Available online 8 October 2015
A review of the relaxant effect of various medicinal plants on tracheal smooth muscle, their possible mechanism(s) and potency
- Neurogenic Inflammation Research Centre and Department of Physiology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, IR Iran
- Received 14 July 2015, Revised 4 October 2015, Accepted 6 October 2015, Available online 8 October 2015
Abstract
Ethnopharmacological relevance
The
therapeutic effects of the medicinal plants described in the current
review on obstructive pulmonary diseases have found mention in ancient
Iranian medical texts and in traditional folk medicine. These effects
are attributed to their bronchodilatory activity, which relaxes the
smooth muscles of the airway. Therefore, in the present review, the
relaxant effects of various extracts, fractions and constituents of
medicinal plants on tracheal smooth muscle are reviewed in light of
their therapeutic effects on obstructive pulmonary diseases.
Materials and methods
The
online literature was searched using Medline, PubMed, ScienceDirect,
Scopus, Google Scholar, Web of Science and SID (for articles written in
Persian). Moreover, local books on ethnopharmacology from 1918 to 2014
were searched with keywords such as tracheal smooth muscle, airway
smooth muscle, relaxant effect, bronchodilatory effect and related
mechanisms to identify studies on the relaxant effects of medicinal
plants on tracheal smooth muscle and the possible mechanism(s) of these
effects.
Results
All studied
plants showed significant relaxant effects on tracheal smooth muscle,
which were similar or superior to the effect of theophylline at the used
concentrations. According to the results, most of these plants also
showed an inhibitory effect on muscarinic and histamine (H1)
receptors, whereas some plants showed more pronounced stimulatory
effects on the beta-adrenergic receptor. Some of the studied plants also
showed inhibitory effects on calcium and potassium channels.
Conclusion
The
present article reviewed the relaxant effects of several medicinal
plants on tracheal smooth muscle, which were comparable or superior to
the effect of theophylline at the studied concentration. The possible
mechanisms of the relaxant effects of the studied medicinal plants and a
comparison of these effects were also reviewed. This review presents
the fractions and constituents of plants with potent relaxant effects on
tracheal smooth muscle, which can be used to treat obstructive
pulmonary disease.
Chemical compounds studied in this article
- Carvacrol (PubChem CID: 10364);
- dithymoquinone or nigellone (PubChem CID: 398941);
- safranal (PubChem CID: 61041);
- thymoquinone (PubChem CID: 10281);
- thymol (PubChem CID: 6989g);
- umbelliprenin (PubChem CID: 1781413);
- p-cymene (PubChem CID: 7463);
- cuminaldehyde (PubChem CID: 326);
- trans-anethole (PubChem CID: 637563);
- alpha-pinene (PubChem CID: 6654);
- β-pinene (PubChem CID: 14896);
- saponins (PubChem CID: 11007422);
- apigenin (PubChem CID: 5280443);
- alpha-phellandrene (PubChem CID: 7460);
- crocetin (PubChem CID: 5281232)
Keywords
- Medicinal plants;
- Relaxant effects;
- Smooth muscle;
- Trachea;
- Possible mechanisms;
- Toxicological effects
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