Antiprotozoal Activity Of Some Egyptian Plants

Abstract

Trypanosomiasis and leishmaniasis are neglected tropical diseases caused by the parasites Trypanosoma and Leishmania, respectively. The emergence of drug-resistance, high toxicity which can result in unpleasant side effects and the need for cost-effective drugs in combating these diseases gives rise to this study [1 – 3]. The antitrypanosomal activity of methanol extracts of 17 Egyptian medicinal plants belonging to 10 families was determined in vitro against trypamastogotes forms of T. brucei. Out of these extracts compound 7 showed good activity (IC50 values < or = 8.18 µg/ml), 5 revealed a moderate activity (IC50 values between 12.13 and 8.72 µg/ml) and others (4) did not show any activity (IC50 values > 20 µg/ml). The extract of Asteriscus hierochuntica was the most promising one showing IC50 and IC90 values were 1.18 and 1.89 (µg/ml), respectively. This is the first report of in vitro antitrypanosomal activity of these plants. The high activity of the extract of A. hierochuntica makes it a promising candidate with others, for the isolation of compounds which could develop into new lead for drug against human African trypanosomiasis. The extracts were also tested in vitro against Leishmania donovani (promastigotes, axenic amastigotes and intracellular amastigotes in THP1 cells) using standard procedures [4]. Only three plant extracts showed selective antileishmanial activity against intercellular amastigotes in THP1 cells; extract of Crotalaria aegyptiaca showed the most potent activity of IC50 value 6.48 µg/ml whereas Pergullaria tommentosa and Panicum turgidum exhibited activity with IC50 (µmg/ml) values of 11.22 and 13.68 respectively. These can possibly be promising candidates to the antileishmanial drug discovery.