Our cellular machinery operates on such an incredible micro-scale of interaction, that it’s tough for most of us to even scratch the surface of how a virus works. To get a sense of size, nearly half a billion viruses could fit on the head of a pin. Yet, this is the level where all life happens. The scale that our growth, health, and cellular maintenance occurs each and every day.
Really, viruses are like packets of genetic material. They have a protein coat, either DNA or RNA, and a few other parts. Their genetics rely on the same mechanisms which allow our own bodies to assemble amino-acids and create proteins (building blocks for life). And although not cells themselves, they can commandeer our own and cause serious havoc.
The Basics of How COVID-19 Infects
Viruses influence the genetic code our cells use to produce building blocks (proteins, enzymes). And if you think of a genetic disease, we know that cells can have a mistake in their instructions (DNA) and end up producing the wrong blocks – a microscopic detail which can lead to big health problems.
So, when a virus infects a cell it does something similar, but that itself doesn’t make it infectious. Instead, this happens when it causes just the right change: our cells shift gears to produce different proteins, no longer for our own health, but instead to be assembled during viral replication.
Successful viruses do this through a couple tricks. Some, like COVID-19, can camouflage from a normal immune response, blocking our defenses which otherwise stop a virus. The novel coronavirus also has different pieces – it can figuratively ‘pick and choose’ to increase its success in taking over cellular control once it has gained access.
Proteins involved in COVID-19
The novel coronavirus uses one protein especially to first get inside our cells; the spike protein attaches to the ACE2 enzyme, found in lungs, arteries, heart, kidney, and intestines. Normally, this enzyme helps these cells respond to a hormone related to blood pressure control. You can think of the enzyme as like a gateway that COVID-19 can bind with.
Once it has attached to the enzyme, interaction occurs to begin pushing genetic material towards the inside-cell. It inserts itself, infects the cell, and begins releasing inhibitors (proteases like 3CLpro) which counteract natural defenses.
As the genetic material begins making viral proteins, these same proteases also break apart remaining bits of the original virus so that it can replicate.
For this reason, one big subject of antiviral drug research for COVID-19 is protease inhibitors. Here, we’ve reviewed at least one potential, natural example in this category.
Other Target Proteins against COVID-19
There are at least two types of potential inhibitors against the novel coronavirus. The first one, is a drug or natural molecule which can bind to proteases (e.g. 3CLpro) to prevent their essential roles in replication.
And one other type are inhibitors which interfere with viral signaling. That includes interfering with the process the virus uses to inject its genome (after binding to ACE2); drug targets being investigated may also get between the proteases to stop them from working directly on the virus, limiting replication.
In light of extensive research originally with the 2003 SARS epidemic, scientists already have some leads on these target proteins. Also, at least one report quantifies a 96% genetic similarity to the SARS strain of coronavirus,  which may carry some same findings for potential drug treatments.
The Bottom Line
There are at least a handful of target proteins, and many studies are reporting potential anti-COVID-19 activities of many FDA approved drugs, such as those originally in the treatment of HIV. 
The SARS epidemic also began research of a number of natural compounds found naturally in a balanced diet, a torch that COVID-19 research has picked up in full force. Numerous, abundantly found antioxidants, polyphenols, flavonals, and other plant metabolites found in a healthy diet are under evaluation for the possibility of some level of antiviral activities. [2-5]
That’s not to say a healthy diet is a cure (or that there is any cure currently at all) for COVID-19, but it’s thought provoking. In the very least, it’s a reasonable assumption that a balanced diet carries little risks, and may give an edge to our immunity, if not simply our nutritional status.
According to the anti-inflammatory food pyramid, healthy diet might include a balance of fruits, veggies, legumes, medicinal roots, mushrooms, wild-caught salmon, olive oil, and dark chocolate.
Also, enjoying a high quality green tea, such as matcha, may also offer added dietary fortification since it contains levels of natural antioxidants and polyphenols, which may protect against free radicals and other stressors.
Ultimately, these are simply some measures you might consider as researchers continue identifying and approving safe treatment options.
-Team Matcha Kari
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 Bouchentouf, S., & Missoum, N. (2020). Identification of Compounds from Nigella Sativa as New Potential Inhibitors of 2019 Novel Coronasvirus (Covid-19): Molecular Docking Study.
 Khaerunnisa, S., Kurniawan, H., Awaluddin, R., Suhartati, S., & Soetjipto, S. (2020). Potential Inhibitor of COVID-19 Main Protease (Mpro) From Several Medicinal Plant Compounds by Molecular Docking Study. Prepr. doi10. 20944/preprints202003. 0226. v1, 1-14.
 Utomo, R. Y., & Meiyanto, E. (2020). Revealing the Potency of Citrus and Galangal Constituents to Halt SARS-CoV-2 Infection.
 Mohammad Faheem Khan, Mohsin Ali Khan, Zaw Ali Khan et al. Identification of Dietary Molecules as Therapeutic Agents to Combat COVID-19 Using Molecular Docking Studies, 27 March 2020, PREPRINT (Version 1)
 Wen, C. C., Kuo, Y. H., Jan, J. T., Liang, P. H., Wang, S. Y., Liu, H. G., ... & Hou, C. C. (2007). Specific plant terpenoids and lignoids possess potent antiviral activities against severe acute respiratory syndrome coronavirus. Journal of medicinal chemistry, 50(17), 4087-4095.