Investigation on the Expectorant Effect of Extracts from Primula veris L.

Abstract

BACKGROUND: At present, coughing can be regulated by medications such as dextromethorphan and codeine, which are associated with side effects, including drug drowsiness or dependency. Thus, there is an increasing demand for drugs that promote expectorant activities with fewer adverse effects. The root of Primula veris L. (Primulaceae) is an herbal medicine that has been used as an expectorant drug for thousands of years in folk medicine. AIM: The present study aims to create an in-depth pharmacological study of the expectorant activity of P. veris to create new drugs in different directions which are appropriate and promising. MATERIALS AND METHODS: The expectorant effect of thick extracts of the study plant was studied on the influence of the motor activity of the ciliated epithelium and the secretory function of the bronchi. The expectorant activities of the ethanol extracts of leaves and rhizomes with roots from P. veris were evaluated using classical animal models. The expectorant assay was performed with phenol red secretion in the mouse trachea. After gastric administration of the test extracts in mice, 2.5% phenol red solution was injected intraperitoneally. The trachea was dissected and the optical density of tracheal secretion was measured. RESULTS: The results of the studies showed that a thick extract of primrose rhizomes with roots has a high ability to secrete sputum, which is almost not inferior to the Hedelix drops comparator (ivy extract) – 126.6% and 146.4%, respectively. Extract from the leaves of P. veris is characterized by less pronounced activity, which, at a dose of 200 mg/kg, was 74.5%. CONCLUSION: The results of the present study provide evidence that P. veris can be used as an expectorant herbal medicine and that triterpene saponins may be the main active ingredients of Primula veris responsible for its bioactivities.