Evaluation of the antileishmanial and cytotoxic effects of various extracts of garlic (Allium sativum) on Leishmania tropica

Cutaneous leishmaniasis (CL) is a major public health problem in tropical and subtropical countries worldwide. Treatment of CL by pentavalent antimony compounds remains a challenge because of limited efficacy, toxic side effects and drug resistance. In the present study, in vitro antileishmanial and cytotoxic activity of garlic extracts against promastigote forms of Leishmania tropica and murine macrophages was evaluated by colorimetric cell viability (MTT) assay. The results revealed that the methanolic and aqueous extracts of garlic were effective in inhibiting promastigote growth of L. tropica with IC₅₀ (50 % inhibitory concentrations) values 12.3 and 19.2 µg/ml, respectively. In addition, methanolic and aqueous extracts of garlic showed low cytotoxicity against murine macrophages with CC₅₀ (cytotoxicity concentration for 50 % of cells) values 291.4 and 348.2 µg/ml, respectively. Findings of present study were the first step in the search for new antileishmanial drugs. However, further works are required to evaluate exact effect of these extracts in volunteer human subjects.