In vitro study of anti-coccidial activity of Ocimum gratissimum and Vernonia amygdalina leaves extracts against Eimeria magna and Eimeria media

Background Ocimum gratissimum and Vernonia amygdalina are used in traditional medicine for their various biological properties, but few studies have assessed their antioxidant and anticoccidial capacities and toxicity. The aim of this study was to evaluate the antioxidant capacity, anticoccidial activity (against Eimeria magna and Eimeria media ), phytochemical content and toxicity of leaves extracts from two plants. Methodology: Aqueous and acetonic extracts of the leaves of both plants were prepared and analysed for their polyphenol, flavonoid and tannin contents. Antioxidant activity was measured via the DPPH method. The anticoccidial effects of increasing concentrations of extracts were tested on Eimeria oocysts and sporozoites. Toxicity was assessed by mortality tests on Artemia salina larvae and clinical tests on rats. Result The results show that extracts of V. amygdalina leaves have greater antioxidant and anticoccidial capacities than those of O. gratissimum . The acetone extracts of the two plants presented lower EC ₅₀ values (2.4025 ± 0.0385) for O. gratissimum and 3.541 ± 0.112 for V. amygdalina ) than did the aqueous extracts. With respect to anti-ocyst activity, acetone extracts of V. amygdalina inhibited sporulation of E. magna oocysts by up to 91% at 40 mg/mL (p˂0.05). Toxicity tests revealed that the extracts were not toxic to Artemia salina . No major histological changes were observed. O. gratissimum and V. amygdalina extracts have significant antioxidant and anticoccidial properties and are nontoxic for antioxidant and anticoccidial applications. Conclusion This study shows that extracts of O. gratissimum and V. amygdalina possess antioxidant and anticoccidial properties, with superior efficacy for V. amygdalina . These extracts have potential as natural alternatives for the management of coccidiosis in farm animals, helping to reduce the use of synthetic antiparasitics and promote sustainable agricultural practices. Further studies on their long-term effects and their application in livestock farming are required.