used as folk medicine in West Africa. However, no systemic investigation directed to the identification of the active ingredients in M. micrantha has been done. Therefore, this study investigated the effects of M. micrantha on the cardiac contractility of the isolated frog heart. Also, two sequential fractions from M. micrantha were separated and their effects on cardiac contractility investigated. M. micrantha concentration-dependently suppressed cardiac contractility. Separation of the cardioactive components in series by column chromatography (Sephadex G-50, Column 2.5 x 30 cm and 1 x 20 cm) produced two fractions which facilitated a leftward shift of the dose-response curve of the cardiodepressant effects suggesting that column chromatograph is effective in the isolation of the cardioactive ingredients in M. micrantha. The data suggest that M. micrantha contains cardioactive components and that contractions of the isolated functional frog heart can be used as a pharmacological activity marker during the process of isolation of cardioactive ingredients in M. micrantha.
Asunto(s)
Corazón/efectos de los fármacos , Plantas Medicinales/química , África Occidental , Animales , Antiarrítmicos/farmacología , Frecuencia Cardíaca/efectos de los fármacos , Técnicas In Vitro , Contracción Miocárdica/efectos de los fármacos , Extractos Vegetales/química , Extractos Vegetales/farmacología , Hojas de la Planta/química , Rana pipiensRESUMEN
In our search for therapeutic agents from natural sources with potential for the treatment of opportunistic infections in patients afflicted with acquired immunodeficiency syndrome (AIDS), we investigated antibacterial and antifungal activities of water extracts of Cassia alata (C. alata). The extracts are traditionally used in Ivory Coast, West Africa to treat bacterial infections caused by Escherichia coli (E. coli), and fungal infections caused by Candida albicans (C. albicans) and dermatophytes. Our working hypothesis was that the extract contains active ingredient(s) which can be isolated, identified and developed into useful antibacterial/antifungal agents for the treatment of opportunistic infections in patients with AIDS. We used the broth dilution and agar dilution methods. Specifically, we focused on E. coli and C. albicans and the effectiveness of the extracts was evaluated relative to those of standard antibacterial agent chloramphenicol and antifungal agent amphotericin B. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for the water extract of C. alata against E. coli were 1.6 mg/ml and 60 mg/ml, respectively; corresponding data for chloramphenicol were 2 micrograms/ml and 10 micrograms/ml. Similarly, the MIC and minimum fungicidal concentration (MFC) for the extract against C. albicans were 0.39 mg/ml and 60 mg/ml in contrast to 0.58 micrograms/ml and 0.98 micrograms/ml for amphotericin B. From the dose-response curve plots, the extract had an IC50 of 31 mg/ml for E. coli and 28 mg/ml for C. albicans. The data suggest that C. alata extracts contain agent(s) which have therapeutic potential and might be useful if isolated and developed for the treatment of opportunistic infections of AIDS patients.
Asunto(s)
Infecciones Oportunistas Relacionadas con el SIDA/tratamiento farmacológico , Antiinfecciosos/uso terapéutico , Antifúngicos/uso terapéutico , Cassia , Plantas Medicinales , Antibacterianos , Candida albicans/efectos de los fármacos , Evaluación Preclínica de Medicamentos , Escherichia coli/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Extractos Vegetales/uso terapéuticoRESUMEN
In our search for therapeutic agents from natural sources with potential for the treatment of opportunistic infections in patients afflicted with acquired immunodeficiency syndrome (AIDS), we investigated antibacterial and antifungal activities of water extracts of Cassia alata (C. alata). The extracts are traditionally used in Ivory Coast, West Africa to treat bacterial infections caused by Escherichia coli (E. coli), and fungal infections caused by Candida albicans (C. albicans) and dermatophytes. Our working hypothesis was that the extract contains active ingredient(s) which can be isolated, identified and developed into useful antimicrobial/antifungal agents for the treatment of opportunistic infections in patients with AIDS. We used the broth dilution and agar dilution methods. Specifically, we focused on E. coli and C. albicans and the effectiveness of the extracts was evaluated relative to those of standard antibacterial agent chloramphenicol and antifungal agent amphotericin B. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for the water extract of C. alata against E. coli were 1.6 mg/ml and 60 mg/ml respectively; corresponding data for chloramphenicol were 2 ug/ml. Similarly, the MIC and minimum fungicidal concentration (MFC) for the extract against C. albicans were 0.39 mg/ml and 60 mg/ml in contrast to 0.58 ug/ml and 0.98 ug/ml for amphotericin B. From the dose-response curve plots, the extract had an IC50 of 31 mg/ml for E. coli and 28 mg/ml for C. albicans. The data suggest that C. alata extracts contain agent(s) which have therapeutic potential and might be useful if isolated and developed for the treatment of opportunistic infections of AIDS patients.