Journal of Clinical & Experimental Pharmacology

Bioassay-directed isolation of hypotensive alkaloids from Holarrhena pubescens

World Congress on Pharmacology

July 20-22, 2015 Brisbane, Australia

K Aftab, S B Usmani, S Begum and B S Siddiqui

Posters-Accepted Abstracts: Clin Exp Pharmacol

Abstract:

Holarrhena pubescens belongs to the family Apocynacea, commonly known as ?Kurchi? is highly reputed in traditional medicine as a remedy for amoebic dysentery and other intestinal ailment. Bioassay-directed fractionation of the ethanolic extract of Holarrhena pubescens resulted in the isolation of steroidal alkaloids (Holamide and Pubscinine). In anaesthetized rats, the Holamide and Pubscinine caused a fall in blood pressure in a dose-dependent manner. Pretreatment of animals Atropine completely abolished the hypotensive response of Acetycholine; whereas hypotensive effect of Holamide and Pubscinine were not modified by Atropine. Similarly Acetylcholine produced contractile effect in guinea-pig ileum, which was antagonized by atropine; however both (Holamide and Pubscinine) failed to produce any stimulant response on guinea-pig ileum. These data indicate that the steroidal alkaloids i.e. Holamide and Pubscinine from Holarrhena pubescens mediated hypotensive response through a mechanism different to that of Acetycholine.