Table 1 Different approaches used for the treatments against COVID-19 with the reaction mechanism

Remdesivir

Acts as an inhibitor of RNA-dependent RNA polymerase of coronaviruses

[16]

Favipiravir

An inhibitor of the RNA-dependent RNA polymerase (RdRp) enzyme, it acts as a purine nucleotide and inhibits viral protein synthesis. And recently, some studies have demonstrated its ability to induce lethal mutagenesis in vitro against SARS-CoV-2

[189]

Ribavirin

Acts as a guanosine analogue that ensures chain termination by inhibiting RNA polymerase and therefore limiting viral replication

[189]

Chloroquine (CQ) and hydroxychloroquine (HCQ)

CQ and HCQ are regulators of the immune system by affecting cell signaling and the expression of pro-inflammatory cytokines

[190]

Glucocorticoids

Glucocorticoids were utilized to reduce CS symptoms in patients with severe COVID-19 problems, including ARDS, acute kidney difficulties, acute cardiac injuries, and elevated D-dimer levels

[186]

Teicoplanin and other glycol-peptides

Act by inhibiting cathepsin B and cathepsin L in target cells

[189]

Monoclonal or polyclonal antibodies

Antibodies, both monoclonal and polyclonal can be proposed as prophylactic tools by targeting haemagglutinin binding against viral infections. Ongoing studies to develop monoclonal or polyclonal antibodies to the coronavirus are mainly targeting MERS-CoV2

[189]

Convalescent plasma

Convalescent plasma has been extensively recommended for COVID-19, but the effect of convalescent plasma cannot be discerned from the impact of the patient's concomitant diseases, stage of disease or impact of other treatments. Further investigations are desired to test and validate the efficacy of Convalescent plasma for the treatment of COVID-19

[191]

Herbal medicine

During the COVID-19 epidemic in China, some traditional Chinese medicines were widely used, such as Astragali Radix, Glycyr-rhizome Radix Et Rhizoma, and Fructus forsythia. Therefore, rigorous clinical trials on large populations should be conducted for the validation and determination of the active substances in order to be able to manufacture drugs based on these active substances on a large scale in the near future

[189]