Insights into the trypanothione system in antimony-resistant and sensitive Leishmania tropica clinical isolates.

Pentavalent antimonials are the mainstay treatment against different clinical forms of leishmaniasis. The emergence of resistant isolates in endemic areas has led to treatment failure. Unraveling the underlying resistance mechanism would assist in improving the treatment strategies against resistant isolates. This study aimed to investigate the RNA expression level of glutathione synthetase (GS), Spermidine synthetase (SpS), trypanothione synthetase (TryS) genes involved in trypanothione synthesis, and thiol-dependent reductase (TDR) implicated in drug reduction, in antimony-sensitive and -resistant Leishmania tropica isolates. We investigated 11 antimony-resistant and 11 antimony-sensitive L. tropica clinical isolates from ACL patients. Drug sensitivity of amastigotes was determined in mouse macrophage cell line J774A.1. The RNA expression level in the promastigote forms was analyzed by quantitative real-time PCR. The results revealed a significant increase in the average expression of GS, SpS, and TrpS genes by 2.19, 1.56, and 2.33-fold in resistant isolates compared to sensitive ones. The average expression of TDR was 1.24-fold higher in resistant isolates, which was insignificant. The highest correlation coefficient between inhibitory concentration (IC50) values and gene expression belonged to the TryS, GS, SpS, and TDR genes. Moreover, the intracellular thiol content was increased 2.17-fold in resistant isolates compared to sensitive ones and positively correlated with IC50 values. Our findings suggest that overexpression of trypanothione biosynthesis genes and increased thiol content might play a key role in the antimony resistance of L. tropica clinical isolates. In addition, the diversity of gene expression in the trypanothione system and thiol content among L. tropica clinical isolates highlighted the phenotypic heterogeneity of antimony resistance among the parasite population.

[The Effect of Oleuropein on The Mitochondrial Membrane Potential and Generation of Reactive Oxygen Species on Leishmania tropica Promastigotes]. / Oleuropein'in Leishmania tropica Promastigotlari Üzerinde Mitokondri Membran Potansiyeli ve Reaktif Oksijen Türlerinin Olusumuna Etkisi.

Leishmania parasites, which are reported to be endemic in 98 countries around the world, infect humans as well as wild and domestic carnivores and small mammals, and are transmitted by sand flies (Phlebotomus, dwarf sandflies). It is reported that 350 million people are at risk and two million new cases are seen in the world every year. It has been reported that different drugs (topical paromomycin, oral miltefosine, ketoconazole, rifampin, and zinc) have been tried in studies especially in endemic regions in the treatment of cutaneous leishmaniasis, and response to treatment has been obtained at different rates. Today, the search for alternative treatments continues and many studies have been carried out for this purpose. For centuries, olive leaf extracts have been used to maintain health. Oleuropein has numerous health benefits, including antioxidant, antimicrobial, anti-inflammatory, antiatherogenic, anticarcinogenic, antiviral activities, cardio- and neuroprotective, hepatoprotective effects. The aim of this study was to determine and understand the mode of action of oleuropein, the cell death mechanisms caused by oleuropein in L.tropica promastigotes. In this study, the phenolic and flavonoid content of oleuropein was determined by HPLC method. The antioxidant capacity and the amount of oleuropein were determined. Afterwards, morphological and physiological (mitochondrial membrane potential, formation of reactive oxygen species, Annexin V binding) changes triggered by oleuropein in L.tropica promastigotes were investigated using flow cytometry. Our studies revealed that apoptotic properties such as mitochondrial dysfunction, production of reactive oxygen species, flip-flop action of phosphatidylserine could induce cell death in L.tropica promastigotes. It has been observed that oleuropein induced typical apoptotic morphological features in L.tropica promastigotes. Total phenolic content and total flavonoid content values of oleuropein extract were determined as 33 mg/g and 229 mg/g. The radical removal method was used to investigate the antioxidant capacity of methanol extracts against free radicals. Total antioxidant content of oleuropein extract was determined as 87%. In addition, the amount of oleuropein in the oleuropein extract was determined as 21. 1% by HPLC. The oleuropein dose that killed 50% of L.tropica promastigotes, that is the IC50 value, was detected as 46.6 µg/mL after 24 hours. It was observed that the parasites in the control group preserved their typical morphological features with a single nucleus, flagella, kinetoplast and narrow cell body at both 24 and 48 hours. It was observed that as oleuropein concentrations increased, the and kinetoplasts of L.tropica promastigotes could not be distinguished from each other, they moved away from the narrow cell body structure, they lost their flagella and turned into a round form, and they moved away from the typical form of the parasite. The percentage of Annexin V+ apoptotic cells was found to be 2.9 ± 0.4% in the untreated control group, and 38.1 ± 6.9% in the oleuropein-treated group. Polarization in the mitochondrial membrane of healthy promastigotes caused an approximately 1.7-fold change in the direction of depolarization in oleuropein-treated promastigotes. According to these findings, oleuropein triggered mitochondria-related death in L.tropica promastigotes. Moreover, 1.4 ± 0.2 fold increase in reactive oxygen species production was detected in oleuropein-treated promastigotes compared to the untreated control group. Comparisons between groups were made using the independent sample t test method. In conclusion, phenolic compounds of olive leaf extract oleuropein induced apoptotic cell death in L.tropica promastigotes. Our results support that olive products such as oleuropein may have anti-parasitic effects.

GC/MS analysis, anti-leishmanial and relaxant activity of essential oil of Chenopodium ambrosioides (L.) from Malakand region.

Chenopodium ambrosioides is abundantly available in Malakand region. As constituents and concentrations of essential oils vary based on its geographical location, we carried our current study to extract and evaluate its possible relaxant activity in rabbits' jejunum and anti-leishmanial activity against promastigotes of Leishmania tropica. The essential oil was obtained from aerial fresh parts through steam distillation followed by GC/MS analysis. Antispasmodic activity was performed on spontaneous and KCl induced contractions. Curves for calcium concentration response (CCRCs) were prepared with and without different concentrations of essential oils and verapamil - a standard calcium channel blocker as per our reported procedures. GC/MS analysis indicated that the essential oil contains 4-carene (56.59%) and o-cymene (41.46%), the two most abundant compounds previously reported from this species. The LD50 value for acute toxicity is 279.66±2.2mg/kg. The essential oil have significant antileishmanial activity with LC50 of Log10 (1.83±0.0026) ×10-6mg/ml, potent relaxant activity on rabbits' jejunal preparations with respective EC50 = 1.46±0.15mg/ml for spontaneous activity. For KCl (80mM) induced contractions, EC50=0.26±0.02mg/ml. In CCRCs, the oil produced a right shift as exhibited by verapamil. More, its relaxant activity, which is mediated through calcium channel blocking mechanism, proves a rationale for its traditional use in gut spasm.

Bioactive Levan-Type Exopolysaccharide Produced by Pantoea agglomerans ZMR7: Characterization and Optimization for Enhanced Production.

Levan is an industrially important, functional biopolymer with considerable applications in the food and pharmaceutical fields owing to its safety and biocompatibility. Here, levan-type exopolysaccharide produced by Pantoea agglomerans ZMR7 was purified by cold ethanol precipitation and characterized using TLC, FTIR, 1H, and 13C NMR spectroscopy. The maximum production of levan (28.4 g/l) was achieved when sucrose and ammonium chloride were used as carbon and nitrogen sources, respectively, at 35°C and an initial pH of 8.0. Some biomedical applications of levan like antitumor, antiparasitic, and antioxidant activities were investigated in vitro. The results revealed the ability of levan at different concentrations to decrease the viability of rhabdomyosarcoma and breast cancer cells compared with untreated cancer cells. Levan appeared also to have high antiparasitic activity against the promastigote of Leishmania tropica. Furthermore, levan had strong DPPH radical scavenging (antioxidant) activity. These findings suggest that levan produced by P. agglomerans ZMR7 can serve as a natural biopolymer candidate for the pharmaceutical and medical fields.

The leishmanicidal effect of Lucilia sericata larval saliva and hemolymph on in vitro Leishmania tropica.

BACKGROUND: Leishmaniasis is a major parasitic disease worldwide, except in Australia and Antarctica, and it poses a significant public health problem. Due to the absence of safe and effective vaccines and drugs, researchers have begun an extensive search for new drugs. The aim of the current study was to investigate the in vitro leishmanicidal activity of larval saliva and hemolymph of Lucilia sericata on Leishmania tropica. METHODS: The effects of different concentrations of larval products on promastigotes and intracellular amastigotes of L. tropica were investigated using the mouse cell line J774A.1 and peritoneal macrophages as host cells. The 3-(4.5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and direct observation and counting method were used to assess the inhibitory effects and cell cytotoxicity of the larval products. The effects of larval products on the amastigote form of L. tropica were quantitatively estimated by calculating the rate of macrophage infection, number of amastigotes per infected macrophage cell, parasite load and survival index. RESULTS: The 50% cytotoxicity concentration (CC50) value of both larval saliva and hemolymph was 750 µg/ml, and the 50% inhibitory concentration (IC50) values were 134 µg/ml and 60 µg/ml for larval saliva and larval hemolymph, respectively. The IC50 for Glucantime, used a positive control, was (11.65 µg/ml). Statistically significant differences in viability percentages of promastigotes were observed for different doses of both larval saliva and hemolymph when compared with the negative control (p ≤ 0.0001). Microscopic evaluation of the amastigote forms revealed that treatment with 150 µg/ml larval hemolymph and 450 µg/ml larval saliva significantly decreased the rate of macrophage infection and the number of amastigotes per infected macrophage cell. CONCLUSION: Larval saliva and hemolymph of L. sericata have acceptable leishmanicidal properties against L. tropica.

Phytofabrication of cobalt oxide nanoparticles from Rhamnus virgata leaves extract and investigation of different bioactivities.

The tunable cobalt oxide nanoparticles (CoONPs) are produced due to the phytochemicals present in Rhamnus virgata (RhV) leaf extract which functions as reducing and stabilization agents. The synthesis of CoONPs was confirmed using different analytical techniques: UV-Vis spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), dynamics light scatterings (DLS), Fourier-transform infrared spectroscopy (FTIR), energy dispersive X-ray, and Raman spectroscopy analyses. Furthermore, multiple biological activities were performed. Significant antifungal and antibacterial potentials have been reported. The in vitro cytotoxic assays of CoONPs revealed strong anticancer activity against human hepatoma HUH-7 (IC50 : 33.25 µg/ml) and hepatocellular carcinoma HepG2 (IC50 : 11.62 µg/ml) cancer cells. Dose-dependent cytotoxicity potency was confirmed against Leishmania tropica (KMH23 ); amastigotes (IC50 : 58.63 µg/ml) and promastigotes (IC50 : 32.64 µg/ml). The biocompatibility assay using red blood cells (RBCs; IC50 : 4,636 µg/ml) has confirmed the bio-safe nature of CoONPs. On the whole, results revealed nontoxic nature of RhV-CoONPs with promising biological potentials.

In vitro anti-leishmanial activity of Prunus armeniaca fractions on Leishmania tropica and molecular docking studies.

Prunus armeniaca (L.) is a member of the Rosaceae, subfamily Prunoideae, shows anticancer, antitubercular, antimutagenic, antimicrobial, antioxidant, and cardioprotective activities. Here we fractionated the leaves extract of this highly medicinally important plant for antileishmanial activity. In the current study, the leaves extract was fractionated and characterized using column and thin layer chromatography by n-hexane, ethyl acetate, and methanol solvents. Twelve fractions were isolated and subjected for evaluation of their cytotoxicity and in vitro antileishmanial activity against promastigotes and amastigotes of Leishmania tropica. Among all fractions used, the fraction (F7) exhibited the strongest antileishmanial activity. The bioactive fraction was further characterized by spectroscopy (FTIR, UV-Vis), and GC-MS analysis. The in silico docking was carried out to find the active site of PTR1. All derived fractions exhibited toxicity in the safety range IC50 > 100 µg/ml. The fraction (F7) showed significantly the highest antipromastigotes activity with IC5011.48 ± 0.82 µg/ml and antiamastigotes activity with IC50 21.03 ± 0.98 µg/ml compared with control i.e. 11.60 ± 0.70 and 22.03 ± 1.02 µg/ml respectively. The UV-Vis spectroscopic analysis revealed the presence of six absorption peaks and the FTIR spectrum revealed the presence of alkane, aldehyde, carboxylic acid, thiols, alkynes, and carbonyls compounds The GC-MS chromatogram exhibited the presence of nine compounds: (a) benzeneethanol, alpha, beta dimethyl, (b)carbazic acid, 3-(1 propylbutylidene)-, ethyl ester, (c)1, 2-benzenedicarboxylic acid, diisooctyl ester, (d)benzeneethanamine a-methyl, (e)2aminononadecane, (f)2-heptanamine-5-methyl, (g)cyclobutanol, (h)cyclopropyl carbine, and (i)nitric acid, nonyl ester. Among all compounds, the 1, 2-benzenedicarboxylic acid, diisooctyl ester bound well to the PTR1 receptor. Fraction (F7) showed acceptable results with no cytotoxicity. However, in vivo studies are required in the future.

The potential role of nicotinamide on Leishmania tropica: An assessment of inhibitory effect, cytokines gene expression and arginase profiling.

Leishmaniasis represents a major health concern worldwide which has no effective treatment modality. Nicotinamide (NAm) has been used for a wide range of applications from anticancer to antimicrobial usage. This study aimed to assess the effect of NAm combination on Leishmania tropica Inhibition, as well as on cytokines gene expression and arginase (ARG) activity in L. tropica-infected macrophages in an in vitro model. The leishmanicidal effects of NAm and Glucantime (meglumine antimoniate, MA) alone and in combination (NAm/MA) were evaluated using a colorimetric assay and macrophage model. Additionally, immunomodulatory effects and enzymatic activity were assessed by analyzing Th1 and Th2 cytokines gene expression and ARG level, respectively, in infected macrophages treated with NAm and MA, alone and in combination. Findings indicated that the NAm/MA combination demonstrated greater inhibitory effects on L. tropica promastigotes and amastigotes compared with each drug individually. Docking results proved the affinity of NAm to IFN-γ, which can affirm the increased levels of IFN-γ, IL-12p40 and TNF-α as well as reductions in IL-10 secretion with a dose-response effect, especially in the combination group. The NAm/MA combination also showed a significant reduction in the level of ARG activity at all concentrations used compared to each drug individually. These findings indicate higher effectiveness of NAm plus MA in reducing parasite growth, promoting immune response and inhibiting ARG level. This combination should be considered as a potential therapeutic regimen for treatment of volunteer patients with anthroponotic cutaneous leishmaniasis (ACL) in future control programs.

Molecular Docking, Antioxidant, Anticancer and Antileishmanial Effects of Newly Synthesized Quinoline Derivatives.

BACKGROUND: Due to the pressing need and adverse effects associated with the available anti-cancer agents, an attempt was made to develop the new anti-cancer agents with better activity and lesser adverse effects. OBJECTIVE: Synthetic approaches based on chemical modification of quinoline derivatives have been undertaken with the aim of improving anti-cancer agents' safety profile. METHODS: In the present study, quinoline derivatives 6-hydroxy-2-(4-methoxyphenyl) quinoline-4-carboxylic acid (M1) and 2-(4-chlorophenyl)-6-hydroxyquinoline-4-carboxylic acid (M3) were synthesized by the reaction of aldehyde and pyruvic acid. The complete reaction was indicated by thin-layer chromatography. Newly synthesized M1and M3were tested for in silico and in vitro studies. RESULTS: M1 and M3 were docked against selected targets. Both the test compounds showed good affinity against all targets except the p300\CBP-associated factor target as there was no H-bond formed by M1. IC50 values of M1 and M3 against 1, 1-diphenyl-picrylhydrazyl free radical scavenging activity were 562 and 136.56ng/mL, respectively. In brine shrimp lethality assay, M1 and M3 showed IC50 value of 81.98 and 139.2ng/mL, respectively. IC50 values recorded for M1 and M3 in tumor inhibition activity were 129 and 219µg/mL, respectively. M1 and M3 exhibited concentration-dependent anti-cancer effects against human cell lines of hepatocellular carcinoma (HepG2) and colon cancer (HCT-116). Against HepG2 cells, M1 and M3 exhibited IC50 of 88.6 and 43.62µg/mL, respectively. M1 and M3 utilized against HCT-116 cell lines possessed IC50 values of 62.5 and 15.3µg/mL. M1 and M3 also showed an anti-leishmanial effect with IC50 values of 336.64 and 530.142µg/mL, respectively. CONCLUSION: From the results of pharmacological studies, we conclude that the newly synthesized compound showed enhanced anti-oxidant, anti-cancer and anti-leishmanial profile with good yield.

Camel nanobodies: Promising molecular tools against leishmaniasis.

AIM: To characterize several anti-Leishmania tropica nanobodies and to investigate their effect on Leishmania infection. METHODS: Several immunological tests were implied to characterize five different (as confirmed by sequencing) anti-L tropica nanobodies (NbLt05, NbLt06, NbLt14, NbLt24 and NbLt36) against parasite lysates or intact cells from different stages, promastigotes and amastigotes. Direct inhibitory effect of these nanobodies on parasite infection cycle on macrophages was tested in cell culture. RESULTS: All the five nanobodies (with distinguished characteristics) were more specific to L tropica than to L major, but could equally recognize the lysate and the outer surface of the intact cells from the two main stages of the parasite. Nanobodies recognized several leishmania antigens (majorly between 75 and 63 kDa), and their proteinaceous nature was confirmed. Because of its role in leishmania life cycle, gp63 was considered a potential antigen candidate for nanobodies, and bioinformatics predicted such interaction. All nanobodies have a negative effect on the infectivity of L tropica, as they decreased the number of infected macrophages and the amastigotes inside those macrophages. CONCLUSION: Such anti-leishmania nanobodies, with outstanding characteristics and important target, can be of great use in the development of promising treatment strategies against leishmaniasis.

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.

Facile green synthesis approach for the production of chromium oxide nanoparticles and their different in vitro biological activities.

Green synthesis of nanoparticles using plants has become a promising substitute for the conventional chemical synthesis methods. In the present study, our aim was to synthesize chromium oxide nanoparticles (Cr2 O3 NPs) through a facile, low-cost, eco-friendly route using leaf extract of Rhamnus virgata (RV). The formation of Cr2 O3 NPs was confirmed and characterized by spectroscopic profile of UV-Vis, EDX, FTIR, and XRD analyses. The UV-visible spectroscopy has confirmed the formation of Cr2 O3 NPs by the change of color owing to surface plasmon resonance. The bioactive functional groups present in the leaf extract of RV involved in reduction and stabilization of Cr2 O3 NPs were determined by FTIR analysis. Based on XRD analysis, crystalline nature of Cr2 O3 NPs was determined. The morphological shape and elemental composition of Cr2 O3 NPs were investigated using SEM and EDX analyses, respectively. With growing applications of Cr2 O3 NPs in biological perspectives, Cr2 O3 NPs were evaluated for diverse biopotentials. Cr2 O3 NPs were further investigated for its cytotoxicity potentials against HepG2 and HUH-7 cancer cell lines (IC50 : 39.66 and 45.87 µg/ml), respectively. Cytotoxicity potential of Cr2 O3 NPs was confirmed against promastigotes (IC50 : 33.24 µg/ml) and amastigotes (IC50 : 44.31 µg/ml) using Leishmania tropica (KMH23 ). The Cr2 O3 NPs were further evaluated for antioxidants, biostatic, alpha-amylase, and protein kinase inhibition properties. Biocompatibility assay was investigated against human macrophages which confirmed the nontoxic nature of Cr2 O3 NPs. Overall, the synthesized Cr2 O3 NPs are biocompatible and nontoxic and proved to possess significant biopotentials. In future, different in vivo studies are needed to fully investigate the cytotoxicity and mechanism of action associated with these Cr2 O3 NPs.

Antileishmanial effect of rapamycin as an alternative approach to control Leishmania tropica infection.

Cutaneous leishmaniosis (CL) is a parasitic disease in animals and human with no satisfactory treatments and vaccination. Rapamycin is a potent inhibitor of mammalian target of rapamycin (mTOR) with various applications. Here, the effect of rapamycin alone or in combination with two other drugs, namely amphotericin B (AmB) and glucantime, was investigated against Leishmania tropica infection. In vitro viability and electron microscopy evaluation of the parasites showed detrimental changes in their appearance and viability. Treatment with clinically relevant dose of rapamycin (10.2 µg/dose) is able to control the parasite load in BALB/c mice infected with L. tropica. Furthermore, the cytokine profiles showed significant polarization towards Th1 immune response. Surprisingly, combination therapy with either AmB or glucantime was not efficient. Rapamycin is showed an effective alternative therapy against leishmaniosis caused by L. tropica.

Novel Hydrophilic Riminophenazines as Potent Antiprotozoal Agents.

SAR studies on a set of novel hydrophilic C-2 aminopyridinyl riminophenazines bearing variously functionalized basic side chains at C-3 were conducted. The novel compounds were evaluated for in vitro activity against two different species of Leishmania promastigotes, intramacrophage Leishmania amastigotes, chloroquine-sensitive and chloroquine-resistant strains of P. falciparum, and also against mature-stage P. falciparum gametocytes. Their cytotoxicity was evaluated as well on BMDM cell lines. Most of the new compounds potently inhibited the growth of both genera of protozoa with IC50 values in the high nanomolar range and good selectivities versus mammalian cells. Besides their potent activity against asexual intraerythrocytic stages of P. falciparum, three compounds showed potential as transmission-blocking agents. The key role of the hydrophilic C-2 aminopyridinyl substituent to improve the leishmanicidal activity and the influence of the length and the nature of the basic side chain on the antiprotozoal activity and cytotoxicity were underlined.

Spectroscopic characterizations, structural peculiarities, molecular docking study and evaluation of biological potential of newly designed organotin(IV) carboxylates.

In the search for new therapeutic agents we have synthesized 13 new organotin(IV) carboxylate derivatives of (E)-4-((4-methoxy-2-nitrophenyl)amino)-4-oxobut-2-enoic acid. The synthesized complexes were characterized by several spectroscopic techniques. A chelating or bridging bidentate nature of the carboxylate ligand was suggested from the solid state FT-IR results. Solution state multinuclear NMR (1H, 13C and 119Sn) results reveal that the geometry around the Sn atom in triorganotin(IV) complexes is trigonal bipyramidal and in diorganotin(IV) complexes is octahedral. The ligand, (E)-4-((4-methoxy-2-nitrophenyl)amino)-4-oxobut-2-enoic acid, complex 1 and complex 2 were also analyzed by single crystal X-ray technique and the results fully supports the spectroscopic data. For 1 and 2 the geometry optimized by the single crystal X-ray analyses is distorted trigonal bipyramidal. The interaction of the studied compounds with SS-DNA was investigated by UV-Vis. Spectroscopy and Molecular docking showing an intercalative mode of binding. The evaluation of the screened compounds for cancer treatment displays even higher than that of the vincristine used as a standard drug. Similarly the performance of the tested compounds as an antileishmanial agent considers them very close in activity to the standard drug, amphotericin B. The antibacterial results show that the most of the compounds have a moderate sensitivity against the studied bacterial pathogens.

Biosynthesis of anti-leishmanial natural products in callus cultures of Artemisia scoparia.

Clinically, available synthetic chemotherapeutics in the treatment for leishmaniasis are associated with serious complications, such as toxicity and emergence of resistance. Natural products from plants can provide better remedies against the Leishmania parasite and can possibly minimize the associated side effects. In this study, various extracts of the callus cultures of Artimisia scoparia established in response to different plant growth regulators (PGRs) were evaluated for their anti-leishmanial effects against Leishmania tropica promastigotes, followed by an investigation of the possible mechanism of action through reactive apoptosis assay using fluorescent microscopy. Amongst the different callus extracts, higher anti-leishmanial activity (IC50:19.13 µg/mL) was observed in the callus raised in-vitro in the presence of 6-Benzylaminopurine (BA) plus 2,4-Dichlorophenoxyacetic Acid (2,4-D) at the concentration of 1.5 mg/L, each. Further, the results of apoptosis assay showed a large number of early-stage apoptotic (EA) and late-stage apoptotic (LA) cells in the Leishmania under the effect of callus extract grown in-vitro at BA plus 2,4-D. For the determination of the potent natural products in the callus extracts responsible for the anti-leishmanial activity, extracts were subjected to Gas chromatography-mass spectrometry (GC-MS) for the metabolite analysis. Nonetheless, higher levels of the metabolites, such as nerolidol (22%), pelletierine (18%), aspidin (15%) and ascaridole (11%) were detected in the callus grown in vitro at BA plus 2,4-D (1.5 mg/L, each). This protocol determines a novel method of production of anti-leishmanial natural products through callus cultures of A. scoparia, a medicinal plant.

A Novel Niosomal Combination of Selenium Coupled with Glucantime against Leishmania tropica.

There is no effective treatment modality available against different forms of leishmaniasis. Therefore, the aim of this study was to improve the penetration and efficacy of selenium and glucantime coupled with niosomes and compared them with their simple forms alone on in vitro susceptibility assays. In this study, the niosomal formulations of selenium and in combination with glucantime were prepared. The size and morphology of the niosomal formulations were characterized and the effectivity of the new formulation was also evaluated using in vitro MTT assay, intra-macrophage model, and gene expression profile. From the results obtained, no cytotoxicity effect was observed for niosomal and simple forms of drugs, as alone or in combination. Niosomal formulations of the drugs significantly showed more inhibitory effects (P ≤ 0.001) than the simple drugs when the selectivity index was considered. The gene expression levels of Interleukin (IL-10) significantly decreased, while the level of IL-12 and metacaspase significantly increased (P ≤ 0.001). The results of the present study showed that selenium plus glucantime niosome possess a potent anti-leishmanial effect and enhanced their lethal activity as evidenced by the in vitro experiments.

Gene expression analysis of antimony resistance in Leishmania tropica using quantitative real-time PCR focused on genes involved in trypanothione metabolism and drug transport.

Pentavalent antimonials remain the treatment of choice for all the clinical forms of leishmaniasis. The increasing rates of antimony resistance are becoming a serious health problem in treatment of anthroponotic cutaneous leishmaniasis (ACL). Accordingly, unraveling molecular markers is crucial for improving medication strategies and monitoring of drug-resistant parasites. Different studies have suggested the importance of genes involved in trypanothione metabolism and drug transport. In this regard, present study was designed to investigate the RNA expression level of five genes including γ-GCS, ODC, TRYR (involved in trypanothione metabolism), AQP1 (acts in drug uptake) and MRPA (involved in sequestration of drug) in sensitive and resistant Leishmania tropica isolates. Seven antimony-resistant and seven antimony-sensitive L. tropica clinical isolates were collected from ACL patients. Drug sensitivity test was performed on the samples as well as reference strains; afterwards, gene expression analysis was performed on clinical isolates by quantitative real-time PCR. The results revealed that the average expression level of AQP1 gene was decreased (0.47-fold) in resistant isolates compared to sensitive ones whereas MRPA (2.45), γ-GCS (2.1) and TRYR (1.97) was upregulated in resistant isolates. The average expression of ODC (1.24-fold) gene was not different significantly between sensitive and resistant isolates. Our findings suggest that AQP1, MRPA, GSH1 and TRYR can be considered as potential molecular markers for screening of antimony resistance in some L. tropica clinical isolates.

A single-group trial of end-stage patients with anthroponotic cutaneous leishmaniasis: Levamisole in combination with Glucantime in field and laboratory models.

Currently, there is no satisfactory treatment modality available for cutaneous leishmaniasis (CL). The major objective of the present study was to explore the effect of immunomodulator-levamisole in combination with Glucantime in end-stage unresponsive patients with anthroponotic CL (ACL). Twenty end-stage unresponsive patients with ACL were identified for participation in this single-group trial study. Simultaneously, each patient was received a combination of levamisole pills along with Glucantime during the remedy course. Several in vitro complementary experiments were performed to evaluate the mode of action of levamisole and Glucantime alone and in combination using a macrophage model, in vitro MTT assay, flow cytometry and quantitative real time PCR (qPCR). Overall, 75% of the patients showed complete clinical cure, 10% partially improved and the remaining (15%) had underlying chronic diseases demonstrated no response to the treatment regimen. In in vitro studies, there was no cytotoxic effect associated with these drugs in the range of our experiments. The findings by the flow cytometric analysis represented that the highest apoptotic values corresponded to the drugs combination (32.23%) at 200 µg/ml concentration. Finally, the gene expression level of IL-12 p40, iNOS and TNF-α promoted while the level of IL-10 and TGF-ß genes reduced as anticipated. The findings clearly indicated that the combination of levamisole and Glucantime should be considered in end-stage unresponsive patients with ACL who have not responded to basic treatments. The immunomodulatory role of levamisole in mounting immune system as documented by the in vitro experiments and further substantiated by this single-group trail study was highlighted.

Linalool loaded on glutathione-modified gold nanoparticles: a drug delivery system for a successful antimicrobial therapy.

In the present study, antimicrobial activity of Linalool loaded on Glutathione-modified Gold nanoparticles prepared by novel method was investigated. The aim of this study is to evaluate the antimicrobial activity of Linalool-gold nanoparticles (LIN-GNPs) against Gram's positive bacteria Staphylococcus aureus, Gram's negative bacteria Escherichia coli, and against Leishmania tropica. Gold nanoparticles were synthesized using the chemical method. Colour change, UV-Vis spectrum, FTIR and SEM confirmed the characterization of gold nanoparticles and LIN-GNPs. The antibacterial study was including agar well diffusion method, MIC, MBC. The mode of action was determined by cellular material release assay, SEM and AO/EtBr for ROS detection. Anti-parasitic activity was evaluated using MTT assay. FTIR spectral analysis investigated that Linalool was loaded on gold nanoparticles. SEM showed that the Gold nanoparticles and LIN-GNPs were generally found to be spherical in shape and the size was ranged 5-11 nm for GNPs and 15-20 nm for LIN-GNPs. The results of antibacterial activity demonstrated that Linalool alone had low activity against gram-positive and gram-negative bacteria. While the results showed that gram-positive bacteria were more effective by LIN-GNPs. LIN-GNPs acted on the bacterial cell membrane, resulting in loss of integrity and increased permeability of cell wall and stimulated ROS production that leads to damage of bacterial nucleic acid. The anti-parasitic activity results indicated the high activity of LIN-GNPs on L. tropica compared with Linalool and Gold nanoparticles. These results proved that LIN-GNPs have great potential as antimicrobial activity and could be used as a developing strategy for a successful antimicrobial therapeutic agent.