scholarly journals Antileishmanial Activity and Synergistic Effects of Amphotericin B Deoxycholate with Allicin and Andrographolide against Leishmania martiniquensis In Vitro

Pathogens ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 49 ◽  
Author(s):  
Nuchpicha Intakhan ◽  
Wetpisit Chanmol ◽  
Pradya Somboon ◽  
Michelle D. Bates ◽  
Vanessa Yardley ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Synergistic Effects ◽  
Leishmania Species ◽  
Host Cells ◽  
Intracellular Amastigotes ◽  
Fold Reduction ◽  
Amphotericin B Deoxycholate ◽  
Dose Reduction Index ◽  
First Time

Leishmania (Mundinia) martiniquensis is a causative agent of visceral leishmaniasis, but in HIV-infected patients both visceral and disseminated cutaneous leishmaniasis are presented. Recurrence of the disease after treatment has been reported in some cases indicating that improved chemotherapy is required. In this study, the susceptibility of L. martiniquensis to Amphotericin B deoxycholate (AmB), allicin, and andrographolide was evaluated and the synergistic effects of allicin or andrographolide combined with AmB against L. martiniquensis intracellular amastigotes in mouse peritoneal exudate macrophages (PEMs) were investigated in vitro for the first time. The results showed that L. martiniquensis was highly susceptible to AmB as expected, but allicin and andrographolide had selectivity index (SI) values greater than 10, indicating promise in both compounds for treatment of host cells infected with L. martiniquensis. Four AmB/allicin combinations presented combination index (CI) values less than 1 (0.58–0.68) for intracellular amastigotes indicating synergistic effects. The combination with the highest dose reduction index (DRI) allowed an approximately four-fold reduction of AmB use in that combination. No synergistic effects were observed in AmB/andrographolide combinations. The data provided in this study leads for further study to develop novel therapeutic agents and improve the treatment outcome for leishmaniasis caused by this Leishmania species.

scholarly journals Pharmacokinetics and Pharmacodynamics of Amphotericin B Deoxycholate, Liposomal Amphotericin B, and Amphotericin B Lipid Complex in an In Vitro Model of Invasive Pulmonary Aspergillosis

2010 ◽  
Vol 54 (8) ◽  
pp. 3432-3441 ◽  
Author(s):  
Jodi M. Lestner ◽  
Susan J. Howard ◽  
Joanne Goodwin ◽  
Lea Gregson ◽  
Jayesh Majithiya ◽  
...  
Keyword(s):  
Confocal Microscopy ◽  
Amphotericin B ◽  
Liposomal Amphotericin ◽  
Invasive Pulmonary Aspergillosis ◽  
Host Cells ◽  
Pulmonary Aspergillosis ◽  
Lipid Complex ◽  
Amphotericin B Deoxycholate ◽  
Amphotericin B Lipid Complex

ABSTRACT The pharmacodynamic and pharmacokinetic (PK-PD) properties of amphotericin B (AmB) formulations against invasive pulmonary aspergillosis (IPA) are not well understood. We used an in vitro model of IPA to further elucidate the PK-PD of amphotericin B deoxycholate (DAmB), liposomal amphotericin B (LAmB) and amphotericin B lipid complex (ABLC). The pharmacokinetics of these formulations for endovascular fluid, endothelial cells, and alveolar cells were estimated. Pharmacodynamic relationships were defined by measuring concentrations of galactomannan in endovascular and alveolar compartments. Confocal microscopy was used to visualize fungal biomass. A mathematical model was used to calculate the area under the concentration-time curve (AUC) in each compartment and estimate the extent of drug penetration. The interaction of LAmB with host cells and hyphae was visualized using sulforhodamine B-labeled liposomes. The MICs for the pure compound and the three formulations were comparable (0.125 to 0.25 mg/liter). For all formulations, concentrations of AmB progressively declined in the endovascular fluid as the drug distributed into the cellular bilayer. Depending on the formulation, the AUCs for AmB were 10 to 300 times higher within the cells than within endovascular fluid. The concentrations producing a 50% maximal effect (EC50) in the endovascular compartment were 0.12, 1.03, and 4.41 mg/liter for DAmB, LAmB, and ABLC, respectively, whereas, the EC50 in the alveolar compartment were 0.17, 7.76, and 39.34 mg/liter, respectively. Confocal microscopy suggested that liposomes interacted directly with hyphae and host cells. The PK-PD relationships of the three most widely used formulations of AmB differ markedly within an in vitro lung model of IPA.

scholarly journals In Vitro and In Vivo Activities of a Triterpenoid Saponin Extract (PX-6518) from the Plant Maesa balansae against Visceral Leishmania Species

2004 ◽  
Vol 48 (1) ◽  
pp. 130-136 ◽  
Author(s):  
Louis Maes ◽  
Dirk Vanden Berghe ◽  
Nils Germonprez ◽  
Ludo Quirijnen ◽  
Paul Cos ◽  
...  
Keyword(s):  
Leishmania Donovani ◽  
Human Fibroblasts ◽  
Subcutaneous Administration ◽  
Leishmania Species ◽  
Host Cells ◽  
Triterpenoid Saponin ◽  
Sodium Stibogluconate ◽  
Triterpenoid Saponins

ABSTRACT The in vitro and in vivo activities of a mixture of six oleane triterpene saponins, recovered from the methanolic extract of the leaves of the Vietnamese plant Maesa balansae (PX-6518), were evaluated against drug-sensitive visceral Leishmania strains. The in vitro 50% inhibitory concentration (IC50) against intracellular Leishmania infantum amastigotes was 0.04 μg/ml. The cytotoxic concentrations causing 50% cell death (CC50s) were about 1 μg/ml in murine macrophage host cells and >32 μg/ml in human fibroblasts (MRC-5 cell line). Evaluation in the Leishmania donovani BALB/c mouse model indicated that a single subcutaneous administration of 0.4 mg/kg at 1 day after infection reduced liver amastigote burdens by about 95% in all treated animals. If treatment was delayed until 14 days after infection, a dose of 1.6 mg/kg of body weight was required to maintain the same level of activity. Single 250-mg/kg doses of sodium stibogluconate (Pentostam) 1 and 14 days after infection produced comparable efficacies. A single dose of PX-6518 at 2.5 mg/kg administered 5 days before infection was still 100% effective in preventing liver infection, suggesting a particularly long residual action. Spleen and bone marrow could not be cleared by PX-6518 nor sodium stibogluconate. PX-6518 did not show activity after oral dosing at up to 200 mg/kg for 5 days. This study concludes that triterpenoid saponins from M. balansae show promising in vitro and in vivo antileishmanial potential and can be considered as new lead structures in the search for novel antileishmanial drugs.

scholarly journals Defining the early stages of intestinal colonisation by whipworms

2020 ◽  
Author(s):  
María A. Duque-Correa ◽  
David Goulding ◽  
Claire Cormie ◽  
Catherine Sharpe ◽  
Judit Gali Moya ◽  
...  
Keyword(s):  
Intestinal Epithelium ◽  
Early Stage ◽  
Proximal Colon ◽  
Host Cells ◽  
Parasitic Nematodes ◽  
Metazoan Parasites ◽  
Multiple Cells ◽  
First Time

ABSTRACTHundreds of millions of people are infected with whipworms (Trichuris trichiura), large metazoan parasites that live in the caecum and proximal colon. Whipworms inhabit distinct multi-intracellular epithelial burrows that have been described as syncytial tunnels. However, the interactions between first-stage (L1) larvae and the host epithelia that determine parasite invasion and establishment in the syncytium remain unclear. In vivo experiments investigating these events have been severely hampered by the limited in situ accessibility to intracellular infective larvae at the bottom of the crypts of Lieberkühn, and the lack of genetic tools such as fluorescent organisms that are readily available for other pathogens but not parasitic nematodes. Moreover, cell lines, which do not mimic the complexity of the intestinal epithelium, have been unsuccessful in supporting infection by whipworm larvae. Here, we show that caecaloids grown in an open crypt-like conformation recapitulate the caecal epithelium. Using this system, we establish in vitro infections with T. muris L1 larvae for the first-time, and provide clear evidence that syncytial tunnels are formed at this early stage. We show that larval whipworms are completely intracellular but woven through multiple cells. Using the caecaloids, we are able to visualise the pathways taken by the larvae as they burrow through the epithelial cells. We also demonstrate that larvae degrade the mucus layers overlaying the epithelium, enabling them to access the cells below. We show that early syncytial tunnels are composed of enterocytes and goblet cells that are alive and actively interacting with the larvae during the first 24 h of the infection. Progression of infection results in damage to host cells and by 72 h post-infection, we show that desmosomes of cells from infected epithelium widen and some host cells appear to become liquified. Collectively, our work unravels processes mediating the intestinal epithelium invasion by whipworms and reveals new specific interactions between the host and the parasite that allow the whipworm to establish on its multi-intracellular niche. Our study demonstrates that caecaloids can be used as a relevant in vitro model to investigate the infection biology of T. muris during the early colonisation of its host.

scholarly journals In vivo analysis of influenza A mRNA secondary structures identifies critical regulatory motifs

2019 ◽  
Vol 47 (13) ◽  
pp. 7003-7017 ◽  
Author(s):  
Lisa Marie Simon ◽  
Edoardo Morandi ◽  
Anna Luganini ◽  
Giorgio Gribaudo ◽  
Luis Martinez-Sobrido ◽  
...  
Keyword(s):  
Secondary Structure ◽  
Influenza A ◽  
Host Cells ◽  
Messenger Rnas ◽  
Infected Cells ◽  
In Vivo Analysis ◽  
First Time ◽  
Negative Sense

AbstractThe influenza A virus (IAV) is a continuous health threat to humans as well as animals due to its recurring epidemics and pandemics. The IAV genome is segmented and the eight negative-sense viral RNAs (vRNAs) are transcribed into positive sense complementary RNAs (cRNAs) and viral messenger RNAs (mRNAs) inside infected host cells. A role for the secondary structure of IAV mRNAs has been hypothesized and debated for many years, but knowledge on the structure mRNAs adopt in vivo is currently missing. Here we solve, for the first time, the in vivo secondary structure of IAV mRNAs in living infected cells. We demonstrate that, compared to the in vitro refolded structure, in vivo IAV mRNAs are less structured but exhibit specific locally stable elements. Moreover, we show that the targeted disruption of these high-confidence structured domains results in an extraordinary attenuation of IAV replicative capacity. Collectively, our data provide the first comprehensive map of the in vivo structural landscape of IAV mRNAs, hence providing the means for the development of new RNA-targeted antivirals.

scholarly journals In VitroCombination of Isavuconazole with Micafungin or Amphotericin B Deoxycholate against Medically Important Molds

2014 ◽  
Vol 58 (11) ◽  
pp. 6934-6937 ◽  
Author(s):  
Aspasia Katragkou ◽  
Matthew McCarthy ◽  
Joseph Meletiadis ◽  
Vidmantas Petraitis ◽  
Patriss W. Moradi ◽  
...  
Keyword(s):  
Combination Therapy ◽  
Invasive Aspergillosis ◽  
Amphotericin B ◽  
Aspergillus Flavus ◽  
Aspergillus Terreus ◽  
Synergistic Activity ◽  
Content Type ◽  
Amphotericin B Deoxycholate ◽  
Combination Studies

ABSTRACTWhether isavuconazole, an extended-spectrum triazole, possesses synergistic activity in combination therapy with echinocandins or amphotericin B for the treatment of invasive molds infections has not been studied. Ourin vitrocombination studies showed that isavuconazole and micafungin are synergistically active againstAspergillus fumigatus,Aspergillus flavus,Aspergillus terreus, andCunninghamella bertholletiae. These results suggest that isavuconazole, in combination with micafungin, may have a role in the treatment of invasive aspergillosis and warrants further investigation.

scholarly journals In Vitro Susceptibilities of Leishmania donovani Promastigote and Amastigote Stages to Antileishmanial Reference Drugs: Practical Relevance of Stage-Specific Differences

2009 ◽  
Vol 53 (9) ◽  
pp. 3855-3859 ◽  
Author(s):  
Marieke Vermeersch ◽  
Raquel Inocêncio da Luz ◽  
Kim Toté ◽  
Jean-Pierre Timmermans ◽  
Paul Cos ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Leishmania Donovani ◽  
Crystalline Substance ◽  
Sodium Stibogluconate ◽  
Cellular Mechanisms ◽  
Intracellular Amastigotes ◽  
Discovery Research ◽  
Drug Discovery Research ◽  
Primary Mouse

ABSTRACT The in vitro susceptibilities of the reference strain Leishmania donovani MHOM/ET/67/L82 to sodium stibogluconate, amphotericin B, miltefosine, and the experimental compound PX-6518 were determined for extracellular log-phase promastigotes, established axenic amastigotes, fresh spleen-derived amastigotes, and intracellular amastigotes in primary mouse peritoneal macrophages. Susceptibility to amphotericin B did not differ across the various axenic models (50% inhibitory concentrations [IC50], 0.6 to 0.7 μM), and amphotericin B showed slightly higher potency against intracellular amastigotes (IC50, 0.1 to 0.4 μM). A similar trend was observed for miltefosine, with comparable efficacies against the extracellular (IC50, 0.4 to 3.8 μM) and intracellular (IC50, 0.9 to 4.3 μM) stages. Sodium stibogluconate, used either as Pentostam or as a crystalline substance, was inactive against all axenic stages (IC50, >64 μg SbV/ml) but showed good efficacy against intracellular amastigotes (IC50, 22 to 28 μg SbV/ml); the crystalline substance was about two to three times more potent (IC50, 9 to 11 μg SbV/ml). The activity profile of PX-6518 was comparable to that of sodium stibogluconate, but at a much higher potency (IC50, 0.1 μg/ml). In conclusion, the differential susceptibility determines which in vitro models are appropriate for either drug screening or resistance monitoring of clinical field isolates. Despite the more complex and labor-intensive protocol, the current results support the intracellular amastigote model as the gold standard for in vitro Leishmania drug discovery research and for evaluation of the resistance of field strains, since it also includes host cell-mediated effects. Axenic systems can be recommended only for compounds for which no cellular mechanisms are involved, for example, amphotericin B and miltefosine.

scholarly journals Strategy To Create Chimeric Proteins Derived from Functional Adhesin Regions of Mycoplasma pneumoniae for Vaccine Development

2009 ◽  
Vol 77 (11) ◽  
pp. 5007-5015 ◽  
Author(s):  
Nicol Schurwanz ◽  
Enno Jacobs ◽  
Roger Dumke
Keyword(s):  
Respiratory Tract ◽  
Mycoplasma Pneumoniae ◽  
Recombinant Proteins ◽  
Vaccine Development ◽  
Chimeric Protein ◽  
Host Cells ◽  
Vitro Assay ◽  
Bronchial Epithelial ◽  
First Time

ABSTRACT The cell wall-less bacterium Mycoplasma pneumoniae is one of the most common agents of respiratory tract diseases in humans. Adhesin-mediated binding of the bacteria to host cells is a crucial step in colonization and subsequent pathogenesis. For the first time, we expressed 16 recombinant proteins covering almost the whole major adhesin P1 and the adherence-associated protein P30 to characterize these proteins immunologically and functionally. We describe a new in vitro assay using several human cell lines in combination with fluorescence-activated cell sorting analysis to screen antisera raised against the recombinant proteins quantitatively for adherence inhibition activity. The protein derived from the nearly C-terminal part of the P1 adhesin (amino acids [aa] 1288 to 1518) and the protein P30 (aa 17 to 274) especially showed prominent immunoreactivity with sera from M. pneumoniae-immunized guinea pigs as well as with M. pneumoniae-positive patient sera. We demonstrate that the same protein regions are involved in mediating cytadherence since antibodies against these adhesin regions decrease mycoplasma adhesion to human cells significantly. For further vaccine studies, we optimized the immunogenic and adherence-mediating properties of the antigen by combining both the P1 and the P30 regions in a novel chimeric protein. Antibodies against this protein show an increased reduction of M. pneumoniae adherence to human bronchial epithelial cells by 95%, which is comparable to results with polyspecific anti-M. pneumoniae animal serum. Our strategy results in a promising defined antigen candidate for reducing or even preventing M. pneumoniae colonization of the respiratory tract in future vaccination studies.

scholarly journals PPAR-gamma Fun(gi) With Prostaglandin

2020 ◽  
Vol 17 ◽  
pp. 155076291989964
Author(s):  
Robert J. Evans ◽  
Simon A. Johnston
Keyword(s):  
Partial Agonist ◽  
Ppar Gamma ◽  
Host Cells ◽  
Culture Models ◽  
Important Regulator ◽  
Inflammatory Phenotypes ◽  
First Time ◽  
Cell Culture Models

In our recent publication, we show for the first time that the fungal pathogen Cryptococcus neoformans is able to manipulate host cells by producing eicosanoids that mimic those found in the host. Using complementary in vivo zebrafish and in vitro macrophage cell culture models of Cryptococcus infection, we found that these eicosanoids manipulate host innate immune cells by activating the host receptor PPAR-gamma which is an important regulator of macrophage inflammatory phenotypes. We initially identified PGE2 as the eicosanoid species responsible for this effect; however, we later found that a derivative of PGE2—15-keto-PGE2—was ultimately responsible and that this eicosanoid acted as a partial agonist to PPAR-gamma. In this commentary, we will discuss some of the concepts and conclusions in our original publication and expand on their implications and future directions.

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