Bamboo polyphenols protects against Escherichia coli-induced liver injury in broilers by attenuating inflammatory responses.

Avian colibacillosis, caused by avian pathogenic Escherichia coli (APEC), is a highly prevalent disease worldwide and leads to substantial economic losses in the poultry industry annually. Despite the well-documented bioactivities of various plant polyphenols, the therapeutic potential of bamboo polyphenols (BP) against APEC infection remains largely unexplored. In this study, we investigated the antibacterial and anti-inflammatory effects of BP both in vitro and in vivo. The results demonstrated that BP inhibited the growth and killed APEC at relatively low concentrations in bacteriostatic and bactericidal assays. Liver histopathological examination and bacterial load determination revealed that treatment with BP reduced inflammatory cell infiltration and significantly decreased bacterial burden in liver tissue. Moreover, BP markedly downregulated the mRNA expression levels of inflammatory cytokines, chemokines, and pro-inflammatory markers, and suppressed the phosphorylation of p65, p38, and ERK1/2 both in vitro and in vivo. Additionally, BP inhibited LPS-induced ROS expression in vitro. These findings show that BP exerts antibacterial and anti-inflammatory effects by inhibiting bacterial growth, suppressing the NF-κB and MAPK pathways, and reducing ROS levels. This offers a new theoretical basis for controlling bacterial diseases in livestock and poultry, as well as a novel strategy against bacterial resistance.