Bioactive activities of natural products against herpesvirus infection

Abstract

More than 90% of adults have been infected with at least one human herpesvirus, which establish long-term latent infection for the life of the host. While anti-viral drugs exist that limit herpesvirus replication, many of these are ineffective against latent infection. Moreover, drug-resistant strains of herpesvirus emerge following chemotherapeutic treatment. For example, resistance to acyclovir and related nucleoside analogues can occur when mutations arise in either HSV thymidine kinase or DNA polymerases. Thus, there exists an unmet medical need to develop new anti-herpesvirus agents with different mechanisms of action. In this Review, we discuss the promise of anti-herpetic substances derived from natural products including extracts and pure compounds from potential herbal medicines. One example is Glycyrrhizic acid isolated from licorice that shows promising antiviral activity towards human gammaherpesviruses. Secondly, we discuss anti-herpetic mechanisms utilized by several natural products in molecular level. While nucleoside analogues inhibit replicating herpesviruses in lytic replication, some natural products can disrupt the herpesvirus latent infection in the host cell. In addition, natural products can stimulate immune responses against herpesviral infection. These findings suggest that natural products could be one of the best choices for development of new treatments for latent herpesvirus infection, and may provide synergistic anti-viral activity when supplemented with nucleoside analogues. Therefore, it is important to identify which natural products are more efficacious anti-herpetic agents, and to understand the molecular mechanism in detail for further advance in the anti-viral therapies.

Bioactive natural products with anti-herpes simplex virus properties

“…Phenolic compounds are plant secondary metabolites that are produced in response to microbial infections. They are abundant in many plants and have a broad spectrum of antiviral and antioxidant effects [62]…”

In vitro cytotoxicity and biological activities of Genipa americana (Rubiaceae) ethanolic extracts

“…Antiviral therapy is more effective on human herpes viruses, nevertheless the animal herpes viruses can serve as models and to better understand this family of virus through in-vitro and vivo experiments (Field et al, 2006;Son et al, 2013). In the case of equine alphaherpes virus infections, the use of antivirals combined with other measures is beneficial and well- studied (Garré et al, 2007;Vissani et al, 2016).…”

“…The suid alphaherpes virus is widely studied as a model for herpes virus biology, but there are diverse studies on antivirals from medicinal plants aiming in the future to decrease the infection in addition to vaccination and the negative impact of this disease on pig industry (Pomeranz et al, 2010;Son et al, 2013). For suid alphaherpes virus, less intensive antiviral activity was seen with the BE and LE extracts.…”

“…Moreover, the synthetic drugs lead to emergence of resistance strains. Thus, medicinal plants would be an alternative to overcome this and they could either substitute or complement synthetic drugs (Chattopadhyay and Naik, 2007;Son et al, 2013).…”

A Novel Tricyclic Polyketide, Vanitaracin A, Specifically Inhibits the Entry of Hepatitis B and D Viruses by Targeting Sodium Taurocholate Cotransporting Polypeptide

“…The isolation of this compound from fungal metabolites and its chemical identification have been reported (40). A number of small molecules derived from natural sources have been reported to be inhibitors of vial infections, including those of human immunodeficiency virus, HCV, herpesviruses, and influenza virus (41)(42)(43)(44)(45). However, the poor understanding of the mode of action in most of these cases has hampered the development of antiviral drugs based on these findings, suggesting that mechanis- tic analysis, especially the identification of the target molecule, is a very important issue for drug development.…”