In vitro and in vivo therapeutic activity of Parthenium hysterophorus against Trypanosoma evansi.

Crude 50% ethanolic extract of P. hysterophorus flowers exhibited trypanocidal activity in vitro at all the four concentrations tested i.e. 5, 50, 500 and 1000 micrograms/ml. In vivo trial revealed that the extract exerted antitrypanosomal effect at doses of 100 and 300 mg/kg body wt, i.p. as evidenced by significantly reduced (P < 0.01) mean parasitaemia on days 3, 4, 5 and 6 when compared with untreated control group. Further at 100 and 300 mg/kg, body wt doses, the survival period was significantly (P < 0.05) prolonged as compared to control group. The extract was, however, found toxic to the animals at 1000 mg/kg dose.