by Dr Manish Pandit
A recent article looked at the presence of a furin cleavage site on the spike glycoprotein of the nCovid-19 virus as below:
What does the furin-like cleavage site on the nCovid 19 do? Does it increase the ability of the virus to increase the number of humans infected by it?
The authors above conclude that “the insertion of a similar cleavage site in the infectious bronchitis virus (IBV) S-protein results in higher pathogenicity, pronounced neural symptoms and neurotropism in infected chickens”
This statement is confirmed by Cheng et al., 2019. Thus the cleavage site on the nCovid-19 is not found on other Coronaviruses, it does have the potential and as we can see from the Italian experience of the virus, it is set for a much higher pathogenicity than normal viruses.
Furin and Furin cleavage sites in relation to primary pneumonia:
Furin is highly expressed in lung tissue hence the Furin-like cleavage site on the nCovid 19 allows the virus to gain specific entry into respiratory cells. The special problem is that this Furin like cleavage site ensures that this virus has a potential of resulting in higher rates of primary pneumonia. This impression has nothing to detract from it in real life. (In fact Italian sources confirm this).
This ability of the nCovid virus to cause an exudative reaction in the alveoli and a primary pneumonia is what has overwhelmed the capacity of even a first world country such as Italy. Ventilators and ITU beds are in short supply around the world, but the United States and Italy lead the world in the amount of ITU beds which are available at any given moment. Unfortunately Italy also has a significant demographic of older people (>70 years) of age and the immune systems of the older demographic seem particularly vulnerable to nCovid 19. This is the reason why war time triage like situations have developed in Northern Italy (97.1% of the mortality figures are in the >60 years age group of patients) and this is also why Governments around the world are closing down schools and putting curbs on mass gatherings in an effort to reduce the spread of the Coronavirus. There is one unexplained statistic in the mortality rates available so far and that is the disproportionately high death rates in males compared to females (80:20). This will need investigating further.
The next question is what can be used to inhibit the virus? No studies as far as I know have been done in Coronavirus but some similar studies can be found in Dengue which were done by Chinese scientists.
Luteolin as a proprotein convertase Furin inhibitor:
The question which arises is whether anything can inhibit the “proprotein convertase Furin”
or not? Chinese investigators found that Luteolin which is widely found in Flavinoids such as Thyme/Brocolli and Pepper can indeed inhibit dengue virus replication through inhibition of the proprotein convertase Furin as below.
Hence it is not a completely unreasonable extrapolation from the above to hypothesise that these Flavinoids such as pepper and other foods may have the potential to partially reduce pathogenicity of nCovid 19 which appears to rely on a similar mechanism for entry into the respiratory cell.
This sort of an approach has long been thought of by many investigators for treatment of infectious diseases including the following :
Obviously more studies need to be performed in the future as they undoubtedly will be, but for now, social distancing and other measures such as hand washing are imperative to reduce the risk of overwhelming the health system of any country. Countries at the bottom of the ITU bed and Ventilator situation should consider carefully what their options are. This is not a situation which can be taken lightly by any population or any Government. The damage to economies (especially daily wage earners) and companies reliant on travel may be significant.