Aim: The objective of the present study was to investigate in vitro anticoccidial effect of olive pulp (Olea europaea L var. Chemlal) extract on the destruction of Eimeria spp. oocysts isolated from infected chickens naturally.
Materials and methods: The olive pulp (OP) powder was stirred manually in aqueous ethanol in preparation for extraction using the microwave-assisted extraction system. The identification of the phenolic compounds was obtained by ultra-high-performance liquid chromatography-mass spectrometry with electrospray ionisation (HPLC-ESI-MS). The treatment of Eimeria oocyst with OP extract and standard compounds (quercetin and oleuropein) leads to their lysis as shown by the release of substances absorbing at 273 nm.
Results: Our results showed that the maximum number of reduced oocysts was recorded after 8 h of incubation of optimum OP extract, quercetin and oleuropein for different periods of time. Also, the number of Eimeria oocysts decreased considerably with increase concentrations after adding the optimum of OP extract in concentration ranging from 0.023 to 0.371 mg/ml. Positive correlation between the optimum OP extract concentrations and the number of Eimeria oocysts reduced was R2 = 0.959. From this in vitro experiment, it can be concluded that the OP extract possesses an anti-Eimeria spp activity.
Conclusion: To our knowledge, this is the first time that quercetin and oleuropein were tested to evaluate their anticoccidial activity. The findings of this study showed that phenolic compound of OP extract tested separately possesses anti-Eimeria spp. effect. Further studies should be carried out to test its in vivo efficacy of the OP bioactive compounds in broiler chickens.
Keywords: Anticoccidial activity; Chickens; Co-products; In vitro; Olea europea L. var. Chemlal.