Screening of West African plants for anthelmintic activity

Eighteen plants traditionally used for the treatment of human and animal helminthiasis in Africa were screened for anthelmintic activity using the Nippostrongylus - rat model. Aloe barteri, Terminalia avicennioides, Annona senegalensis, Cassia occidentalis, Anogeissus leiocarpus and Diospyros mespiliformis showed significant activity, giving deparasitizations of 92, 89, 75, 69, 60 and 58% respectively compared to untreated controls

Recherche sur l'activite anthelmintique des plantes de l'Afrique de l'Ouest

Eighteen plants traditionally used for the treatment of human and animal helminthiasis in Africa were screened for anthelmintic activity using the Nippostrongylus - rat model. Aloe barteri, Terminalia avicennioides, Annona senegalensis, Cassia occidentalis, Anogeissus leiocarpus and Diospyros mespiliformis showed significant activity, giving deparasitizations of 92, 89, 75, 69, 60 and 58% respectively compared to untreated controls

Pharmacokinetics of diminazene in plasma and lymph of goats

Diminazene aceturate is one of a limited number of drugs currently being used in animals to treat the tsetse fly-transmitted protozoal disease, African trypanosomiasis. Efficacy of the drug at the recommended single IM administered doses of 3.5 and 7.0 mg/kg of body weight is widely acknowledged. However, resistance to the drug at these dosages has been reported. Although the mechanisms of resistance to diminazene are poorly understood, field and experimental data indicate that it may develop naturally through administration of subcurative doses, or as a result of cross-resistance. Evidence from other experimental studies indicates that there are additional mechanisms by which trypanosomes may develop resistance to diminazene aceturate. For instance, some populations ot Trypanosoma brucei and T. vivax are refractory to treatment because of their ability to invade the CNS, a site that is believed to be poorly accessible to diminazene. Furthermore, in recent studies carried out in goats, it has been documented that the ability of T. Congolense IL 3274 to survive treatment with diminazene depends on the stage of infection when treatment is administered; populations of the parasite reappeared in animals that were treated on day 19 after tsetse fly challenge, whereas all goats were cured when treated on day 1 of infection. Because trypanosomes are confined to the skin on day 1 after infection, but thereafter invade the blood circulation, it is possible that the efficacy of the treatment on day 1 is attributable to exposure of the small number of parasites, relative to later stages of infection, to higher concentrations of drug than those attained in blood. The objective of the study reported here was to determine whether diminazene's pharmacokinetics differ between plasma and lymph draining the skin of goats and therefore account for the variation in therapeutic activity of the drug at different stages of a tsetse fly-transmitted infection. Peripheral lymph was used for this work because it appears to be identical in composition to tissue interstitial fluid, into which trypanosomes are inoculated by infected tsetse flies when feeding

Pharmacokinetics of imidocarb in normal dogs and goats

The pharmacokinetics of imidocarb was studied in seven mongrel dogs and eight crossbred goats. An intravenous bolus dose (4 mg/kg) of 12% imidocarb dipropionate solution was injected into the cephalic vein in dogs and the jugular vein in goats. The plasma concentration of imidocarb was measured by spectrophotometry. The experimental data were analysed using a two-compartment open model. The apparent volume of the central compartment was significantly higher (P<O.O 1) in dogs than in goats. The significantly larger (P<0.05) apparent specific volume of distribution in goats than in dogs may be attributed to passive diffusion followed by ion trapping of the drug in rumen fluid. Neither the half-life nor body clearance differed significantly between dogs (tl/2' 207 ± 45 min; CIB, l.47 ± 0.38 ml/min kg) and goats (tY2' 251 ± 94 min; CtB, 1.62 ± 0.50 ml/min kg). While almost 80% of the dose had been eliminated at 8 h in both species, the high ratio of the imidocarb level in the peripheral-to-central compartment in goats suggests that a prolonged period may be required for complete elimination of the drug