Extracts from plants used in Mexican traditional medicine activate Ca2+-dependent chloride channels in Xenopus laevis oocytes
Por:
Rojas A., Mendoza S., Moreno J., Arellano R.O.
Publicada:
1 ene 2003
Resumen:
The two-electrode voltage-clamp technique was employed to investigate the effects of chloroform-methanol (1:1) extracts derived from five medicinal plants on Xenopus laevis oocytes. When evaluated at concentrations of 1 to 500 ?g/ml, the extracts prepared from the aerial parts of Baccharis heterophylla H.B.K (Asteraceae), Chenopodium murale L. (Chenopodiaceae), Desmodium grahami Gray (Leguminosae) and Solanum rostratum Dun (Solanaceae) produced concentration-dependent oscillatory inward currents in the oocytes, while the extract of Gentiana spathacea did not induce any response. The reversal potential of the currents elicited by the active extracts was - 17 ± 2 mV and was similar to the chloride equilibrium potential in oocytes. These ionic responses were independent of extracellular calcium. However, they were eliminated by overnight incubation with BAPTA-AM (10 ?M), suggesting that the currents were dependent on intracellular Ca2+ increase. Thus the plant extracts activate the typical oscillatory Ca2+-dependent Cl- currents generated in the Xenopus oocyte membrane more probably via a mechanism that involves release of Ca2+ from intracellular reservoirs. These observations suggest that Xenopus oocyte electrophysiological recording constitutes a suitable assay for the study of the mechanisms of action of herbal medicines.
Filiaciones:
Rojas A.:
Facultad de Química, Universidad Autónoma de Querétaro, Centro Universitario, Querétaro, Mexico
Facultad de Química, Universidad Autonoma de Queretaro, Centro Universitario, Querétaro, C.P. 76010, Mexico
Mendoza S.:
Facultad de Química, Universidad Autónoma de Querétaro, Centro Universitario, Querétaro, Mexico
Moreno J.:
Facultad de Química, Universidad Autónoma de Querétaro, Centro Universitario, Querétaro, Mexico
Arellano R.O.:
Centro de Neurobiología, Univ. Nacional Autonoma de Mexico, Querétaro, Mexico
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