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Microorganisms Feb 2022The sterol biosynthesis pathway of spp. is used as a pharmacological target; however, available information about the mechanisms of the regulation and remodeling of...
The sterol biosynthesis pathway of spp. is used as a pharmacological target; however, available information about the mechanisms of the regulation and remodeling of sterol-related genes is scarce. The present study investigated compensatory mechanisms of the sterol biosynthesis pathway using an inhibitor of HMG-CoA reductase (simvastatin) and by developing drug-resistant parasites to evaluate the impact on sterol remodeling, cross-resistance, and gene expression. Simvastatin-resistant parasites (SimR) underwent reprogramming of sterol metabolism manifested as an increase in cholestane- and stigmastane-based sterols and a decrease in ergostane-based sterols. The levels of the transcripts of sterol 24-C-methyltransferase (SMT), sterol C14-α-demethylase (C14DM), and protease subtilisin (SUB) were increased in SimR. SimR was cross-resistance to ketoconazole (a C14DM inhibitor) and remained sensitive to terbinafine (an inhibitor of squalene monooxygenase). Sensitivity of the SimR mutant to other antileishmanial drugs unrelated to the sterol biosynthesis pathway, such as trivalent antimony and pentamidine, was similar to that of the wild-type strain; however, SimR was cross-resistant to miltefosine, general serine protease inhibitor --tosyl-l-phenylalanine chloromethyl ketone (TPCK), subtilisin-specific inhibitor 4-[(diethylamino)methyl]--[2-(2-methoxyphenyl)ethyl]--(3R)-3-pyrrolidinyl-benzamide dihydrochloride (PF-429242), and tunicamycin. The findings on the regulation of the sterol pathway can support the development of drugs and protease inhibitors targeting this route in parasites.
PubMed: 35208853
DOI: 10.3390/microorganisms10020398 -
Iranian Journal of Pharmaceutical... 2021Cutaneous leishmaniasis is caused by protozoa of the genus and spread by sandflies. The standard therapy for this ailment is the first-line medication of pentavalent...
Cutaneous leishmaniasis is caused by protozoa of the genus and spread by sandflies. The standard therapy for this ailment is the first-line medication of pentavalent antimonial and the second drug line of pentamidine amphotericin B. All are practiced over the years and exhibit adverse toxicity effects. Herbal product-derived medicine is a promising potential source for treating parasitic diseases. Xanthatin, a xanthanolide sesquiterpene lactone, is isolated from L. treats several ailments in many countries. In the present study, we investigated the leishmanicidal activity of the xanthatin by using a metabolomics-based analysis in J774 macrophages and amastigotes phases in . Xanthatin was isolated and identified by NMR spectroscopy. Macrophage toxicity of xanthatin performed by MTT assay. Macrophages infected by the promastigote stationary phase, the infection rate (IR), and multiplication index (MI) were calculated. Axenic amastigotes were treated with xanthatin. Cell quenching and metabolite extraction were performed, and the metabolome profile was analyzed with NMR spectroscopy. Outliers were classified by using multivariate statistical analysis software, and relevant metabolites and pathways were worked out. The xanthatin IC rate defined 0.75 µg/mL base on macrophages viability and also activity of xanthatin on amastigotes showed the best leishmanicidal activity in IR and MI values of 53% and 62.5%, respectively. Xanthatin altered amino sugars and nucleotide sugars metabolism, starch and sucrose metabolism, cyanoamino acid, and galactose metabolism. Our finding revealed that the main target of xanthatin is carbon metabolism, which is an essential step for amastigotes virulence.
PubMed: 35194428
DOI: 10.22037/ijpr.2021.114937.15122 -
Frontiers in Cellular and Infection... 2022Leishmaniasis is one of the major public health concerns in Latin America, Africa, Asia, and Europe. The absence of vaccines for human use and the lack of effective... (Review)
Review
Leishmaniasis is one of the major public health concerns in Latin America, Africa, Asia, and Europe. The absence of vaccines for human use and the lack of effective vector control programs make chemotherapy the main strategy to control all forms of the disease. However, the high toxicity of available drugs, limited choice of therapeutic agents, and occurrence of drug-resistant parasite strains are the main challenges related to chemotherapy. Currently, only a small number of drugs are available for leishmaniasis treatment, including pentavalent antimonials (Sb), amphotericin B and its formulations, miltefosine, paromomycin sulphate, and pentamidine isethionate. In addition to drug toxicity, therapeutic failure of leishmaniasis is a serious concern. The occurrence of drug-resistant parasites is one of the causes of therapeutic failure and is closely related to the diversity of parasites in this genus. Owing to the enormous plasticity of the genome, resistance can occur by altering different metabolic pathways, demonstrating that resistance mechanisms are multifactorial and extremely complex. Genetic variability and genome plasticity cause not only the available drugs to have limitations, but also make the search for new drugs challenging. Here, we examined the biological characteristics of parasites that hinder drug discovery.
Topics: Amphotericin B; Antiprotozoal Agents; Genetic Variation; Humans; Leishmania; Leishmaniasis
PubMed: 35141175
DOI: 10.3389/fcimb.2022.826287 -
Iranian Journal of Parasitology 2021are a causative agent of keratitis (AK) in immunocompetent individuals. Since access to propamidine isethionate (Brolene®) as a first-line treatment has been limited...
BACKGROUND
are a causative agent of keratitis (AK) in immunocompetent individuals. Since access to propamidine isethionate (Brolene®) as a first-line treatment has been limited in recent years, in the current study, we examined the effects of pentamidine isethionate against trophozoite and cyst forms of .
METHODS
This experimental study was conducted in the Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran, during 2019-2020. Pentamidine isethionate at concentrations of 50, 100, 200, 400, 600, 800, and 1000 μM were tested against trophozoites and cyst stages of T4 genotype, at 24- and 48-hour incubation period, and the viability was determined by trypan blue staining. In addition, the cytotoxic effect of the drug was examined in cells using the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay.
RESULTS
The 50% inhibitory concentration (IC50) of pentamidine isethionate on trophozoite after 24 and 48h were 97.4 μM and 60.99 μM. These results on cyst after 24 and 48h were 470 μM and 175.5 μM, respectively. In MTT assay, the drug showed an inhibitory effect on cell growth with IC50 values of 115.4 μM and 87.42 μM after 24h and 48h, respectively.
CONCLUSION
Pentamidine isethionate exhibited an inhibitory effect on trophozoite and cyst. Given that the trophozoicidal activity of the drug is in the safe dose, it could be suggested as an alternative in patients with AK; however, further investigation is needed in an animal model to confirm the data.
PubMed: 35082884
DOI: 10.18502/ijpa.v16i4.7868 -
Frontiers in Immunology 2021is one cause of a rare and severe brain infection called granulomatous amoebic encephalitis (GAE), which has a mortality rate of >90%. Diagnosis of GAE is difficult...
is one cause of a rare and severe brain infection called granulomatous amoebic encephalitis (GAE), which has a mortality rate of >90%. Diagnosis of GAE is difficult because symptoms are non-specific. Here, we report a case of amoebic encephalomyelitis (encephalitis and myelitis) in a woman with breast cancer. She sustained trauma near a garbage dump 2 years ago and subsequently developed a skin lesion with a infection. She experienced dizziness, lethargy, nausea and vomiting, inability to walk, and deterioration of consciousness. Next-generation sequencing of cerebrospinal fluid (CSF) samples revealed , and MRI of both brain and spinal cord showed abnormal signals. T-cell receptor (TCR) sequencing of the CSF identified the Top1 TCR. A combination of amphotericin B, flucytosine, fluconazole, sulfamethoxazole, trimethoprim, clarithromycin, pentamidine, and miltefosine was administrated, but she deteriorated gradually and died on day 27 post-admission.
Topics: Adult; Amebiasis; Balamuthia mandrillaris; Breast Neoplasms; Encephalomyelitis; Fatal Outcome; Female; High-Throughput Nucleotide Sequencing; Humans; Magnetic Resonance Imaging
PubMed: 35069540
DOI: 10.3389/fimmu.2021.768065 -
ACS Omega Dec 2021We report the evaluation of a small library of azole-bisindoles for their antileishmanial potential, in terms of efficacy on promastigotes and intracellular...
We report the evaluation of a small library of azole-bisindoles for their antileishmanial potential, in terms of efficacy on promastigotes and intracellular amastigotes. Nine compounds showed good activity on MHOM/TN/80/IPT1 promastigotes with IC values ranging from 4 to 10 μM. These active compounds were also tested on human (THP-1, HEPG2, HaCaT, and human primary fibroblasts) and canine (DH82) cell lines. was selected as the best compound, with no quantifiable cytotoxicity in mammalian cells, to test the efficacy on intracellular amastigotes. significantly reduced the infection index of both human and canine macrophages with an effect comparable to the clinically used drug pentamidine. emerges as a new anti-infective agent with remarkable antileishmanial activity and no cytotoxic effects on human and canine cells.
PubMed: 34984300
DOI: 10.1021/acsomega.1c05611 -
International Journal of Molecular... Dec 2021S100B is an astrocytic protein behaving at high concentration as a damage-associated molecular pattern molecule. A direct correlation between the increased amount of...
S100B is an astrocytic protein behaving at high concentration as a damage-associated molecular pattern molecule. A direct correlation between the increased amount of S100B and inflammatory processes has been demonstrated, and in particular, the inhibitor of S100B activity pentamidine has been shown to ameliorate clinical scores and neuropathologic-biomolecular parameters in the relapsing-remitting experimental autoimmune encephalomyelitis mouse model of multiple sclerosis. This study investigates the effect of arundic acid (AA), a known inhibitor of astrocytic S100B synthesis, in the chronic experimental autoimmune encephalomyelitis, which is another mouse model of multiple sclerosis usually studied. By the daily evaluation of clinical scores and neuropathologic-molecular analysis performed in the spinal cord, we observed that the AA-treated group showed lower severity compared to the vehicle-treated mice, particularly in the early phase of disease onset. We also observed a significant reduction of astrocytosis, demyelination, immune infiltrates, proinflammatory cytokines expression and enzymatic oxidative reactivity in the AA-treated group. Overall, our results reinforce the involvement of S100B in the development of animal models of multiple sclerosis and propose AA targeting the S100B protein as a focused potential drug to be considered for multiple sclerosis treatment.
Topics: Animals; Caprylates; Disease Models, Animal; Encephalomyelitis, Autoimmune, Experimental; Female; Mice; Mice, Inbred C57BL; Molecular Targeted Therapy; Multiple Sclerosis; S100 Calcium Binding Protein beta Subunit
PubMed: 34948360
DOI: 10.3390/ijms222413558 -
Revista Espanola de Quimioterapia :... Feb 2022To determine the rate of microbiological confirmation in the diagnosis of Pneumocystis jirovecii pneumonia in patients treated with intravenous pentamidine and the...
OBJECTIVE
To determine the rate of microbiological confirmation in the diagnosis of Pneumocystis jirovecii pneumonia in patients treated with intravenous pentamidine and the potential correlation with treatment effectiveness and safety.
METHODS
Single-centre retrospective study (2010-2020), which included those patients who received intravenous pentamidine treatment for at least 48 hours. The sample collection procedure and the microbiological analysis performed were recorded. Efficacy was determined by 14-day mortality rate and admission to the Intensive Care Unit (ICU), and disease control was determined by length of hospital stay and time from completion of treatment to discharge. The safety profile was assessed according to the Common Terminology Criteria for Adverse Events (CTCAE) v5.0.
RESULTS
A total of 17 patients with P. jirovecii pneumonia were treated with pentamidine (76.5% male (n=13); mean age [standard deviation]: 58.6 [15.5]). Microbiological confirmation of the pathogen was established in 47.1% (n=8) of cases. Targeted use of pentamidine significantly reduced the time from treatment completion to hospital discharge (p=0.019). The safety profile was acceptable, with grade I toxicity occurring in one patient.
CONCLUSIONS
The study shows that more than 50% of patients receive treatment based on a presumptive diagnosis and without adhering to the established recommendations, with repercussions on the duration of admission and recovery of the patient. Future studies with a larger sample size will be necessary to consolidate the results obtained.
Topics: Adult; Aged; Antifungal Agents; Female; Humans; Male; Middle Aged; Pentamidine; Pneumocystis carinii; Pneumonia, Pneumocystis; Retrospective Studies
PubMed: 34854660
DOI: 10.37201/req/064.2021 -
PLoS Neglected Tropical Diseases Nov 2021Cutaneous Leishmaniasis (CL) is endemic in French Guiana but cases are usually sporadic. An outbreak signal was issued on May 15th 2020 with 15 suspected cases after a...
BACKGROUND
Cutaneous Leishmaniasis (CL) is endemic in French Guiana but cases are usually sporadic. An outbreak signal was issued on May 15th 2020 with 15 suspected cases after a military training course in the rainforest. An outbreak investigation was carried out.
METHODOLOGY/PRINCIPAL FINDINGS
Thirty cases were confirmed. Leishmania guyanensis was the most frequent species (90%). The most frequent presentation was ulcerative (90%). Lesions on the face and hands were frequent (40% each). Eight cases (26%) presented a poor outcome after treatment with pentamidine and required a second line with amphotericin B. Three of them required further treatments with meglumine antimoniate or miltefosine. Two spots within the training area were deemed as likely sites of contamination, due to illegal logging. The isolated Leishmania strains did not form a separate cluster. Participation in Week 13 of year 2020 was associated with infection (OR = 4.59 [1.10-19.83]; p = 0.016) while undergoing only the "Fighting" exercise was protective (OR = 0.1 [0-0.74]; p = 0.021). There was no association between infection and other risk factors at the individual level. The attack rate of Regiment B (14/105 = 13.3%) was significantly higher (OR = 4.22 [1.84-9.53], p = 0.0001) compared to Regiment A (16/507 = 3.2%). The attack rate during this training course (30/858 = 3.5%) was significantly higher (OR 2.29 [1.28-4.13]; p = 0.002) than for other missions in French Guiana during the same period (22/1427 = 1.5%).
CONCLUSIONS
This outbreak could be explained by a combination of factors: climatic conditions around week 13, at-risk activities including night trainings, absence of impregnation, a lesser experience of rainforest duties in Regiment B and illegal logging attracting sandflies on military training grounds.
Topics: Adult; Antiprotozoal Agents; Disease Outbreaks; Female; French Guiana; Humans; Leishmania; Leishmaniasis, Cutaneous; Male; Middle Aged; Military Personnel; Pentamidine; Phylogeny; Young Adult
PubMed: 34797836
DOI: 10.1371/journal.pntd.0009938 -
BMC Pharmacology & Toxicology Nov 2021Leishmania aethiopica (L. aethiopica) is responsible for different forms of cutaneous leishmaniasis (CL) in Ethiopia. Treatment heavily depends on limited drugs,...
INTRODUCTION
Leishmania aethiopica (L. aethiopica) is responsible for different forms of cutaneous leishmaniasis (CL) in Ethiopia. Treatment heavily depends on limited drugs, together with drawbacks like toxicity and microbial resistance. The current research aimed to investigate in vitro growth inhibitory activity of Medicines for Malaria Ventures - Pathogen Box (MMV - PB) compounds against L. aethiopica clinical isolate.
METHODOLOGY
Four hundred MMV - PB compounds were screened against L. aethiopica using resazurin based colourimetric assay. Compounds with > 70% inhibition were further tested using macrophage based intracellular amastigote assay. Cytotoxic and hemolytic activity of candidate hits were assessed on THP1- cells and sheep red blood cells (RBCs), respectively. In vitro drug interaction study was also conducted for the most potent hit using the combination index method.
RESULTS
At the test concentration of 1 μM, twenty-three compounds showed > 50% inhibition of promastigotes parasite growth, of which 11 compounds showed > 70% inhibition. The 50% growth inhibition (IC) of the 11 compounds was ranged from 0.024 to 0.483 μM in anti-promastigote assay and from 0.064 to 0.899 μM in intracellular amastigote assay. Candidate compounds demonstrated good safety on sheep RBCs and THP-1 cell lines. MMV688415 demonstrated a slight hemolytic activity on sheep RBC (5.3% at 25 μM) and THP-1 cell line (CC = 25 μM) while MMV690102 inhibited half of THP-1 cells at 36.5 μM (selectivity index = 478). No synergistic activity was observed from the combinations of MMV690102 and amphotericin B (CI > 1), and MMV690102 and Pentamidine (CI > 1) at lower and higher combination points.
CONCLUSION
The present study identified a panel of compounds that can be used as a novel starting point for lead optimization. MMV690102 appears to be the most potent inhibitor against L. aethiopica promastigotes and amastigotes. Future works should investigate the antileishmanial mechanism of action and in vivo antileishmanial activities of identified hits.
Topics: Animals; Antiprotozoal Agents; Cell Survival; Drug Synergism; Erythrocytes; Hemolysis; Humans; Leishmania; Macrophages, Peritoneal; Mice; Sheep; THP-1 Cells
PubMed: 34784983
DOI: 10.1186/s40360-021-00538-2