COVID-19 and Nicotinic Cholinergic System

September 25, 2020

The second day of the Summit started with the hot topic “COVID-19 and nicotinic cholinergic system: an interaction which affects Public Health”, discussed by Professors Konstantinos Poulas and Konstantinos Farsalinos.

Consistent clinical observations have shown a low prevalence of smoking among hospitalized COVID-19 patients; the number of smokers showing severe COVID-19 that requires hospitalization is by far lower than expected based on population smoking rates. Still, the very few smokers who are eventually hospitalized are having increased odds for adverse outcomes.

In April 2020, it was hypothesized for the first time that the nicotinic cholinergic system may be implicated in the pathophysiology of severe COVID-19 and recently researchers decided to check this hypothesis. More specifically, given that dysfunction of the nicotinic cholinergic system could explain clinical manifestations of COVID-19, there may be a direct interaction between SARS-CoV-2 and the nicotinic cholinergic system.

The cholinergic anti-inflammatory pathway is an important regulator of the inflammatory response –if functional, it could block not the infection of COVID-19 itself, but the expression of its severe symptoms.

The proper functioning of the cholinergic anti-inflammatory pathway is mediated mainly by the nicotinic cholinergic system. The interference of SARS-CoV-2 with nicotinic cholinergic receptors leads to the undermining of the anti-inflammatory function of the cholinergic anti-inflammatory pathway and to severe symptoms.

Therefore, the prevention of the effect of SARS-CoV-2 on the nicotinic cholinergic system could have potential therapeutic implications, if we could find a way to protect the nicotinic cholinergic receptors from SARS-CoV-2 getting bound to them. A pharmacological agent that could prevent that binding could be nicotine.

Nicotine has well-established pharmacological effects and has been available for years as an approved medication in various forms. Therefore, nicotine represents a compound with promising prospects if proven to be associated with therapeutic benefits, while other approved compounds that have the capacity to interfere with the nicotinic cholinergic receptors could also be examined for potential effects, Professors Poulas and Farsalinos concluded.