INVESTIGATIONS OF CERTAIN NIGERIAN MEDICINAL PLANTS – Part. I. Preliminary Pharmacological and Phytochemical Screenings for Cardiac Activity¹

Summary

Certain Nigerian medicinal plants have been submitted to a preliminary pharmacological screening for cardiac activity using a method based on isolated toad hearts which were proved satisfactory for the purpose. The cardio–active drugs were also screened phytochemically for alkaloids and cardiac glycosides. Some 111 reputed Nigerian drugs from 33 species and 8 families were examined, of which 44 drugs from 14 species were cardio–active. Active and non–cardio–active drugs are listed.

Three classes of cardio–active drugs were recognised, showing respectively (a) cardiotoxic activity (6 drugs), (b) cardiotonic activity (28 drugs), (c) cardio–toxic followed by marked cardiotonic activities (10 drugs). Generally the different morphological members of one species possessed the same type of cardio–activity, but the leaves of Callichilia monopodialis and of Hedranthera barteri were cardiotoxic whereas roots and stems of the two species were cardiotonic. Ten drugs contained alkaloids, 24 contained cardiac glycosides, but the ten drugs of class (c) above were of uncertain composition.

Detailed investigations of certain of these drugs will be published later.

Zusammenfassung

Eine Reihe nigerianischer Pflanzenarten, deren örtliche Anwendung Herzwirksamkeit vermuten läßt, wurde pharmakologisch an Bufo regalis und chemisch auf Alkaloide und herzwirksame Glykoside geprüft. Es ergaben sich drei Gruppen, Pflanzen mit (a) cardiotoxischer Wirkung, (b) cardiotonischer Wirkung, (c) cardiotoxischer Wirkung, der eine cardiotonische folgt. Wirksame Pflanzenteile und deren Wirkstoffe sind aus Tabelle 1 zu ersehen.