Medicinal Plants: A Repository of Antiviral Metabolites

Abstract

The global disease burden caused by viral infection has persuaded scientists to develop novel and more effective antiviral drugs. Synthetic antiviral drugs contain substances other than viruses, which have the ability to offer defensive or therapeutic effects in favor of virus-infected host. Medicinal plants, on the other hand, have proven to be potent sources of antiviral agents with some major advantages over conventional drug therapy due to their broad therapeutic potency and limited side effects. Medicinal plants synthesize and preserve a variety of biochemical products possessing potential therapeutic index, aiding elimination/inhibition of viruses. This mini-review provides an insight into medicinal plants and their metabolites explaining their potential role as major alternatives in the treatment of viral infections.

Therapeutic potential of medicinal plants against COVID-19: The role of antiviral medicinal metabolites

“… Amaryllidaceae Stem Ethanol Chloroform Lycorine, glycyrrhizin Severe acute respiratory syndrome-associated coronavirus (SARS-CoV) Li et al (2005b) Glycyrrhiza uralensis Fisch. Licorice Fabaceae Root Methanol Echinatin Root extract is effective against HIV, RSV, herpes viruses, and severe acute respiratory syndrome-related coronavirus (SARS-CoV), which causes a serious type of pneumonia Yeh et al (2013) Glycyrrhiza glabra L. Licorice, Liquorice, Sweetwood Fabaceae Root & Leaves Aqueous, Methanol glycyrrhizin, glycyrrhetic acid, glabridin, liquiritin Corona virus, type A influenza virus, Japanese encephalitis, herpes simplex, vesicular stomatitis virus, Newcastle disease virus (NDV) ( Ashraf et al, 2017 ; Damle 2014 ; Hussain et al, 2017 ) Isatis tinctoria L. Dyer's woad, or glastum Brassicaceae Leaves Aqueous, Methanol Indole type glucosinolates Antibacterial and Antifungal activity; an ancient dye plant Ullah et al (2017b) Fagonia indica L. Dhamasa Zygophyllaceae Leaves ethanol extract flavonoids, sterols and triterpenoids Antileishmanial effects Ullah et al (2017a) Alysicarpus monilifer (L.) DC. Necklace-pod alyce clover Fabaceae Stem and leaves ...…”

“…Furthermore, many studies have been conducted on pure compounds isolated from many different plants for their potent activities against different viruses ( Hussain et al, 2017 ). Notable plants from which anti-viral metabolites have been isolated include Aloe barbadensis (Aloe gel), Artemisia annua (artemisinin) ( Efferth et al, 2008 ), Glycyrrhiza glabra (Glycyrrhizinic acid) ( Pompei et al, 2009 ), Sylibum marianum (Sylimarin) ( Polyak et al, 2013 ), and Phyllanthus urinaria (Ellagic acid) ( Kang et al, 2006 ).…”

“…Experiments have revealed that there are many important plant-based compounds i.e. secondary metabolites with marked antiviral activities These include alkaloids, flavonoids (such as quercetin), lignans (phyllanthine), polyphenolcs (tannins), and terpenoids (Glycyrrhizinic acid), which have shown strong anti -HSV, influenza, HIV, HCV, and anti-dengue activities ( Hussain et al, 2017 ).…”

Plant-derived antiviral drugs as novel hepatitis B virus inhibitors: Cell culture and molecular docking study

“…Traditional herbal products and drugs of indigenous origin have an ancient history of curing several chronic and infective diseases. A range of various plant metabolites are shown to impede virus replication without affecting the host physiology or with limited side-effects (Martin and Ernst, 2003, Hussain et al, 2017). In addition to their ability to interfere directly with viral replication, these natural products may also modulate the host immune response against infection (Kurokawa et al, 2010).…”

Natural Plant Products: A Less Focused Aspect for the COVID-19 Viral Outbreak

“…However, to be successful, plant-based herbal medicines have to address the issue of genetic variability of viruses, competent replication of DNA and RNA viruses within the host cells, and their capability to survive in the host cells ( Wagner and Hewlett, 1999 ; Jassim and Naji, 2003 ). In contrast to synthetic drugs, some of the plant-based metabolites hinder the replication of viruses without disturbing the host metabolism; which consequently have restricted side effects as drugs ( Hussain et al, 2017 ).…”