The spasmolytic properties of the aqueous extract of
Aframomum melegueta
(K Schum) and
Citrus aurantifolia
(Christm and Panzer) (AMCA) mixture were tested on isolated rat trachea. Inhibition of the contraction was observed the in
presence of the AMCA (EC
50 = 1.80 ± 0.48 mg/mL) after a pre contraction of the trachea by acetylcholine (10
-5
M). With
propranolol (10
-6
M), the spasmolytic activity of the mixture was inhibited and the concentration-response curve shifted to the
right. The EC
50 value was then 2.60 ± 0.41 mg/mL. AMCA also inhibited contraction induced by KCl (4.10
-2
M) with EC
50
value = 1.86 ± 0.65 mg/mL. These results clearly show the relaxing effect of the aqueous extract on the isolated rat trachea. This
effect involved some β-adrenergic receptor inhibition.
