title: The main relaxant constituents of Nigella sativa methanolic fraction on Guinea pig tracheal chains.
abstract: Our previous studies demonstrated the preventive effect of Nigella sativa extract on asthma and water-soluble substances of this extract, especially its methanol fraction were responsible for this relaxation on contracted tracheal chains of guinea pigs. For the first time, the present study has been conducted to determine the main constituents of its methanolic extract. Four constituents of 20%-methanolic fraction, consisting of two flavonoids (20-20% and 21-20% fractions) and two polysaccharides (1-20% and 2-20% fractions), were purified by analytical and preparative HPLC. The relaxant effects of four cumulative concentrations of each constituent (50, 100, 150 and 200 mg/lit) in comparison with saline (1 ml) as negative control and four cumulative concentrations of theophylline (0.2, 0.4, 0.6 and 0.8 mM) as positive control were examined on methacholine-precontracted guinea pig tracheal chains (n=6). All concentrations of theophylline and most concentrations of 20-20, 21-20 fractions showed significant relaxant effects compared to that of saline. 20-20 fraction (Comferol diglucoside) was the most potent bronchodilator. Their relaxant effects were lower than that of theophylline. Polysaccharides (1-20, 2-20 fractions) did not have any relaxant effects compared to that of saline. These results revealed that two flavonoids of 20%-methanolic fraction of Nigella sativa were its main relaxant constituents.
authors.affiliation: Tuberclosis and Lung Research Center, Tabriz University of Medical Sciences, Tabriz, Iran and Department of Physiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran. r_keyhanmanesh@yahoo.com.
authors.forename: Rana
authors.initials: R
authors.lastname: Keyhanmanesh
authors.forename: Horeyeh
authors.initials: H
authors.lastname: Bagban
authors.forename: Hossein
authors.initials: H
authors.lastname: Nazemieh
authors.forename: Fariba
authors.initials: F
authors.lastname: Mirzaei Bavil
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Alipour
mesh_terms: D000818:Animals; D001993:Bronchodilator Agents / Q000494:pharmacology*; D005260:Female; D005419:Flavonoids / Q000494:pharmacology; D006168:Guinea Pigs; D008297:Male; D009130:Muscle, Smooth / Q000187:drug effects; D031881:Nigella sativa / Q000737:chemistry*; D008517:Phytotherapy / Q000379:methods*; D010936:Plant Extracts / Q000494:pharmacology*; D014132:Trachea / Q000187:drug effects*
chemical_list: D001993:Bronchodilator Agents; D005419:Flavonoids; D010936:Plant Extracts