The effects of baicalin on piglets challenged with Glaesserella parasuis

Shulin Fu,Yunfei Zhang,Yu Liu,Ling Guo,Zhongyuan Wu,Chien-An Andy Hu,Sanling Zuo,Jun Liu,Yinsheng Qiu,Chun Ye,Yongqing Hou,Ronghua Yin

doi:10.1186/s13567-020-00826-5

Abstract

Glaesserella parasuis (G. parasuis) causes porcine vascular inflammation and damage. Baicalin is reported to have antioxidant and anti-inflammatory functions. However, whether baicalin protects piglets against G. parasuis challenge and the potential protective mechanism have not been investigated. Therefore, in this study, we comprehensively examined the protective efficacy of baicalin in piglets challenged with G. parasuis and the possible protective mechanism. Our results show that baicalin attenuated the release of the inflammation-related cytokines interleukin (IL) 1β, IL6, IL8, IL10, and tumour necrosis factor α (TNF-α) and reduced high mobility group box 1 (HMGB1) production and cell apoptosis in piglets infected with G. parasuis. Baicalin also inhibited the activation of the mitogen-activated protein kinase (MAPK) signalling pathway and protected piglets against G. parasuis challenge. Taken together, our data suggest that baicalin could protect piglets from G. parasuis by reducing HMGB1 release, attenuating cell apoptosis, and inhibiting MAPK signalling activation, thereby alleviating the inflammatory response induced by the bacteria. Our results suggest that baicalin has utility as a novel therapeutic drug to control G. parasuis infection.

Highlights

Glaesserella parasuis (G. parasuis), which belongs to the family Pasteurellaceae, is responsible for Glässer’s disease in pigs
The results demonstrated that G. parasuis increased cell apoptosis after the piglets were challenged with the bacterium compared with the level in the control piglets (p < 0.01, Figure 4), but caspase 3 expression was inhibited in the Ethyl pyruvate (EP) and flunixin meglumine (FM) groups (p < 0.05, Figure 4)
Baicalin (25–100 mg/kg body weight (BW)) attenuated cell apoptosis in piglets challenged with G. parasuis compared with that in the infection group piglets (p < 0.05 for 25, p < 0.01 for 50 and 100, Figure 4)

Summary

Introduction

Glaesserella parasuis (G. parasuis), which belongs to the family Pasteurellaceae, is responsible for Glässer’s disease in pigs. The typical characteristics of Glässer’s disease are fibrinous polyserositis, arthritis, meningitis, and frequent symptoms of pneumonia [1]. 15 serovars have been identified with the heat-stable antigen extraction method [2], but a significant percentage of isolates has not been classified by this method [3]. Serovar 5 is thought to be highly virulent, and epidemiological studies have shown that serovars 4, 5, and 13 are the current epidemic strains in China [3]. With changes in the breeding patterns in pigs, the economic losses caused by G. parasuis have become more severe.

Methods

Results

Conclusion