Fish Skin Mucus Peptides Show Antiviral Activity Against Herpes Simplex Virus | Research

The takeaway

Antimicrobial peptides in fish skin mucus showed activity against herpes simplex virus type 1, with species containing higher AMP levels demonstrating stronger antiviral effects.

AMP levels predict antiviral potency
Fish species with higher cathelicidin, hepcidin, and other AMP levels in their mucus showed stronger antiviral activity against HSV-1

What the researchers found

Skin mucus from three fish species showed antiviral activity against herpes simplex virus type 1 (HSV-1), with sea bream and rainbow trout mucus demonstrating higher activity (2-4 and 2-5 inhibition, respectively) than sea bass (2-2). The higher antiviral activity correlated with higher levels of antimicrobial peptides — cathelicidin, hepcidin, galectin 2, and C10ORF99 — in the mucus of the more effective species.

The association between AMP levels and antiviral potency suggests these peptides contribute directly to the antiviral defense of fish skin mucus, pointing to their potential as novel antiviral agents or supplements.

Why it matters

While antimicrobial peptides are well-studied for their antibacterial properties, antiviral activity — especially against human viruses like HSV-1 — is less explored. Finding that fish skin mucus peptides can inhibit a common human virus opens a new source for antiviral drug discovery. Fish produce AMPs in abundance as their first-line defense, and these peptides have been refined by evolution to work in the challenging aquatic environment.

The numbers in context

3 fish species tested · HSV-1 inhibition: sea bream 2-4, rainbow trout 2-5, sea bass 2-2 · 4 AMPs measured (cathelicidin, hepcidin, galectin 2, C10ORF99) · Higher AMPs = higher antiviral activity

How the study worked

Skin mucus was collected from sea bream, rainbow trout, and sea bass. Antiviral activity against HSV-1 was evaluated using standard viral inhibition assays. Levels of four antimicrobial peptides (cathelicidin, hepcidin, galectin 2, C10ORF99), superoxide dismutase (SOD), catalase (CAT), and immunoglobulin M were measured in the mucus. Correlations between AMP levels and antiviral activity were assessed.

Who was studied

In vitro antiviral testing of skin mucus from three fish species (sea bream, rainbow trout, sea bass) against HSV-1

What this study cannot tell us

The study measured antiviral activity of crude mucus rather than purified individual peptides, making it impossible to determine which specific AMP is responsible for the antiviral effect. The antiviral activity was only tested against HSV-1 — activity against other viruses is unknown. The inhibition titers (2-2 to 2-5) are relatively modest. No mechanism of antiviral action was elucidated. The leap from fish mucus to human therapeutic application requires extensive development.

How to read the evidence

This is a preliminary in vitro study testing crude fish mucus against a single virus. The correlation between AMP levels and antiviral activity is suggestive but does not prove causation. No purified peptide testing or mechanism studies were performed.

When this study was published

Published in 2024, this study contributes to the growing interest in fish-derived antimicrobial peptides as potential therapeutic agents, though the field is still in early discovery stages.

The bigger picture

The search for new antivirals is increasingly turning to nature's own defense systems. Fish skin mucus is a rich but underexplored source of antimicrobial peptides that have evolved to protect against the microbe-rich aquatic environment. If specific peptides responsible for the antiviral activity can be isolated and characterized, they could serve as templates for developing novel antiviral drugs — particularly important given the growing challenge of antiviral resistance.

Questions still open

Which specific antimicrobial peptide in the mucus is most responsible for the anti-HSV-1 activity?
Do these fish mucus peptides have activity against other clinically important viruses?
Could purified fish AMPs be developed into topical antiviral treatments for herpes infections?

Common questions

Why would fish mucus fight human viruses?

Fish skin mucus is their equivalent of our immune barrier — it's packed with antimicrobial peptides evolved over millions of years to fight off waterborne pathogens. These peptides work by disrupting pathogen membranes or blocking infection mechanisms that are shared across many types of organisms. Since herpes viruses have an outer lipid envelope, peptides that disrupt membranes can potentially inactivate them regardless of whether the virus normally infects fish or humans.

Could this lead to a new herpes treatment?

It's very early-stage research. The next steps would be isolating the specific peptides responsible, testing them against HSV-1 in purified form, understanding their mechanism, and ensuring they're safe for human use. However, topical antiviral peptides derived from natural sources are an active area of drug development, and fish mucus represents a largely untapped reservoir of these molecules.

Read the original research

Evaluation of potential antiviral activities of antimicrobial peptides in fish mucus.

Fundamental & clinical pharmacology, 38(4), 695-702

View on PubMed ↗Publisher’s paper ↗

Citation

Dik, Irmak; Dik, Burak; Tufan, Öznur; Er, Ayşe. (2024). Evaluation of potential antiviral activities of antimicrobial peptides in fish mucus.. Fundamental & clinical pharmacology, 38(4), 695-702. https://doi.org/10.1111/fcp.12996