Tropical Journal of Pharmaceutical Research

Original Research Article | OPEN ACCESS

Relaxant Activity of the Methanol Extract of Acanthus Montanus (Nees) T Anderson (Acanthaceae) on Isolated Guinea Pig Trachea

O O Adeyemi¹ , U O Mgbeokwere², S O Okpo³

¹Department of Pharmacology, College of Medicine, University of Lagos, PMB 12003; ²Department of Pharmacy, Lagos University Teaching Hospital Lagos; ³Department of Pharmacology & Toxicology, University of Benin, PMB 1154, Benin City, Nigeria.

For correspondence:- O Adeyemi Email: ooadey@yahoo.com

Received: 7 March 2012 Accepted: 18 June 2012 Published: 18 October 2012

Citation: Adeyemi OO, Mgbeokwere UO, Okpo SO. Relaxant Activity of the Methanol Extract of Acanthus Montanus (Nees) T Anderson (Acanthaceae) on Isolated Guinea Pig Trachea. Trop J Pharm Res 2012; 11(5):777-782 doi: 10.4314/tjpr.v11i5.11

© 2012 The authors.
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Abstract

Purpose: To evaluate the effects of the methanol extract of Acanthus montanus on guinea pig trachealis muscle.

Methods: Guinea pig tracheae were set up in 10 ml organ baths. The effect of the methanol extract of Acanthus montanus (0.5 - 8 mg/ml) on the spontaneous tone of the trachea and carbachol-precontracted trachea in the absence and presence of propranolol, glibenclamide and procaine was studied.

Results: The extract (0.5 – 8.0 mg/ml) produced a concentration-dependent relaxation of the intrinsic tone in tracheal preparations which was completely blocked by propranolol (3 x 10^-7 M), glibenclamide (10^-7 M) and procaine (10^-3 M). The extract (0.5 - 8 mg/ml) produced a concentration-dependent relaxation of carbachol (10^-5M)-precontracted trachea. This effect of the extract was partially blocked by propranolol (3 x 10^-7M), procaine (10^-3M) and glibenclamide (10^-7M) with a progressive increase in the median effective concentration (EC₅₀) values as follows: control, 0.66mg/ml > propranolol, 1.42mg/ml > glibenclamide, 1.54mg/ml > procaine, 2.04 mg/ml.

Conclusion: The results obtained suggest that the extract produces a non-specific smooth muscle relaxant effect mediated via b-adrenergic receptor mechanism or potassium channels.

Keywords: Acanthus montanus, Trachea, Carbachol, Potassium channels, Propranolol, Glibenclamide, Procaine