Abstract

Infections due to protozoa of the genus of Leishmania are responsible for a significant burden of disease, especially in the developing countries. Furthermore, the incidence of leishmaniasis continues to rise due to lack of a vaccine. Drugs commonly used for the treatment of the disease show varying level of effectiveness and also have associated side effects. There is therefore, a need to develop newer drug therapies. The aim of our study was to assess antiprotozoal activity of the ethanolic and methanolic extracts of leaf of Satureja khuzestanica against Leishmania major promastigotes. In this study, the in vitro leishmanicidal effects of Satureja khuzestanica leaves on L. major were evaluated. The ethanolic and methanolic extracts were prepared by maceration method. The extracts were dried and re-dissolved in dimethyl sulfoxide (DMSO) 1% solvent. L. major cells were then tested with serial concentrations (0.07 to 19.9 mg ml-1) of the extracts. The ethanolic and methanolic extracts of leaf of Satureja khuzestanica inhibited the parasite after 24 h incubation against L. major promastigotes, which gave IC_{100 =} 2.4 and 4.8 mg ml^-1 and IC₅₀ = 0.3 and 0.6 mg ml^-1, respectively. Glucantime as positive control inhibited the growth of L. major promastigotes with IC_{50 =} 10.6 mg ml^-1. These data reveal that Satureja khuzestanica leaf extracts contain active compounds, which could serve as an alternative agent in the control of cutaneous leishmaniasis. Further studies would therefore be needed to see its in vivo clinical response and associated toxicities.

Key words: Leishmania, Satureja khuzestanica, medicinal plant, promastigote.