Glycyrrhizin, the major ingredient in licorice root, has shown effectiveness against SARS virus in scientific studies
It has been effective in treating viruses such as herpes, HIV, hepatitis, influenza, encephalitis and pneumonia
Glycyrrhizin outperformed conventional antiviral medications against SARS in research published in the journal The Lancet
The substance seems to work earlier in the virus replication cycle, compared to other medications, inhibiting adsorption and penetration of the virus
During the COVID-19 pandemic, social distancing and hygiene seem to be having some effect on "flattening the curve" and slowing the spread of the virus. The use of ultraviolet (UV) light to decontaminate medical facilities, proper hand-washing and disinfectants, equipment and even protective facemasks also seems to be useful.
But people will still contract COVID-19, and effective treatments are lacking and needed. That's why some scientific studies are looking at a natural product that has long been known to have antiviral effects1 – glycyrrhizin, the major active constituent in licorice root.
Glycyrrhizin was valued in ancient Arabia and Greece for treating coughs and in China for relieving irritation of the mucous membranes. In modern times, glycyrrhizin has been shown to be a formidable antiviral, fighting herpes, HIV, hepatitis, influenza, encephalitis and pneumonia as well as less known viruses like respiratory syncytial virus, arboviruses, vaccinia virus and vesicular stomatitis virus.2
Still, it's glycyrrhizin's effectiveness against SARS (severe acute respiratory syndrome) that has scientists hoping this important natural substance may be a tool against COVID-19.
Glycyrrhizin Has Medicinal Properties
You may think of licorice as an extract, a sweetener or even a candy, like Good and Plenty, but it's actually complex biochemically and offers important medical benefits. According to PubChem, a database of chemical molecules maintained by the National Center for Biotechnology Information,3
"Glycyrrhizic acid is extracted from the root of the licorice plant; Glycyrrhiza glabra. It is a triterpene glycoside with glycyrrhetinic acid that possesses a wide range of pharmacological and biological activities ... potential immunomodulating, anti-inflammatory, hepato- and neuro-protective, and antineoplastic activities.
Glycyrrhizin modulates certain enzymes involved in inflammation and oxidative stress, and downregulates certain pro-inflammatory mediators, thereby protecting against inflammation- and reactive oxygen species (ROS)-induced damage. Glycerrhizin may also suppress the growth of susceptible tumor cells."
According to Botanical Medicine, the anti-inflammatory actions of glycyrrhizin (GL) may stem from suppression of cytokines:4
"As testimony to its anti-inflammatory properties, glycyrrhizin alleviated allergic asthma in an experimental mouse model, increased the IL-4 and IL-5 levels, decreased eosinophil counts and IgE levels, and upregulated total IgG2a in serum.
These results indicated that glycyrrhizin interfered with the production of IgE by decreasing the IgE-stimulating cytokines. It also attenuated lung inflammation and mucus production in mice."
Glycyrrhizin Works Against SARS, a COVID-19-Like Virus
SARS-CoV-2,5 the virus that causes COVID-19, is similar to SARS-CoV-1, the coronavirus that surfaced in 2003. Its genome shares 79.5% of the SARS-CoV-1 genome's information and both enter human alveolar epithelial cells through binding with ACE2 receptors.6
Early SARS-CoV-1 patients were given the viral compound ribavirin, but it showed little benefit.7 Corticosteroids were also tried in SARS-CoV-1 patients and patients with MERS (Middle East Respiratory Syndrome), which occurred 10 years later, but there was "no evidence showing that the mortality of SARS-CoV-1 and MERS patients was reduced," as reported in the International Journal of Biological Sciences.8