Integrative In Vivo and Transcriptomics-Guided In Silico Profiling of Citrus sinensis Phytochemicals as Multi-Target...

Coccidiosis, caused by Eimeria species, is a parasitic disease responsible for intestinal injury, oxidative stress, and significant economic losses in animal production. The increasing emergence of anticoccidial drug resistance has intensified the search for effective plant-derived alternatives. This study evaluated the in vivo anticoccidial activity of Citrus sinensis leaf extract (CSLE) against Eimeria papillata infection in mice and investigated its potential molecular mechanisms through integrated transcriptomic, molecular docking, and ADMET analyses. GC-MS profiling identified 43 phytochemicals, from which major compounds were prioritized based on abundance, docking affinity, active-site interactions, and pharmacokinetic safety predictions. In vivo treatment of infected C57BL/6 mice with CSLE (150, 300, and 600 mg/kg) significantly reduced oocyst shedding in a dose-dependent manner, with the highest dose decreasing counts to 9.8 × 10⁶ oocysts/g and improving body weight gain and jejunal histology. Transcriptomic analysis indicated that parasite persistence was associated with suppression of host IFN-γ signaling, whereas CSLE partially restored immune responsiveness. Molecular docking demonstrated strong binding of Cholestan-3-ol, Estra-1,3,5(10)-trien-17β-ol, and a secoyohimban derivative to CDPK1, PKG, and HSP90, exceeding amprolium affinity. ADMET analysis supported favorable safety and pharmacokinetic properties. Overall, CSLE showed strong dose-dependent anticoccidial activity through multiple mechanisms, highlighting its potential as a natural alternative for coccidiosis control.