1. Bronchodilator activity of Mikania glomerata Sprengel on human bronchi and guinea-pig trachea.
- Author
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Soares de Moura R, Costa SS, Jansen JM, Silva CA, Lopes CS, Bernardo-Filho M, Nascimento da Silva V, Criddle DN, Portela BN, Rubenich LM, Araujo RG, and Carvalho LC
- Subjects
- Animals, Aorta, Thoracic drug effects, Bronchoconstrictor Agents pharmacology, Guinea Pigs, Humans, In Vitro Techniques, Male, Mesenteric Arteries drug effects, Muscle, Smooth drug effects, Plant Extracts pharmacology, Plant Leaves chemistry, Rats, Rats, Wistar, Vasodilation drug effects, Asteraceae chemistry, Bronchi drug effects, Bronchodilator Agents pharmacology, Muscle Relaxation drug effects, Trachea drug effects
- Abstract
The effects of aqueous extracts and hydro-alcoholic extract (HAE), and of a dichloromethane fraction (MG1) obtained from the HAE of Mikania glomerata leaves on isolated respiratory and vascular smooth muscle have been investigated. Aqueousextracts and HAE induced a significant inhibition on the histamine contractions on the isolated guinea-pig trachea. HAE extract induced a concentration-dependent relaxation on guinea-pig trachea pre-contracted with histamine (IC50 0.34 (0.29-0.39) mg mL(-1)), acetylcholine (IC50 0.72 (0.67-0.77) mg mL(-1)) or K+ (IC50 1.41 (1.18-1.64) mg mL(-1)) and on isolated human bronchi precontracted with K+ (IC50 0.34 (0.26-0.42) mg mL(-1)). The dichloromethane fraction induced a concentration dependent relaxation in guinea-pig trachea precontracted with K+ (IC50 0.017 (0.012-0.022) mg mL(-1)). The dichloromethane fraction had also a small vasodilator effect on the isolated mesenteric vascular bed and on the isolated rat aorta, and a significant reduction of the oedema induced by subplantar injections of Bothropsjararaca venom in mice. When tested on plasmid DNA, MG1 did not damage the DNA. Chromatographic analysis showed the presence of 11.4% w/w coumarin in MG1. The results supported the indication of M. glomerata products for the treatment of respiratory diseases where bronchoconstriction is present.
- Published
- 2002
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