Background: Asl-us-Soos (Glycyrrhiza glabra L.) has been used as a therapeutic agent in the treatment of respiratory, digestive, and neurological disorders since ancient times in Unani Medicine. Its therapeutic uses have been documented in Unani pharmacopeia, classical textbooks, and manuscripts based on experience in clinical practices. Asl-us-Soos (AS) and its compound preparations are recommended in the treatment of respiratory diseases such as Dhat al-Janb (pleurisy), Dhat al-Ri'a (pneumonia), Jamod us Sadr (pulmonary apoplexy), Diq al-Nafas (asthma), Sil (thiasis), and Diq (pulmonary tuberculosis).
Objectives: This review aimed to provide insight into ethno-medicinal uses, pharmacological activities, and phytochemical profile of AS. The review also highlights the prospects in the development of potential drug molecules for various respiratory ailments.
Methods: This review is based on a search of authentic Unani classical literature and major databases such as Science Direct, Medline (via PubMed), Google Scholar, Scopus, and Web of Science. The studies published between January 2001 and February 2022 were included in this study.
Results: This review found that AS had medicinal uses in various respiratory disorders. Its roots are used as single drug and compound formulations for the treatment of dry cough, bronchial asthma, bronchitis, and pneumonia. In addition, AS contains active phytoconstituents such as glycyrrhizin (glycyrrhizic acid), isoliquiritigenin, glabridin, and licochalcone A. They have been extensively studied using in vitro and in vivo models and were found to exhibit pharmacological effects in pulmonary tuberculosis, pulmonary carcinoma, emphysema, bronchial asthma, pneumonia, and upper respiratory tract infections. Moreover, glycyrrhizin has been found to possess therapeutic potential against COVID-19.
Conclusion: This review concludes that AS is a potent anti-tumor, anti-inflammatory, anti-microbial, anti-oxidant, expectorant, and antitussive drug. This plant could be an important source for the development of new drug compounds for various respiratory diseases.