title: Study on the mechanism of the bronchodilatory effects of Cynodon dactylon (Linn.) and identification of the active ingredient.
abstract: BACKGROUND
  In the traditional medicine, Cynodon dactylon (Linn.) is used in asthma, but scientific studies to provide evidence for medicinal uses are sparse. Thus this study was undertaken to provide evidence for medicinal use in asthma as a bronchodilator, and to identify active ingredient(s).
  
  
  METHODS
  In vivo, acetylcholine (Ach)-induced bronchospasm was conducted in guinea pig while isolated rat tracheal strip was suspended in organ bath to measure the concentration response curve using multichannel data acquisition system.
  
  
  RESULTS
  The chloroform extract of Cynodon dactylon (CECD) protected against Ach-induced bronchospasm in guinea pigs, similar to atropine. In the in vitro studies, CECD relaxed carbachol (CCh) and high K+-induced contraction of rat tracheal strip, similar to atropine and verapamil respectively, suggesting antimuscarinic and calcium channel blocking (CCB) activities, which were confirmed by right ward shifting of CCh and Ca(+2) concentration response curve (CRC). The phosphodiestrase (PDE) inhibitory activity was confirmed by potentiation of isoprenaline-induced inhibitory response, similar to papaverine. Densitometry analyses led to the identification of scopoletin as an active ingredient. Effectively, it significantly inhibited high K+, and Ca(+2) induced contractile response, similar to verapamil. The phosphodiestrase (PDE) inhibitory activity was confirmed by direct evidence of potentiation of isoprenaline-induced inhibitory response, similar to papaverine.
  
  
  CONCLUSIONS
  These results suggest that the bronchodilator activity of CECD is partly due to presence of scopoletin, and mediated possibly through CCB and PDE inhibition.
authors.forename: Maulik R
authors.initials: MR
authors.lastname: Patel
authors.forename: Yagnik S
authors.initials: YS
authors.lastname: Bhalodia
authors.forename: Nimish L
authors.initials: NL
authors.lastname: Pathak
authors.forename: Maulik S
authors.initials: MS
authors.lastname: Patel
authors.forename: Kunal
authors.initials: K
authors.lastname: Suthar
authors.forename: Nilesh
authors.initials: N
authors.lastname: Patel
authors.forename: Dharmesh K
authors.initials: DK
authors.lastname: Golwala
authors.forename: Nurudin P
authors.initials: NP
authors.lastname: Jivani
mesh_terms: D000109:Acetylcholine; D000818:Animals; D001986:Bronchial Spasm / Q000139:chemically induced / Q000188:drug therapy / Q000503:physiopathology*; D001993:Bronchodilator Agents / Q000494:pharmacology* / Q000627:therapeutic use; D002121:Calcium Channel Blockers / Q000494:pharmacology / Q000627:therapeutic use; D002217:Carbachol / Q000494:pharmacology; D031744:Cynodon; D005260:Female; D006168:Guinea Pigs; D006632:Histamine; D066298:In Vitro Techniques; D008297:Male; D018727:Muscarinic Antagonists / Q000494:pharmacology / Q000627:therapeutic use; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology / Q000627:therapeutic use; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology* / Q000627:therapeutic use; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D014132:Trachea / Q000187:drug effects / Q000502:physiology
chemical_list: D001993:Bronchodilator Agents; D002121:Calcium Channel Blockers; D018727:Muscarinic Antagonists; D010726:Phosphodiesterase Inhibitors; D010936:Plant Extracts; D006632:Histamine; D002217:Carbachol; D000109:Acetylcholine; D011188:Potassium