Antileishmanial Activity Research Articles

Development and Characterization of Pharmaceutical Systems Containing Rifampicin

Rifampicin is a potent antimicrobial drug with some suboptimal properties, such as poor stability, low solubility, and variable bioavailability. Therefore, in the current study, a multicomponent complex between rifampicin, γ-cyclodextrin, and arginine was prepared with the aim of improving drug properties. Solubility was evaluated by phase-solubility studies. The mechanism of interaction was established through proton nuclear magnetic resonance spectroscopy and molecular modeling. Physicochemical characterization was investigated using Fourier transform-infrared spectroscopy, powder X-ray diffraction, and scanning electron microscopy. The dissolution properties, antimicrobial activity (antibacterial, antibiofilm, and antileishmanial), and stability of the different samples were studied. The results obtained in this investigation demonstrate that multicomponent complexes can improve the water solubility and dissolution rate of rifampicin, as well as its antibacterial and antileishmanial action, and present suitable stability. In conclusion, rifampicin complexed with γ-cyclodextrin and arginine is an attractive approach for developing pharmaceutical dosage forms of rifampicin with increased antimicrobial activities.

Synthesis and biological evaluation of 9-aryl-1,8-dioxo-octahydroxanthene derivatives as antileishmanial agents

In the current research, we designed and synthesized various derivatives of 9-aryl-1,8-dioxo-octahydroxanthene using flow chemistry technique and explored in vitro study for antileishmanial activity against the promastigote as well as amastigote form of Leishmania donovani strain. Among the tested analogs by various cell viability assays, six compounds exhibited antileishmanial activity with IC50 value ranging from 24.81 to 52.33 μM. Further, the functional dynamics study sheds light on the structural role of various functional groups presents in the xanthene derivatives for defining the actual antileishmanial activity. Molecular dynamics simulation data presented here attempts to provide a structural and mechanistic explanation of threonine synthase inhibition against Leishmania donovani by xanthene derivatives. Described structure–activity-relation advocates for further modification of the xanthene scaffolds for the accomplishment of challenging antileishmanial drugs.

Antileishmanial activity of 5-nitroindazole derivatives.

Currently, there is no safe and effective vaccine against leishmaniasis and existing therapies are inadequate due to high toxicity, cost and decreased efficacy caused by the emergence of resistant parasite strains. Some indazole derivatives have shown in vitro and in vivo activity against Trichomonas vaginalis and Trypanosoma cruzi. On that basis, 20 indazole derivatives were tested in vitro against Leishmania amazonensis. To evaluate the in vitro activity of twenty 2-benzyl-5-nitroindazolin-3-one derivatives against L. amazonensis. For the selection of promising compounds, it is necessary to evaluate the indicators for in vitro activity. For this aim, a battery of studies for antileishmanial activity and cytotoxicity were implemented. These results enabled the determination of the substituents in the indazole derivatives responsible for activity and selectivity, through the analysis of the structure-activity relationship (SAR). In vitro cytotoxicity against mouse peritoneal macrophages and growth inhibitory activity in promastigotes were evaluated for 20 compounds. Compounds that showed adequate selectivity were tested against intracellular amastigotes. The SAR from the results in promastigotes was represented using the SARANEA software. Eight compounds showed selectivity index >10% and 50% inhibitory concentration <1 µM against the promastigote stage. Against intracellular amastigotes, four were as active as Amphotericin B. The best results were obtained for 2-(benzyl-2,3-dihydro-5-nitro-3-oxoindazol-1-yl) ethyl acetate, with 50% inhibitory concentration of 0.46 ± 0.01 µM against amastigotes and a selectivity index of 875. The SAR study showed the positive effect on the selectivity of the hydrophilic fragments substituted in position 1 of 2-benzyl-5- nitroindazolin-3-one, which played a key role in improving the selectivity profile of this series of compounds. 2-bencyl-5-nitroindazolin-3-one derivatives showed selective and potent in vitro activity, supporting further investigations on this family of compounds as potential antileishmanial hits.

2-Aminofluorene based triazole cocktailed with organosilane as UV-visible and fluorescence sensor for the highly selective detection of Fe(iii) ion and its anti-leishmanial activity

This paper synthesizes triazole-attached 2-aminofluorene-based organosilane for sensing Fe3+ion using UV-Vis and fluorescence. Probe6a's inhibitory effect on the leishmania protein was studied. DFT explained6a's complexation with Fe3+ion.

Prosopis strombulifera aqueous extract reduces T cell response and ameliorates type I diabetes in NOD mice.

New products with tolerogenic properties on T cell response are necessary to improve current efficacy, cost and side effects of immunosuppressants. Prosopis strombulifera aqueous extract (PsAE) have reported cytotoxic, antitumoral, antiatherogenic and antileishmanial activities, containing phytochemicals with immune-related activities. Despite these, there are no previous studies with respect to PsAE suppressive properties over T cell proliferation and their function. Because of previous antecedents, this study aims to evaluate the effect of PsAE on T cell activation, proliferation, cytokine production, and to investigate its effect over an invivo model of type 1 diabetes (T1D). Splenocytes and sorted CD4+/CD8+ from wild type C57BL/6 mice were cultured to determine activation, IFN-γ release and T-cell proliferation after polyclonal stimulation. NOD (non-obese diabetic) mice were used to study the effects of orally administered extract on glycemia, insulitis stages and perforin-1 (PRF-1)/granzyme-B (GRZ-B) expression. In primary cultures, the plant extract impairs T cell activation, decreases IFN-γ release, and reduces proliferation after different polyclonal stimuli. Invivo, PsAE improves NOD mice glycemic levels and T1D progression by diminution of pancreas insulitis and reduction of PRF-1 and GRZ-B mRNA expression. To our knowledge, this is the first report characterizing the therapeutic properties of PsAE on T cell activation. The current work provides evidence about invitro and invivo immunosuppressive effects of PsAE and promotes this plant extract as a complementary and alternative treatment in autoimmune T-cell mediated diseases as T1D.

Meso-Carbazole decorated BODIPYs – an electron donor–acceptor system with excellent fluorosolvato/vapochromic behavior, aggregation-induced emission, and antileishmanial activity

meso-Carbazole BODIPY generates an electron donor–acceptor system with multiple photo responses and has excellent anti-leishmanial activity.

Anti-leishmanial, immunomodulatory and anti-oxidative activity of quercetin against cutaneous leishmaniasis caused by Leishmania major

Objective: To evaluate the in vitro and in vivo efficacy of quercetin and its immunomodulatory and anti-oxidative activity against Leishmania major (L. major). Methods: L. major promastigotes and amastigotes were incubated with different concentrations of quercetin to estimate EC50. For in vivo study, the base of tails of mice was infected with L. major. After developing ulcers in the inoculation site, mice were treated with 50 mg/kg quercetin orally for 28 consecutive days. The wound-healing potential of quercetin was evaluated by histopathological analysis of tissue sections stained by hematoxylin and eosin as well as Masson's trichrome. In addition, the levels of tumor necrosis factor-α, interleukin-6, malondialdehyde, and adiponectin, the ferric reducing ability of plasma, as well as superoxide dismutase and glutathione peroxidase activities were measured. Results: The EC50 values of quercetin against L. major promastigotes and intracellular amastigotes were 0.27 and 0.85 μM, respectively. Histopathological analysis showed that fewer inflammatory cells, more fibroblasts, and more collagen deposition were observed in tissue sections of quercetin-treated mice. In addition, treatment with quercetin markedly increased glutathione peroxidase activity, the ferric reducing ability of plasma and adiponectin levels while decreasing malondialdehyde, interleukin-6, and tumor necrosis factor-α levels. Conclusions: Quercetin shows anti-leishmanial activity, immunomodulatory, anti-oxidative, and anti-inflammatory effects. Therefore, it may be further explored as an effective drug in treating leishmaniasis.

Ultrasound Assisted Facile Synthesis of 2-Benzylidenebenzofuran-3(2H)-ones

2-Benzylidenebenzofuran-3(2H)-ones commonly known as aurones, are an important class of oxygen heterocyclic compounds of flavonoid family. They exhibit some biological activities such as antioxidant, antifungal, anticancer, enzyme inhibitory, antiparasitic and antileishmanial activities. They are also responsible for imparting yellow color to the flowers and fruits. Owing to their varied importance, a simple and efficient method for the synthesis of 2-benzylidenebenzofuran-3(2H)-ones involving the reaction of 1-(2'-hydroxy-phenyl)-3-phenyl-propenones with copper acetate in ethanol under ultrasonic irradiation conditions has been described. The present method offers a faster reaction and a higher yield than conventional methods.

Synthesis and Evaluation of the Antileishmanial Activity of Novel Eugenol Analogs Containing 1,2,3-Triazole Fragments against Intracellular Leishmania braziliensis

This investigation describes the synthesis of eugenol analogs presenting 1,2,3-triazole fragments and evaluation of their antileishmanial activity. The alkylation of guaiacol (1) with allyl bromide afforded 1-(allyloxy)-2-methoxybenzene (2) (93% yield). The Claisen rearrangement conducted with 1 gave ortho eugenol (3) (82% yield). Alkylation procedures performed with 3 produced 1-allyl3-methoxy-2-(prop-2-yn-1-yloxy)benzene (4) (73% yield) and 1-allyl-3-methoxy-2-(pent-4-yn1-yloxy)benzene (6) (53% yield). The copper(I)-catalyzed alkyne-azide cycloaddition (CuAAC) reactions involving alkynes 4 and 6 with different benzylic azides afforded twenty-two eugenol analogs with 1,2,3-triazole functionalities (48-93% yield). We screened the compounds at 10 μmol L-1 against Leishmania braziliensis intracellular amastigotes during macrophage infection. The action of these compounds was compared with the known leishmanicidal drug amphotericin B. None of the analogs were toxic to macrophages at 10 μmol L-1. The cytotoxic concentration at 50% (CC50), effective concentration at 50% (EC50), and selectivity index (SI) were determined to the best compounds 4-((2-allyl-6-methoxy)phenoxymethyl)-1-(4-chlorobenzyl)-1H-1,2,3-triazole (8c) and 4-((2-allyl-6-methoxy)phenoxymethyl)-1-(4-trifluoromethoxybenzyl)-1H-1,2,3-triazole (8h). They showed a significant leishmanicidal effect, with EC50 of 28.09 µmol L-1 (8c) and 52.03 µmol L-1 (8h). The SIs were 9.7 for 8c and &gt; 5.7 for 8h. These compounds have the potential as new leishmanicidal agents against L. braziliensis and may represent a starting point for the development of alternative treatments for cutaneous leishmaniasis.

Structure-activity effects in the anti-leishmanial activity of di-alkyl gallium quinolin-8-olates.

Six (G1-G6) novel organogallium complexes of the general formula [Ga(R)2quin] (where R = Et, iPr, nBu, tBu, sBu and hexyl; quin = quinolin-8-olate, C9H6NO) have been synthesised and fully characterised. Single crystal X-ray diffraction shows the complexes adopt a five-coordinate geometry through dimerisation. Complexes G1-G5 were analytically pure and could undergo further biological analysis. [Ga(hex)2quin] G6 could not be satisfactorily purified and was excluded from biological assays. 1H NMR spectroscopy indicated the complexes are stable to hydrolysis over 24 hours in 'wet' d6-DMSO. Complexes G1-G5 were assessed for their anti-leishmanial activity towards three separate strains: L. major, L. amazonensis and L. donovani, with varied results toward the promastigote form. G1 and G2 were found to be the most selective with little to no toxicity towards mammalian cell lines. Amastigote invasion assays on the three strains showed that [Ga(nBu)2quin] G3 and [Ga(tBu)2quin] G4 gave the best all round anti-parasitic activity with percentage infection ranges of 1.50-3.00% and 3.25-7.50% respectively, with G3 out-performing the drug control amphotericin B in all three assays. The activity was found to correlate with lipophilicity and water solubility, with the most effective G3 proving the most lipophilic and least water soluble.

Antileishmanial and cytotoxic activity of dillapiole n-butyl ether

ABSTRACT Among the neglected diseases, American cutaneous leishmaniasis (ACL) still remains highly endemic in some tropical regions. The currently available drugs for treatment are highly toxic, prompting the search for new therapeutic options. The aim of this study was to evaluate the toxic potential of dillapiole n-butyl ether (DBE) against Leishmania amazonensis and L. guyanensis, as well as its toxicity on human peripheral blood mononuclear cells (PBMCs) in vitro. For cell cytotoxicity, concentrations of DBE that ranged from 7.8 to 500 µM were used for 48 and 72 h. For the evaluation of the antileishmanial activity, DBE was tested at concentrations of 0.28 to 18 µM for 24, 48, and 72 h. A value of 36 µM was used for the amastigote assay. The selectivity index (SI) was determined by dividing the CC50/IC50 (macrophages/promastigotes). DBE exhibited a CC50 of 203.9 ± 0.5 µM in 72 h. DBE inhibited promastigote forms with an IC50 of 3.0 µM for both Leishmania species for 72 h. The standard, Pentacarinat®, showed an IC50 of 2.9 µM and 0.3 µM, respectively. The SI of DBE for both species was 67.9 for 72 h. DBE inhibited intracellular forms of L. amazonensis by 65.5% after 48 h. In molecular modeling, DLpOl-F showed two hydrogen bonds (SER418 and 421). DBE demonstrated promising in vitro antileishmanial potential.

Expanding the scope of novel 1,2,3-triazole derivatives as new antiparasitic drug candidates.

We have previously shown that prenyl and aliphatic triazoles are interesting motifs to prepare new chemical entities for antiparasitic and antituberculosis drug development. In this opportunity a new series of prenyl-1,2,3-triazoles were prepared from isoprenyl azides and different alkynes looking for new antimalarial drug candidates. The compounds were prepared by copper(i) catalyzed dipolar cycloaddition of the isoprenyl azide equilibrium mixture providing exclusively 1,4-disubstituted 1,2,3-triazoles in a regiospecific fashion. The complete collection of 64 compounds was tested on chloroquine-sensitive (CQ sensitive), Sierra Leone (D6), and the chloroquine-resistant, Indochina (W2), strains of Plasmodium falciparum and those compounds which were not previously reported were also tested against Leishmania donovani, the causative agent for visceral leishmaniasis. Thirteen analogs displayed antimalarial activity with IC50 below 10 μM, while the antileishmanial activity of the newly reported analogs could not improve upon those previously reported. Compounds 1o and 1r were identified as the most promising antimalarial drug leads with IC50 below 3.0 μM for both CQ-sensitive and resistant P. falciparum strains with high selectivity index. Finally, a chemoinformatic in silico analysis was performed to evaluate physicochemical parameters, cytotoxicity risk and drug score. The validation of a bifunctional farnesyl/geranylgeranyl diphosphate synthase PfFPPS/GGPPS as the potential target of the antimalarial activity of selected analogs should be further investigated.

Naphthyl bearing 1,3,4-thiadiazoleacetamides targeting the parasitic folate pathway as anti-infectious agents: in silico, synthesis, and biological approach.

Malaria is still a complex and lethal parasitic infectious disease, despite the availability of effective antimalarial drugs. Resistance of malaria parasites to current treatments necessitates new antimalarials targeting P. falciparum proteins. The present study reported the design and synthesis of a series of a 2-(4-substituted piperazin-1-yl)-N-(5-((naphthalen-2-yloxy)methyl)-1,3,4-thiadiazol-2-yl)acetamide hybrids for the inhibition of Plasmodium falciparum dihydrofolate reductase (PfDHFR) using computational biology tools followed by chemical synthesis, structural characterization, and functional analysis. The synthesized compounds were evaluated for their in vitro antimalarial activity against CQ-sensitive PfNF54 and CQ-resistant PfW2 strain. Compounds T5 and T6 are the most active compounds having anti-plasmodial activity against PfNF54 with IC50 values of 0.94 and 3.46 μM respectively. Compound T8 is the most active against the PfW2 strain having an IC50 of 3.91 μM. Further, these active hybrids (T5, T6, and T8) were also evaluated for enzyme inhibition assay against PfDHFR. All the tested compounds were non-toxic against the Hek293 cell line with good selectivity indices. Hemolysis assay also showed non-toxicity of these compounds on normal uninfected human RBCs. In silico molecular docking studies were carried out in the binding pocket of both the wild-type and quadruple mutant Pf-DHFR-TS to gain further insights into probable modes of action of active compounds. ADME prediction and physiochemical properties support their drug-likeness. Additionally, they were screened for antileishmanial activity against L. donovani promastigotes to explore broader applications. Thus, this study provides molecular frameworks for developing potent antimalarials and antileishmanial agents.

Antileishmanial evaluation of triazole-butenolide conjugates: design, synthesis, in vitro screening, SAR and in silico ADME predictions.

In the quest to discover novel scaffolds with leishmanicidal effects, a series of 23 compounds containing the most promising 1,2,3-triazole and highly potent butenolide in one framework were synthesized. The synthesized conjugates were screened against Leishmania donovani parasite; five of them showed moderate antileishmanial activity against promastigotes (IC50 30.6 to 35.5 μM) and eight of them exhibited significant activity against amastigotes (IC50 ≤12 μM). Compound 10u was found to be the most active (IC50 8.4 ± 0.12 μM) with the highest safety index (20.47). The series was further evaluated against Plasmodium falciparum (3D7 strain) and seven compounds were found to be moderately active. Among them, again 10u emerged as the most active compound (IC50 3.65 μM). In antifilarial assays against adult female Brugia malayi, five compounds showed grade II inhibition (50-74%). Structure-activity relationship (SAR) analysis suggested a substituted phenyl ring, triazole and butenolide as essential structural features for bioactivity. Moreover, the results of in silico ADME parameter and pharmacokinetic studies indicated that the synthesized triazole-butenolide conjugates abide by the required criteria for the development of orally active drugs, and thus this scaffold can be used as a pharmacologically active framework that should be considered for the development of potential antileishmanial hits.

Targeting Leishmania donovani sterol methyltransferase for leads using pharmacophore modeling and computational molecular mechanics studies

The mortalities and morbidities of leishmaniasis are high and the disease is under reported globally. The absence of vaccines coupled with chemotherapeutic challenges including chemoresistance, scarcity and toxicity have made the fight against leishmaniasis an arduous one. Furthermore, the treatment options currently available for leishmaniasis are long and sometimes require hospitalization. There is therefore the need to explore novel pathways to identify new compounds with alternative mechanisms of action. A pharmacophore-based screening was employed in identifying new potential inhibitors with unique scaffolds targeting Leishmania donovani sterol methyltransferase (LdSMT), a key enzyme for ergosterol biosynthesis. To accomplish this, 22,26-azasterol, a known inhibitor of this target and five other derivatives with IC50 less than 10 μM were used to generate a robust 3D pharmacophore model via LigandScout with a score of 0.9144. The validated model was used as a query to screen a library of 69034 natural products obtained from the InterBioScreen Limited. Compounds with pharmacophore fit scores above 50 were docked against the modelled structure of LdSMT. Altogether, ten molecules with binding energies between −7 and −11 kcal/mol were identified as potential bioactive molecules. The molecular dynamics simulation and molecular mechanics Poisson–Boltzmann surface area (MM-PBSA) calculations reinforced the results from the docking studies suggesting the selected hits bind effectively at the active sites of the target protein. The compounds were observed to bind in the S-adenosine-L-homocysteine binding pocket of the modelled LdSMT with Trp208 and Val330 predicted as key residues critical for ligand binding. Prediction of biological activity with probability of activity (Pa) greater than probability of inactivity (Pi) revealed that seven compounds (STOCKIN-54848, STOCKIN-89115, STOCKIN-68720, STOCKIN-44724, STOCKIN-76694, STOCKIN-47277 and STOCKIN-95708) possessed antileishmanial properties. STOCKIN-89115, STOCKIN-68720, STOCKIN-44724, and STOCKIN-47277 were predicted to be membrane permeability inhibitors, while all ten hit compounds possessed antineoplastic activity. The compounds have the propensity of disrupting ergosterol biosynthesis leading to the suppression of growth in Leishmania donovani. The compounds were predicted to have good absorption, distribution, metabolism, excretion and toxicity profiles, hence their potential antileishmanial activity can be exploited upon experimental corroboration.

Design, development and formulation of Miltefosine loaded Mannosylated Liposomes for Anti-leishmanial activity

Design, development and formulation of Miltefosine loaded Mannosylated Liposomes for Anti-leishmanial activity

Chemical composition, in vitro larvicidal and antileishmanial activities of the essential oil from Citrus reticulata Blanco fruit peel.

Numerous studies have investigated the chemical composition and biological activities of essential oils from different Citrus species fruit peel, leaves and flowers. This paper aims to investigate the chemical composition, larvicidal and antileishmanial activities of essential oil from Citrus reticulata fruit peel (CR-EO). CR-EO was obtained by hydrodistillation in a Clevenger-type apparatus and its chemical composition was analyzed by GC-MS and GC-FID. Limonene (85.7%), ɣ-terpinene (6.7%) and myrcene (2.1%) were identified as its major components. CR-EO showed high activity against promastigote forms of Leishmania amazonensis (IC50 = 8.23 µg/mL). CR-EO also exhibited high larvicidal activity against third instar Aedes aegypti larvae at a lethal concentration (LC50 = 58.35 µg/mL) and 100% mortality at 150 µg/mL. This study suggests, for the first time, the potential use of CR-EO against this important mosquito-borne viral disease caused by the genus Aedes.

Antileishmanial effects of Crotalaria spectabilis Roth aqueous extracts on Leishmania amazonensis.

Fifteen polar extracts from leaf, seed, pod, stem, flower and root of Crotalaria spectabilis were prepared using aqueous systems, based on the principles of green chemistry, and showed different protease inhibitor (PI) activities on trypsin, papain, pepsin and the extracellular L. amazonensis serine protease (LSPIII). The most pronounced inhibitory effect on LSPIII was observed in leaf (CS-P), root, stem, flower (CS-FPVPP) and pod (CS-VA) extracts. Crotalaria extracts exhibited low cytotoxicity on macrophages; however, they decreased the viability of L. amazonensis promastigotes and amastigotes, as observed in leaf (CS-AE, CS-P, CS-T and CS-PVPP), seed (CS-ST), flower and root (CS-RA) extracts. CS-P was chosen to study PI and secondary metabolites and a 10-12 kDa protein, analyzed by mass spectrometry, was identified as a serine PI homologous with papaya latex serine PI. Glycosylated flavonoids, such as quercetins, vitexin and tricin were the major secondary metabolites of CS-P. The presence of PIs in C. spectabilis is a new finding, especially in other organs than seeds since PIs have been reported only in seed legumes. Besides, this is the first report of antileishmanial activity of C. spectabilis extracts and the identification of serine polypeptide PI and glycosylated flavonoids from leaf.

Evaluation of Antileishmanial Activities of a Peganum Harmala and Achillea Millefolium Essential oils and their combinations against Leishmania Infantum Promastigotes

Medicinal plants and their derivations are used as safe agents for the treatment of parasitic diseases. This preliminary study investigates antileishmanial activities of Peganum harmala essential oil (PHEO), Achillea millefolium essential oils (AMEO) and their combinations against Leishmania infantum promastigotes. A standard strain of L. infantum promastigote was cultured in a 96-well Novy-MacNeal-Nicolle media culture and antileishmanial activities of glucantime, PHEO, AMEO, an equal ratio of both and 80% PHEO+20%AMEO were investigated in concentrations of 10, 100, 500 and 1000 mg/mL and interval times of 24h, 48h and 72h. The results showed that greatest inhibition was observed in 50PHEO+ AMEO and lowest inhibition was seen in control group. The increased time and increased concentration significantly increased their efficiencies. The analyses showed a significant interaction between time and agents [F (10, 360)=7.84, P=0.000]. The agents showed better effects with increased time. In sum, an equal combination of PHEO and AMEO showed its potential as an antileishmanial safe structure and must be considered for future studies.

Efficacy of pentamidine-loaded chitosan nanoparticles as a novel drug delivery system for Leishmania tropica.

The present study compares the in vitro effects of nanoparticles loaded pentamidine drug and conventional pentamidine on Leishmania tropica. Herein, pentamidine-loaded chitosan nanoparticles (PTN-CNPs) have been synthesized through an ionic gelation method with sodium tripolyphosphate (TPP). Next, the physical characteristics of PTN-CNPs were determined through the surface texture, zeta potential, in vitro drug release, drug loading content (DLC), and encapsulation efficacy (EE) and compared its efficacy with free pentamidine (PTN) drug against promastigotes and axenic amastigotes forms of L. tropica in vitro. The PTN-CNPs displayed a spherical shape having a size of 88 nm, an almost negative surface charge (-3.09 mV), EE for PTN entrapment of 86%, and in vitro drug release of 92% after 36 h. In vitro antileishmanial activity of PTN-CNPs and free PTN was performed against Leishmania tropica KWH23 promastigote and axenic amastigote using 3-(4, 5- dimethylthiazol-2-yl)-2, 5-diphenyletetrazolium bromide (MTT) assay. It was observed that the effect of PTN-CNPs and free PTN on both forms of the parasite was dose and time dependent. Free PTN presented low efficacy even at higher dose (40 µg/ml) with 25.6 ± 1.3 and 26.5 ±1.4 mean viability rate of the promastigotes and axenic amastigotes, respectively after 72 hrs incubation. While PTN-CNPs showed strong antileishmanial effects on both forms of parasite with 16 ± 0.4 and 19 ± 0.7 mean viability rate at the same higher concentration (40 µg/ml) after 72 hrs incubation. Half maximal inhibitory concentration (IC50) values of PTN-CNPs toward promastigotes and amastigotes were obtained as 0.1375 µg/ml and 0.1910 µg/ml, respectively. In conclusion, PTN-CNPs effectively inhibited both forms of the L. tropica; however, its effect was more salient on promastigotes. This data indicates that the PTN-CNPs act as a target drug delivery system. However, further research is needed to support its efficacy in animal and human CL.