LAUSR

Objective: The aim of this study was to evaluate the antileishmanial activity of new chalcon compounds. Methods: Biopsies from psitive lymph node aspiration were aseptically inoculated into vacutainers containing Novy-MacNealNicolle (NNN) medium. Cultures were incubated at 25 ◦C. Promastigotes were transferred into tissue culture flasks containing LIT media supplemented with 10% fetal calf serum (FCS), genatmycin and benzylpenicillin. Promastigote density was adjusted to 2 × 106 parasites/ml using LIT complete media. A volume of 100 l from parasite culture was transferred into 96-well microtiter plate. Various concentrations of chalcones solution were added (100 l) in triplicates. A negative control (DMSO), and positive control (amphotericin B) were treated similarly. The plates were incubated at 25 ◦C for 72 hours. Parasites were counted by using hemocytometer. To investigate the molecular mechanism of action of chalcones different leishmania donovani targets were downloaded from protein data bank. The tested compounds were docked into these targets using Sybyl and the corresponding scores were recorded. Results: Chalcones, at dose range 200–0.05 g/ml, showed 99.11 ± 1.19– 12.14 ± 2.77% promastigote inhibitory activity, and the positive control showed 94.79 ± 1.96 –18.29 ± 7.61% inhibitory activity at the same dose range. The IC50 values for chalcones rang from0.8 ± 0.09– 0.13 ± 0.05 g/ml and 0.24 ± 0.02 g/ml for amphotericin B. In silico study revealed that this activity could be mediated through Adeninephosphoribosyle transferase (Cscore6.21–4.72) inhibition for chalcon. Conclusion: Chalcone compounds showed promising activity against Leishmania donovani promastigotes when compared to amphotericin B.