12/09/2021
Here are a couple of pieces from an article about N-Acetyl-Cysteine
(https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7649937/)
N-Acetylcysteine, a Forgotten Immune-Modulating Agent
N-acetylcysteine (NAC), a precursor of the antioxidant glutathione, has been used to loosen thick mucus in the lungs and treat acetaminophen overdose for decades. However, NAC can also boost the immune system, suppress viral replication, and reduce inflammation. Despite these valuable features, NAC has been mostly overlooked throughout SARS-Cov and MERS-Cov epidemics, as well as the current COVID-19 pandemic.
In 1997, De Flora et al demonstrated that oral administration of NAC (600mg, bid) significantly improved cell-mediated immunity, shifting from anergy to normoergy in seniors (Figure 1A).21 Anergy represents a lack of reaction from immune cells to foreign substances, such as bacteria and viruses. Unsurprisingly, NAC treatment significantly decreased the frequency of influenza, as well as the severity and duration of most symptoms (Figure 1B). Although the infection rates of influenza virus (H1N1 Singapore 6/86) were similar in the two groups, only 25% of virus-infected subjects in NAC group developed flu symptoms, contrasting with 79% of the subjects in the placebo group. As a result, NAC may improve compromised cellular immunity and prevent development of certain respiratory virus-caused diseases, thus raising the question: Can NAC administration benefit COVID-19 patients?
NAC Can Reduce the Incidence of Pneumonia
Given that oral NAC (600mg, bid) significantly decreased the frequency and severity of influenza, oral NAC may reduce the incidence of pneumonia as well. One study has demonstrated that about 37% of mechanically ventilated patients develop pneumonia, namely, ventilator-associated-pneumonia (VAP) in an intensive care unit. NAC (600 mg, bid) treated patients developed significantly less clinically confirmed pneumonia compared with placebo group patients (26.6% VS 46.6%).34
Oral Administration of NAC
The gut is the largest immune organ we have,51 carrying 70% of all lymphocytes in the body. Absorbed in the small intestine, oral NAC interacts with epithelial cells and immune cells, potentially boosting our immune system to combat virus infection. One capsule of 600 mg NAC can reach a level of 16 μM NAC in the peripheral blood in half an hour after administration. Although it has been labeled as “low bioavailability” for decades, if administrated within 8–10 hours of acetaminophen overdose, oral administration of NAC displays the same capacity of detoxification as given by the IV route.52
NAC Inhalation
Under FDA guideline, to loosen mucus, MAYO clinic suggests inhaling 3 to 5 milliliters (mL) of a 20% solution or 6 to 10 mL of a 10% solution using a nebulizer, three or four times a day. For NAC, 10% is equivalent to 613 mM. Highly concentrated NAC can effectively reduce viral replication and significantly alleviate pneumocyte damage, as well as excessive immune responses.
