Growing societal concerns to replace coccidiostats in poultry farms lead to the use of alternatives as plant bio-actives. To investigate natural molecules modes of action we designed this in vitro study to screen anti-protozoal activity of 4 spices or medicinal plants described by non-volatile active molecules (MedP) (Fabacea powder, Urticaceae extract, Punicaceae extract, Acanthaceae extract) and 3 essentials oils (EO) (Lilaceae EO, Lamiaceae EO, Lauraceae EO) against 3 different stages of E. tenella. First, cytotoxicity of samples was evaluated using MTS test against MDBK cells. The lowest dilution of each MedP or EO samples showing no cytotoxicity (lethal dose 10%) was used to perform 3 antiprotozoal tests. Sporozoite viability test was conducted in triplicate with Evans blue dye (incubation 41°C for 1h). Invasion inhibition test was performed in 96 microplate: 1.5×104 MDBK cells,infected with sporozoites (MOI = 1), were incubated with each sample (4 replicates) at 41°C. E. tenella strain expressed an enzymatic activity which can be quantify. After 2h, substrate was added and enzymatic reaction measured after 2h incubation at 37°C. Invasion rate was calculated as percentage of samples respective absorbance compared to absorbance of control. Finally, 5 ×105 non sporulated oocysts were incubated in triplicate with each MedP or each EO samples in solution of potassium dichromate (2%) at 26°C for 72h. Sporulation rate was defined as percentage of sporulated oocysts intested samples compared to sporulated oocysts in control. Mann-Whitney test was used to compare each sample rate to control. The 4 MedP samples were less cytotoxic than 3 EO samples (MedP dilutedat 10-2, EO diluted at 10-4-10-6). MedP samples showed antiprotozoal activity against different E. tenella stages: sporozoites viability rate were between 76.2% and 27% (p = 0.05). Urticaeae extract showed also a sporulation rate of 68.8% (p=0.05). Punicaceae extract exhibited invasion rate of 74% (p<0.001) and sporulation rate of 81.6% (p=0.05). EOs showed only direct anti sporozoites activity (sporozoites viability rates between 76.7% and 81.6% (p=0.05)). MedP group showed antiprotozoal activity against different E. tenella stages, on the contrary of EOs, which only targeted sporozoites. Thisstudy helps to understand how bio-actives plants could act in association to reduce E. tenella pathogenicity.