Study on the therapeutic effect of Rubia cordifolia stem on chicken diarrhea caused by Escherichia Coli

This study explored the therapeutic effect and mechanism of Rubia cordifolia stem on Escherichia coli-induced diarrhea in chickens. A total of 180 one-day-old white-feathered broilers were adaptively reared for 7 days and randomly assigned into six groups: blank control group, Escherichia coli model group, enrofloxacin group, 1000 mg/kg Rubia cordifolia stem group, 2000 mg/kg Rubia cordifolia stem group, and 4000 mg/kg Rubia cordifolia stem group, with 30 birds per group, six replicates and five broilers per replicate. The influences of different doses of the extract on growth performance, diarrhea severity, intestinal morphology, antioxidant status, immune-inflammatory response and intestinal microbiota were evaluated, and its mechanism was analyzed via network pharmacology and molecular docking. Results indicated that Rubia cordifolia stem improved growth performance, alleviated diarrhea, attenuated intestinal mucosal injury, significantly enhanced serum antioxidant enzyme activities, downregulated ileal pro-inflammatory gene expression, and upregulated immunoglobulin and anti-inflammatory factor levels. It also reshaped intestinal flora and restored microecological balance (P < 0.05). Network pharmacology analysis identified 25 intersecting targets between Rubia cordifolia L. and Escherichia coli infection. Among them, CASP3, ESR1, BCL2, CDK2, and PTGS2 were recognized as core targets primarily involved in inflammatory regulation and immune response pathways. Molecular docking verification confirmed that the main active ingredients of Rubia cordifolia L. stably bound to these core targets, and β-sitosterol exhibited the optimal binding activity. In summary, Rubia cordifolia stem treated broiler colibacillosis by enhancing antioxidant capacity, inhibiting inflammation, regulating immune function, and maintaining intestinal microecological balance. This study provided experimental and theoretical evidence for the application of Rubia cordifolia stem as an antibiotic substitute in poultry production.