Pharmacognostic Characteristics and Hypotensive Effect of the Stem Bark of Musanga cecropioides R. Br. (Moraceae)

  • BA Ayinde Departments of 1Pharmacognosy and 2Pharmacology/Toxicology, Faculty of Pharmacy,University of Benin, Benin City, Nigeria.
  • EKI Omogbai Departments of 1Pharmacognosy and 2Pharmacology/Toxicology, Faculty of Pharmacy,University of Benin, Benin City, Nigeria.
  • DN Onwukaeme Departments of 1Pharmacognosy and 2Pharmacology/Toxicology, Faculty of Pharmacy,University of Benin, Benin City, Nigeria.
Keywords: Musanga cecropioides, sterm bark, hypotensive effect, ecorce souche, effet hypoteseur

Abstract

Musanga cecropioides (Umbrella tree) is a plant reported to have oxytocic, hypotensive and antidiabetic activities. Pharmacognostic evaluation to establish the identity of the stem bark, as well as experiments to determine the possible pharmacological mechanism of its hypotensive effects, were carried out. Microscopically, the stem bark was observed to contain cork cells, cortical parenchyma, sclereids, fibers, vessels and calcium oxalate crystals. It had a moisture content of 3.68±0.06%, ash value of 10.38±0.12% while the alcohol and water extractive values were 1.29±0.02% and 1.10±0.13%, respectively. It contains saponins, tannins and flavonoids. The water extract of the stem bark produced a dose – related reduction in mean arterial pressure. The mean arterial pressure fell by 4.51±0.5mmHg at 10mg/kg and 65.23±6.28mmHg at 40mg/kg. The hypotensive effect of the extract was not affected by prior administration of either atropine (0.5mg/kg) or promethazine (0.25mg/kg). The extract had no direct effect on the intrinsic myogenic activity of the isolated rat portal vein. However, at 1.0mg/ml, the water extract remarkably reduced both the amplitude and force of contraction of isolated rabbit heart. The hypotensive effect of the extract therefore appears not to be due to a direct vascular effect but due to its effect on cardiac output as a result of inhibition of cardiac activity.

Key Words: Musanga cecropioides, sterm bark, hypotensive effect.

Résumé

Musanga cecropioides (Umbrella tree) est une plante repotée ayant des activitées oxytociques ,hypotensives et anti-diabetiques. L'evaluation pharmacognocsique pour determiner l'identitée de l'écorce souche de même que des experiences pour déterminer le possible mechanisme pharmacologique de son effet hypotenseur on été conduits. Microscopiquement l'ecorce a été observé contenir : cellule cork , parenchyma corticaux,scleroid, vaiseaux,et des crystaux d' oxalate de calcium. Il a une teneur en humidité de 3.68±0.06%, une valeur ash de10.38±0.12% alors que la valeur extrative de l'alcool et de l'eau étaient de 1.29±0.02% and 1.10±0.13% respectivement. Il contient de la sapponine, tannine et la flavonoide. Les extrait acqueux de l'ecorce produsirent une reduction de la pression arterielle moyenne et ce à dose-dependente. la pression arterielle moyenne tombait de 4.51±0.5mmHg à 10mg/kg et 65.23±6.28mmHg à 40mm/kg. L'effet hypotenseur de l'extrait n' était pas affecté par une primo administration soit de l' atropine (0.5mg/kg) ou promethazine (0.25mg/kg). L'extrait n'a eu aucun effet direct sur l'activitée myogenique intrisique des veines portal de souris isolée. Néanmoins à 1.0mg/ml, l'extrait acqueux a reduit remarquablement en même temps l' amplitude et la force de contraction des Coeur de lapin isoles. L'effet hypotenseur de l'extrait apparait donc ne pas être due à un effet vasculaire direct mais probablement due à son effet sur le quantite de sangs pompée par le Coeur ce comme resultat de l inihibation de l'activité cardiaque

Mot cles: Musanga cecropioides, ecorce souche, effet hypoteseur.

West Afr. J. Pharmacol. Drug Res. Vol.19 (1&2) 2003: 37-41
Published
2004-09-30
Section
Articles

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eISSN: 0303-691X