Preliminary Anthelmintic, Phytochemistry and Toxicity Studies of Selected Medicinal Plants in Kenya

Abstract

Anthelmintic resistance occurs at varying degrees for all the available drug molecules used for treatment of helminth infestations hence the need to find alternative medicines. Ethnoveterinary practitioners in Kenya use Carissa edulis, Warburgia ugandensis, Olea africana and Rumex usambarensis for treatment of parasitic helminths infestations in domestic animals. The study was aimed at investigating the anthelmintic properties on these plants. Egg Hatch Inhibition Assay and Fecal Egg Reduction Tests were used to test the in vitro and in vivo anthelmintic activity of the selected medicinal plants. The acute toxicity studies were carried out according to methods described by the OECD guidelines. Standard methods and methods described in literature were applied in the preparation of the extracts, subacute toxicity studies as well as the qualitative and quantitative phytochemistry. Statistical analysis of the results was done using Probit Regression, ANOVA, Independent T Test and the Tukey's Post Hoc Tests. A dose dependent inhibition of egg hatching was observed for all the aqueous and ethanol extracts. The ethanol extract of Olea africana was the most effective extract with an EC50 value of 0.27mg/ml ±0.06. A single dose of 12.5mg/kg of the ethanol extract of Olea africana administered in dogs caused a percentage reduction of 0.89% of strongyle eggs at day 14 which was not statistically significant (P≥0.05) when compared to giving the animals 12.5 mg/kg of Albendazole which caused a percentage reduction of 87.23%. The pre-treatment means in all groups in the single treatment experiment were not statistically significant (P≥0.05) when compared to the post treatment mean using the Independent Sample T Test. Giving dogs repeat doses of 12.5mg/kg of the ethanol extract of Olea africana daily for 8 days caused a percentage reduction of 26.19% of strongyle eggs. The pre-treatment means in all groups in the repeat treatment experiment were not statistically significant (P≥0.05) when compared to the post...............................................................................