title: Isolation of a bronchodilator flavonoid from the Thai medicinal plant Clerodendrum petasites.
abstract: The ethanolic extract of Clerodendrum petasites was tested to evaluate the spasmolytic activity on isolated guinea-pig tracheal smooth muscle. The crude extract (2.25-9.0 mg/ml) dose-dependently caused relaxation of tracheal smooth muscle which was contracted by exposure to histamine. A bioassay-guided fractionation of the crude extract was performed by means of partitioning and centrifugal partition chromatography. Finally the active principle was isolated and identified as the flavonoid hispidulin (EC(50): (3.0+/-0.8)x10(-5) M). These results suggest that hispidulin may be beneficial in the treatment of asthma.
authors.affiliation: Department of Pharmacognosy, Leiden University, 2300 RA, Leiden, The Netherlands. ahazekamp@rocketmail.com
authors.forename: A
authors.initials: A
authors.lastname: Hazekamp
authors.forename: R
authors.initials: R
authors.lastname: Verpoorte
authors.forename: A
authors.initials: A
authors.lastname: Panthong
mesh_terms: D000818:Animals; D001249:Asthma / Q000188:drug therapy; D001993:Bronchodilator Agents / Q000302:isolation & purification / Q000494:pharmacology*; D047309:Flavones; D005419:Flavonoids / Q000302:isolation & purification / Q000494:pharmacology*; D006168:Guinea Pigs; D066298:In Vitro Techniques; D019686:Lamiaceae / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D009119:Muscle Contraction / Q000187:drug effects; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D013056:Spectrophotometry, Ultraviolet; D013785:Thailand; D014132:Trachea / Q000187:drug effects
chemical_list: D001993:Bronchodilator Agents; D047309:Flavones; D005419:Flavonoids; D010936:Plant Extracts; C055957:hispidulin