Antiviral Peptides (AVPs) of Marine Origin as Propitious Therapeutic Drug Candidates for the Treatment of Human Viruses

Abstract

The marine environment presents a favorable avenue for potential therapeutic agents as a reservoir of new bioactive natural products. Due to their numerous potential pharmacological effects, marine-derived natural products-particularly marine peptides-have gained considerable attention. These peptides have shown a broad spectrum of biological functions, such as antimicrobial, antiviral, cytotoxic, immunomodulatory, and analgesic effects. The emergence of new virus strains and viral resistance leads to continuing efforts to develop more effective antiviral drugs. Interestingly, antimicrobial peptides (AMPs) that possess antiviral properties and are alternatively regarded as antiviral peptides (AVPs) demonstrate vast potential as alternative peptide-based drug candidates available for viral infection treatments. Hence, AVPs obtained from various marine organisms have been evaluated. This brief review features recent updates of marine-derived AVPs from 2011 to 2021. Moreover, the biosynthesis of this class of compounds and their possible mechanisms of action are also discussed. Selected peptides from various marine organisms possessing antiviral activities against important human viruses-such as human immunodeficiency viruses, herpes simplex viruses, influenza viruses, hepatitis C virus, and coronaviruses-are highlighted herein.

Keywords: antiviral peptides; infectious diseases; marine peptides; natural products; therapeutic drugs.

Figure 1

Schematic summary of known antiviral mechanisms of the recently reported marine AVPs.

Figure 2

The chemical structures of marine-derived peptides with anti-HIV activity.

Figure 3

The chemical structure of asperterrestide A—a marine-derived fungal peptide possessing inhibitory effects on influenza viruses.

Figure 4

The structures of marine peptides demonstrating anti-HSV activity: ^a The structure of myticin C was generated using SWISS-MODEL modelling (https://swissmodel.expasy.org, accessed on 23 February 2022) [110,111], based on the amino acid sequence from GenBank with accession number AEZ79080.1 [112]. Moreover, the synthetic Pa-MAP is derived from the antifreeze peptide (AFP) HPLC-8^b (as shown by the amino acid sequence), the structural model of which was retrieved from the SWISS-MODEL repository (https://swissmodel.expasy.org/repository, accessed on 23 February 2022) [113], with the UniProtKB AC number Q99013 (ANPB_ PSEAM) [114]. The blue and red colors within the structural model indicate positively and negatively charged residues, respectively.

Figure 5

The chemical structures of marine-microbial-derived peptides possessing anti-HCV properties.

Figure 6

The chemical structure of plitidepsin—a marine-derived peptide exhibiting anti-SARS-CoV-2 activity.