Table 2.

Medicinal plants and natural products with inhibitory activity against various types of coronaviruses.

Scientific/Common Name	Active Principle	Virus/ Antiviral Activity	Reference
Aesculus hippocastanum CN: Horse-chestnut	Aescin (k)	SARS-CoV/Inhibits viral replication	[22]
Allium ampeloprasum Var. porrum J. Gay CN: Leek	Mannose-binding specific lectin (b)	SARS-CoV/Ability to bind to the glycosylated molecules found on the surface of viruses, including the spike glycoprotein	[23] [24]
Allium cepa L. CN: Onion	Flavonols: quercetin, quercetinglycosides (isoquercitrin, quercitrin and rutin) (c) and kaempferol (j)	SARS-CoV2/Interfere with various stages of the coronavirus entry and replication cycle such as PLpro, 3CLpro, and NTPase/helicase; Inhibits ACE by competing with the substrate, N-[3-(2-furyl) acryloyl]-L-phenylalanylglycylglycine	[25] [26]
Brassica oleracea L. CN: Broccoli	Glucosinolate type sinigrin (z)	SARS-CoV/blocks the cleavage process of 3CLpro	[27] [28]
Bupleurum spp. CN: Bupleurum	Oleanane-type saikosaponins (aj)	SARS-CoV/Inhibit human coronavirus entry into cells, general replication, and specific 3CLpro mediated replication	[29]
Cassia tora L. CN:	Anthraquinone derived emodin (a)	Inhibitory activities on angiotensin-converting enzyme.	[28]
Cinnamomumverum J. Presl CN: Cinnamon (cortex)	Butanol (v), procyanidins (ai)	SARS-CoV/Possibly blocks the entry of cells through endocytosis	[30] [31] [32]
Curcuma spp. CN: Turmeric	Curcumin (y), Eugenol (an)	SARS-CoV/Inhibits 3CLpro (y); Good binding affinity with Mpro and S protein (an)	[33] [34]
Citrus spp. CN: Three main species in the country: Citrus maxima (Rumph. ex Burm.) Merr; Citrus medica L.; Citrus reticulata Blanco.	Hesperetin (f) and naringenin (e)	SARS-CoV-2/(f) Inhibits ACE2 and inhibit the entry of virus into cells host by binding to S protein, helicase, and protease sites on the ACE receptor HCoV229E/(e) Partial inhibition of 229E replication in cells silenced for TPC2 by siRNA	[35] [36]
Camellia sinensis Kuntze CN: Green tea	Phenolic compounds: Tannic acid (aa), 3-isotheaflavin-3-galalate (ab) and theaflavin-3,3′-digallate (ac)	Coronavirus in general/Possibly inhibition of RNA polymerase or RNA-dependent proteases; They can also affect the release or assembly of the virus; inhibits ECA and blocking AII receptor binding in vitro, avoiding symptoms of various diseases, especially those of a respiratory nature	[37] [38]
Melia azedarach L. CN: Cinamomo			[39] [37]
Echinacea purpurea Moench CN: Echinaceae®	Caphtharic acid (o), cichoric acid (p) and echinacoside (p)	MERS-CoV, 229E/The extract non-specifically and irreversibly interferes with viral docking receptors (eg, influenza) to block infectivity of pathogens	[40] [41]
Ginkgo biloba L. CN: Ginkgo	Ginkgolide, terpenic lactones, flavonoids, polyphenols, oleic acid, among others.	SARS-CoV/Antiviral mechanism is unclear	[19] [42]
Glycyrrhiza glabra L. CN: Licorice (root)	Licorice (am) y glycyrrhizin (al)	SARS-CoV/Modulate some virus-host fusion functions through the envelope of the repetition domain 2 of the predominant heptad in viral envelopes; Improvement of the function of upper respiratory mucosal immune system; Inhibit viral adsorption and penetration	[29] [22] [43] [44]
Heteromorpha arborescens Cham. CN: Parsley tree	Oleanane-type saikosaponins (aj)	SARS-CoV/Prevent the entry of SARS-CoV into the cell	[45] [46]
Hippeastrum striatum Lam CN: Lily	Lectin agglutinin (w)	SARS-CoV/Inhibits the end of the virus cycle infection	[29] [47]
Lonicera japonica Thunb CN: Madreselva Eriobotrya japonica Thunb CN: Níspero	Quercetin (c), luteoloside (m), chlorogenic acid (x)	SARS-CoV, RSV, HIV, HSV, PRV and NDV/This mechanism possibly is due to diminishing the inflammation mediators and TNF-β, IL-1β expression. Anti-inflammatory, antiviral, antibacterial, antioxidant activity. Enhances the immune response.	[48] [49]
Lycoris spp. CN: hurricane lilies or cluster amaryllis	Lycorine	SARS-CoV/Compound with extensive antiviral activities. However, the antiviral mechanism of this molecule is unclear	[50]
Morus alba L. CN: Tree mulberry	Aliphatic, aromatic phenolic, heterocyclic and aliphatic cyclic compounds	SARS-CoV and MERS-CoV/Antiviral mechanism is unclear	[19] [42]
Nicotiana tabacum L. CN: Tobacco	N-acetylglucosamine specific lectins (b)	SARS-CoV/Ability to bind to the glycosylated molecules found on the surface of viruses, including the spike glycoprotein.	[23] [29]
Paulownia tomentosa Steud CN: Kiri	Flavonoids: (quercetin (c), catechin (d) and naringenin (e) and geranilated flavonoids (tomentin A, tomentin B, tomentin C, tomentin D, tomentin E) (r)	SARS-CoV/Inhibits SARS-CoV (PLpro) by reducing the concentration of pro-inflammatory cytokines (IL-1β) and TNFα	[51]
Pelargonium sidoides D.C. CN: Geranium	Prodelphinidin (af), gallocatechin (ag) and their epigallocatechin stereoisomer (ah)	H1N1, H3N2, HCoV-229E/inhibits the entry and replication of 229E; Also is immunomodulatory and cytoprotective effects, inhibition of the interaction between bacteria and host cells; Inhibits viral hemagglutination and Neuraminidase (NA) activity	[52] [53] [54] [55]
Psidium guajava CN: Guava	Eugenol (an)	SARS-CoV/Good binding affinity with Mpro and S protein	[34] [21]
Scutellaria baicalensis Georgi. CN: Skullcap	Baicalin (g) and scutellarein (l)	SARS-CoV/Inhibits nsP13 in vitro by affecting ATPase activity	[56] [57] [46]
Thuja orientalis L. CN: Tree of life	Essential oils: b-ocimene, 1,8-cineole, a-pinene and b-pinene mainly (ad)	SARS-CoV, HSV-1/Inhibitory activity against viral replication in vitro by visually scoring of the virus-induced cytopathogenic effect post-infection	[58] [29]
Laurus nobilis L. CN: Laurel
Salvia officinalis L. CN: Sage
Urtica dioica L. CN: Nettle	Lectin agglutinin (w)	SARS-CoV/Inhibits the end of the virus cycle infection	[29] [47]
Polygonum cuspidatum L. CN: Japanese knotty grass	Anthraquinone derived emodin (a)	SARS-CoV, HCoV-OC43/inhibits by blocking viral entry by binding to the S protein and interfering with the 3CLpro activity of the SARS-CoV and prevented the formation of the Nsp required for viral replication; Blocked the interaction between SARS-CoV S protein and ACE2, inhibited ion channel 3a and interrupted the release of new coronaviruses	[59] [28]
Senna obtusifolia L. CN: Abejorra	Emodin (a)
Rheum spp. CN: Rhubarb
Aloe spp. CN: Aloe	Aloe emodin (a)		[27]
Vaccinium spp. CN: Blueberry, mortiño, Agráz, among others.	Anthocyanins (t), myricetin (n), gallic acid (u), stilbenoid resveratrol (s) and procyanidins (ai)	SARS-CoV, MERS-CoV/(t) inhibits the production of NO and the secretion of TNF-α in macrophages induced by LPS-INF-γ caused by protocatechic acid, also show ACE inhibitory activity; (n) inhibits the coronavirus helicase protein by affecting the ATPase activity in vitro; Gallic acid decreases the secretion of MCP-1, ICAM-1, and VCAM-1 in endothelial cells; (s) partially mitigates induced cell death and reduces infectious viral replication; (v) possibly blocks the entry of cells through endocytosis	[60] [61] [62] [63]
Vitis vinifera L. CN: Red grape
Zingiber officinale Rosc. CN: Ginger	[6]-gingerol (ak)	SARS-CoV-2/TMPRSS2 receptor blocking	[64] [65]