iparum was used for apicoplast immunofluorescence. The immunofluorescence protocol was similar to that reported with a few minor changes. A solution of 4% paraformaldehyde and 0.1% Triton X-100 was used for fixation and permeabilisation. MOWIOLH 4-88 was used as an antifade agent. Images were taken using a Nikon Eclipse 90i microscope. Results 212141-51-0 web curcumin inhibits growth of P. falciparum cultures in vitro Previous reports have demonstrated the anti-malaria potential of curcumin with IC50 values ranging from 5 to 30 mM. In order to determine the working concentration for 3D7 parasites, an in vitro susceptibility assay against P. falciparum was performed. Molecular docking The crystal structure of P. falciparum tubulin has not yet been determined, so individual monomers of alpha and beta-tubulin were modeled based on the principle of homology modeling by SWISS-MODEL server. Structures of both the monomers were validated using ANOLEA program in the COLORADO 3D server. The dimeric form of parasite tubulin was constructed by assembling these two monomers using the protein-protein docking server HEX. The crystal structure of curcumin has been published. It has been reported that curcumin, in its solid state, exists as a mixture of its keto and enol tautomeric forms. 3D structures of the diketo and enol form were downloaded from PUBCHEM. The PUBCHEM structures 9726632 were in SDF format which were converted to PDB using the NCI Online SMILES Translator. Molecular docking of the protein dimer with curcumin and colchicine was performed using AUTODOCK v4.0. Clusters were generated with an RMS tolerance of 2 angstrom. The Lamarckian Genetic Algorithm was used and 250 GA runs were performed for each docking with 1500000 energy evaluations per run. Docked poses were rendered with PyMOL 31.76% 0 53.57% 0 Curcumin 30.76% 7.14% 26.66% 0 5 Plasmodium falciparum Microtubules and Curcumin 6 Plasmodium falciparum Microtubules and Curcumin Curcumin leads to morphological alterations in the parasite Previously, treatment with microtubule inhibitors has been shown to lead to abnormal morphology of the parasites in vitro. To analyze the gross effects of curcumin on parasite morphology, 5 mM curcumin treated cultures were compared with untreated cultures. before infecting with P. falciparum. If this hypothesis were true, parasite growth should be lower in cultures with pre-treated erythrocytes than in cultures containing non pre-treated erythrocytes. Effects of curcumin on P. falciparum microtubule structures Curcumin is not hemolytic The hemolytic potential of curcumin was determined by incubating isolated erythrocytes with different concentrations of curcumin. Compared to the positive control, all curcumin concentrations showed negligible hemolytic activity, and all were within the permissible limit of 5% for hemolysis. This suggests that the anti-plasmodial activity of curcumin is not a result of a significant hemolytic effect of the compound. Curcumin does not modify erythrocyte properties 8114006 required for growth of P. falciparum To address the hypothesis that curcumin alters the properties of host erythrocytes required for adequate growth of the parasites, we pre-incubated erythrocytes with 5 mM curcumin for 48 hours Plasmodium falciparum Microtubules and Curcumin 8 Plasmodium falciparum Microtubules and Curcumin in the appearance of thick rod-like microtubules whereas vinblastine treatment has the converse effect and results in diffuse tubulin staining in P. falciparum.