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Cell Proliferation Jan 2020We investigated the anti-cancer activity of pentamidine, an anti-protozoal cationic aromatic diamidine drug, in prostate cancer cells and aimed to provide valuable...
OBJECTIVES
We investigated the anti-cancer activity of pentamidine, an anti-protozoal cationic aromatic diamidine drug, in prostate cancer cells and aimed to provide valuable insights for improving the efficacy of prostate cancer treatment.
MATERIALS AND METHODS
Prostate cancer cell lines and epithelial RWPE-1 cells were used in the study. Cell viability, wound-healing, transwell and apoptosis assays were examined to evaluate the influences of pentamidine in vitro. RNA-seq and qPCR were performed to analyse changes in gene transcription levels upon pentamidine treatment. Mitochondrial changes were assessed by measuring mitochondrial DNA content, morphology, membrane potential, cellular glucose uptake, ATP production and ROS generation. Nude mouse xenograft models were used to test anti-tumour effects of pentamidine in vivo.
RESULTS
Pentamidine exerted profound inhibitory effects on proliferation, colony formation, migration and invasion of prostate cancer cells. In addition, the drug suppressed growth of xenograft tumours without exhibiting any obvious toxicity in nude mice. Mechanistically, pentamidine caused mitochondrial DNA content reduction and induced mitochondrial morphological changes, mitochondrial membrane potential dissipation, ATP level reduction, ROS production elevation and apoptosis in prostate cancer cells.
CONCLUSIONS
Pentamidine can efficiently suppress prostate cancer progression and may serve as a novel mitochondria-targeted therapeutic agent for prostate cancer.
Topics: Animals; Cell Proliferation; DNA, Mitochondrial; DNA, Neoplasm; Humans; Male; Membrane Potential, Mitochondrial; Mice; Mice, Nude; Mitochondria; PC-3 Cells; Pentamidine; Prostatic Neoplasms; Xenograft Model Antitumor Assays
PubMed: 31721355
DOI: 10.1111/cpr.12718 -
Journal of Pharmaceutical Sciences Mar 2020Initially developed as a synthetic analogue of insulin, pentamidine (PTM) is an antimicrobial drug that has recently shown in vitro and in vivo anticancer activity....
Initially developed as a synthetic analogue of insulin, pentamidine (PTM) is an antimicrobial drug that has recently shown in vitro and in vivo anticancer activity. Nevertheless, systemic administration of PTM causes severe side effects, especially nephrotoxicity. Here we propose the association of PTM to different biocompatible nanosystems in order to compare the physicochemical characteristics of the loaded nanocarriers and their influence on the drug cytotoxicity toward cancer cells. In particular, PTM (as free base or with different counterions) was encapsulated into liposomes and poly(lactide-co-glycolide) (PLGA) nanoparticles and all the formulations have been deeply characterized concerning mean diameter, polydispersity index, zeta potential, stability, morphology, PTM loading, and drug release profile. The anticancer activity was evaluated on a human ovarian cancer cell line over 72 h. Results showed that PTM is efficiently loaded into liposomes with a transmembrane citrate or sulfate gradient; concerning PLGA nanoparticles, important association occurred, thanks to ionic interactions between the drug and the polymer. The in vitro studies confirmed the anticancer activity of PTM, which was gradually released with different profiles depending on the drug form and the nanocarrier structure.
Topics: Drug Carriers; Drug Delivery Systems; Humans; Lipids; Nanoparticles; Particle Size; Pentamidine; Polymers
PubMed: 31751563
DOI: 10.1016/j.xphs.2019.11.011 -
PLoS Neglected Tropical Diseases Apr 2021Human African trypanosomiasis (HAT or sleeping sickness) is caused by the parasite Trypanosoma brucei sspp. The disease has two stages, a haemolymphatic stage after the...
BACKGROUND
Human African trypanosomiasis (HAT or sleeping sickness) is caused by the parasite Trypanosoma brucei sspp. The disease has two stages, a haemolymphatic stage after the bite of an infected tsetse fly, followed by a central nervous system stage where the parasite penetrates the brain, causing death if untreated. Treatment is stage-specific, due to the blood-brain barrier, with less toxic drugs such as pentamidine used to treat stage 1. The objective of our research programme was to develop an intravenous formulation of pentamidine which increases CNS exposure by some 10-100 fold, leading to efficacy against a model of stage 2 HAT. This target candidate profile is in line with drugs for neglected diseases inititative recommendations.
METHODOLOGY
To do this, we evaluated the physicochemical and structural characteristics of formulations of pentamidine with Pluronic micelles (triblock-copolymers of polyethylene-oxide and polypropylene oxide), selected candidates for efficacy and toxicity evaluation in vitro, quantified pentamidine CNS delivery of a sub-set of formulations in vitro and in vivo, and progressed one pentamidine-Pluronic formulation for further evaluation using an in vivo single dose brain penetration study.
PRINCIPAL FINDINGS
Screening pentamidine against 40 CNS targets did not reveal any major neurotoxicity concerns, however, pentamidine had a high affinity for the imidazoline2 receptor. The reduction in insulin secretion in MIN6 β-cells by pentamidine may be secondary to pentamidine-mediated activation of β-cell imidazoline receptors and impairment of cell viability. Pluronic F68 (0.01%w/v)-pentamidine formulation had a similar inhibitory effect on insulin secretion as pentamidine alone and an additive trypanocidal effect in vitro. However, all Pluronics tested (P85, P105 and F68) did not significantly enhance brain exposure of pentamidine.
SIGNIFICANCE
These results are relevant to further developing block-copolymers as nanocarriers, improving BBB drug penetration and understanding the side effects of pentamidine.
Topics: Animals; Blood-Brain Barrier; Female; Humans; Male; Mice; Mice, Inbred BALB C; Neglected Diseases; Pentamidine; Trypanocidal Agents; Trypanosoma brucei gambiense; Trypanosoma brucei rhodesiense; Trypanosomiasis, African; Tsetse Flies
PubMed: 33857146
DOI: 10.1371/journal.pntd.0009276 -
Revista Da Sociedade Brasileira de... 2013We aimed to assess and synthesize the information available in the literature regarding the treatment of American tegumentary leishmaniasis in special populations. We... (Review)
Review
We aimed to assess and synthesize the information available in the literature regarding the treatment of American tegumentary leishmaniasis in special populations. We searched MEDLINE (via PubMed), EMBASE, LILACS, SciELO, Scopus, Cochrane Library and mRCT databases to identify clinical trials and observational studies that assessed the pharmacological treatment of the following groups of patients: pregnant women, nursing mothers, children, the elderly, individuals with chronic diseases and individuals with suppressed immune systems. The quality of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. The available evidence suggests that the treatments of choice for each population or disease entity are as follows: nursing mothers and children (meglumine antimoniate or pentamidine), patients with renal disease (amphotericin B or miltefosine), patients with heart disease (amphotericin B, miltefosine or pentamidine), immunosuppressed patients (liposomal amphotericin), the elderly (meglumine antimoniate), pregnant women (amphotericinB) and patients with liver disease (no evidence available). The quality of evidence is low or very low for all groups. Accurate controlled studies are required to fi ll in the gaps in evidence for treatment in special populations. Post-marketing surveillance programs could also collect relevant information to guide treatment decision-making.
Topics: Aged; Amphotericin B; Antiprotozoal Agents; Child; Chronic Disease; Evidence-Based Medicine; Female; Humans; Immunocompromised Host; Leishmaniasis, Cutaneous; Meglumine; Meglumine Antimoniate; Organometallic Compounds; Pentamidine; Phosphorylcholine; Pregnancy; Risk Factors
PubMed: 24474006
DOI: 10.1590/0037-8682-0104-2013 -
Asian Pacific Journal of Tropical... Jun 2012The control of Leishmania infection relies primarily on chemotherapy till date. Resistance to pentavalent antimonials, which have been the recommended drugs to treat... (Review)
Review
The control of Leishmania infection relies primarily on chemotherapy till date. Resistance to pentavalent antimonials, which have been the recommended drugs to treat cutaneous and visceral leishmaniasis, is now widespread in Indian subcontinents. New drug formulations like amphotericin B, its lipid formulations, and miltefosine have shown great efficacy to treat leishmaniasis but their high cost and therapeutic complications limit their usefulness. In addition, irregular and inappropriate uses of these second line drugs in endemic regions like state of Bihar, India threaten resistance development in the parasite. In context to the limited drug options and unavailability of either preventive or prophylactic candidates, there is a pressing need to develop true antileishmanial drugs to reduce the disease burden of this debilitating endemic disease. Notwithstanding significant progress of leishmanial research during last few decades, identification and characterization of novel drugs and drug targets are far from satisfactory. This review will initially describe current drug regimens and later will provide an overview on few important biochemical and enzymatic machineries that could be utilized as putative drug targets for generation of true antileishmanial drugs.
Topics: Aminoquinolines; Amphotericin B; Antigens, Protozoan; Antimony Sodium Gluconate; Antiprotozoal Agents; Caspase Inhibitors; Cyclin-Dependent Kinases; Drug Discovery; Enzyme Inhibitors; Folic Acid Antagonists; Humans; Leishmaniasis; Macrophages; Microbodies; Mitogen-Activated Protein Kinase Kinases; Paromomycin; Pentamidine; Phosphorylcholine; Polyamines; Protease Inhibitors; Sterols; Sulfhydryl Compounds; Topoisomerase Inhibitors
PubMed: 22575984
DOI: 10.1016/S1995-7645(12)60084-4 -
International Journal of Molecular... Sep 2023Combining pentamidine with Gram-positive-targeting antibiotics has been proven to be a promising strategy for treating infections from Gram-negative bacteria (GNB)....
Combining pentamidine with Gram-positive-targeting antibiotics has been proven to be a promising strategy for treating infections from Gram-negative bacteria (GNB). However, which antibiotics pentamidine can and cannot synergize with and the reasons for the differences are unclear. This study aimed to identify the possible mechanisms for the differences in the synergy of pentamidine with rifampicin, linezolid, tetracycline, erythromycin, and vancomycin against GNB. Checkerboard assays were used to detect the synergy of pentamidine and the different antibiotics. To determine the mechanism of pentamidine, fluorescent labeling assays were used to measure membrane permeability, membrane potential, efflux pump activity, and reactive oxygen species (ROS); the LPS neutralization assay was used to evaluate the target site; and quantitative PCR was used to measure changes in efflux pump gene expression. Our results revealed that pentamidine strongly synergized with rifampicin, linezolid, and tetracycline and moderately synergized with erythromycin, but did not synergize with vancomycin against , , , and . Pentamidine increased the outer membrane permeability but did not demolish the outer and inner membranes, which exclusively permits the passage of hydrophobic, small-molecule antibiotics while hindering the entry of hydrophilic, large-molecule vancomycin. It dissipated the membrane proton motive force and inactivated the efflux pump, allowing the intracellular accumulation of antimicrobials that function as substrates of the efflux pump, such as linezolid. These processes resulted in metabolic perturbation and ROS production which ultimately was able to destroy the bacteria. These mechanisms of action of pentamidine on GNB indicate that it is prone to potentiating hydrophobic, small-molecule antibiotics, such as rifampicin, linezolid, and tetracycline, but not hydrophilic, large-molecule antibiotics like vancomycin against GNB. Collectively, our results highlight the importance of the physicochemical properties of antibiotics and the specific mechanisms of action of pentamidine for the synergy of pentamidine-antibiotic combinations. Pentamidine engages in various pathways in its interactions with GNB, but these mechanisms determine its specific synergistic effects with certain antibiotics against GNB. Pentamidine is a promising adjuvant, and we can optimize drug compatibility by considering its functional mechanisms.
Topics: Linezolid; Vancomycin; Rifampin; Pentamidine; Escherichia coli; Reactive Oxygen Species; Anti-Bacterial Agents; Gram-Negative Bacteria; Tetracycline; Erythromycin
PubMed: 37762115
DOI: 10.3390/ijms241813812 -
The Indian Journal of Medical Research Mar 2006Major therapeutic obstacles in the treatment of visceral leishmaniasis (VL) include the alarming increase in antimonial unresponsiveness especially in Bihar, India and... (Review)
Review
Major therapeutic obstacles in the treatment of visceral leishmaniasis (VL) include the alarming increase in antimonial unresponsiveness especially in Bihar, India and relapses in HIV-Leishmania co-infected patients. The therapeutic armamentarium for VL is currently plagued with several limitations as the available drugs are toxic, majority are effective only parenterally and need to be administered for extended periods. The first orally effective drug, miltefosine has been approved for treating VL. In antimony refractory zones, pentavalent antimony has been largely replaced by amphotericin B deoxycholate, but prolonged hospitalization, toxic effects, and requirement for monitoring greatly hamper its widespread application in endemic regions. Lipid formulations of amphotericin B, a remarkable advance in amphotericin B therapy, have greatly reduced toxicity enabling large doses to be delivered over a short period. Even a single dose treatment with liposomal amphotericin B cures > 90 per cent patients; however, the stumbling block is its prohibitive cost that precludes its widespread accessibility in endemic countries. Studies using paromomycin in VL are encouraging, and judging by the preliminary results of a recently concluded phase III trial, it could be an extremely useful and affordable antileishmanial drug. Other orally effective drugs include the azoles and allopurinol but these have met with limited success owing to either poor efficacy or unacceptable toxicity. Sitamaquine has undergone limited evaluation, and the data suggest effective antileishmanial activity; its role has to be delineated for which additional developmental studies are proposed. This review highlights the progress made in the treatment of VL, including the multiple mechanisms of action of antileishmanial drugs with a view to enable the researcher to undertake the challenge of providing affordable and effective chemotherapy.
Topics: Administration, Oral; Amphotericin B; Animals; Antimony Sodium Gluconate; Antineoplastic Agents; Antiprotozoal Agents; Humans; Immunologic Factors; Leishmania; Leishmaniasis, Visceral; Pentamidine
PubMed: 16778315
DOI: No ID Found -
Frontiers in Pharmacology 2015Drug resistance in pathogenic protozoa is very often caused by changes to the 'transportome' of the parasites. In Trypanosoma brucei, several transporters have been... (Review)
Review
Drug resistance in pathogenic protozoa is very often caused by changes to the 'transportome' of the parasites. In Trypanosoma brucei, several transporters have been implicated in uptake of the main classes of drugs, diamidines and melaminophenyl arsenicals. The resistance mechanism had been thought to be due to loss of a transporter known to carry both types of agents: the aminopurine transporter P2, encoded by the gene TbAT1. However, although loss of P2 activity is well-documented as the cause of resistance to the veterinary diamidine diminazene aceturate (DA; Berenil(®)), cross-resistance between the human-use arsenical melarsoprol and the diamidine pentamidine (melarsoprol/pentamidine cross resistance, MPXR) is the result of loss of a separate high affinity pentamidine transporter (HAPT1). A genome-wide RNAi library screen for resistance to pentamidine, published in 2012, gave the key to the genetic identity of HAPT1 by linking the phenomenon to a locus that contains the closely related T. brucei aquaglyceroporin genes TbAQP2 and TbAQP3. Further analysis determined that knockdown of only one pore, TbAQP2, produced the MPXR phenotype. TbAQP2 is an unconventional aquaglyceroporin with unique residues in the "selectivity region" of the pore, and it was found that in several MPXR lab strains the WT gene was either absent or replaced by a chimeric protein, recombined with parts of TbAQP3. Importantly, wild-type AQP2 was also absent in field isolates of T. b. gambiense, correlating with the outcome of melarsoprol treatment. Expression of a wild-type copy of TbAQP2 in even the most resistant strain completely reversed MPXR and re-introduced HAPT1 function and transport kinetics. Expression of TbAQP2 in Leishmania mexicana introduced a pentamidine transport activity indistinguishable from HAPT1. Although TbAQP2 has been shown to function as a classical aquaglyceroporin it is now clear that it is also a high affinity drug transporter, HAPT1. We discuss here a possible structural rationale for this remarkable ability.
PubMed: 25814953
DOI: 10.3389/fphar.2015.00032 -
PLoS Pathogens Feb 2016The chemotherapeutic arsenal against human African trypanosomiasis, sleeping sickness, is limited and can cause severe, often fatal, side effects. One of the classic and...
The chemotherapeutic arsenal against human African trypanosomiasis, sleeping sickness, is limited and can cause severe, often fatal, side effects. One of the classic and most widely used drugs is pentamidine, an aromatic diamidine compound introduced in the 1940s. Recently, a genome-wide loss-of-function screen and a subsequently generated trypanosome knockout strain revealed a specific aquaglyceroporin, TbAQP2, to be required for high-affinity uptake of pentamidine. Yet, the underlying mechanism remained unclear. Here, we show that TbAQP2 is not a direct transporter for the di-basic, positively charged pentamidine. Even though one of the two common cation filters of aquaglyceroporins, i.e. the aromatic/arginine selectivity filter, is unconventional in TbAQP2, positively charged compounds are still excluded from passing the channel. We found, instead, that the unique selectivity filter layout renders pentamidine a nanomolar inhibitor of TbAQP2 glycerol permeability. Full, non-covalent inhibition of an aqua(glycero)porin in the nanomolar range has not been achieved before. The remarkable affinity derives from an electrostatic interaction with Asp265 and shielding from water as shown by structure-function evaluation and point mutation of Asp265. Exchange of the preceding Leu264 to arginine abolished pentamidine-binding and parasites expressing this mutant were pentamidine-resistant. Our results indicate that TbAQP2 is a high-affinity receptor for pentamidine. Taken together with localization of TbAQP2 in the flagellar pocket of bloodstream trypanosomes, we propose that pentamidine uptake is by endocytosis.
Topics: Animals; Aquaglyceroporins; Drug Resistance; Humans; Pentamidine; Trypanocidal Agents; Trypanosoma brucei brucei; Trypanosomiasis, African
PubMed: 26828608
DOI: 10.1371/journal.ppat.1005436 -
The Biochemical Journal Apr 1996A transport system for pentamidine in Leishmania donovani and Leishmania amazonensis promastigotes and axenic amastigotes has been identified and characterized....
A transport system for pentamidine in Leishmania donovani and Leishmania amazonensis promastigotes and axenic amastigotes has been identified and characterized. Pentamidine is not metabolized by these parasites. Its uptake process is saturable, carrier-mediated and energy-dependent. This drug does not inhibit purine or pyrimidine uptake, whereas it inhibits uptake of several amino acids non-competitively and that of putrescine and spermidine competitively. The results suggest that pentamidine shares polyamine-carrier systems in these parasites.
Topics: Animals; Antiprotozoal Agents; Biological Transport, Active; Kinetics; Leishmania donovani; Leishmania mexicana; Pentamidine; Putrescine; Spermidine
PubMed: 8615840
DOI: 10.1042/bj3150631