Novel coumarin-isatin hybrids as potent antileishmanial agents: Synthesis, in silico and in vitro evaluations.

Leishmaniasis being one of the six major tropical diseases that affects nearly 0.7-1.3 million people annually, has so far limited and high toxic therapeutic options. Herein, we report the synthesis, in silico, and in vitro evaluations of novel coumarin-incorporated isatin hydrazones (Spf-1 - Spf-10) as highly potent and safe antileishmanial agents. Molecular docking was initially carried out to decipher the binding confirmation of lead molecules towards the active cavity of the target protein (Leishmanolysin gp63) of Leishmania tropica. Among all the docked compounds, only Spf-6, Spf-8, and Spf-10 showed high binding affinities due to a pattern of strong conventional hydrogen bonds and hydrophobic π-interactions. The molecular dynamics simulations showed the stable pattern of such bonding and structure-based confirmation with a time scale of 50 ns towards the top compound (Spf-10) and protein. These analyses affirmed the high stability of the system. Three out of ten compounds evaluated for their antileishmanial activity against Leishmania tropica promastigotes and amastigotes were found to be active at micromolar concentrations (IC50 range 0.1-4.13 µmol/L), and most importantly, they were also found to be highly biocompatible when screened for their toxicity in human erythrocytes.

Synthesis and computational studies of highly selective inhibitors of human recombinant tissue non-specific alkaline phosphatase (h-TNAP): A therapeutic target against vascular calcification.

In this study, we have discovered small druglike molecules as selective inhibitors of human tissue-nonspecific alkaline phosphatase (h-TNAP), an enzyme critical for the regulation of extracellular matrix calcification. The upregulation of h-TNAP is associated with various pathologies particularly the vascular calcification (VC). Selective inhibition of h-TNAP over h-NPP1 may serve as a useful therapeutic strategy against vascular calcification. A series of novel triazolyl pyrazole derivatives (10a-y) in which thiol bearing triazole moiety as the zinc binding functional group was introduced to a pyrazole based pharmacophore was synthesized and evaluated as potent and selective inhibitors of h-TNAP over h-NPP1. The biological screening against h-TNAP, h-IAP, h-NPP1 and h-NPP3 showed that many of the synthesized compounds are selective inhibitors of TNAP. Particularly, the compounds 10a-h, 10j, 10m-q, 10u, 10w and 10x displayed high potency and complete selectivity towards h-TNAP over h-NPP1. Compound 10q emerged as a highly potent inhibitor (IC50 = 0.16 µM or 160 nM) against h-TNAP with 127-fold increased inhibition compared to levamisole. On the other hand, compound 10e was found to be most selective inhibitor against the tested APs and NPPs (IC50 = 1.59 ± 0.36 µM). Binding sites architecture analysis, molecular-docking and molecular dynamics simulations (MDS), revealed the basis for h-TNAP and h-IAP ligand selectivity as well as selectivity towards h-TNAP over h-NPP1. These newly discovered inhibitors are believed to represent valuable lead structures to further streamline the generation of candidate compounds to target VC.

Self-Nanoemulsifying Drug Delivery System (SNEDDS) for Improved Oral Bioavailability of Chlorpromazine: In Vitro and In Vivo Evaluation.

Background and Objectives: Lipid-based self-nanoemulsifying drug delivery systems (SNEDDS) have resurged the eminence of nanoemulsions by modest adjustments and offer many valuable opportunities in drug delivery. Chlorpromazine, an antipsychotic agent with poor aqueous solubility-with extensive first-pass metabolism-can be a suitable candidate for the development of SNEDDS. The current study was designed to develop triglyceride-based SNEDDS of chlorpromazine to achieve improved solubility, stability, and oral bioavailability. Materials and Methods: Fifteen SNEDDS formulations of each short, medium, and long chain, triglycerides were synthesized and characterized to achieve optimized formulation. The optimized formulation was characterized for several in vitro and in vivo parameters. Results: Particle size, zeta potential, and drug loading of the optimized SNEDDS (LCT14) were found to be 178 ± 16, -21.4, and 85.5%, respectively. Long chain triglyceride (LCT14) showed a 1.5-fold increased elimination half-life (p < 0.01), up to 6-fold increased oral bioavailability, and 1.7-fold decreased plasma clearance rate (p < 0.01) compared to a drug suspension. Conclusion: The findings suggest that SNEDDS based on long-chain triglycerides (LCT14) formulations seem to be a promising alternative for improving the oral bioavailability of chlorpromazine.

Antileishmanial, DNA Interaction, and Docking Studies of Some Ferrocene-Based Heteroleptic Pentavalent Antimonials.

A series of ferrocenyl pentavalent antimonials (1-8) were synthesized and characterized by elemental analysis, FT-IR, and multinuclear ((1) H and (13) C) NMR spectroscopy. These antimonials were evaluated for their antileishmanial potential against Leishmania tropica KWH23, and by biocompatibility and membrane permeability assays. Moreover, mechanistic studies were carried out, mediated by DNA targeting followed by computational docking of ferrocenyl antimonials against the leishmanial trypanothione reductase enzyme. It was observed that the antimonials 1-8 were 390-fold more efficacious (IC50 ) as compared with the standard antimonial drug used. Cytotoxicity results showed that these antimonials are highly active even at low concentrations and are biocompatible with human macrophages. Antimonials 1-8 exhibited extensive intercalation with DNA and, furthermore, docking interactions highlighted the potential interactive binding of the anitimonials within the trypanothione reductase active site, with van der Waals interactions contributing significantly to the process. Hence, it is suggested that the reported antimonials demonstrate high efficacy, less toxicity, and target multiple sites of the Leishmania parasite.

UGT1A1 gene mutations in Pakistani children suffering from inherited nonhemolytic unconjugated hyperbilirubinemias.

Two inherited unconjugated hyperbilirubinemias, Crigler-Najjar syndrome and Gilbert syndrome, arise due to deficiency of UGT1A1 enzyme activity. Crigler-Najjar syndrome type 1 (CN1) lies at the extreme severe end of the spectrum of UGT1A1 activity characterized by complete absence, followed by the less severe Crigler-Najjar syndrome type 2 (CN2). Gilbert syndrome is the mild form having only partial loss of UGT1A1 activity. The present study aimed to identify molecular genetic defects underlying unconjugated hyperbilirubinemias in children from six consanguineous Pakistani families. The patients were clinically diagnosed by exclusion of other unconjugated hyperbilirubinemias. Differential diagnosis of CN1 and CN2 was made on the basis of patient's response to phenobarbitone. The promoter region, coding exons, and adjacent splice sites of the UGT1A1 gene were PCR amplified from genomic DNA of all patients and their families, and were sequenced. DNA sequence analysis identified five different homozygous mutations: two novel missense mutations p.Y230C (proband A) and p.D36N (proband B), a 4-bp insertion c.622-625dupCAGC/p.Q208QfsX50 (probands C and E), a nonsense mutation p.R341X (proband D), and a TA insertion A(TA)7TAA in the promoter region (proband F). The present study extends the spectrum of UGT1A1 gene mutations and may be helpful in the diagnosis of Crigler-Najjar syndrome and Gilbert syndrome.

A homozygous nonsense mutation in the human desmocollin-3 (DSC3) gene underlies hereditary hypotrichosis and recurrent skin vesicles.

Desmosomes are the major players in epidermis and cardiac muscles and contribute to intercellular binding and maintenance of tissue integrity. Two important constituents of desmosomes are transmembrane cadherins named desmogleins and desmocollins. The critical role of these desmosomal proteins in epithelial integrity has been illustrated by their disruption in mouse models and human diseases. In the present study, we have investigated a large family from Afghanistan in which four individuals are affected with hereditary hypotrichosis and the appearance of recurrent skin vesicle formation. All four affected individuals showed sparse and fragile hair on scalp, as well as absent eyebrows and eyelashes. Vesicles filled with thin, watery fluid were observed on the affected individuals' scalps and on most of the skin covering their bodies. A scalp-skin biopsy of an affected individual showed mild hair-follicle plugging. Candidate-gene-based homozygosity linkage mapping assigned the disease locus to 8.30 cM (8.51 Mbp) on chromosome 18q12.1. A maximum multipoint LOD score of 3.30 (theta = 0.00) was obtained at marker D18S877. Sequence analysis of four desmoglein and three desmocollin genes, contained within the linkage interval, revealed a homozygous nonsense mutation (c.2129T>G [p.Leu710X]) in exon-14 of the desmocollin-3 (DSC3) gene.

Synthesis of N-(1-methyl-1H-indol-3-yl)methyleneamines and 3,3-diaryl-4-(1-methyl-1H-indol-3-yl)azetidin-2-ones as potential antileishmanial agents.

A series of N-(1-methyl-1H-indol-3-yl)methyleneamines and eight new 3,3-diaryl-4-(1-methyl-1H-indol-3-yl)azetidin-2-ones have been synthesized and screened for their antileishmanial activity against Leishmania major. 3,3-Diaryl-4-(1-methyl-1H-indol-3-yl)azetidin-2-ones have been synthesized by the Staudinger's ketene-imine cycloaddition employing two 2-diazo-1,2-diarylethanones as the precursors of diarylketenes. A marked improvement in anti-parasitic activity is observed by transformation of the methyleneamines to azetidin-2-ones in seven out of eight compounds. Two compounds displayed antileishmanial activity comparable to that of the clinically used antileshmanial drug, amphotericine B.

Impact of an indigenously produced multi-enzyme complex from Bacillus subtilis KT004404 on growth and blood parameters in broiler chicken.

A 42-days experiment was conducted on a day old birds (n = 400) to evaluate the effect of enzyme supplements in feed on the growth, blood parameters, phosphorous content in bones, and nitrogen retention. Different treatments included: control (C) without enzyme supplement, while the other three groups included enzyme mixture T1 and T2 with two commercially available enzyme mix, and T3 with indigenously produced multi-enzyme complex from Bacillus subtilis KT004404. Birds that were fed with indigenously produced multi-enzyme complex showed significant weight gain as compared to other groups. The total feed intake of the birds fed with enzyme supplements was higher than the birds in the control group. The feed conversion ratio was significantly improved (p < 0.05) in treatment groups (T1, T2, T3) as compared to the control. The blood parameters which were analyzed included uric acid, triglycerides, total cholesterol, and serum proteins i.e. globulin and albumin. Birds fed with the enzyme in the group T1, T2 and T3 exhibited higher (p < 0.05) body weight gain. Tibia ash content was significantly higher (p < 0.05) in T1, T2, and T3 as compared to the control. The results of the current study indicate that supplementing poultry feed with the exogenous multi-enzyme produced from Bacillus subtilis KT004404 improved the growth of the birds, feed utilization, and exhibited beneficial effects on the blood parameters, phosphorous and nitrogen retention in broiler chicken.

Isolation and Characterization of Leishmanial Adenine Aminohydrolase as a Drug Target.

BACKGROUND: Search for new drug targets is becoming imperative these days, given that marketed chemotherapeutic drugs have lost their efficacy against harmful agents because of adaptability to climatic changes and co-evolving vectors to new hosts. In the wake of such a challenge, the prominence of biochemical studies is increasing by way of exploring selective enzymes and investigating their structural and functional properties through biochemical kinetic parameter Km for the application of IC50 using designed drugs. Recently, discovered Adenine Aminohydrolase (EC 3.5.4.2) in Leishmania has been found to be absent in mammalian purine salvage pathway and thus considered as a promising drug target against infectious agents. OBJECTIVES: The objective of this study is to isolate and characterize AAH by learning its kinetic mode of action using preferred substrate Adenine and additives estimated through expected product formation Hypoxanthine. Bioassays designed to measure exact Enzyme kinetic parameter Km value through establishing hyperbolic curve of an enzyme reaction with the use of exact values of cellular quantities for IC50 application under experimental conditions devised by presteady state approach for SSA validity. METHODS: Following saturation kinetic, the plot of hyperbolic equilibrium curve developed using initial rates of product formation as a function of (Si) through forward shift under circumstance dG0 the system allows product and reactant favored reactions in relation to (Ef) ≈ [E0 = KM] until complete saturation and estimates Km and Vmax of enzyme system under applied conditions. M-M equation used to assess experimental initial rate data for estimation of Km on excel using Solver and nonlinear least square coefficient correlation "R2" using logarithmic equation for nonlinear curve assessment. RESULTS: UV/Vis spectrophotometer selectively analyzed reacting components confirming Enzyme characteristic reaction constant Km equal toi15. 0 ± 2 µ mol acquired from the Hyperbolic curve developed through the use of exact (Si) ranges at selected parameter Km and Vmax. The curve assessed by Michaelis Menten equation provides Km value=14.99 µmol and non-linear least square coefficient correlation "R2" value equal to 0.9895, along with that optimized lysis buffer formulation. In the docked complexes, the interactive amino acids identified were MSE441, ALA 364, GLN363, MSE518, VAL362, GLY517, ASP538, ALA445, TYR521, and TYR444. 2D interactions revealed hydrophobic and alkyl interactions at the noncompetitive binding site of the enzyme and therefore recommended as potential inhibitors against 3ICS protein. CONCLUSION: This study encourages biochemical analysis of the novel enzymes with the use of presteady state rationale in association with the computational tools as an effective way of designing drugs in a short time against selective enzymes to meet the current challenge efficiently.

First report on the molecular prevalence of Mycoplasma capricolum subspecies capripneumoniae (Mccp) in goats the cause of contagious caprine pleuropneumonia (CCPP) in Balochistan province of Pakistan.

Contagious caprine pleuropneumonia (CCPP) caused by Mycoplasma capricolum subspecies capripneumoniae (Mccp) is a disease of goats which causes high morbidity and mortality and is reported in many countries of the world. There are probably no reports on the molecular prevalence of Mccp, Mycoplasma capricolum subsp. capricolum (Mcc) and Mycoplasma putrefaciens (Mp) in Balochistan and any other part of Pakistan. Thirty goats (n = 30) with marked respiratory symptoms were selected and procured from forty goat flocks in Pishin district of Balochistan in 2008. The genomic deoxyribonucleic acid (DNA) from the lung samples (n = 30) of the slaughtered goats was purified and subjected to polymerase chain reaction (PCR) assays for the presence of Mycoplasma mycoides cluster members and Mp. The PCR-RFLP (restriction fragment length polymorphism) was also used to further confirm the Mccp. Of the thirty lung samples 17 (56.67%) were positive for the molecular prevalence of Mcc, Mccp and Mp. In total the molecular prevalence was observed as 17.65% for Mccp (n = 3), 70.59% for Mcc (n = 12) and 11.76% for Mp (n = 2). The RFLP profile has also validated the PCR results of Mccp by yielding two bands of 190 and 126 bp. The results of PCR-RFLP coupled with the presence of fibrinous pleuropneumonia and pleurisy during postmortem of goats (n = 3) strongly indicated the prevalence of CCPP in this part of world. Moreover the prevalence of Mcc and Mp is also alarming in the study area. We report for the very first time the molecular prevalence of Mcc, Mccp, and Mp in the lung tissues of goats in the Pishin district of Balochistan, Pakistan.

Antispasmodic and vasodilator activities of Morinda citrifolia root extract are mediated through blockade of voltage dependent calcium channels.

BACKGROUND: Morinda citrifolia (Noni) is an edible plant with wide range of medicinal uses. It occurs exclusively in tropical climate zone from India through Southeast Asia and Australia to Eastern Polynesia and Hawaii. The objective of this study was to explore the possible mode(s) of action for its antispasmodic, vasodilator and cardio-suppressant effects to rationalize its medicinal use in gut and cardiovascular disorders. METHODS: Isolated tissue preparations such as, rabbit jejunum, rat and rabbit aorta and guinea pig atria were used to test the antispasmodic and cardiovascular relaxant effects and the possible mode of action(s) of the 70% aqueous-ethanolic extract of Morinda citrifolia roots (Mc.Cr). RESULTS: The Mc.Cr produced a concentration-dependent relaxation of spontaneous and high K(+) induced contractions in isolated rabbit jejunum preparations. It also caused right ward shift in the concentration response curves of Ca(++), similar to that of verapamil. In guinea-pig right atria, Mc.Cr caused inhibition of both atrial force and rate of spontaneous contractions. In rabbit thoracic aortic preparations, Mc.Cr also suppressed contractions induced by phenylephrine (1.0 µM) in normal- Ca(++) and Ca(++)-free kreb solutions and by high K(+), similar to that of verapamil. In rat thoracic aortic preparations, Mc.Cr also relaxed the phenylephrine (1.0 µM)-induced contractions. The vasodilatory responses were not altered in the presence of L-NAME (0.1 mM) or atropine (1.0 µM) and removal of endothelium. CONCLUSIONS: These results suggest that the spasmolytic and vasodilator effects of Mc.Cr root extract are mediated possibly through blockade of voltage-dependent calcium channels and release of intracellular calcium, which may explain the medicinal use of Morinda citrifolia in diarrhea and hypertension. However, more detailed studies are required to assess the safety and efficacy of this plant.

Antileishmanial, antimicrobial and antifungal activities of some new aryl azomethines.

A series of eighteen azomethines has been synthesized by the reaction of appropriate primary aromatic amines with aryl and/or heteroaryl carboxaldehydes. The synthesized azomethines have been evaluated for their in vitro antileishmanial, antibacterial and antifungal activities. The results revealed some antifungal activity of most of the synthesized compounds, whereas the antileishmaniasis activity results highlighted that all synthesized azomethines inhibited parasite growth and most of them showed highly potent action towards Leishmania major promastigotes. No remarkable bactericidal activities were observed.

Reactive oxygen species generating photosynthesized ferromagnetic iron oxide nanorods as promising antileishmanial agent.

Aim: To investigate the photodynamic therapeutic potential of ferromagnetic iron oxide nanorods (FIONs), using Trigonella foenum-graecum as a reducing agent, against Leishmania tropica. Materials & methods: FIONs were characterized using ultraviolet visible spectroscopy, x-ray diffraction and scanning electron microscopy. Results: FIONs showed excellent activity against L. tropica promastigotes and amastigotes (IC50 0.036 ± 0.003 and 0.072 ± 0.001 µg/ml, respectively) upon 15 min pre-incubation light-emitting diode light (84 lm/W) exposure, resulting in reactive oxygen species generation and induction of cell death via apoptosis. FIONs were found to be highly biocompatible with human erythrocytes (LD50 779 ± 21 µg/ml) and significantly selective (selectivity index >1000) against murine peritoneal macrophages (CC50 102.7 ± 2.9 µg/ml). Conclusion: Due to their noteworthy in vitro antileishmanial properties, FIONs should be further investigated in an in vivo model of the disease.

Quantitation of the cancer marker LASA using immobilized enzymes in a semiautomated system.

Cancer patients are found to have elevated serum levels of lipid-associated sialic acid (LASA). LASA measurement provides a valuable test for the diagnosis of human cancer. The currently used measurement methods are tedious and nonselective. Here we report a method based on immobilized enzyme minicolumns in a flow system for the analysis of this clinically important analyte. Three enzymes comprising two minicolumns are introduced online and the analyte in a precisely injected volume of 20 microL is made to pass through these immobilized enzyme columns. The final product of the reaction is detected amperometrically. Neuraminidase and NANA-aldolase are coimmobilized on controlled pore glass, followed by a column of pyruvate oxidase. The method was applied to the quantitation of LASA in the sera of normal individuals and patients with cancer of the esophagus. We observed no loss of activity of the immobilized enzymes after analyzing about 300 samples. The sample throughput was 30 samples per hour.

Mannosylated thiolated paromomycin-loaded PLGA nanoparticles for the oral therapy of visceral leishmaniasis.

AIM: The present study evaluates the efficacy of paromomycin (PM)-loaded mannosylated thiomeric nanoparticles for the targeted delivery to pathological organs for the oral therapy of visceral leishmaniasis. MATERIALS & METHODS: Mannosylated thiolated chitosan (MTC)-coated PM-loaded PLGA nanoparticles (MTC-PLGA-PM) were synthesized and evaluated for morphology, drug release, permeation enhancing and antileishmanial potential. RESULTS: MTC-PLGA-PM were spherical in shape with a size of 391.24 ± 6.91 nm and an encapsulation efficiency of 67.16 ± 14%. Ex vivo permeation indicated 12.73-fold higher permeation of PM with MTC-PLGA-PM against the free PM. Flow cytometry indicated enhanced macrophage uptake and parasite killing in Leishmania donovani infected macrophage model. In vitro antileishmanial activity indicated 36-fold lower IC50 for MTC-PLGA-PM as compared with PM. The in vivo studies indicated 3.6-fold reduced parasitic burden in the L. donovani infected BALB/c mice model. CONCLUSION: The results encouraged the concept of MTC-PLGA-PM nanoparticles as promising strategy for visceral leishmaniasis.

Novel mutations in G protein-coupled receptor gene (P2RY5) in families with autosomal recessive hypotrichosis (LAH3).

Autosomal recessive hypotrichosis (LAH3) is a rare hair disorder characterized by sparse hair on scalp and the rest of the body of affected individuals. Recently mutations in a G protein-coupled receptor gene, P2RY5, located at LAH3 locus, have been reported in several families with autosomal recessive hypotrichosis simplex and woolly hair. For the present study, 22 Pakistani families with autosomal recessive hypotrichosis were enrolled. Genotyping using microsatellite markers linked to three autosomal recessive forms of hypotrichosis (LAH1, LAH2, LAH3) showed the linkage of 2 families to the LAH2 locus and 14 to the LAH3 locus. The remaining 6 families were not linked to any of the three loci. Families linked to LAH3 locus were further subjected to screening of the P2RY5 gene with direct DNA sequencing. Three previously reported variants, c.69insCATG (p.24insHfs52), c.188A > T (p.D63V) and c.565G > A (p.E189K) were observed in eight families. Four novel nonsynonymous sequence variants, c.8G > C (p.S3T), c.36insA (p.D13RfsX16), c.160insA (p.N54TfsX58) and c.436G > A (p.G146R) were found to segregate within six families.

Design of mannosylated oral amphotericin B nanoformulation: efficacy and safety in visceral leishmaniasis.

The aim of this study was to evaluate mannose-anchored thiolated chitosan (MTC) based nanocarriers (NCs) for enhanced permeability, improved oral bioavailability and anti-parasitic potential of amphotericin B (AmB). Transgenic Leishmania donovani parasites expressing red fluorescent protein DsRed2 and imaging-flow cytometry was used to investigate parasitic burdens inside bone marrow-derived macrophages ex vivo. Cytokine estimation revealed that MTC nanocarriers activated the macrophages to impart an explicit immune response by higher production of TNF-α and IL-12 as compared to control. Cells treated with MTC NCs showed a significantly higher magnitude of nitrite and propidium iodide (PI) fluorescence intensity in contrast to cells treated with AmB. Concerning to apparent permeability coefficient (Papp) results, the MTC NCs formulation displayed more specific permeation across the Caco-2 cell monolayer as compared to AmB. The half-life of MTC NCs was about 3.3-fold persistent than oral AmB used as positive control. Also, t oral bioavailability of AmB was increased to 6.4-fold for MTC NCs compared to AmB for positive control. Acute oral evaluation indicated that MTC NCs were significantly less toxic compared to the AmB. Based on these findings, MTC NCs seems to be promising for significant oral absorption and improved oral bioavailability of AmB in leishmaniasis chemotherapy.

Mannosylated thiolated polyethylenimine nanoparticles for the enhanced efficacy of antimonial drug against Leishmaniasis.

AIM: Our aim was to inhibit trypanothione reductase (TR) and P-gp efflux pump of Leishmania by the use of thiolated polymers. Thus, increasing the intracellular accumulation and therapeutic effectiveness of antimonial compounds. METHODS: Mannosylated thiolated chitosan and mannosylated thiolated chitosan-polyethyleneimine graft were synthesized and characterized. Meglumine antimoniate-loaded nanoparticles were prepared and evaluated for TR and P-gp efflux pump inhibition, biocompatibility, macrophage uptake and antileishmanial potential. RESULTS: Thiomers inhibited TR with Ki 2.021. The macrophage uptake was 33.7- and 18.9-fold higher with mannosylated thiolated chitosan-polyethyleneimine graft and mannosylated thiolated chitosan nanoparticles, respectively, as compared with the glucantime. Moreover, the in vitro antileishmanial activity showed 14.41- and 7.4-fold improved IC50 for M-TCS-g-PEI and M-TCS, respectively as compared with glucantime. CONCLUSION: These results encouraged the concept that TR and P-gp inhibition by the use of thiomers improves the therapeutic efficacy of antimonial drugs.

Redox biology of Leishmania and macrophage targeted nanoparticles for therapy.

Intramacrophage parasite 'Leishmania' has developed various mechanisms for proficient uptake into macrophages and phagosome regulation to avoid macrophage's oxidative burst induced by peroxide, hydroxyl radical, hypochlorous acid and peroxynitrite production. One major barrier for impairing the accession of old fashioned anti-Leishmanial drugs is intrinsic incapability to pass through cell membranes and limiting their abilities to ultimately destroy intracellular pathogens. Receptor-mediated targeted drug delivery to the macrophages by using nanoparticles emerges as promising strategy to improve therapeutic efficacy of old-fashioned drug. Receptor-mediated targeted nanoparticles can migrate across the cell membrane barriers and release enclosed drug cargo at sites of infection. This review is focusing on Leishmania-macrophage signaling alterations, its association with drug resistance and role of nanoparticles for receptor mediated macrophage targeting.

Development of mannose-anchored thiolated amphotericin B nanocarriers for treatment of visceral leishmaniasis.

AIM: Our goal was to improve treatment outcomes for visceral leishmaniasis by designing nanocarriers that improve drug biodistribution and half-life. Thus, long-acting mannose-anchored thiolated chitosan amphotericin B nanocarrier complexes (MTC AmB) were developed and characterized. MATERIALS & METHODS: A mannose-anchored thiolated chitosan nanocarrier was manufactured and characterized. MTC AmB was examined for cytotoxicity, biocompatibility, uptake and antimicrobial activities. RESULTS: MTC AmB was rod shaped with a size of 362 nm. MTC AmB elicited 90% macrophage viability and 71-fold enhancement in drug uptake compared with native drug. The antileishmanial IC50 for MTC AmB was 0.02 µg/ml compared with 0.26 µg/ml for native drug. CONCLUSION: These studies show that MTC can serve as a platform for clearance of Leishmania in macrophages.