title: Studies on cardio-suppressant, vasodilator and tracheal relaxant effects of Sarcococca saligna.
abstract: Sarcococca saligna is a shrub that is traditionally used for its medicinal properties in Pakistan. In this study we report the cardio-suppressant, vasodilator and tracheal relaxant activities of the aqueous-methanolic extract (Ss.Cr) of the plant. Ss.Cr, that tested positive for the presence of saponins, flavonoids, tannins, phenols, and alkaloids, exhibited a dose-dependent (0.3-5 mg/mL) negative inotropic and chronotropic effect on the isolated guinea-pig atrium which was resistant to atropine (1 microM) and aminophylline (10 microM) pretreatment. In rabbit thoracic aorta, Ss.Cr dose-dependently (0.1-3 mg/mL) relaxed the high K+ (80 mM) and phenylephrine (PE, 1 microM)-induced contractions, indicating a possible Ca++ channel blocking (CCB) effect. When tested against PE (1 microM) control peaks in normal Ca++ and Ca++-free Kreb's solution, Ss.Cr exhibited dose-dependent (0.1-3 mg/mL) inhibition, being more potent in relaxing the PE responses in Ca++-free Kreb's solution, thus indicating specific blockade of Ca++ release from the intracellular stores. Ss.Cr also relaxed the agonist-induced contractions in: a) rat aorta irrespective of the presence of endothelium or nitric oxide synthase inhibitor L-NAME and b) rabbit and guinea-pig tracheal strips. The data shows that Ss.Cr possesses possible Ca++ channel blocking activity which might be responsible for its observed cardio-suppressant, vasodilator and tracheal relaxant effects though more tests are required to confirm this Ca++ channel blocking effect.
authors.affiliation: Department of Biological and Biomedical Sciences, The Aga Khan University Medical College, Karachi, Pakistan.
authors.forename: Muhammad Nabeel
authors.initials: MN
authors.lastname: Ghayur
authors.forename: Anwarul Hassan
authors.initials: AH
authors.lastname: Gilani
mesh_terms: D000628:Aminophylline / Q000494:pharmacology; D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology*; D001285:Atropine / Q000037:antagonists & inhibitors / Q000494:pharmacology; D001993:Bronchodilator Agents / Q000494:pharmacology*; D031234:Buxaceae / Q000737:chemistry*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D006168:Guinea Pigs; D006325:Heart Atria / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D018727:Muscarinic Antagonists / Q000494:pharmacology; D009130:Muscle, Smooth / Q000187:drug effects*; D009200:Myocardial Contraction / Q000187:drug effects; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D010154:Pakistan; D010656:Phenylephrine / Q000494:pharmacology; D010936:Plant Extracts / Q000494:pharmacology; D011189:Potassium Chloride / Q000494:pharmacology; D011817:Rabbits; D051381:Rats; D017207:Rats, Sprague-Dawley; D014132:Trachea / Q000187:drug effects*; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology*
chemical_list: D000889:Anti-Arrhythmia Agents; D001993:Bronchodilator Agents; D002121:Calcium Channel Blockers; D004791:Enzyme Inhibitors; D018727:Muscarinic Antagonists; D010936:Plant Extracts; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D010656:Phenylephrine; D000628:Aminophylline; D011189:Potassium Chloride; D001285:Atropine; D019331:NG-Nitroarginine Methyl Ester