Asiatic Acid Alleviates LPS-Induced Pyroptosis and Endoplasmic Reticulum Stress-Mediated Apoptosis via Inhibiting the HMGB1/TLR4/NF-κB Pathway in Broiler Hepatocytes

Abstract

Lipopolysaccharides (LPS) is the major compoent of Gram-negative bacteria and an important factor in inducing inflammation, which usually leads to multiple organ failure in broilers, seriously affecting the growth performance of broilers and hindering the development of poultry farming. Under the policy of prohibiting antibiotics in feed, it has become more urgent to find natural drugs to prevent liver damage caused by LPS in broilers. Asiatic acid (AA) is a pentacyclic triterpene that has been proven to have anti-inflammatory and antioxidant effects. However, the protective effects of AA in LPS-induced liver damage in broilers still need to be clarified. This study aims to explore the complete mechanism of AA against LPS-induced acute liver injury (ALI) in broilers. A total of 60 broilers (1 day old) were randomly divided into the control group, LPS group, LPS+AA (15, 30 and 60 mg/kg) group and control+AA (60 mg/kg) group. At 16, 18 and 20 days of age, the broilers were attacked with LPS (0.5 mg/kg) to construct liver injury model. H&E staining assessed liver pathological changes. The mRNA and protein expression levels related to the HMGB1/TLR4/NF-κB pathway, pyroptosis, and ERS-mediated apoptosis in the liver tissue were detected. Our results founded that intraperitoneal injection of LPS in broilers increased the activities of AST and ALT, as well as raising the related gene and protein expression of the HMGB1/TLR4/NF-κB pathway, pyroptosis, and ERS-mediated apoptosis. Interestingly, AA improved LPS-induced liver damage and decreased the activities of AST and ALT in broilers. Additionally, AA mitigated LPS-induced ALI by reducing the mRNA levels and protein expressions of the HMGB1/TLR4/NF-κB pathway, pyroptosis and ERS-mediated apoptosis. In conclusion, the present study investigated that AA mitigated LPS-induced ALI in broilers by reducing pyroptosis and ERS-mediated apoptosis via inhibition of the HMGB1/TLR4/NF-κB pathway. Therefore, AA may serve as a potential feed additive for the prevention of LPS-induced ALI in broilers.