Schematic diagram of SARS-CoV-2. Credit: Sci. Rep. 11, 23122 (2021)
Researchers have synthesised a hydrated chloride salt that halted the growth of coronavirus in cultured kidney epithelial cells from a monkey1.
The salt bound to a viral enzyme and specific proteins that help SARS-CoV-2 to grow inside host cells. The salt is non-toxic to the epithelial cells, say researchers at the University of North Bengal in West Bengal, India, suggesting its potential as a therapeutic agent against SARS-CoV-2 infection.
Scientists, led by Subires Bhattacharyya and Bhaskar Biswas, chose phenazine, a compounds found in soil-dwelling and marine pathogens. Taking their cue from previous studies which showed the medicinal properties of phenazine-based compounds, the team prepared the hydrated phenazinium chloride salt.
The researchers allowed SARS-CoV-2 to infect cultured epithelial cells from a monkey’s kidney. The infected cells were then exposed to a non-toxic concentration of the salt. The salt exposure stopped the virus replicating.
Molecular docking studies revealed that the salt molecules possibly arrested the growth of the virus by binding to the main protease, an enzyme that aids the virus to grow inside the host cells. The molecules disrupted the functions of specific non-structural proteins – nsp2, nsp7 and nsp8 – that contribute to viral growth and virulence. Molecular dynamics simulation showed that the salt molecules formed stable structures with the viral enzyme and proteins.
The salt also displayed antibacterial properties. It inhibited the growth of pathogenic bacteria such as Streptococcus pneumoniae, Escherichia coli and Klebsiella pneumoniae by wrinkling and destroying their cell membrane.
