# Acute and Subacute Toxicity of Sialidase From Clostridium perfringens Type A in Mice (Mus musculus): Organ-Specific Damage and Immune Response

## TL;DR

This study examines the safety of a sialidase enzyme from a type of bacteria in mice, finding that high doses cause organ damage and immune suppression.

## Contribution

The study provides new insights into the in vivo toxicity profile of Clostridium perfringens sialidase in mice.

## Key findings

- High doses of sialidase caused lung inflammation, liver congestion, and kidney inflammation in mice.
- Immunosuppressive effects were observed, including reduced white blood cell and lymphocyte counts.
- Doses of 187.5 and 375 mU/mL were safe, but toxicity was evident at 750 mU/mL.

## Abstract

Sialidases, enzymes produced by Clostridium perfringens Type A, play a critical role in cleaving sialic acid residues essential for viral entry into host cells. By targeting pathogens such as coronaviruses, influenza, and paramyxoviruses, sialidase represents a promising therapeutic candidate. While in vitro studies confirm its efficacy against influenza, evaluating its safety profile in vivo is imperative. This study investigates the acute and subacute toxicity of sialidase from C. perfringens Type A in BALB/c mice (Mus musculus). Acute toxicity involved a single intranasal dose followed by a 14-day observation, while subacute toxicity encompassed daily doses for 30 days. Mice were administered 187.5, 375, or 750 mU/mL of sialidase, with saline as the control. No mortality or overt toxicity occurred, but significant histopathological alterations were evident in the lungs and liver at higher doses. Observed effects included lung inflammation and edema, liver congestion, and kidney inflammation. Hematological analysis revealed immunosuppressive effects, including reduced white blood cell and lymphocyte counts, alongside dose-dependent IL-6 expression changes. Sialidase doses of 187.5 and 375 mU/mL were deemed safe, whereas toxicity became pronounced at 750 mU/mL.