scholarly journals Interaction between Miltefosine and Amphotericin B: Consequences for Their Activities towards Intestinal Epithelial Cells and Leishmania donovani Promastigotes In Vitro

2006 ◽  
Vol 50 (11) ◽  
pp. 3793-3800 ◽  
Author(s):  
Cécile Ménez ◽  
Marion Buyse ◽  
Madeleine Besnard ◽  
Robert Farinotti ◽  
Philippe M. Loiseau ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Leishmania Donovani ◽  
Biological Activities ◽  
Intestinal Barrier ◽  
Oral Route ◽  
Transepithelial Transport ◽  
Physicochemical Interaction ◽  
Cell Monolayers ◽  
Permeability Enhancement

ABSTRACT The aim of this study was to evaluate the potential of a combination of two antileishmanial drugs, miltefosine (HePC) and amphotericin B (AMB), when administered by the oral route. Caco-2 cell monolayers were used as a validated in vitro model of the intestinal barrier and Leishmania donovani promastigotes as a model for evaluating the effect of the drug combination. Spectroscopic measurements demonstrated that HePC and AMB associate, leading to the formation of mixed aggregates in which AMB is solubilized as monomers. The incubation of the association of HePC and AMB with Caco-2 cell monolayers, at a concentration higher than 5 μM, led to (i) a reduction of the HePC-induced paracellular permeability enhancement in Caco-2 cell monolayers, (ii) an inhibition of the uptake of both drugs, and (iii) a decrease in the transepithelial transport of both drugs, suggesting that a pharmacokinetic antagonism between HePC and AMB could occur after their oral administration. However, the combination did not exhibit any antagonism or synergy in its antileishmanial activity. These results demonstrated a strong physicochemical interaction between HePC and AMB, depending on the concentration of each, which could have important consequences for their biological activities, if they are administered together.

scholarly journals Enhanced Transepithelial Permeation of Gallic Acid and (−)-Epigallocatechin Gallate across Human Intestinal Caco-2 Cells Using Electrospun Xanthan Nanofibers

Pharmaceutics ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 155 ◽  
Author(s):  
Adele Faralli ◽  
Elhamalsadat Shekarforoush ◽  
Ana Mendes ◽  
Ioannis Chronakis
Keyword(s):  
Gallic Acid ◽  
Epigallocatechin Gallate ◽  
Electrospun Nanofibers ◽  
Transepithelial Transport ◽  
Efflux Transporters ◽  
Polyphenol Compounds ◽  
Cell Monolayers ◽  
Permeability Enhancement ◽  
Release Studies

Electrospun xanthan polysaccharide nanofibers (X) were developed as an encapsulation and delivery system of the poorly absorbed polyphenol compounds, gallic acid (GA) and (−)-epigallocatechin gallate (EGCG). Scanning electron microscopy was used to characterize the electrospun nanofibers, and controlled release studies were performed at pH 6.5 and 7.4 in saline buffer, suggesting that the release of polyphenols from xanthan nanofibers follows a non Fickian mechanism. Furthermore, the X-GA and X-EGCG nanofibers were incubated with Caco-2 cells, and the cell viability, transepithelial transport, and permeability properties across cell monolayers were investigated. An increase of GA and EGCG permeability was observed when the polyphenols were loaded into xanthan nanofibers, compared to the free compounds. The observed in vitro permeability enhancement of GA and EGCG was induced by the presence of the polysaccharide nanofibers, which successfully inhibited efflux transporters, as well as by tight junctions opening.

scholarly journals Heterogeneous expression of Pil3 pilus is critical for Streptococcus gallolyticus translocation across polarized colonic epithelial monolayers

2019 ◽  
Author(s):  
Mariana Martins ◽  
Laurence du Merle ◽  
Patrick Trieu-Cuot ◽  
Shaynoor Dramsi
Keyword(s):  
Intestinal Barrier ◽  
Opportunistic Pathogen ◽  
Oral Route ◽  
Elderly Persons ◽  
Dependent Manner ◽  
Bacterial Surface ◽  
Streptococcus Gallolyticus ◽  
Heterogeneous Expression ◽  
Colonic Cells

ABSTRACTStreptococcus gallolyticus subspecies gallolyticus (Sgg) is an opportunistic pathogen responsible for septicaemia and endocarditis in elderly persons. Sgg is also a commensal of the human gastrointestinal tract. Here we demonstrate that Sgg strain UCN34 translocates across tight intestinal barriers in vitro in a Pil3-dependent manner. Confocal images of UCN34 passage across human colonic cells reveals that Sgg utilizes a paracellular pathway. Pil3 was previously shown to be expressed heterogeneously and WT UCN34 consists of about 90% of Pil3low and 10% of Pil3high cells. We found that both the Δpil3 mutant and the Pil3+ overexpressing variant could not translocate across Caco-2 and T84 barriers. Interestingly, combining live Δpil3 mutant cells with fixed Pil3+ variants in a 10:1 ratio (mimicking UCN34 WT population) allowed efficient translocation of the Δpil3 mutant. These experiments demonstrate that heterogeneous expression of Pil3 plays a key role in optimal translocation of Sgg across the intestinal barrier.ABSTRACT IMPORTANCEStreptococcus gallolyticus subsp. gallolyticus (Sgg) is an opportunistic pathogen responsible for septicemia and infective endocarditis in elderly persons. Sgg is a commensal of the rumen of herbivores and transmission to humans most probably occurs through the oral route. In this work, we have studied how this bacterium crosses the intestinal barrier using well-known in vitro models. Confocal microscopy images revealed that Sgg UCN34 can traverse the epithelial monolayer in between adjacent cells. We next showed that passage of Sgg from the apical to the basolateral compartment is dependent on the heterogenous expression of the Pil3 pilus at the bacterial surface. We hypothesize that Pil3high cocci adhere firmly to epithelial cells to activate transient opening of tight junctions thereby allowing the traversal of Pil3low bacteria.

Nanocargos: A Burgeoning Quest in Cancer Management

2020 ◽  
Vol 10 (2) ◽  
pp. 149-163
Author(s):  
Atul Jain ◽  
Teenu Sharma ◽  
Sumant Saini ◽  
Om Prakash Katare ◽  
Vandana. Soni ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Oral Delivery ◽  
Imaging Techniques ◽  
Intestinal Barrier ◽  
Oral Route ◽  
In Vitro Models ◽  
In Vitro Toxicity ◽  
Cancer Management ◽  
Surface Modified

Cancer, a complex series of diseased conditions, contributes to a significant health problem and is a leading cause of mortalities across the world. Lately, with the advent of improved diagnostics and imaging techniques, and newer advanced oral chemotherapeutics; millions of cancer affected people can lengthen their life span. Despite all the challenges associated with an active chemotherapeutic molecule like microenvironment and the intestinal barrier of the gastrointestinal tract (GIT) etc., the oral delivery remains the most acceptable route of drug administration. In this regard, nanotechnology has played a significant role in the counteracting the challenges encountered with newly developed molecules and aiding in improving their bioavailability and targetability to the tumour site, while administering through the oral route. Several literature instances document the usage of nanostructured drug delivery systems such as lipid-based, polymerbased or metallic nanomaterials to improve the efficacy of chemotherapy. Besides, sitespecific targeted surface-modified drug delivery system designed to deliver the active molecule has opened up to the newer avenues of nanotechnology. However, the issue of potential toxicity allied with nanotechnology cannot be compromised and thus, needs specific ethical regulations and guidelines. The various in vitro models have been developed to evaluate the in vitro toxicity profile which can be further correlated with the invivo model. Thus, this review provides a summarized account of the various aspects related to the role of nanotechnology in cancer therapy and various related issues thereof; that must be triumphed over to apprehend its full promise.

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.

Transepithelial phosphate transport in rabbit proximal tubular cells adapted to phosphate deprivation

1994 ◽  
Vol 266 (6) ◽  
pp. C1609-C1618 ◽  
Author(s):  
S. J. Scheinman ◽  
R. Reid ◽  
R. Coulson ◽  
D. B. Jones ◽  
S. M. Ford
Keyword(s):  
Primary Cultures ◽  
Phosphate Transport ◽  
Progressive Increase ◽  
Transepithelial Transport ◽  
Cortical Cells ◽  
Cell Monolayers ◽  
Pi Transport ◽  
Overnight Incubation ◽  
Proximal Tubular

Both renal and nonrenal cells in culture adapt to deprivation of Pi by increasing Na-dependent Pi uptake. We studied whether this change in uptake is reflected in an increased renal transepithelial Pi transport. We grew primary cultures of rabbit renal cortical cells in plastic flasks and subcultured them onto Millicell-HA filters. This produced cell monolayers, which structurally and functionally resembled proximal tubule. These cells performed Na-dependent net transepithelial transport of 32Pi in the apical-to-basolateral direction that was inhibited by phosphonoformic acid in the apical fluid or by ouabain in the basolateral fluid or by preincubation with parathyroid hormone. Overnight incubation at low Pi concentrations led to a progressive increase in 5-min Na-dependent Pi uptake into cell monolayers. Na-dependent Pi uptake was threefold higher following overnight incubation at 25 microM Pi, compared with 3 mM Pi, and the increase was one-half maximal with incubation at an extracellular Pi concentration ([Pi]) of 300 microM. This was associated with a decrease in Na-dependent transepithelial Pi flux to the basolateral fluid by the same cells, which fell dramatically following incubation at < or = 300 microM Pi. There was no change in Na-dependent uptake or transepithelial transport of L-glutamine. This adaptation to Pi deprivation in vitro appears to serve to restore depleted cell stores of Pi rather than to regulate transepithelial Pi transport.

scholarly journals Orally Active Antiviral Tripeptide Glycyl-Prolyl-Glycinamide Is Activated by CD26 (Dipeptidyl Peptidase IV) before Transport across the Intestinal Epithelium

2005 ◽  
Vol 49 (3) ◽  
pp. 1087-1092 ◽  
Author(s):  
Ina Hubatsch ◽  
Lucia Lazorova ◽  
Anders Vahlne ◽  
Per Artursson
Keyword(s):  
Intestinal Epithelium ◽  
Dipeptidyl Peptidase ◽  
Oral Route ◽  
Dipeptidyl Peptidase Iv ◽  
Drug Candidate ◽  
Absorption Mechanism ◽  
Apparent Permeability ◽  
Cell Monolayers ◽  
Orally Active

ABSTRACT The tripeptide amide glycyl-prolyl-glycinamide (GPG-amide) is a new antiretroviral drug candidate, but its absorption mechanism is unknown. In this investigation, the transport and metabolism of GPG-amide were studied in a model of the human intestinal epithelium, Caco-2 cell monolayers. The results show that when the tripeptide amide came into contact with the apical enterocyte membrane, it was degraded by CD26 (dipeptidyl peptidase IV) to glycylproline and the antiretrovirally active metabolite glycinamide. Glycinamide retained antiretroviral activity in vitro after transport through the Caco-2 cell monolayers. The transport of glycinamide across Caco-2 cell monolayers occurred via passive diffusion with an apparent permeability coefficient of about 2 × 10−6 cm s−1, which suggests that it is absorbed by the oral route in sufficient amounts to be considered for oral administration. In conclusion, the tripeptide GPG-amide acts as a prodrug that is activated by CD26 to release the orally active antiretroviral compound glycinamide.

scholarly journals Discovery of Safe and Orally Effective 4-Aminoquinaldine Analogues as Apoptotic Inducers with Activity against Experimental Visceral Leishmaniasis

2011 ◽  
Vol 56 (1) ◽  
pp. 432-445 ◽  
Author(s):  
Partha Palit ◽  
Abhijit Hazra ◽  
Arindam Maity ◽  
R. S. K. Vijayan ◽  
Prabu Manoharan ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Oral Delivery ◽  
Leishmania Donovani ◽  
Reactive Oxygen Species Generation ◽  
Oral Route ◽  
Apoptotic Pathway ◽  
Content Type ◽  
Lead Compounds

ABSTRACTNovel antileishmanials are urgently required to overcome emergence of drug resistance, cytotoxic effects, and difficulties in oral delivery. Toward this, we investigated a series of novel 4-aminoquinaldine derivatives, a new class of molecules, as potential antileishmanials. 4-Aminoquinaldine derivatives presented inhibitory effects onL. donovanipromastigotes and amastigotes (50% inhibitory concentration range, 0.94 to 127 μM). Of these, PP-9 and PP-10 were the most effectivein vitroand demonstrated strong efficaciesin vivothrough the intraperitoneal route. They were also found to be effective against both sodium antimony gluconate-sensitive and -resistantLeishmania donovanistrains in BALB/c mice when treated orally, resulting in more than 95% protection. Investigation of their mode of action revealed that killing by PP-10 involved moderate inhibition of dihydrofolate reductase and elicitation of the apoptotic cascade. Our studies implicate that PP-10 augments reactive oxygen species generation, evidenced from decreased glutathione levels and increased lipid peroxidation. Subsequent disruption ofLeishmaniapromastigote mitochondrial membrane potential and activation of cytosolic proteases initiated the apoptotic pathway, resulting in DNA fragmentation and parasite death. Our results demonstrate that PP-9 and PP-10 are promising lead compounds with the potential for treating visceral leishmaniasis (VL) through the oral route.

scholarly journals Mechanism of Amphotericin B Resistance inLeishmania donovani Promastigotes

1998 ◽  
Vol 42 (2) ◽  
pp. 352-357 ◽  
Author(s):  
Nicolas Mbongo ◽  
Philippe M. Loiseau ◽  
Marie A. Billion ◽  
Malka Robert-Gero
Keyword(s):  
Amphotericin B ◽  
Leishmania Donovani ◽  
Saturated Fatty Acids ◽  
Major Fatty Acid ◽  
Fluorescence Measurement ◽  
Wild Type ◽  
Drug Pressure ◽  
Resistant Cells

ABSTRACT Amphotericin B (AmB)-resistant Leishmania donovanipromastigotes were selected by increasing drug pressure, and their biological features were compared with those of the wild-type parent strain. The 50% inhibitory concentration for resistant cells was 20 times higher than that for the wild-type. Resistance was stable after more than 40 passages in drug-free medium, and resistant promastigotes were infective to macrophages in vitro but lost their virulence in vivo. They had 2.5 times longer generation time, decreased AmB uptake, and increased AmB efflux in comparison to the wild type. Fluorescence measurement with a specific plasma membrane probe, 1-[4-(trimethylammonio)-1,6-diphenylhexa]-1,3,5-triene, showed increased membrane fluidity in drug-resistant promastigotes. Analysis of lipid composition showed that in resistant cells saturated fatty acids were prevalent, with stearic acid as the major fatty acid, and the major sterol was an ergosterol precursor, the cholesta-5, 7, 24-trien-3β-ol and not ergosterol as in the AmB-sensitive strain.

scholarly journals Activity of the Novel Immunomodulatory Compound Tucaresol against Experimental Visceral Leishmaniasis

2000 ◽  
Vol 44 (6) ◽  
pp. 1494-1498 ◽  
Author(s):  
Aden C. Smith ◽  
Vanessa Yardley ◽  
John Rhodes ◽  
Simon L. Croft
Keyword(s):  
Leishmania Donovani ◽  
Dose Range ◽  
Optimal Dose ◽  
Oral Route ◽  
Optimum Dose ◽  
The Novel ◽  
Once Daily ◽  
Reduced Activity ◽  
Liver Infection

ABSTRACT Tucaresol, a novel immunomodulator, was inactive againstLeishmania donovani amastigotes in both peritoneal and bone marrow macrophages in vitro at concentrations between 100 and 1 μM, with toxicity to macrophages and parasites at 300 μM. However, against L. donovani in BALB/c mice at doses between 80 and 1.25 mg/kg of body weight administered once daily by the oral route during days 7 to 11 of infection, an optimal dose of 5 mg/kg produced a 43.8 to 62.4% suppression of liver amastigotes, with significantly reduced activity at the extremes of the dose range. This response was not related to levels of infection. No interaction with the standard pentavalent antimonial sodium stibogluconate (Pentostam) was observed during this period of infection. The optimum dose of 5 mg/kg was ineffective when administered during the first week of infection and was most effective against the liver infection when administered during weeks 2 to 3 of infection (42.3 to 46.8% inhibition) and against the splenic infection when administered during week 6 of infection (59.5% inhibition). The optimum dose of tucaresol against L. donovani in C57BL/6 mice was 5 mg/kg, which produced a 40.8 to 48.7% suppression of liver amastigotes when administered in a range of 80 to 1.25 mg/kg during days 7 to 11 of infection. The drug had no activity against L. donovani infections in C.B-17scid mice when the same regimen was used.

scholarly journals Immunoadjuvant Chemotherapy of Visceral Leishmaniasis in Hamsters Using Amphotericin B-Encapsulated Nanoemulsion Template-Based Chitosan Nanocapsules

2013 ◽  
Vol 57 (4) ◽  
pp. 1714-1722 ◽  
Author(s):  
Shalini Asthana ◽  
Anil K. Jaiswal ◽  
Pramod K. Gupta ◽  
Vivek K. Pawar ◽  
Anuradha Dube ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Amphotericin B ◽  
Leishmania Donovani ◽  
Transforming Growth Factor ◽  
Treatment Options ◽  
Interleukin 12 ◽  
Necrosis Factor Alpha ◽  
Content Type

ABSTRACTThe accessible treatment options for life-threatening neglected visceral leishmaniasis (VL) disease have problems with efficacy, stability, adverse effects, and cost, making treatment a complex issue. Here we formulated nanometric amphotericin B (AmB)-encapsulated chitosan nanocapsules (CNC-AmB) using a polymer deposition technique mediated by nanoemulsion template fabrication. CNC-AmB exhibited good steric stabilityin vitro, where the chitosan content was found to be efficient at preventing destabilization in the presence of protein and Ca2+. A toxicity study on the model cell line J774A and erythrocytes revealed that CNC-AmB was less toxic than commercialized AmB formulations such as Fungizone and AmBisome. The results ofin vitro(macrophage-amastigote system; 50% inhibitory concentration [IC50], 0.19 ± 0.04 μg AmB/ml) andin vivo(Leishmania donovani-infected hamsters; 86.1% ± 2.08% parasite inhibition) experiments in conjunction with effective internalization by macrophages illustrated the efficacy of CNC-AmB at augmenting antileishmanial properties. Quantitative mRNA analysis by real-time PCR (RT-PCR) showed that the improved effect was synergized with the upregulation of tumor necrosis factor alpha (TNF-α), interleukin-12 (IL-12), and inducible nitric oxide synthase and with the downregulation of transforming growth factor β (TGF-β), IL-10, and IL-4. These research findings suggest that a cost-effective CNC-AmB immunoadjuvant chemotherapeutic delivery system could be a viable alternative to the current high-cost commercial lipid-based formulations.

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