Chlorhexidine and SARS-CoV-2 main protease

Abstract

As the beginning of the COVID-19 pandemic, numerous attempts have been made to identify specific antiviral mouth rinses which may help reduce the salivary viral load of severe acute respiratory syndrome coronavirus 2 (SARS-CoV2). Although the results from in vivo well-controlled clinical studies are yet pending, many contemporary antimicrobial mouth rinses have been explored for potential antiviral properties with respect to SARS-CoV-2. The most widely used compounds such as povidone-iodine, chlorhexidine, hydrogen peroxide, and essential oils have been known to have antiviral activity by targeting the outer lipid membrane or by denaturing the capsid proteins of enveloped virus SARS-CoV. Until now, there has been scanty scientific evidence on the molecular basis of interaction of the gold standard antimicrobial mouth rinse as an underlying mechanism of its anti-SARS-CoV-2 effect. The current communication reports the findings of our in silico docking study pertaining to understand the interactions of chlorhexidine with the most well-studied target of the SARS-CoV main protease.

Effects of Chlorhexidine and Povidone-Iodine on the SARS-CoV-2 Load: A Systematic Review and Meta-analysis

“…The use of 1% PVP-I and 0.2% CHX mouthwash increased the mean Ct value more strongly than distilled water after 30seconds of rinsing in patients infected with SARS-CoV-2. 33 These results agree with those of Jain et al 44…”

“…43 CHX at 0.12% has produced Ct values of 10.5±0.5 and 11±1.0 after 30 and 60seconds of exposure, respectively, compared to Ct values of 9.5±0.5 and 11±2, respectively, for 1% PVP-I, indicating the efficacy of both mouthwashes against SARS-CoV-2. 44 However, another in vitro study using a mouthwash containing 0.12% CHX gluconate (0.12%) in combination with 0.05% cetylpyridinium chloride as an antiseptic failed to inactivate SARS-CoV-2 sufficiently after 30seconds. 45 Despite these findings, the authors acknowledged that CHX could reduce the viral load in the mouth based on its persisting effects opposed to short-term treatment with antiseptics .…”