IN VITRO EFFECT OF BURKEA AFRICANA BURKE, 1840 (FABACEAE-CESALPINOIDEAE) ETHANOLIC BARK EXTRACT ON THE NEMATODE HAEMONCHUS CONTORTUS RUDOLPHI, 1803

In order to seek an alternative to conventional means of small ruminants heamonchosis treatment and valorise biodiversity, an acute toxicity test was conducted by incubating adult worms of Haemonchus contortus in a Phosphate Buffered Saline culture medium, containing increasing concentrations of Burkea africana trunk bark extracts. The positive control consisted of a levamisole solution, while the negative control consisted of a PBS solution containing DMSO. The anthelmintic activity, assessed every 6 hours for 24 hours, was expressed as a percentage of mortality. The data obtained show that, the ethanolic extract of the bark of Burkea africana display anthelmintic activity against Haemonchus contortus. The average values of 18h-LC50 were of 0.56 ± 0.10 mg/ml for the levamisole and 0.75 ± 0.09 mg/ml for the peel. After 24 hours, the mean LC50 values were of 0.09 ± 0.05 mg/ml, for peel and 0.27 ± 0.09 mg/ml for levamisole. The LC50 variance analysis, both after 18 and 24 h, shows that there is no significant difference (P> 0.05) between the anthelmintic activity of the ethanol extract of the bark and that of Levamisole. These results confirm the efficacy of the extract of Burkea africana, used in traditional medicine to treat diseases caused by nematodes. An acute toxicity test, performed on white mice (Mus musculus), revealed that Burkea africana ethanolic bark extract was not toxic at a dose of 2500 mg/kg body weight. Given these data, the ethanolic extract of Burkea africana bark could be envisaged as an alternative to conventional fight against small ruminant's haemonchosis. Keywords: Acute toxicity, anthelminthic activity, haemonchosis, lethal concentration, Mus musculus, plant extract