Purpose:
In previous studies, the aqueous extract of
Combretum molle was shown to inhibit disturbances of
breathing induced by acetylcholine. The aim of this
study was to elucidate the mechanism of this inhibition.
Methods:
The aqueous extract of Combretum molle and an
anti-asthmatic, salbutamol (reference), were tested at
varying concentrations for their inhibitory effects on
breathing. Acetylcholinesterase (AChE) was extracted
from rabbit duodenum and its activity determined by
Ellman’s assay using acethylthiocholine iodide (ACTH) as
substrate. The rate of hydrolysis of
acetylcholinesterase was spectrophotometrically
monitored at 412 nm.
Results:
The results indicate that in the presence of C. molle
extract, a considerable reduction in the variation of
breathing amplitudes occurred. Furthermore, the extract
probably contains anti-AChE substances. C. molle exerted
non-competitive inhibition of acetylcholinesterase with
Michaelis-Menten constant (KM) of 192 μM and
velocity at maximal concentration of substrate (Vmax)
of 4444 µM/min.
Conclusion:
These results support the use of C. molle leaf in the
Pharmacopoeia of Ivory Coast as an anti-asthmatic, in
view of its inhibitory effect on breathing disturbances.
Keywords:
Combretum molle, Acetylcholinesterase, Breathing
disturbances, Salbutamol, Anti-asthmatic
