Anthelmintic efficacy and safety of selected medicinal plants against mixed gastrointestinal nematodes in artificially infected sheep

Abstract

There has been widespread resistance to anthelmintics by pathogenic helminths to an extent where there is multi-drug resistance against all major classes of conventional anthelmintics. This world-wide phenomenon calls for urgent search for different approaches to the control of helminthosis including novel anthelmintic products. The purpose of the study was to determine the efficacy and safety of selected plants, which are frequently used in the treatment and control of helminthosis, in artificially infected sheep under controlled laboratory conditions. The selected plant species were, Albizia anthelmintica Brongn, Embelia schimperi L., Myrsine africana L. and Rapanea melanophloeos (L.) Mez. Thirty six male Dorper lambs, aged between 6 and 8 months, artificially infected with mixed gastrointestinal nematodes (GIN) under controlled laboratory conditions, were used for the study. Efficacy was determined using percentage fecal egg count reduction test (FECRT %) and percentage total worm count reduction (TWCR %). Safety of the remedies was assessed using health, hematological and biochemical parameters. The FECR % against the mixed gastrointestinal nematodes was -55, 7.6, 34.2, 69.3 and 83.3% for Albizia anthelmintica, Embelia schimperi, Rapanea melanophloeos, albendazole and Myrsine africana respectively. TWCR% of 60.7, 44.6, 66, 69.7 and 35.6 percent were recorded for Albizia anthelmintica, Embelia schimperi, Myrsine Africana, Rapanea melanophloeos, and albendazole groups respectively. It was concluded that some of the remedies like M. africana have good efficacy at safe levels and should further be evaluated to determine the most optimum dosages. The gastrointestinal nematodes used in this study were resistant to albendazole.