Farmers use plant extracts as a potential source of anthelmintic compounds against gastrointestinal nematodes in goats. The objective of the study was to investigate the in vitro anthelmintic activity of aqueous (cold and boiled) and methanolic extracts of Cissus quadrangularis Linn., Aloe marlothii A. Berger, Albizia anthelmintica Brongn., Cissus rotundifolia (Forssk.) Vahl., Sclerocarya birrea (A. Rich.) Hochst, and Vachellia xanthophloea (Benth.) P.J.H. Hurter plants against gastrointestinal nematodes (GIN). Plants were used in two forms: dry and fresh. Decoction (boiled water), infusion (cold water), and methanolic extracts at concentrations of 8, 16, 24, 32, and 40% v/v were tested in vitro on mortality of L3 nematodes. Linear relationships were observed between larvae mortality and extract concentration of the boiled fresh form of C. rotundifolia (P < 0.01), fresh form of cold-water of A. marlothii (P < 0.05), fresh form of cold-water and methanolic C. quadrangularis (P < 0.01), dry form of cold-water and methanolic S. birrea (P < 0.0001), and dry form of cold-water and fresh form of methanolic V. xanthophloea (P < 0.05). Quadratic relationships were observed between larvae mortality and extract concentration of the fresh form of methanolic C. rotundifolia (P < 0.05), fresh form of methanolic A. anthelmintica (P < 0.01), the fresh form of methanol and the dry form of boiled A. marlothii (P < 0.001), fresh form of methanolic (P < 0.05) and dry form of boiled S. birrea (P < 0.01), fresh form of cold and boiled water of V. xanthophloea (P < 0.0001), and dry form of boiled water and methanolic V. xanthophloea (P < 0.05). The crude plant extracts of C. quadrangularis, A. marlothii, A. anthelmintica, C. rotundifolia, S. birrea, and V. xanthophloea could be considered as an integrated approach to achieve sustainable nematode control in goats.
Keywords: Anthelmintic activity; Ethnoveterinary medicine; Gastrointestinal parasites; Phytochemicals.