Abstract
This paper examines the effects of extracts, chromatographic fractions, and pure compounds from Zygophyllum gaetulum (Zygophyllaceae) on electrically-induced contractions of isolated guinea-pig ileum and morphine withdrawal in vitro. The results indicated that all the extracts, partially purified fractions from the MeOH extract and two pure triterpenene saponins, significantly and dose-dependently reduced both the electrical contractions of the ileum and morphine withdrawal. The two active compounds are triterpenene acid bisdesmosides with different sugar residues at C-3 and C-28 of the aglycones.