# Anemoside B4 attenuates intestinal damage in chickens infected with Eimeria tenella: Mechanisms involving antioxidant defense, immune modulation, and barrier repair

## TL;DR

Anemoside B4 helps repair chicken intestinal damage from Eimeria tenella by reducing inflammation, boosting antioxidants, and improving gut barrier function.

## Contribution

AB4 shows a tripartite mechanism of antioxidant, immune, and barrier repair efficacy comparable to conventional anticoccidials.

## Key findings

- AB4 showed significantly higher radical scavenging activity than Diclazuril.
- AB4 reduced cecal lesion scores and improved the CD4⁺/CD8⁺ ratio in chickens.
- AB4 enhanced tight junction gene expression and restored intestinal villus architecture.

## Abstract

This study aimed to investigate the reparative effects and underlying mechanisms of Anemoside B4 (AB4) on intestinal damage induced by Eimeria tenella (E. tenella) infection in chickens. Eighty 14-day-old broilers were allocated into four groups: control (CON), E. tenella-infected (E. tenella), AB4-treated (E. tenella+AB4), and diclazuril-treated (E. tenella+DC). Infected birds were orally inoculated with 4 × 10⁴ sporulated oocysts, followed by oral administration of AB4 (40 mg/kg BW) or Diclazuril (1 ml/bird, 0.2 mg/mL) at 12 hours post-infection. Key findings demonstrated that AB4 exhibited significantly superior radical scavenging activity (82.7–93.1 %) against superoxide anion, 2,2-diphenyl-1-picrylhydrazyl (DPPH), and hydroxyl radicals compared to Diclazuril (<16.3 %) . The Anticoccidial Index (ACI) for the AB4 group (163.05) indicated moderate efficacy and was comparable to the diclazuril group (161.69) (P>0.05), with significantly reduced cecal lesion scores. Concurrently, AB4 downregulated serum pro-inflammatory cytokines (IFN-γ, IL-6) and upregulated IL-10, enhanced the splenic CD4⁺/CD8⁺ ratio (with superior restoration to Diclazuril at D14, P<0.01), and promoted expression of tight junction genes (ZO-1, P<0.01; Occludin, P<0.05 at D7/D14), corroborated by histopathological evidence of intact cecal villus architecture. These results establish that AB4 effectively mitigates coccidial enteritis through a tripartite synergistic mechanism involving potent antioxidant activity, immune homeostasis restoration, and intestinal barrier repair, offering comparable efficacy to conventional anticoccidials with enhanced safety as an eco-friendly alternative.