Veterinary Research Forum

Abstract Pasteurella multocida is a widespread zoonotic pathogen associated with severe hepatic inflammatory responses. Although traditional medicinal plants like Tribulus terrestris L. (TL) possess anti-inflammatory properties, their protective effects against P. multocida-induced liver injury remain insufficiently studied. This study established a P. multocida-induced liver injury model to evaluate the protective efficacy of TL extract. Thirty-two male Kunming mice were randomly assigned to four groups: control, model, penicillin-streptomycin, and TL extract. Interventions included daily intra-peritoneal injection of P. multocida (50.00 CFU mL^-1) followed by treatment with antibiotics or TL extract (1,000 mg kg^-1 daily) for 7 consecutive days. Therapeutic potential was evaluated using histopathological analyses (H&E and Masson's staining), RT-qPCR, western blot, immunohistochemistry, and immunofluorescence to assess inflammatory cytokines and NFκB pathway activation. TL extract significantly attenuated hepatic fibrosis and inflammatory cell infiltration. Following infection, NFκB pathway activation was indicated by up-regulated NFκB1 and down-regulated inhibitor of nuclear factor kappa B alpha (IκBα) expressions, alongside increased pro-inflammatory cytokines TNF-α and IL-1β. Treatment with antibiotics or TL reversed these changes. TL likely suppressed NFκB activation by down-regulating the tumor necrosis factor receptor superfamily member 1A (TNFRsf1a) receptor. Furthermore, decreased phosphorylation of IκBα and reduced TNF-α and IL-1β after treatment indicated effective inhibition of NFκB signaling and inflammation, effects comparable to antibiotic treatment. In conclusion, our research reveals that TL extract alleviates P. multocida-induced hepatic inflammation by inhibiting NFκB activation, highlighting its potential as a plant-derived therapeutic agent for bacterial liver injury.