Evaluation of in vitro antileishmanial activity of curcumin and its derivatives "gallium curcumin, indium curcumin and diacethyle curcumin".

BACKGROUND AND OBJECTIVES

Leishmania parasites are intracellular haemoflagellates that infect macrophages of the skin and viscera to produce diseases in their vertebrates hosts. Antileishmania therapy is based on pentavalent antimony compounds which toxicity of these agents and the persistence of side effects are severe. Curcumin was identified to be responsible for most of the biological effects of turmeric. Turmeric plant extracts (curcumin and other derivatives) have anti-inflammatory, anti-arthritic, antioxidant, anti-microbial, antileishmanial, hepato protective, anti-cancer, anti-ulcer and anti diabetic activity.

MATERIALS AND METHODS

Stock solutions of curcumin, indium curcumin, diacetylcurcumin and Gallium curcumin were made up in DMSO. From the each stock solution serial dilutions were made with phosphate buffered saline and 100 µl of each prepared concentration was added to each well of 96-well micro plate. All tests were performed in triplicate. Negative control only received RPMI-1640 medium with a parasite density of 106 parasites /ml and the positive control contained varying concentrations of standard antileishmania compound, Amphotericine B. MTT solution was prepared as 5 mg/ml in RPMI-1640 and 20 µl of this concentration was added to each well. Antileishmania effects of test agents and control were evaluated by using the MTT assay.

RESULTS

Mean growth inhibition of triplicate for each concentration of test agents and control were measured. The IC50 values for curcumin, gallium curcumin [ga (CUR) 3], indium curcumin [in (CUR)3], Diacethyle Curcumin (DAC ) and Amphotericine B were 38 µg/ml, 32 µg/ml, 26 µg/ml, 52 µg/ml and 20 µg/ml respectively. Indium curcumin [in (CUR) 3] with IC50 values of 26 µg/ml was more effective than other three test agents against Leishmania. Mean growth inhibition of triplicate for Amphotericine B as control drug, was 20 µg/ml.

CONCLUSIONS

Indium curcumin and Gallium curcumin complex showed more antileishmanial activity than curcumin and diacetylcurcumin and could be suitable candidates for further investigations.