Research Highlight

Herbal compound stops coronavirus-triggered inflammation, viral replication

doi:10.1038/nindia.2021.47 Published online 30 March 2021

Glycyrrhizin, an active ingredient in the roots of the Yashtimadhu plant (Glycyrrhiza glabra), could stop the replication of the novel coronavirus, a study reveals1.

The compound has been found to protect specific human lung epithelial cells by reducing viral-protein-mediated inflammation in these cells, a team of researchers from the National Brain Research Centre in Gurugram in India has shown in experiments.

Glycyrrhizin, they say, looks promising as a potential drug candidate for treating COVID-19, which is currently being treated with repurposed drugs.

Previous studies had shown that glycyrrhizin could be used against viral infections such as hepatitis and various respiratory diseases. However, its potential to inhibit the growth of the novel coronavirus was unexplored.

To test glycyrrhizin’s potential against the virus, the scientists, led by Ellora Sen, expressed specific viral proteins in human lung epithelial cells in laboratory conditions. The viral proteins triggered inflammation in these cells.

The researchers found that glycyrrhizin treatment dampened inflammation in these cells, preventing death. The untreated cells, however, succumbed to inflammation.

Glycyrrhizin curbed inflammation by disrupting the activity of high mobility group box 1 (HMGB1), a protein that triggers the release of cytokines, specific immune molecules and ferritin, an iron-storing compound from macrophage, a type of immune cells.

Inhibiting HMGB1 protected the epithelial cells by halting the surge of cytokines. This also attenuated the replication of the virus. Given the resurgence of COVID-19 cases, glycyrrhizin might be a viable option for treatment, the researchers note. 


References

1. Gowda, P. et al. Glycyrrhizin prevents SARS-CoV-2 S1 and Orf3a induced high mobility group box 1 (HMGB1) release and inhibits viral replication. Cytokine. 142, 155496 (2021)