title: Possible presence of calcium channel blocker(s) in Rubia cordifolia: an indigenous medicinal plant.
abstract: Crude extract of Rubia cordifolia (RC) was tested in isolated tissue preparations for its possible calcium channel antagonistic activity. RC suppressed the spontaneous contractions of guinea-pig atria, rabbit jejunum and rat uterus in a concentration dependent manner (0.1-3 mg/ml). In rabbit aorta, it inhibited norepinephrine (10 microM) and KCl (80 mM) induced contractions. Replacement of physiological salt solution with calcium free solution abolished the spontaneous movements of rabbit jejunum. However, addition of calcium (25 micrograms/ml) in the tissue bath restored the spontaneous movements. When the tissues were pretreated with plant extract (1 mg/ml) or verapamil (0.5 microgram/ml), addition of calcium failed to restore spontaneous contractions. These results indicate that the plant extract exhibits spasmolytic activity similar to that of verapamil suggestive of presence of calcium channel blocker like constituent(s) in this plant.
authors.affiliation: Department of Pharmacology, Aga Khan University Medical College, Karachi.
authors.forename: A H
authors.initials: AH
authors.lastname: Gilani
authors.forename: K H
authors.initials: KH
authors.lastname: Janbaz
authors.forename: M
authors.initials: M
authors.lastname: Zaman
authors.forename: A
authors.initials: A
authors.lastname: Lateef
authors.forename: A
authors.initials: A
authors.lastname: Suria
authors.forename: H R
authors.initials: HR
authors.lastname: Ahmed
mesh_terms: D000818:Animals; D001011:Aorta / Q000187:drug effects; D002121:Calcium Channel Blockers / Q000032:analysis*; D005260:Female; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007583:Jejunum / Q000187:drug effects; D008297:Male; D008519:Medicine, Traditional; D009119:Muscle Contraction / Q000187:drug effects; D010154:Pakistan; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology*; D010946:Plants, Medicinal / Q000737:chemistry*; D011817:Rabbits; D051381:Rats; D014599:Uterus / Q000187:drug effects
chemical_list: D002121:Calcium Channel Blockers; D010936:Plant Extracts