# The Extract of the Endophytic Fungus Penicillium compactum Inhibits the Replication of Human Coronavirus

## TL;DR

A fungal extract from Penicillium compactum was found to inhibit the replication of human coronavirus in cells.

## Contribution

This study is the first to demonstrate antiviral activity of Penicillium compactum extract against human coronavirus.

## Key findings

- PCE reduced the expression of viral proteins in infected cells.
- PCE decreased viral RNA levels in both cells and their medium.
- PCE treatment reduced the production of infectious viral particles.

## Abstract

Fungal extracts have been reported to exert diverse biological activities, including anti-inflammatory, antibacterial, and antiviral effects. However, the anti-coronaviral properties of fungal extracts remain largely unexplored. In this study, we demonstrated that the Penicillium compactum extract (PCE) inhibits the replication of human coronavirus. RD cells were infected with human coronavirus and subsequently treated with PCE. PCE treatment reduced the expression of viral proteins and ameliorated virus-induced cytopathic effects. In addition, PCE markedly decreased viral RNA levels in both the cells and the conditioned medium. Finally, we confirmed that PCE treatment reduced the production of infectious viral particles. Collectively, these findings indicate that PCE exhibits potent antiviral activity against human coronavirus.