Inhibition of Severe Acute Respiratory Syndrome Coronavirus 2 Replication by Hypertonic Saline Solution in Lung and Kidney Epithelial Cells

Machado, Rafael R. G.; Glaser, Talita; Araujo, Danielle B.; Petiz, Lyvia Lintzmaier; Oliveira, Danielle B. L.; Durigon, Giuliana S.; Leal, Alessandra L.; Pinho, João Renato R.; Ferreira, Luis C. S.; Ulrich, Henning; Durigon, Edison L.; Guzzo, Cristiane Rodrigues

[Image: see text] An unprecedented global health crisis has been caused by a new virus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We performed experiments to test if a hypertonic saline solution was capable of inhibiting virus replication. Our data show that 1.2% NaCl inhibited virus replication by 90%, achieving 100% of inhibition at 1.5% in the nonhuman primate kidney cell line Vero, and 1.1% of NaCl was sufficient to inhibit the virus replication by 88% in human epithelial lung cell line Calu-3. Furthermore, our results indicate that the inhibition is due to an intracellular mechanism and not to the dissociation of the spike SARS-CoV-2 protein and its human receptor. NaCl depolarizes the plasma membrane causing a low energy state (high ADP/ATP concentration ratio) without impairing mitochondrial function, supposedly associated with the inhibition of the SARS-CoV-2 life cycle. Membrane depolarization and intracellular energy deprivation are possible mechanisms by which the hypertonic saline solution efficiently prevents virus replication in vitro assays.