Antileishmanial activity of Artemisia aucheri, Ferula asa-foetid and Gossypium hirsutum extracts on Leishmania major promastigotes in vitro

Leishmaniasis is a complex disease with a broad spectrum of clinical features, usually divided into cutaneous leishmaniasis [CL], muco-cutaneous leishmaniasis [MCL], and visceral leishmaniasis [VL]. Plant extracts or plant-derived compounds are likely to provide a valuable source of new medicinal agents. In endemic countries, a number of traditional plants are commonly used to treat infectious conditions. Advances in the research of natural products for the treatment of leishmaniasis have been recently reviewed. To evaluate, anti-Leishmanial activity of three plant extracts on Leishmania major promastigotes as compared to a trivalent antimonial compound [tartar emetic], in vitro. promastigote stages of L.major [MRHO/IR/75/ER] were transferred to RPMI-1640 medium, supplemented with 10% fetal calf serum [PCS] and antibiotics then grown at 25 +/- 2°C. The biological activity of plant extracts in comparison to potassium antimonyl tartrate [Sb[lll]] on L.major promastigotes were assessed by using a MTT assay. The optical density [OD] due to cleavage of the tetrazolium salt MTT [3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide] into a colored product formazan by the parasite was measured by ELISA reader. The IC50 values [50% inhibitory concentrations] were determined, accordingly. All experiments were repeated in duplicate plant extracts and tartar emetic inhibited the growth of promastigote forms of L.major in vitro after 72 hour of incubation and drug control had a 50% inhibitory concentration [IC50] of 4.7 pg/ml, and microC50 values of plant extracts Artemisia aucheri, Ferula asa-foetida and Gossypium hirsutum were 7.5, 5.9 and 3.6 microg/ml, respectively. Although Gossypium hirsutum was more effective than others, but all extracts had profound effect on promastigotes of L.major. Plant extracts including Artemisia aucheri, Ferula asa-foetida and Gossypium hirsutum have anti-leishmanial effects in vitro. Further works are required to evaluate the exact effect of these extracts on Leishmania species in animal models