Matrine provides a protective effect against Eimeria tenella challenge by alleviating intestinal barrier damage.

As a virulent and harmful protozoan, Eimeria tenella (E.tenella) causes harmful chicken coccidiosis, inducing high economic losses in the chicken industry. The management of the coccidial disease has been greatly hampered by drug resistance. Matrine is an active ingredient from Ku Shen (Radix Sophorae Flavescentis), a typical pesticide in chinese medicine. The aim of this study was to examine matrine's possible effectiveness in the treatment of coccidiosis and its protective function on the intestinal barrier. The anticoccidial index (ACI), the levels of anti-oxidant indexes, and secretory immunoglobulin A (sIgA) were detected. The levels of mRNA and protein expression of Occludin, ZO-1, and Claudin-1 were determined through quantitative real-time PCR (RT-qPCR) and immunohistochemistry (IHC) analysis. Matrine exhibited a moderate ACI value, and ACI values of 122.51 and 143.42 corresponded to 5 and 10 mg/kg of matrine, respectively. Compared to the infective control group, the expression of tight junction proteins significantly increased in the matrine-treatment group by RT-PCR and IHC analysis, which are essential for the mucosal immune system and the intestinal barrier. Besides, the matrine-treatment group showed a more complete intestinal structure, fewer bleeding spots, and coccidian by histopathology analysis. We also found that, matrine significantly enhanced the antioxidant ability and significantly increased the content of sIgA. Above all, matrine was considered an efficient drug against E.tenella by the anti-oxidant efficacy, and the ability to protect the composition and function of the intestinal barrier.