Skeletal muscle relaxant effect of Chonemorpha macrophylla in experimental animals

Abstract

OBJECTIVE: To study the skeletal muscle relaxant property of Chonemorpha macrophylla (CM). MATERIALS AND METHOD: The skeletal muscle relaxant effect of the alcoholic extract of CM was studied on isolated frog rectus abdominis muscle, isolated rat phrenic nerve diaphragm muscle preparation and in intact young chicks. The parameter studied in the isolated muscle or isolated nerve muscle preparations was the extent of inhibition of acetylcholine or electrically-induced contraction of skeletal muscles. In intact chicks, the drug was administered i.v. in wing veins and the onset, duration and nature of paralysis were recorded. In all the experiments, the effect of the drug was compared with that of gallamine and succinylcholine. RESULTS: The alcoholic extract of CM reduced the acetylcholine-induced contraction of isolated frog rectus abdominis and electrically stimulated contractions of rat phrenic nerve diaphragm in a dose-dependent manner. In unanaesthetized chicks, it produced spastic type of paralysis with extension of the neck and limbs. The effects were similar to the effects of succinylcholine but different from those of gallamine. CONCLUSION: The alcoholic extract of CM possesses skeletal muscle relaxant property. It produces depolarizing type of muscle paralysis similar to that produced by succinylcholine.