Razi Journal of Medical Sciences

  Background: Respiratory tract is continuously exposed to environmental pollutants, respiratory pathogens and dispersed toxins in the air. Respiratory tract clearance through mucociliary system is the main defensive mechanism in the upper and lower airways. Various studies demonstrated the effectiveness of herbal drugs, however little studies conducted about mechanism of action of these drugs.

  Methods: In this prospective case-series, saccharin test as a measure of mucociliary clearance time, was conducted on 40 subsequently healthy volunteers presenting to otolaryngology clinic of Firoozgar Hospital. Time between placing saccharin over nasal mucosa to sensation of sweet flavor in the pharynx was recorded. Saccharin test was re-performed after administration of 3 doses of 7.5 cc of Prospan syrup. Data were analyzed by Wilcoxon signed ranked test and SPSS V.16.

  Results: In this study 32 patients (80%) were male and 8 were female (20%) with mean age of 38.4±12.07 years. Mean of time between “placing saccharin on nasal mucosa” to “sensation of sweet flavor in the pharynx” was 15.55±3.67 minutes before Prospan administration and 10.31±4.94 minutes after 3 doses of Prospan. Average reduction in the time of sweet sensation in the pharynx was 5.23±3.7 minutes.

  Conclusion: This study in conjunction with preliminary studies regarding the effectiveness of the extract of dried Hedera helix leaves on respiratory symptoms shows that “improvement in the function of mucociliary system” is one of the main mechanisms of actions of this drug.