Bronchorelaxation Activity of Coptosapelta Flavescens Korth Root’s Methanol Extract by In-Vitro Inhibition of Calcium Channel

Abstract

The objective of this study was to examine the bronchorelaxation effect of the methanol extract of Coptosapelta flavescens Korth roots (MECFR) by inhibiting calcium channel on guinea pig bronchial rings. Both Experiment I and II used isolated bronchial rings incubated with 3 concentrations of MECFR, DMSO (negative control) and Verapamil (positive control) in a Ca2+-free medium, given 60 mM KCl (I) or 2?M histamin (II), and contracted with cumulative dose of CaCl2 to obtain CaCl2 dose-response curve (DRC). All MECFR’s (3 concentrations) DRCs shifted to the right, similar to Verapamil’s, and with smaller Emax and pD2 compared to the negative control’s DRC for both experiments I and II, indicating that MECFR inhibits both extracellular Ca2+ influx and Ca2+ release, results in a decrease in intracellular Ca2+ levels. It can be concluded that MECFR has bronchorelaxation activity through inhibition of Ca2+ channel. Keyword: Calcium channel, Coptosapelta flavescens Korth’s roots, bronchorelaxation.