Abstract
In our continuation of search for antitrypanosomal agents from medicinal plants and other sources, Brassica oleracea (cabbage) fruits and leaves were screened for their antitrypanosomal and cytotoxicity effects .Methanolic plant extracts (MPES) of B. Oleracea fruits and leaves at different concentrations (250-1000 µg/ml) were tested against Trypanosoma evansi on Vero cell line grown in Dulbecco’s Modified Eagle Medium (DMEM) with foetal calf serum (FCS) (20-40%) at appropriate conditions. In vivo infectivity test of incubated MPES of B. Oleracea fruits, leaves and medium with trypanosomes were done in mice. In vitro cytotoxicity of the test extracts at concentrations (1.56-100 µg/ml) were performed on Vero cells but without FCS. Both MPES of B. oleracea fruits and leaves demonstrated trypanocidal activity, which ranged from immobilization, reduction and to the killing of trypanosomes. At 500 µg/ml of MPES of B. oleracea fruits and leaves with trypanosomes undergoing incubation, there were marked reductions of trypanosomes (19.33±0.33) (15.33±0.33) in the corresponding ELISA plate wells. But at 1000 µg/ml of MPE of B. oleracea fruits, there was no complete killing of the trypanosomes (5.33±0.33) as to that of MPE of leaves where trypanosomes could not be detected at 7 h of incubation, which was statistical comparable to the standard drug, diminazine aceturate at concentration of 50 µg/ml at 4 h of incubation. Trypanosomes counts decreased in concentration and time –dependent manner with significant difference (P<0.05). In in vivo infectivity test, group of mice inoculated with contents of ELISA plate wells with apparently killed trypanosomes survived for more than 30 days. While, the other group of mice inoculated with contents of ELISA plate wells with reduced trypanosomes in the incubated medium died of parasitaemia. MPES of B. oleracea fruits, leaves and diminazine aceturate (Berenil) were cytotoxic to Vero cells at all concentrations except at 1.56, 1.56 and 6.25-1.56 µg/ml, respectively. There were moderate antitrypanosomal effects