title: In vitro vasorelaxation mechanisms of bioactive compounds extracted from Hibiscus sabdariffa on rat thoracic aorta.
abstract: BACKGROUND
  In this study, we suggested characterizing the vasodilator effects and the phytochemical characteristics of a plant with food usage also used in traditional treatment of arterial high blood pressure in Senegal.
  
  
  METHODS
  Vascular effects of crude extract of dried and powdered calyces of Hibiscus sabdariffa were evaluated on isolated thoracic aorta of male Wistar rats on organ chambers. The crude extract was also enriched by liquid-liquid extraction. The various cyclohexane, dichloromethane, ethyl acetate, butanol extracts obtained as well as the residual marc were subjected to Sephadex LH-20 column chromatography. The different methanolic eluate fractions were then analyzed by Thin Layer (TLC) and High Performance Liquid Chromatography (HPLC) and their vascular effects also evaluated.
  
  
  RESULTS
  The H. Sabdariffa crude extract induced mainly endothelium-dependent relaxant effects. The endothelium-dependent relaxations result from NOS activation and those who not dependent to endothelium from activation of smooth muscle potassium channels. The phytochemical analysis revealed the presence of phenolic acids in the ethyl acetate extract and anthocyans in the butanolic extract. The biological efficiency of the various studied extracts, in term of vasorelaxant capacity, showed that: Butanol extract > Crude extract > Residual marc > Ethyl acetate extract. These results suggest that the strong activity of the butanolic extract is essentially due to the presence of anthocyans found in its fractions 43-67.
  
  
  CONCLUSIONS
  These results demonstrate the vasodilator potential of hibiscus sabdariffa and contribute to his valuation as therapeutic alternative.
authors.affiliation: Laboratoire de Physiologie Pharmaceutique, Faculté de Médecine, Pharmacie et Odontologie, Université Cheikh Anta Diop, Dakar, Sénégal. mamadousarr@ucad.sn.
authors.forename: Mamadou
authors.initials: M
authors.lastname: Sarr
authors.forename: Saliou
authors.initials: S
authors.lastname: Ngom
authors.forename: Modou O
authors.initials: MO
authors.lastname: Kane
authors.forename: Alassane
authors.initials: A
authors.lastname: Wele
authors.forename: Doudou
authors.initials: D
authors.lastname: Diop
authors.forename: Bocar
authors.initials: B
authors.lastname: Sarr
authors.forename: Lamine
authors.initials: L
authors.lastname: Gueye
authors.forename: Ramaroson
authors.initials: R
authors.lastname: Andriantsitohaina
authors.forename: Aminata S
authors.initials: AS
authors.lastname: Diallo