Evaluation of Native and Non-Native Plants as Sustainable Anticoccidials: In Vitro Inhibition of the Exogenous Phase of an Argentinian Chicken Eimeria Isolate by Senna spectabilis Var. spectabilis

Eimeria spp. causes severe production inefficiencies and welfare concerns in the poultry industry worldwide. Due to widespread resistance to anticoccidials, plant-derived bioactive compounds have emerged as alternative control strategies. This study aimed to evaluate the in vitro sporulation effect of methanolic extracts from of Melia azedarach and Senna spectabilis var. spectabilis against an Argentinian (Arg) isolate, containing a mix of three Eimeria spp., as well as pure Eimeria acervulina, and Eimeria tenella compared to the reference strains E. tenella Wisconsin and E. acervulina Houghton. A total of 4x105 unsporulated oocyst were incubated with six concentrations of extracts ranging from 2.5 to 80 mg/mL at 28ºC and 180 rpm for 72 h. The sporulation index (SI%) relativized to a negative control (NC) showed significant differences (p < 0.005) in all Eimeria spp. incubated with extracts of mature fruits of S. spectabilis at 80 and 40 mg/mL with SI ranging from 34.3 to 80% and 60 to 85%, respectively, depending on the species or strain. No significant differences were found with the other extracts assayed. Thus, S. spectabilis stands out as a strong candidate for use as a sustainable alternative in the prevention of chicken coccidiosis.