Macrophage and Leishmania: an unacceptable coexistence.

Research over the past year has revealed several significant and interesting advances in the biology of macrophage, key cells responsible in body's host defense against invading pathogens and in immune responses. Perturbation of macrophage surface with different bacterial pathogens leads to activate general signal transduction pathways of macrophages, including activation of NADPH oxidase, nitric oxide synthase, and so on. However, in this review, the results of macrophage interactions only with Leishmania parasites, which harbors the host macrophages, are discussed.

Targeted delivery of arjunglucoside I using surface hydrophilic and hydrophobic nanocarriers to combat experimental leishmaniasis.

The purpose of the present study was to investigate the therapeutic efficacy of the indigenous drug arjunglucoside I (AG) against in vivo models of experimental leishmaniasis by incorporating it in surface hydrophilic co-polymeric nanogel particles of size less than 100 nm diameter and to compare its efficacy with that of the free drug as well as the drug encapsulated in hydrophobic poly-dl-lactide (PLA) nanoparticles. The drug AG, having glucose at the terminal end of the glycosidic chain, was isolated from an indigenous source. Drug-incorporated ultra-low-sized nanogels (approximately 90 nm in diameter) composed of cross-linked random co-polymer of N-isopropylacrylamide (NIPAAM) and N-vinyl pyrrolidone(VP) were prepared, characterized and used as delivery vehicles to combat experimental leishmaniasis in hamster models.

Macrophage specific drug delivery in experimental leishmaniasis.

Macrophage-specific delivery systems are the subject of much interest nowadays, because of the fact that macrophages act as host cells for many parasites and bacteria, which give rise to outbreak of so many deadly diseases(eg. leishmaniasis, tuberculosis etc.) in humans.

Harmine: evaluation of its antileishmanial properties in various vesicular delivery systems.

Harmine, a beta-carboline amine alkaloid isolated from Peganum harmala, was tested for its antileishmanial properties both in vitro and in vivo. In vitro antileishmanial activity of harmine was encouraging and prompted us to confirm the activity in vivo in hamster models. Harmine was tested both in free form and in different vesicular forms viz.

The effect of beta-tubulin-specific antisense oligonucleotide encapsulated in different cationic liposomes on the suppression [correction of supression] of intracellular L. donovani parasites in vitro.

An antisense oligonucleotide (20 mer) targeted to the parasite beta-tubulin gene and encapsulated in cationic liposomes, was used to test its antileishmanial activity in vitro. Cationic liposomes containing dioleyl trimethyl ammonium propane (DOTAP) were found to have higher antileishmanial activity (88% at 4 microM oligonucleotide) compared to two other liposomes with stearyl amine (SA) and cetyl trimethyl ammonium bromide (CTAB) as cations. Dot-blot experiments were performed to analyse the expression of beta-tubulin mRNA using beta-tubulin-specific radiolabelled DNA as a probe.