Hypotensive activity of the ethanol extract of Pavetta crassipes leaves.
Pavetta crassipes leaf is routinely used locally in Nigeria for the management of respiratory disorders and hypertension. The hypotensive and other cardiovascular effects of Pavetta crassipes were investigated in cats and rats. The effects of the extract on rat and cat blood pressures, isolated rat atria, rat portal vein, isolated rat aorta and rat vas deferens were studied. Specific receptor antagonists (atropine, mepyramine, phentolamine, propranolol) were used to elucidate the underlying mechanism(s) involved in the cardiovascular changes induced by P. crassipes. The results revealed that the ethanolic extract of Pavetta crassipes lowered the blood pressures of cats and rats in a dose dependent manner. The extract also caused a concentration-dependent decrease in the force of contraction of the isolated rat atria and rat portal vein. The decreases in blood pressure values were attenuated in the presence of a beta-adrenoceptor antagonist, propranolol. The extract also attenuated isoprenaline-induced contraction of the rat atria. However, the extract did not affect contractions evoked by KCl, norepinephrine and 5-HT on the rat aorta. Pavetta crassipes contains biologically active substances that may be useful in the management of hypertension.
Amos
Samson
S
Department of Pharmacology and Toxicology, National Institute for Pharmaceutical Research and Development (NIPRD), Nigeria. sa7h@virginia.edu
Akah
Peter Achunike
PA
Binda
Lucy
L
Enwerem
Nkechi Mercy
NM
Ogundaini
Abiodun
A
Wambebe
Charles
C
Hussaini
Isa Marte
IM
Gamaniel
Karniyus Shingu
KS
D000818:Animals; D001011:Aorta / Q000187:drug effects; D020517:Atrial Appendage / Q000187:drug effects / Q000502:physiology; D001794:Blood Pressure / Q000187:drug effects; D002415:Cats; D004305:Dose-Response Relationship, Drug; D000431:Ethanol; D005260:Female; D006973:Hypertension / Q000188:drug therapy*; D007022:Hypotension / Q000139:chemically induced*; D007275:Injections, Intravenous; D008297:Male; D016488:Medicine, African Traditional; D051379:Mice; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology; D008517:Phytotherapy; D010936:Plant Extracts / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry*; D011169:Portal Vein / Q000187:drug effects; D051381:Rats; D019666:Rubiaceae / Q000737:chemistry*; D014649:Vas Deferens / Q000187:drug effects
D010936:Plant Extracts; D000431:Ethanol