RESUMEN
The main therapeutic compounds available against Leishmaniasis disease is pentavalent antimonyfcg compounds i.e. Glucantime and Pentostam. New antileishmanial compound is needed due to the emerge of drug-resistant leishmania agents in recent years. In the present study the antileishmanial activity of new 1, 3, 4 thiadiazole derivatives were evaluated. Promastigote stages of the parasites were cultured in RPM1-1640 containing 10% FBS, 100 lU/ml penicillin and 100 micro g/ml streptomycin. Mouse peritoneal exudate macrophages [MPEM] isolated from the peritoneal cavity of BALB/c mice were used and the macrophages were counted and the cell suspension was adjusted to 5X10[5] cell/ml. Macrophage monolayers in 8-well chamber slides were infected with stationary phase promastigote, at a 5:1 parasite/cell proportion and incubated at 37°C and 5% CO[2]. Serial dilution of thiadiazole compounds and tartar emetic as the control was added to the slide chambers and parasite survival index [PSI] was measured after 5 days. The Thiazolyl blue reduction [MTT test] was used to determine the antileishmanial effect of the compounds on extra celluto forms of the parasite and after 72 h. The CD's were read by 96-well scanner and IC[50] were calculated. Two thiadiazole compounds showed 6-67% antileishmanial activity in 4.6 micro g/ml concentration against intracellular forms of the parasites and also in MTT assay IC[50] of 3.6 -7.6 micro g/ml was determined. Due to high antileishmanial activity of some compounds, further studies on structure and activity of these compounds and new highly active derivatives is expected