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Parasites & Vectors Sep 2020The control of schistosomiasis has been centered to date on a single drug, praziquantel, with shortcomings including treatment failure, reinfection, and emergence of...
BACKGROUND
The control of schistosomiasis has been centered to date on a single drug, praziquantel, with shortcomings including treatment failure, reinfection, and emergence of drug resistance. Drug repurposing, combination therapy or nanotechnology were explored to improve antischistosomal treatment. The aim of the present study was to utilize a novel combination of the three strategies to improve the therapeutic profile of praziquantel. This was based on a fixed-dose nanocombination of praziquantel and miltefosine, an antischistosomal repurposing candidate, co-loaded at reduced doses into lipid nanocapsules, for single dose oral therapy.
METHODS
Two nanocombinations were prepared to provide 250 mg praziquantel-20 mg miltefosine/kg (higher fixed-dose) or 125 mg praziquantel-10 mg miltefosine/kg (lower fixed-dose), respectively. Their antischistosomal efficacy in comparison with a non-treated control and their praziquantel or miltefosine singly loaded counterparts was assessed in murine schistosomiasis mansoni. A single oral dose of either formulation was administered on the initial day of infection, and on days 21 and 42 post-infection. Scanning electron microscopic, parasitological, and histopathological studies were used for assessment. Preclinical data were subjected to analysis of variance and Tukey's post-hoc test for pairwise comparisons.
RESULTS
Lipid nanocapsules (~ 58 nm) showed high entrapment efficiency of both drugs (> 97%). Compared to singly loaded praziquantel-lipid nanocapsules, the higher nanocombination dose showed a significant increase in antischistosomal efficacy in terms of statistically significant decrease in mean worm burden, particularly against invasive and juvenile worms, and amelioration of hepatic granulomas (P ≤ 0.05). In addition, scanning electron microscopy examination showed extensive dorsal tegumental damage with noticeable deposition of nanostructures.
CONCLUSIONS
The therapeutic profile of praziquantel could be improved by a novel multiple approach integrating drug repurposing, combination therapy and nanotechnology. Multistage activity and amelioration of liver pathology could be achieved by a new praziquantel-miltefosine fixed-dose nanocombination providing 250 mg praziquantel-20 mg miltefosine/kg. To the best of our knowledge, this is the first report of a fixed-dose nano-based combinatorial therapy for schistosomiasis mansoni. Further studies are needed to document the nanocombination safety and explore its prophylactic activity and potential to hinder the onset of resistance to the drug components.
Topics: Administration, Oral; Animals; Disease Models, Animal; Drug Combinations; Drug Compounding; Female; Humans; Male; Mice; Nanocapsules; Phosphorylcholine; Praziquantel; Schistosoma mansoni; Schistosomiasis mansoni; Schistosomicides
PubMed: 32933556
DOI: 10.1186/s13071-020-04346-1 -
Biochimica Et Biophysica Acta.... Feb 2020Multi-spanning membrane proteins usually require solubilization to allow proper purification and characterization, which generally impairs their structural and...
Multi-spanning membrane proteins usually require solubilization to allow proper purification and characterization, which generally impairs their structural and functional integrity. We have tested the efficacy of several commonly used detergents and membrane-mimicking nanodiscs with respect to solubilization, spectral properties, thermal stability and oligomeric profile of two membrane proteins from the eubacterial rhodopsin family, green proteorhodopsin (PR) and Gloeobacter violaceus rhodopsin (GR). Good solubilization was observed for the detergents TritonX-100 and dodecylphosphocholine (DPC), but DPC in particular strongly affected the thermal stability of PR and especially GR. The least deleterious effects were obtained with n-dodecyl-β-D-maltopyranoside (DDM) and octyl glucose neopentyl glycol (OGNG), which adequately stabilized the native oligomeric and monomeric state of PR and GR, respectively. The transition from the oligomeric to the monomeric state is accompanied by a small red-shift. Both GR and PR were rather unstable in SMA-nanodiscs, but the highest thermal stability was realized by the MSP-nanodisc environment. The size of the MSP-nanodisc was too small to fit the PR hexamer, but large enough to contain the PR monomer and GR trimer. This permitted the comparison of the photocycle of trimeric GR in a membrane-mimicking (MSP-nanodisc) and a detergent (DDM) environment. The ultrarapid early phase of the photocycle (femto- to picosecond lifetimes) showed very similar kinetics in either environment, but the slower part, initiated with proton transfer and generation of the M intermediate, proceeded faster in the nanodisc environment. The implications of our results for the biophysical characterization of PR and GR are discussed.
Topics: Bacterial Proteins; Cyanobacteria; Detergents; Lipid Bilayers; Maltose; Nanoparticles; Phosphorylcholine; Protein Stability; Rhodopsin; Thioglucosides
PubMed: 31672539
DOI: 10.1016/j.bbamem.2019.183113 -
Experimental Parasitology 2021The failures in the treatment of leishmaniasis is an increasing problem around the world, especially related to resistance. Thus, we describe the synthesis and in vivo...
The failures in the treatment of leishmaniasis is an increasing problem around the world, especially related to resistance. Thus, we describe the synthesis and in vivo anti-Leishmania activity of alkylphosphocholine and alkyltriazoles; besides, their likely action mechanisms stem from some eventual inhibition of parasite enzymes using computational tools. These compounds were tested in an in vivo hamster model infected with Leishmania Leishmania infantum chagasi. Fifty days after parasite inoculation, the two compounds 12-azidedodecylphosphocholine (3) and 3-(1-(12-fluorododecyl)-1H-1,2,3-triazol-1-yl)propano-1-ol (9), were separately administered once a day as oral suspensions (25 and 12.5 mg/kg/day, respectively) during ten days, and their efficacy was compared to the reference compound pentavalent antimonial Glucantime (GLU). Compound 3 significantly reduced the number of parasites in the spleen (4.93 × 10 amastigotes/g) and liver (4.52 × 10 amastigotes/g). Compound 9 reduced the number of amastigotes in the spleen to 1.30 × 10 and 1.36 × 10 amastigotes/g in the liver. GLU was the most effective overall treatment (7.50 × 10 and 2.28 × 10 amastigotes/g in the spleen and liver, respectively). The high activity levels of these compounds in vivo may stem from their high in vitro leishmanicidal activity and lipophilicity. The in silico absorption, distribution, metabolism, and excretion studies also showed some anti-Leishmania potential. Compound 9 had more lipophilic characteristics than those of compound 3. In silico studies of the nine enzymes of compounds 3 and 9 showed significant evidence of interactions with nicotimidase and tyrosine aminotransferase, demonstrating possible inhibition enzymes present in L. (L.) infantum chagasi. These compounds could be a promising template for developing a new class of leishmanicidal agents, by oral route, and deserve further investigation to explore different therapeutic regimens.
Topics: Administration, Oral; Animals; Antiprotozoal Agents; Cricetinae; DNA, Complementary; Female; Leishmania infantum; Leishmaniasis, Visceral; Liver; Mesocricetus; Molecular Docking Simulation; Phosphorylcholine; RNA; Spleen; Triazoles
PubMed: 34144040
DOI: 10.1016/j.exppara.2021.108123 -
The Journal of Antimicrobial... Nov 2023To improve visceral leishmaniasis (VL) treatment in Eastern Africa, 14- and 28-day combination regimens of paromomycin plus allometrically dosed miltefosine were... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVES
To improve visceral leishmaniasis (VL) treatment in Eastern Africa, 14- and 28-day combination regimens of paromomycin plus allometrically dosed miltefosine were evaluated. As the majority of patients affected by VL are children, adequate paediatric exposure to miltefosine and paromomycin is key to ensuring good treatment response.
METHODS
Pharmacokinetic data were collected in a multicentre randomized controlled trial in VL patients from Kenya, Sudan, Ethiopia and Uganda. Patients received paromomycin (20 mg/kg/day for 14 days) plus miltefosine (allometric dose for 14 or 28 days). Population pharmacokinetic models were developed. Adequacy of exposure and target attainment of paromomycin and miltefosine were evaluated in children and adults.
RESULTS
Data from 265 patients (59% ≤12 years) were available for this pharmacokinetic analysis. Paromomycin exposure was lower in paediatric patients compared with adults [median (IQR) end-of-treatment AUC0-24h 187 (162-203) and 242 (217-328) µg·h/mL, respectively], but were both within the IQR of end-of-treatment exposure in Kenyan and Sudanese adult patients from a previous study. Cumulative miltefosine end-of-treatment exposure in paediatric patients and adults [AUCD0-28 517 (464-552) and 524 (456-567) µg·day/mL, respectively] and target attainment [time above the in vitro susceptibility value EC90 27 (25-28) and 30 (28-32) days, respectively] were comparable to previously observed values in adults.
CONCLUSIONS
Paromomycin and miltefosine exposure in this new combination regimen corresponded to the desirable levels of exposure, supporting the implementation of the shortened 14 day combination regimen. Moreover, the lack of a clear exposure-response and exposure-toxicity relationship indicated adequate exposure within the therapeutic range in the studied population, including paediatric patients.
Topics: Humans; Adult; Child; Paromomycin; Leishmaniasis, Visceral; Antiprotozoal Agents; Kenya; Phosphorylcholine; Uganda; Treatment Outcome
PubMed: 37726401
DOI: 10.1093/jac/dkad286 -
Scientific Reports Feb 2017Perifosine, an Akt inhibitor, has been shown to be effective in controlling neuroblastoma tumor growth. However, studies indicate that in addition to the ability to...
Perifosine, an Akt inhibitor, has been shown to be effective in controlling neuroblastoma tumor growth. However, studies indicate that in addition to the ability to inhibit Akt, other mechanisms contribute to perifosine's anti-tumor activity. To gain insight into perifosine anti-tumor activity in neuroblastoma we have studied changes in the proteome and acetylome after perifosine treatment in SK-N-AS neuroblastoma cells using SILAC labeling, affinity enrichment, high-resolution and LC-MS/MS analysis. Bioinformatic analysis indicates that, a total of 5,880 proteins and 3,415 lysine acetylation sites were quantified in SK-N-AS cells and 216 differentially expressed proteins and 115 differentially expressed lysine acetylation sites were obtained. These differentially expressed proteins and lysine acetylated proteins were involved in a number of different biological functions, metabolic pathways and pathophysiological processes. This study details the impact of perifosine on proteome and lysine acetylome in SK-N-AS cells and expands our understanding of the mechanisms of perifosine action in neuroblastoma.
Topics: Acetylation; Amino Acids; Antineoplastic Agents; Cell Line, Tumor; Chromatography, Liquid; Humans; Lysine; Metabolic Networks and Pathways; Neuroblastoma; Phosphorylcholine; Proteome; Tandem Mass Spectrometry
PubMed: 28165023
DOI: 10.1038/srep42062 -
Antimicrobial Agents and Chemotherapy Jul 2019Host immune responses are pivotal for the successful treatment of the leishmaniases, a spectrum of infections caused by parasites. Previous studies speculated that...
Host immune responses are pivotal for the successful treatment of the leishmaniases, a spectrum of infections caused by parasites. Previous studies speculated that augmenting cytokines associated with a type 1 T-helper cell (Th1) response is necessary to combat severe forms of leishmaniasis, and it has been hypothesized that the antileishmanial drug miltefosine is capable of immunomodulation and induction of Th1 cytokines. A better understanding of the immunomodulatory effects of miltefosine is central to providing a rationale regarding synergistic mechanisms of activity to combine miltefosine optimally with other conventional and future antileishmanials that are currently under development. Therefore, a systematic literature search was performed to evaluate to what extent and how miltefosine influences the host Th1 response. Miltefosine's effects observed in both a preclinical and a clinical context associated with immunomodulation in the treatment of leishmaniasis are evaluated in this review. A total of 27 studies were included in the analysis. Based on the current evidence, miltefosine is not only capable of inducing direct parasite killing but also of modulating the host immunity. Our findings suggest that miltefosine-induced activation of Th1 cytokines, particularly represented by increased gamma interferon (IFN-γ) and interleukin 12 (IL-12), is essential to prevail over the -driven Th2 response. Differences in miltefosine-induced host-mediated effects between , animal model, and human studies are further discussed. All things considered, an effective treatment with miltefosine is acquired by enhanced functional Th1 cytokine responses and may further be enhanced in combination with immunostimulatory agents.
Topics: Animals; Antiprotozoal Agents; Cytokines; Humans; Immunomodulation; Leishmania; Leishmaniasis; Phosphorylcholine
PubMed: 31036692
DOI: 10.1128/AAC.02507-18 -
International Journal For Parasitology.... Aug 2018Anti-leishmanial treatment increasingly encounters therapeutic limitations due to drug toxicity and development of resistance. The effort for new therapeutic strategies...
Anti-leishmanial treatment increasingly encounters therapeutic limitations due to drug toxicity and development of resistance. The effort for new therapeutic strategies led us to work on combinations of chemically different compounds that could yield enhanced leishmanicidal effect. Peptaibols are a special type of antimicrobial peptides that are able to form ion channels in cell membranes and potentially affect cell viability. We assayed the antileishmanial activity of two well studied helical peptaibols, the 16-residue antiamoebin and the 20-residue alamethicin-analogue suzukacillin, and we evaluated the biological effect of their combination with the alkylphosphocholine miltefosine and its synthetic analogue TC52. The peptaibols tested exhibited only moderate antileishmanial activity, however their combination with miltefosine had a super-additive effect against the intracellular parasite (combination index 0.83 and 0.43 for antiamoebin and suzukacillin respectively). Drug combinations altered the redox stage of promastigotes, rapidly dissipated mitochondrial membrane potential and induced concatenation of mitochondrial network promoting spheroidal morphology. These results evidenced a potent and specific antileishmanial effect of the peptaibols/miltefosine combinations, achieved with significantly lower concentrations of the compounds compared to monotherapy. Furthermore, they revealed the importance of exploring novel classes of bioactive compounds such as peptaibols and demonstrated for the first time that they can act in synergy with currently used antileishmanial drugs to improve the therapeutic outcome.
Topics: Animals; Antiprotozoal Agents; Drug Synergism; Humans; In Vitro Techniques; Leishmania infantum; Leishmaniasis, Visceral; Macrophages; Membrane Potentials; Mitochondria; Peptaibols; Phosphorylcholine; Reactive Oxygen Species
PubMed: 29631127
DOI: 10.1016/j.ijpddr.2018.03.005 -
PloS One 2019Calcium silicate-based cements (CSCs) are commonly used for endodontic procedures; however, their antibacterial effects are limited. The objective of this study was to...
Calcium silicate-based cements (CSCs) are commonly used for endodontic procedures; however, their antibacterial effects are limited. The objective of this study was to develop a 2-methacryloyloxyethyl phosphorylcholine (MPC)-incorporated CSC with improved antibacterial properties, while maintaining the original advantageous features of CSC. MPC was incorporated into a commercial CSC (Endocem MTA) at 0 wt% (control), 1.5%, 3.0 wt%, 5.0 wt%, 7.5 wt%, and 10 wt%. The setting time, compressive strength, water sorption, and glycerol contact angle were measured. Protein absorption was measured and bacterial adhesion on the surface was evaluated using Enterococcus faecalis. The bactericidal effect was examined by the disc diffusion test. Mineralization ability was assessed based on calcium ion deposition, as assessed by alizarin red staining, after immersion into Hank's balanced salt solution for 7 days. High concentrations of MPC in CSC (7.5 wt% and 10 wt%) increased the setting time, reduced compressive strength, and reduced wettability. MPC (3 wt%) had greater protein repellent and anti-biofouling effects than those of control and test materials (P < 0.001). However, no bactericidal effect was observed for any control or test materials. There was greater calcium ion deposition on the surface of MPC-supplemented CSC than on the control (P < 0.001). The addition of 3 wt% MPC polymer to CSC confers protein-repellent properties and reduced bacterial attachment, with the potential for improved mineralization.
Topics: Calcium Compounds; Coated Materials, Biocompatible; Dental Cements; Enterococcus faecalis; Methacrylates; Phosphorylcholine; Silicates
PubMed: 30653611
DOI: 10.1371/journal.pone.0211007 -
Antimicrobial Agents and Chemotherapy Aug 2019The arsenal of drugs used to treat leishmaniasis, caused by spp., is limited and beset by toxicity and emergent resistance. Furthermore, our understanding of drug mode...
The arsenal of drugs used to treat leishmaniasis, caused by spp., is limited and beset by toxicity and emergent resistance. Furthermore, our understanding of drug mode of action and potential routes to resistance is limited. Forward genetic approaches have revolutionized our understanding of drug mode of action in the related kinetoplastid parasite Therefore, we screened our genome-scale RNA interference (RNAi) library against the current antileishmanial drugs sodium stibogluconate (antimonial), paromomycin, miltefosine, and amphotericin B. Identification of orthologues of the known antimonial and miltefosine plasma membrane transporters effectively validated our approach, while a cohort of 42 novel drug efficacy determinants provides new insights and serves as a resource. Follow-up analyses revealed the antimonial selectivity of the aquaglyceroporin TbAQP3. A lysosomal major facilitator superfamily transporter contributes to paromomycin-aminoglycoside efficacy. The vesicle-associated membrane protein TbVAMP7B and a flippase contribute to amphotericin B and miltefosine action and are potential cross-resistance determinants. Finally, multiple phospholipid-transporting flippases, including the orthologue of the miltefosine transporter, a putative β-subunit/CDC50 cofactor, and additional membrane-associated hits, affect amphotericin B efficacy, providing new insights into mechanisms of drug uptake and action. The findings from this orthology-based chemogenomic profiling approach substantially advance our understanding of antileishmanial drug action and potential resistance mechanisms and should facilitate the development of improved therapies as well as surveillance for drug-resistant parasites.
Topics: Adenosine Triphosphatases; Amphotericin B; Antimony Sodium Gluconate; Antiprotozoal Agents; Leishmania; Paromomycin; Phosphorylcholine; R-SNARE Proteins; Trypanosoma brucei brucei
PubMed: 31160283
DOI: 10.1128/AAC.00795-19 -
Biochimica Et Biophysica Acta May 2013Using phase contrast and fluorescence microscopy we study the influence of the alkylphospholipid, ALP, 10-(octyloxy) decyl-2-(trimethylammonium) ethyl phosphate, ODPC,...
Using phase contrast and fluorescence microscopy we study the influence of the alkylphospholipid, ALP, 10-(octyloxy) decyl-2-(trimethylammonium) ethyl phosphate, ODPC, in giant unilamellar vesicles, GUVs, composed of DOPC (1,2-dioleoyl-sn-glycero-3-phosphocholine), brain sphingomyelin (SM) and cholesterol (Chol). The results show that adding 100μM ODPC (below CMC) to the outer solution of GUVs promotes DOPC membrane disruption over a period of 1h of continuous observation. On the other hand, the presence of SM and Chol in homogeneous fluid lipid bilayers protects the membrane from disruption. Interestingly, by adding 100μM ODPC to GUVs containing DOPC:SM:Chol (1:1:1), which display liquid ordered (Lo)-liquid disordered (Ld) phase coexistence, the domains rapidly disappear in less than 1min of ODPC contact with the membrane. The lipids are subsequently redistributed to liquid domains within a time course of 14-18min, reflecting that the homogenous phase was not thermodynamically stable, followed by rupture of the GUVs. A similar mechanism of action is also observed for perifosine, although to a larger extent. Therefore, the initial stage of lipid raft disruption by both ODPC and perifosine, and maybe other ALPS, by promoting lipid mixing, may be correlated with their toxicity upon neoplastic cells, since selective (dis)association of essential proteins within lipid raft microdomains must take place in the plasma membrane.
Topics: Cholesterol; Glycerophospholipids; Lipid Bilayers; Membrane Fluidity; Membrane Lipids; Membrane Microdomains; Microscopy, Fluorescence; Microscopy, Phase-Contrast; Models, Chemical; Models, Molecular; Phosphatidylcholines; Phosphorylcholine; Sphingomyelins; Thermodynamics; Unilamellar Liposomes
PubMed: 23376656
DOI: 10.1016/j.bbamem.2013.01.017