Our nasal cavities produce Nitric Oxide, abbreviated as NO. Studies have found that this compound has antiviral effects. Thus, inhaling through the nose, while exhaling through the mouth provides medical benefits, especially in times of a global pandemic. Naturally, it exists in a gaseous state.

NO results in increased blood flow through the lungs while boosting oxygen levels in the blood. Breathing via nose delivers NO directly to the lungs, has helped in fighting SARS infection by blocking the viral replication in the lungs, as two research papers show.

Higher oxygen levels in the blood also make one feel more refreshed providing greater endurance, writes Nobel laureate Louis J. Ignarro, in The Conversation. He is a professor emeritus of molecular and medical pharmacology in the school of medicine, University of California, one of the three pharmacologists to win the Nobel in 1998 for their discovery of how nitric oxide is produced in the body, and it's working.

How Does Nitric Oxide Work?

Inhale via nose
Inhale through the nose Cleveland Clinic

Nitric oxide is a signaling molecule triggering many physiological effects. Clinically, it is used to selectively dilate the pulmonary arteries in newborns having pulmonary hypertension. NO is a gas in its natural state. Based on this, inhaled therapies are developed, that increase oxygen in blood flow. There are instances of blue babies turning pink using the therapy.

One trillion cells in the inner lining of cells (endothelium) produce NO continuously to the 100,000 miles of arteries and veins in our body, mainly - the lungs. This endothelial NO relaxes the smooth muscle of our arteries preventing high blood pressure while promoting blood flow to all organs. It also relaxes smooth muscles in the airways too, easing out breathing. NO also prevents blood clots in arteries. Blood clots occur as an impact of COVID-19 too, and Nitric Oxide can help.

NO is also a principal mediator in erectile tissues, resulting in penile erection and sexual arousal. Viagra works based on this, by enhancing the action of NO. Nitric oxide also forms antimicrobial agents in the body to destroy microorganisms such as bacteria, parasites, and also viruses.

Under Clinical Trials for COVID-19

SARS-CoV-2/COVID-19 Wikimedia Commons

Inhaled NO is now in clinical trials to treat patients with Coronavirus infection. This is based on three principal actions of Nitric Oxide. (1) Dilating pulmonary arteries to increase blood flow through the lungs, (2) dilating airways that increase oxygen delivery to the lungs and blood, finally (3) to directly kill and inhibiting viral growth and halt the spread of SARS-CoV-2 in the lungs.

NO had a direct antiviral effect in SARS, as it reduced the production of viral proteins and its RNA. It also proved effective against SARS-CoV, even in severely ill patients having pneumonia. The 2003 SARS CoV virus, shares most of its genome with the new coronavirus, SARS CoV-2, that causes COVID-19. Thus there are high chances that inhaled NO therapy might be effective in treating coronavirus and its symptoms.

Why Breathe Via Nose?

The sinuses in the nasal cavity continuously produce Nitric Oxide, and this is identical to the NO used clinically. Inhaling through the nose delivers NO directly into the lungs, increasing both airflow and blood flow, simultaneously keeps microorganisms such as virus particles in check. Practicing such breathing to inhale through the nose and exhale through the mouth will surely help.