Antiviral Activity Exerted by Natural Products against Human Viruses

Abstract

Viral infections are responsible for several chronic and acute diseases in both humans and animals. Despite the incredible progress in human medicine, several viral diseases, such as acquired immunodeficiency syndrome, respiratory syndromes, and hepatitis, are still associated with high morbidity and mortality rates in humans. Natural products from plants or other organisms are a rich source of structurally novel chemical compounds including antivirals. Indeed, in traditional medicine, many pathological conditions have been treated using plant-derived medicines. Thus, the identification of novel alternative antiviral agents is of critical importance. In this review, we summarize novel phytochemicals with antiviral activity against human viruses and their potential application in treating or preventing viral disease.

Severe Acute Respiratory Syndrome Coronavirus-2 Inactivation Activity of the Polyphenol-Rich Tea Leaf Extract with Concentrated Theaflavins and Other Virucidal Catechins

“…Phenolics, carotenoids, terpenoids, and alkaloids are well-known antiviral phytochemicals. In the phenolics family, phenolic acids, flavonoids, stilbenes, coumarins, and tannins are known to have antiviral activities [ 13 , 14 ]. The virucidal and antiviral activities of naturally derived polyphenols are widely known; they have been reported to prevent viral absorption and entry to host cells and inhibit viral genome and protein synthesis in infected cells [ 14 ].…”

“…In the phenolics family, phenolic acids, flavonoids, stilbenes, coumarins, and tannins are known to have antiviral activities [ 13 , 14 ]. The virucidal and antiviral activities of naturally derived polyphenols are widely known; they have been reported to prevent viral absorption and entry to host cells and inhibit viral genome and protein synthesis in infected cells [ 14 ]. Catechin is one of the flavonoids contained in the leaves of green tea ( Camellia sinensis ).…”

Antiviral Potential of Plants against Noroviruses

“…The use of cell models in in vitro tests allows for the quick and precise determination of the antiviral activity of various preparations [ 38 ]. All results of in vitro studies on the action of plant-derived active metabolites (e.g., endpoint titration technique (EPTT), virus-induced cytopathic effect inhibition (CPE), virus yield reduction assay, MTT assay, plaque reduction assay, virus deactivation assay, virus adsorption assay, virus attachment, and virus penetration assay [ 39 ]) must also be confirmed by in vivo testing [ 40 , 41 , 42 ], which, at the next stage, is a necessary step in the application for registration with government food and drug control agencies and in making the preparation available to food pharmaceutical industries [ 43 ].…”

Plants and Natural Products with Activity against Various Types of Coronaviruses: A Review with Focus on SARS-CoV-2

“…These compounds are found in different plants, including the Vitis vinifera L. grape and berries of the genus Vaccinium ( Table 2 and Table 3 ) [ 30 ]. Compounds in berries have been suggested to block the virus entry to cells through endocytosis [ 97 ].…”