Synthesis and biological evaluation of a novel series of aryl S,N-ketene acetals as antileishmanial agents.

A series of aryl S,N-ketene acetals 7(a-f) was synthesized and evaluated for their in vitro and in vivo antileishmanial activity against Leishmania donovani. All the 6 compounds exhibited significant in vitro activity against intracellular amastigotes of L. donovani with IC50 values ranging from 1.

Therapeutic switching in leishmania chemotherapy: a distinct approach towards unsatisfied treatment needs.

Current drugs for the treatment of visceral leishmaniasis are inadequate. No novel compound is in the pipeline. Since economic returns on developing a new drug for neglected disease, leishmaniasis is so low that therapeutic switching represents the only realistic strategy.

Enhancement in therapeutic efficacy of miltefosine in combination with synthetic bacterial lipopeptide, Pam3Cys against experimental Visceral Leishmaniasis.

Existing drugs for visceral leishmaniasis (VL) are partially effective, toxic, having high cost and long term treatment. Their efficacies are also compromised due to suppression of immune function associated during the course of infection. Combination therapy including a potential and safe immunostimulant with lower doses of effective drug has proven as a significant approach which is more effective than immunotherapy or drug therapy alone.

Augmentation of antileishmanial efficacy of miltefosine in combination with tuftsin against experimental visceral leishmaniasis.

Current drugs for the treatment of visceral leishmaniasis are inadequate, and their efficacies are also compromised due to suppression of immune function during the course of infection. Miltefosine is the only promising orally active antileishmanial drug, but due to its long half-life, there is risk of development of resistance. To overcome these problems, efforts are needed to develop combination therapy of miltefosine with effective immunostimulating agents where a decrease of parasitic burden and simultaneous enhancement of adaptive immunity can be achieved.

Effect of Pam3Cys induced protection on the therapeutic efficacy of miltefosine against experimental visceral leishmaniasis.

Prophylactic potential of synthetic bacterial lipopeptide and a TLR2 agonist, Pam3Cys was first evaluated against experimental visceral leishmaniasis in rodent model. After establishing the potential its effect on therapeutic efficacy of miltefosine was also studied. Pam3Cys showed 74.

Improved treatment of visceral leishmaniasis (kala-azar) by using combination of ketoconazole, miltefosine with an immunomodulator-Picroliv.

Visceral leishmaniasis (VL) caused by the parasite Leishmania donovani, is a potentially fatal disease. It is characterized by prolonged fever, enlarged spleen and liver, substantial weight loss and progressive anemia. Available drugs are toxic, costly and require prolonged treatment duration viz; 28 days of oral treatment with miltefosine, 30 days infusion with Amphotericin B and 21 days intramascular with paromomycin sulfate.

CpG oligodeoxynucleotide 2006 and miltefosine, a potential combination for treatment of experimental visceral leishmaniasis.

In view of the severe immunosuppression in visceral leishmaniasis (VL), a rational approach to effectively combat the parasitic scourge would be to enhance the immune status of the host. Use of CpG oligodeoxynucleotide (CpG-ODN) against leishmaniasis has previously been reported, especially as an immunomodulator and adjuvant with various immunogens. In the present study, experiments were carried out with BALB/c mice and hamsters infected with Leishmania donovani.

Design and synthesis of novel tetrahydronaphthyl azoles and related cyclohexyl azoles as antileishmanial agents.

A novel series of trans-2-aryloxy-1,2,3,4,-tetrahydronaphthyl azoles and related cyclohexyl azoles were synthesized and evaluated in vitro against Leishmania donovani. Compound 9 identified as most active analog with IC(50) value of 0.64 μg/mL and SI value of 34.

Antileishmanial efficacy of fluconazole and miltefosine in combination with an immunomodulator--picroliv.

The chemotherapy of visceral leishmaniasis (VL) has several limitations including resistance and toxicity of the existing drugs. Downregulation of immune system further aggravates the problems. To combat this situation, leishmanicidal efficacy of already marketed standard antifungal drug, fluconazole under the approach of "therapeutic switching" in combination with standard antileishmanial drug, miltefosine, and a potent immunomodulator agent, picroliv, were evaluated in hamsters infected with Leishmania donovani.

Immunomodulatory effect of picroliv on the efficacy of paromomycin and miltefosine in combination in experimental visceral leishmaniasis.

Combination therapy for the treatment of visceral leishmaniasis has increasingly been advocated as a way to increase treatment efficacy and tolerance, to reduce treatment duration and cost, and to limit the emergence of drug resistance. In the present work, we have adopted a rational approach, which can modulate the immune response to overcome the negative control systems and to boost the positive killing responses. This study was designed to investigate the immunomodulatory effect of picroliv (standardized fraction from the alcoholic extract of root and rhizome of Picrorhiza kurroa) on a combination of paromomycin and miltefosine using Leishmania donovani/hamster model.

CpG oligodeoxynucleotide augments the antileishmanial activity of miltefosine against experimental visceral leishmaniasis.

Objectives: To evaluate the combination of CpG oligodeoxynucleotide (CpG ODN) and miltefosine for the treatment of experimental visceral leishmaniasis (VL).

Methods: The experiments were carried out using BALB/c mice and hamsters, infected with Leishmania donovani. CpG ODN was administered at various doses by the intraperitoneal (ip) route.

Discovery of novel antileishmanial agents in an attempt to synthesize pentamidine-aplysinopsin hybrid molecule.

In an attempt to synthesize pentamidine-aplysinopsin hybrid molecule 25, a lead molecule 8 (containing Z-configured aplysinopsin moiety) was identified for antileishmanial activity. Optimization of lead 8 provided 24 (containing E-configured aplysinopsin) possessing 10 times more activity and 401-fold less toxicity than the drug pentamidine in cell based assays. Synthesis of 24 was possible, surprisingly, because of two innate reactivities of indole-3-carbaldehyde which provided it in diastereo- and regio-selectively pure form without recourse to the long reaction pathway.

Design and synthesis of novel substituted quinazoline derivatives as antileishmanial agents.

4-(Substituted-benzylidine)-2-substituted-5,6-dihydrobenzo[h]quinazoline (5a-p) and 4-(substituted-benzylidine)-2-substituted-3, 4, 5, 6-tetrahydrobenzo[h]quinazoline (6a-p) have been synthesized from 2-(substituted-benzylidine)tetralone-1(3a-d) and several substituted guanidine sulfates(4a-d).These compounds were tested for their in vitro antileishmanial activity. The compounds 6i, 6f, 6g show promising antileishmanial activity against Leishmania donovani.

Synthesis and biological evaluation of novel 4-(hetero) aryl-2-piperazino quinazolines as anti-leishmanial and anti-proliferative agents.

A series of new class of 4-(hetero)aryl-2-piperazino quinazolines were synthesized and assessed for in vitro activity against extracellular promastigotes and intracellular amastigotes of Leishmania donovani. Among the compounds evaluated, compound 4bb and 4cb showed the selectivity index (SI) value>8.03 and 4.

Synthesis and biological evaluation of indolyl bisphosphonates as anti-bone resorptive and anti-leishmanial agents.

A series of indole conjugated bisphosphonate derivatives have been synthesized and evaluated for their in vitro anti-bone resorptive activity using bone marrow osteoclast culture. Two bisphosphonates 23 and 24 significantly inhibited osteoclastogenesis, 23 showed inhibition at 10 and 100 pM which was lower than the concentration of standard drug alendronate, and 24 inhibited osteoclastogenesis at 100 nM which was comparable to alendronate. Two other compounds 13 and 14 also showed inhibition comparable to alendronate, but were cytotoxic in the osteoblast cells.

Influence of Brugia malayi life stages and BmAFII fraction on experimental Leishmania donovani infection in hamsters.

The influence of live Brugia malayi parasites and a Sephadex G-200 fraction of the adult parasite extract (BmAFII) on the progression of Leishmania donovani infection was studied. Inbred hamsters were first infected with B. malayi infective 3rd stage larvae (L3), adult worms or microfilariae (mf), and then with L.