Introduction
Cough is a physiological protective reflex that helps clear foreign particles, irritants, and excessive secretions from the airways. Although it serves an important defensive function, cough is also among the most common clinical symptoms encountered in respiratory disorders. The widespread use of herbal medicines for respiratory health has generated considerable interest in natural therapeutic agents that support airway function while minimizing adverse effects. Among these, licorice has remained a prominent medicinal herb traditionally utilized for managing cough and other respiratory complaints.
Understanding licorice in respiratory care
Licorice is derived from three plant species: Glycyrrhiza uralensis, Glycyrrhiza glabra, and Glycyrrhiza inflata. It has long been valued in traditional medicine for respiratory conditions such as cough, sore throat, asthma, and bronchitis. Its broad therapeutic application is attributed to a diverse range of bioactive constituents that contribute to its respiratory-supportive properties.
The phytochemical profile of licorice includes multiple classes of compounds, such as:
- Flavonoid glycosides
- Flavanones
- Chalcones
- Triterpenoid saponins
- Triterpenes
- Coumarins
- Isoflavones
- Isoflavanes
- Flavones
The presence of these structurally diverse constituents contributes to the multifaceted role of licorice in respiratory wellness and cough management.
Mechanisms supporting cough relief
Licorice is traditionally used in cough associated with phlegm and excessive bronchial secretions. Its pharmacologically active compounds are recognized for supporting respiratory comfort through multiple pathways.
Key constituents associated with respiratory benefits include:
- Glycyrrhizin
- Glycyrrhetinic acid
- Liquiritin and its derivatives
Glycyrrhizin and glycyrrhetinic acid are known for corticosteroid-like activity, which contributes to their role in supporting respiratory health. In addition, liquiritin and related compounds are associated with antitussive properties, making licorice a valuable botanical for symptomatic cough management.
Traditional applications in cough and airway health
Traditional herbal literature describes licorice as both a demulcent and an expectorant. As a demulcent, it helps soothe irritated mucosal surfaces of the throat, providing comfort in sore throat conditions. As an expectorant, it supports the clearance of bronchial mucus and facilitates respiratory tract cleansing.
Common traditional respiratory applications include:
- Cough with phlegm
- Sore throat
- Bronchial mucus accumulation
- Asthma
- Bronchitis
These characteristics have established licorice as a versatile respiratory herb with relevance across a wide spectrum of airway conditions.
Conclusion
Licorice remains an important medicinal plant in respiratory care due to its diverse phytochemical composition and long-standing traditional use. The combination of demulcent, expectorant, and antitussive properties supports its role in managing cough, particularly when associated with phlegm and bronchial congestion. The presence of bioactive compounds such as glycyrrhizin, glycyrrhetinic acid, and liquiritin further highlights its significance as a botanical option for respiratory support and airway health. 1,2
References:
1. Kuang Y, Li B, Fan J, Qiao X, Ye M. Antitussive and expectorant activities of licorice and its major compounds. Bioorg Med Chem. 2018;26(1):278-284. doi:10.1016/j.bmc.2017.11.046. https://www.sciencedirect.com/science/article/abs/pii/S0968089617318539?via%3Dih
2. Wardani RS, Schellack N, Govender T, et al. Treatment of the common cold with herbs used in Ayurveda and Jamu: monograph review and the science of ginger, liquorice, turmeric and peppermint. Drugs Context. 2023;12:2023-2-12. Published 2023 Jun 14. doi:10.7573/dic.2023-2-12. https://pmc.ncbi.nlm.nih.gov/articles/PMC10278442/#sec35