Actions of Banana Tree Extraction on Smooth and Cardiac Muscles and in the Anesthetized Rat

Abstract

Pygmy tribesmen of central and southern Africa have been reported to use the juice of the banana plant stem for hunting animals and in tribal warfare (Heymer, 1974). Wooden arrows or darts may be given a poisonous tip by driving them into the plant stem for 1–2 days. An animal hit by one of these weapons becomes paralyzed but its flesh is safe to eat. An extract prepared from the juice augments, then blocks contractions of both directly or indirectly stimulated skeletal muscles (Singh and Dryden, 1985, 1990). In higher concentrations, the extract induces a sustained muscle contracture which is slowly reversed by removal of the extract. It also increases the rate of spontaneous transmitter release, as measured by the frequency of miniature endplate potentials (Singh and Dryden, 1985). The effect of the extract has now been tested on smooth and cardiac muscle preparations and in the anesthetized rat to assess whether the presumed incapacitation of the animal by the extract-tipped arrows and darts of the Pygny tribesmen was due to paralysis of limb skeletal muscles and the diaphragm or by a collapse of its cardiovascular activity.