In vitro inhibition of [3H]-angiotensin II binding on the human AT1 receptor by proanthocyanidins from Guazuma ulmifolia bark.
A bioassay-guided fractionation of the 70% acetone extract of the bark of Guazuma ulmifolia Lam. on the inhibition of angiotensin II binding to the AT 1 receptor led to the isolation and identification of bioactive oligomeric and polymeric proanthocyanidins consisting mainly of (-)-epicatechin units. The displacement of [3H]-angiotensin II binding was dose-dependent and correlated with the degree of polymerization of the different fractions containing proanthocyanidins. A strong displacement was seen for the residual fraction suggesting that the most active substances corresponding to the highly polymerized proanthocyanidins. Angiotensin II AT 1 receptor binding might be considered as a potentially interesting biological activity of proanthocyanidins contributing to the very broad spectrum of biological activities of the condensed tannins.
Caballero-George
Catherina
C
Department of Pharmaceutical Sciences, University of Antwerp, Antwerp, Belgium.
Vanderheyden
Patrick M L
PM
De Bruyne
Tess
T
Shahat
Abdel-Atty
AA
Van den Heuvel
Hilde
H
Solis
Pablo N
PN
Gupta
Mahabir P
MP
Claeys
Magda
M
Pieters
Luc
L
Vauquelin
Georges
G
Vlietinck
Arnold J
AJ
D000804:Angiotensin II / Q000378:metabolism*; D000872:Anthocyanins / Q000494:pharmacology*; D001665:Binding Sites / Q000187:drug effects; D001667:Binding, Competitive / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D006801:Humans; D019660:Malvaceae; D024301:Plant Bark / Q000737:chemistry*; D010936:Plant Extracts / Q000494:pharmacology; D044945:Proanthocyanidins; D044140:Receptor, Angiotensin, Type 1; D011945:Receptors, Angiotensin / Q000187:drug effects / Q000378:metabolism*; D014316:Tritium
D000872:Anthocyanins; D010936:Plant Extracts; D044945:Proanthocyanidins; D044140:Receptor, Angiotensin, Type 1; D011945:Receptors, Angiotensin; D014316:Tritium; D000804:Angiotensin II; C013221:proanthocyanidin