Properties of Ethnomedicinal Plants and Their Bioactive Compounds: Possible Use for COVID-19 Prevention and Treatment

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic has changed the global scenario. To date, there are no treatment or preventive options. The discovery of a new drug will take time. In addition, the new drug will have side effects, and the virus will gradually become resistant to it. Therefore, it is important to search for a drug with a natural origin.

OBJECTIVE

In this review, we analyzed and summarized various ethnomedicinal plants and their bioactive compounds as a source of antiviral agents for COVID-19 prevention and treatment.

METHODS

From the literature, we selected different natural compounds that can act as potential targets at low cost with broad-spectrum antiviral activity.

RESULTS

Of the 200 Chinese herbal extracts tested for their possible role against SARS-CoV, Lycoris radiata, Artemisia annua, Pyrrosia lingua, and Lindera aggregate showed anti-SARS-CoV effects with the median effective concentration = 2.4-88.2 μg/mL.

CONCLUSION

Ethnomedicinal herbs can be used as an alternative source of novel, promising antiviral agents that might directly or indirectly inhibit the COVID-19 progression.

SARS-CoV-2 proteins: Are they useful as targets for COVID-19 drugs and vaccines?

The proteins of coronavirus are classified to nonstructural, structural, and accessory. There are 16 nonstructural viral proteins beside their precursors (1a and 1ab polyproteins). The nonstructural proteins are named as nsp1 to nsp16 and they act as enzymes, coenzymes, and binding proteins to facilitate the replication, transcription, and translation of the virus. The structural proteins are bound to the RNA in the nucleocapsid (N- protein) or to the lipid bilayer membrane of the viral envelope. The lipid bilayer proteins include the membrane protein (M), envelope protein (E), and spike protein (S). Beside their role as structural proteins, they are essential for the host cells binding and invasion. The SARS-CoV-2 contains six accessory proteins which participates in the viral replication, assembly and virus- host interactions. The SARS-CoV-2 accessory proteins are orf3a, orf6, orf7a, orf7b, orf8, and orf10. The functions of the SARS-CoV-2 are not well known, while the functions of their corresponding proteins in SARS-CoV are either well known or poorly studied. Recently, the Oxford University and Pfizer and BioNTech made SARS-CoV-2 vaccines through targeting the spike protein gene. The US Food and Drug Administration (FDA) and the health authorities of the United Kingdom approved and started vaccination using the Pfizer and BioNTech mRNA vaccine. Also, The FDA of USA approved the treatment of COVID-19 using two monoclonal antibodies produced by Regeneron pharmaceuticals to target the spike protein. The SARS-CoV-2 proteins can be used for the diagnosis, as drug targets and in vaccination trials for COVID-19. For future COVID-19 research, more efforts should be done to elaborate the functions and structure of the SARS-CoV-2 proteins so as to use them as targets for COVID-19 drug and vaccines. Special attention should be drawn to extensive research on the SARS-CoV-2 nsp3, orf8, and orf10.