COVID-19: A promising cure for the global panic

Abstract

The novel Coronavirus disease 2019 (COVID-19) is caused by SARS-CoV-2, which is the causative agent of a potentially fatal disease that is of great global public health concern. The outbreak of COVID-19 is wreaking havoc worldwide due to inadequate risk assessment regarding the urgency of the situation. The COVID-19 pandemic has entered a dangerous new phase. When compared with SARS and MERS, COVID-19 has spread more rapidly, due to increased globalization and adaptation of the virus in every environment. Slowing the spread of the COVID-19 cases will significantly reduce the strain on the healthcare system of the country by limiting the number of people who are severely sick by COVID-19 and need hospital care. Hence, the recent outburst of COVID-19 highlights an urgent need for therapeutics targeting SARS-CoV-2. Here, we have discussed the structure of virus; varying symptoms among COVID-19, SARS, MERS and common flu; the probable mechanism behind the infection and its immune response. Further, the current treatment options, drugs available, ongoing trials and recent diagnostics for COVID-19 have been discussed. We suggest traditional Indian medicinal plants as possible novel therapeutic approaches, exclusively targeting SARS-CoV-2 and its pathways.

Keywords: Coronavirus disease 2019 (COVID-19); Indian traditional medicine; Mechanism of action; SARS-CoV-2; Therapeutic approach.

Graphical abstract

Fig. 1

Structure and binding of COVID-19 virus to ACE2. The above-mentioned figure depicts the structure of the COVID-19 virus. Among the viral structure the S protein has a major role in binding of the virus to the host receptor cells. S protein has two subunits which are the S1 receptor-binding subunit and S2 the membrane fusion subunit; where the earlier one attached itself to the ACE2 receptor of the human host cell and the S2 subunit internalises and creates the membrane fusion among the viral subunit and the ACE2 receptors. This leads to the release of the viral RNA into the host cell and results into respiratory infection.

Fig. 2

Possible mechanism of action of SARS-COV-2. Depiction of the binding of SARS-COV-2 to its receptor ACE-2. The S1 and S2 subunits are subsequently cleaved followed by the shedding of ACE-2 by ADAM 17. This resulting in an increased amount of Angiotensin II leading to respiratory distress. Upon binding, the virus fuses with the membrane and enters the cell, followed by translation, and replication of the proteins. ORF3a, ORF8b,E proteins and the NF-KB pathway activates the inflammasome pathway through various means, leading to the activation of cytokine. This results in a cytokine storm, further resulting in respiratory distress.

Fig. 3

COVID-19 entry into CNS. Entry of human Coronavirus in CNS through olfactory bulb upon nasal infection which causes inflammation and demyelination. Further it reaches the whole brain via Blood Brain Barrier and CSF via Blood- CSF barrier in <7 days. The possible entry of SARS-CoV-2 into the Brain and CNS is important to design effective antiviral drugs. Effective drugs that may cross Blood Brain Barrier and Blood CSF barrier may be taken in to consideration while designing and this could be a promising in treatment strategies.