Table 2.
Natural products potential for managing the clinical symptoms of COVID-19
| Classification of natural products | Compounds and their mechanisms of action |
|---|---|
| Flavonoids | Apigenin (alleviates pulmonary injury through decreasing the levels of TGF-β1 and TNF-α) |
| Baicalin (prevents the interaction of S-protein of SARS-CoV with host angiotensin-converting enzyme 2) | |
| Chalcones (suppresses the activity of proteases of SARS-CoV) | |
| Kaempferol (suppresses the release of SARS-CoV from the infected cells by inhibition of the 3a ion channel) | |
| Luteolin (inhibits the entry of SARS-CoV into host cells through binding to the surface spike protein) | |
| Quercetin (suppresses the entry of SARS-CoV into the cell and the activity of SARS-3CLpro, a viral replication enzyme) | |
| Scutellarein (suppresses the activity of the SARS coronavirus helicase, nsP13, through controlling ATPase activity) | |
| Alkaloids | Cepharanthine (mitigates viral S and N proteins expression, thereby decreasing the replication of virus) |
| Fangchinoline (decreases viral S and N proteins expression, thereby decreasing the replication of virus) | |
| Homoharringtonine (suppresses infection by coronavirus through affecting the replication of coronavirus and inhibits viral protein synthesis) | |
| Indigo (suppresses the activity of 3CLpro, a viral replication enzyme) | |
| Lycorine (suppresses the replication of SARS-CoV by interfering viral RNA translation) | |
| Oxysophoridine (inhibits the replication of SARS-CoV-2) | |
| Tryptanthrin (inhibits the replication of human coronavirus) | |
| Tetrandrine (inhibits viral S and N protein expressions, thereby decreasing the replication of the virus) | |
| Tylophorine (suppresses the virulence of SARS-CoV by inhibiting the replication of virus and apoptosis of host cells induced by virus) | |
| Other groups including triterpenoids | Ascorbic acid (exerts immunomodulating, antifibrotic, antioxidative activities, and protective effects against pulmonary infections) |
| Astragalosides (suppresses the production of nitric oxide and the release of pro-inflammatory cytokines) | |
| Bananin (suppresses SARS-CoV NTPase/helicase and the replication of SARS-CoV) | |
| Cinanserin (suppresses the replication of SARS-CoV) | |
| Cinnamaldehyde (inhibits proteolytic activation of spike protein in SARS-CoV-2 by proteases in host cells) | |
| Curcumin (protects acute lung injury, pulmonary fibrosis, and acute respiratory distress syndrome) | |
| Diallyl thiosulfonate (exerts controlling effects on edema of alveolar inner region, pulmonary fibrosis, infections of respiratory tract, acute lung injury, and sepsis) | |
| Emodin (suppresses the interaction between SARS-CoV spike protein and host angiotensin-converting enzyme 2 and the release of coronavirus from infected cells) | |
| Glycyrrhizin (inhibits the replication, adsorption, and penetration of coronavirus) | |
| Nimbolide (mitigates lung injury and pulmonary fibrosis) | |
| Piperine (exerts anti-inflammatory, antiviral, and antioxidative activities) | |
| Saikosaponins (inhibits the penetration and attachment of human coronavirus) |