Licorice: A Potential Herb in Overcoming SARS-CoV-2 Infections

Abstract

The management of the global pandemic outbreak due to the coronavirus disease (COVID-19) has been challenging with no exact dedicated treatment nor established vaccines at the beginning of the pandemic. Nonetheless, the situation seems to be better controlled with the recent COVID-19 vaccines roll-out globally as active immunisation to prevent COVID-19. The extensive usage and trials done in recent outbreak in China has shown the effectiveness of traditional Chinese Medicines (TCM) in improving the wellbeing of COVID-19 patients. Therefore, COVID-19 Prevention and Treatment guidelines has listed a number of recommended concoctions meant for COVID-19 patients. Licorice, more commonly known as Gancao in Chinese Pinyin, is known as one of the most frequently used ingredients in TCM prescriptions for treatment of epidemic diseases. Interestingly, it is deemed as food ingredient as well, where it is normally used in Western cuisines’ desserts and sweets. The surprising fact that licorice appeared in the top 10 main ingredients used in TCM prescriptions in COVID-19 has drawn great attention from researchers in revealing its biological potential in overcoming this disease. To date, there are no comprehensive review on licorice and its benefits when used in COVID-19. Thus, in this current review, the possible benefits, mechanism of actions, safety and limitations of licorice were explored in hope to provide a quick reference guide for its preclinical and clinical experimental set-up in this very critical moment of pandemic.

The discovery of herbal drugs and natural compounds as inhibitors of SARS-CoV-2 infection in vitro

“…However, glabridin also effectively inhibited SARS-CoV-2 at the entry treatment in our study. Other investigators confirmed that glycyrrhizin and licorice extracts overcome SARS-CoV-2 infection [ 41 , 42 ]. The molecular docking study indicated licorice active compounds such as glycyrrhizic acid, liquiritigenin and glabridin against main protease of SARS-CoV-2.…”

Jing Si Herbal Drink as a prospective adjunctive therapy for COVID-19 treatment: Molecular evidence and mechanisms

“…For example, the molecular docking and network pharmacology approach confirmed that licorice glycoside E can inhibit 3CLpro to block SARS-CoV-2 replication by targeting phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit gamma (PIK3CG) and E2F transcription factor 1 (E2F1) through the PI3K-Akt signaling pathway [ 87 , 88 ]. Furthermore, licorice phenol in Huashi Baidu decoction can bind to Mpro and ACE2, which could hinder SARS-CoV-2 replication and block viral binding sites [89] . Glycyrrhizin, a main compound of licorice, has been reported to have antiviral effects on SARS-associated coronaviruses (CoVs), human immunodeficiency virus type 1 (HIV-1), and chronic hepatitis C virus [ 90 , 91 ].…”

A review on phytochemicals, pharmacological activities, drug interactions, and associated toxicities of licorice (Glycyrrhiza sp.)

“…The active metabolites of licorice such as glycyrrhizin may inhibit the binding of S protein to ACE2 receptor and reduce viral entry (Bailly & Vergoten, 2020), but the exact mechanism is still unknown. Subsequently, they also inhibited the catalytic activity of 3C like protease, essential for viral replication and assembly in the host cell (Ng et al, 2021) (Figure 7).…”