In vitro oocysticidal sporulation inhibition of Eimeria tenella and antioxidant efficacy of ethanolic and aqueous extracts of Conyza aegyptiaca

Abstract

Avian coccidiosis is probably one of the most expensive parasitic diseases with major economic impact on poultry industries worldwide. The purpose of this study was to evaluate the ethanolic and aqueous extracts of Conyza aegyptiaca in terms of phytonutrients, in vitro oocysts sporulation inhibition and antioxidant properties. The extraction process of plant leaf powder (100 g) pulverized using a clean manual grinder was carried out in ethanol and hot water and the yields were calculated as a percentage ratio of extract mass on plant powder mass after solvent evaporation. Phytochemical analysis procedures were performed to determine the presence of phytonutrients. The in vitro oocysticidal sporulation inhibition was determined at five different concentrations (0.25; 0.5; 1; 2 and 4 mg/ml) of each extract in petri dishes each containing 3000 unsporulated oocysts and examined after 24 and 48 hours under a microscope. In vitro antioxidant capacity of extracts was estimated using different assays. Quantitative aqueous extract (11.72%) was higher than ethanolic extract (4.34%). In terms of qualitative yields, ethanolic extract revealed higher phytonutrients investigated (100%) than aqueous extract (42.86%). The sporulation inhibition of ethanolic extract was generally higher than the aqueous extract after 24 and 48 h and varied according to the different tested concentrations. In all the antioxidant assays, ethanolic extract exhibited significant free radical scavenging activity with inhibitory concentration (IC50=26.10±1.09) close to that of ascorbic acid at the probability level of 5% error (p<0.05). The ethanolic extract with higher free radical scavenging activities and ferric reducing effect also showed significant higher content of both phenols (127.01±3.99 mgGAE/g) and flavonoids (108.66±3.49 mgCE/g) than aqueous extracts, suggesting correlation between phenolic content and antioxidant activity. Data from this study could be used for developing bioactive elements for natural anticoccidials and antioxidants of health promoting activities