Exploration of the efficacy of eucalyptus oil (micro-capsules) and mangosteen extract against Eimeria tenella infection in chickens

Due to the increasing prevalence of drug-resistant Eimeria strains, there is an urgent need to develop novel, eco-friendly, and safe alternatives for controlling chicken coccidiosis. This study aimed to investigate the combined anticoccidial efficacy of eucalyptus oil (EO) and mangosteen extract (ME) and develop an advanced delivery system via microencapsulation to enhance their therapeutic potential. In a broiler chick model of Eimeria tenella ( E. tenella ) infection, the combination of EO (100 mg/kg body weight, oral gavage) and ME (250 mg/kg feed) exerted the optimal effect against E. tenella with an anticoccidial index (ACI) of 169, indicating moderate anticoccidial activity. This combined efficacy appears to be multifaceted. It may involve (i) preservation of intestinal barrier integrity, (ii) suppression of oxidative stress and pro-inflammatory cytokine cascade, and (iii) restoration of cecal microbiota homeostasis. EO exhibits poor water solubility, posing challenges for its clinical administration. To address this, the sodium alginate-calcium chloride (CaCl₂) cross-linking method was used to prepare eucalyptus oil microcapsules (EOM). The results showed that the combined in-feed administration of EOM (50 mg/kg feed) and ME (250 mg/kg feed) yielded an ACI of 171. Furthermore, this treatment regimen alleviated cecal tissue damage and mitigated the inflammatory response. In conclusion, the combination of EO and ME may represent a potent, multi-target natural therapy for coccidiosis, and microencapsulation is a viable strategy to facilitate its practical application as a novel feed additive.