Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 4.339
Filtrar
1.
Ann Parasitol ; 68(1): 71-76, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35491675

RESUMO

Leishmaniosis is an insect-borne disease whose clinical manifestations range from skin ulcer to visceral disease. Antimony compounds are currently known to be the main treatment for leishmaniosis, but there are limitations to their use. This study was performed to determine the in vitro and in vivo efficiency of honey on a standard strain of Leishmania major parasite in comparison with glucantime and amphotericin as the first line treatment. Leishmania major was exposed to different concentrations of honey extract at 400, 200, 100, 50, 25, 12.5, 6.25 µg/ml. The effectiveness of honey concentrations was determined by counting the parasite by Neubauer's chamber. Then, using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) colorimetric method, for promastigotes and macrophages then IC50 was calculated. A flow cytometry test was performed and necrosis and apoptosis diagrams were drawn. Next, the effect of the honey on the amastigotes inside macrophage cells was investigated. Finally, for the in vivo experimentation, the parasite was injected in the base of BALB/c mice tails and the resulting wounds were treated with honey. The results of all tests showed that the honey extract at 400 µg/ml concentration had the best effects on all stages. The honey has lethal effects on Leishmania parasite in vitro as well as therapeutic effects on wounds caused by the parasite. Further experiments are recommended to evaluate the performance of the extract on the parasite in volunteer human models.


Assuntos
Antiprotozoários , Mel , Leishmania major , Anfotericina B/farmacologia , Animais , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Humanos , Camundongos , Extratos Vegetais/farmacologia
2.
Arch Microbiol ; 204(6): 295, 2022 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-35508567

RESUMO

Oral candidiasis is a fungal infection caused mainly by Candida albicans and it is a major problem among hematologic malignancy patients. Biofilm formation is an attributable factor to both virulence and drug resistance of Candida species. The aim of the study was to evaluate the biofilm-producing ability of oral C. albicans isolates and to evaluate the inhibitory activity of eucalyptol on Candida biofilm, alone and in combination with antifungal agents. Samples were collected from the oral cavity of 106 patients with hematologic malignancy. The isolated yeasts were identified by PCR-sequencing. Then C. albicans isolates were analyzed for their biofilm-producing ability by crystal violet staining and MTT assay. The minimum biofilm inhibition concentrations (MBIC) of eucalyptol, amphotericin B, itraconazole, and nystatin and the in vitro interaction of eucalyptol with these drugs were tested according to CLSI-M-27-A3 protocol and checkerboard methods, respectively. From 106 patients, 50 (47.2%) were confirmed for oral candidiasis [mean ± SD age 39 ± 14 years; female 31 (62%) and male 19 (38%)]. C. albicans was isolated from 40 of 50 (80%) patients. From 40 C. albicans isolates, 24 (60%) and 16 (40%) were moderate and weak biofilm producer, respectively. The geometric mean MBIC of amphotericin B, itraconazole, nystatin and eucalyptol were 3.93 µg/mL, 12.55 µg/mL, 0.75 µg/mL and 798 µg/mL, respectively. Eucalyptol interacted synergistically with amphotericin B, itraconazole and nystatin against 12.5, 10, and 22.5% of isolates, respectively. Eucalyptol demonstrated promising activity against biofilm of C. albicans when tested alone or combined with antifungal drugs.


Assuntos
Candidíase Bucal , Neoplasias Hematológicas , Adulto , Anfotericina B/farmacologia , Anfotericina B/uso terapêutico , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Biofilmes , Candida , Candida albicans , Candidíase Bucal/tratamento farmacológico , Eucaliptol , Feminino , Neoplasias Hematológicas/complicações , Neoplasias Hematológicas/tratamento farmacológico , Humanos , Itraconazol/farmacologia , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Nistatina/farmacologia
3.
Oncoimmunology ; 11(1): 2068109, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35496500

RESUMO

Immunostimulatory regimens are a game changer in the fight against cancer, but still only a minority of patients achieve clinical benefit. Combination with immunomodulatory drugs and agents converting otherwise non-immunogenic forms of cell death into bona fide "immunogenic cell death" (ICD) could improve the efficacy of these novel therapies. The aim of our study was to investigate conventional Amphotericin B (AmB) as an enhancer of antitumor immune responses. In tumor cell line models, AmB induced ICD with its typical hallmarks of calreticulin (CALR) expression and release of high mobility group box 1 (HMGB1) as well as Adenosine 5'-triphosphate (ATP). Interestingly, in contrast to non-ICD inducing treatments, ICD induction led to up-regulation of PD-L1-expression by ICD experiencing cells, resulting in decreased maturation of dendritic cells (DCs). Blocking this PD-L1 expression on tumor cells could unleash full ICD effects on antigen presenting cells. Even at sub-toxic concentrations, AmB was able to enhance CALR on leukemic blasts, particularly on phagocytic monoblastic THP-1 cells, which also showed features of "M1-like" differentiation after AmB exposure. The ability of AmB to increase the immunogenicity of tumor cells was confirmed in vivo in a mouse vaccination experiment. In conclusion, we demonstrate that AmB can promote antitumor immune responses in a dose-dependent manner by ICD induction, surface translocation of CALR on leukemic blasts even at sub-toxic concentrations, and "M1-like" polarization of phagocytic cells, making it noteworthy as potential booster for cancer immunotherapy. We additionally report for the first time that PD-L1 expression may be a feature of ICD, possibly as a negative feedback mechanism regulating the maturation status of DCs and thus indirectly affecting T-cell priming.


Assuntos
Antígeno B7-H1 , Morte Celular Imunogênica , Anfotericina B/farmacologia , Animais , Biomarcadores , Humanos , Imunoterapia , Camundongos , Fagócitos
4.
Ann Parasitol ; 68(1): 17-22, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35436397

RESUMO

Liposomal amphotericin B (Amph B) has been used effectively to treat leishmaniosis, in spite of its high toxicity appeared in some patients. In our study, Amph B was administered in Leishmania donovani that infected BALB/c male mice using different concentrations to evaluate its efficacy challenge against infection as well as its effect in modulating immunity of the host. We observed that low doses with short duration of Amph B as a therapy regime significantly enhanced the induction of Th1 cytokine (INF-γ), but suppressed Th2 cytokine (IL-10) production. Groups of mice infected with L. donovani and treated with Amph B showed clearly increasing in INF-γ level and reduction in IL-10 level in concentration (3, 4, 5 mg/ml/kg) with best result in 5 mg/ml/kg (accumulation dose 25 mg/ml) than concentrations (6, 7 mg/ml/kg). We hypothesized that Amph B with low doses and short duration regime worked to mediate immunotherapeutic for eliminating the parasite-induced immunosuppression.


Assuntos
Leishmania donovani , Leishmaniose Visceral , Anfotericina B/farmacologia , Anfotericina B/uso terapêutico , Animais , Citocinas , Humanos , Interleucina-10/farmacologia , Interleucina-10/uso terapêutico , Leishmaniose Visceral/tratamento farmacológico , Masculino , Camundongos , Camundongos Endogâmicos BALB C
5.
J Med Microbiol ; 71(4)2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35451946

RESUMO

Introduction. Aspergillus sections Flavi and Nigri comprise clinically relevant and cryptic species that differ significantly in drug susceptibility, meaning that effective treatment depends on correct species identification.Hypothesis/Gap Statement. There are no comprehensive data for molecular identification and antifungal susceptibility testing (AFST) of clinically relevant and cryptic species of Aspergillus sections Flavi and Nigri as the main agents of invasive and non-invasive aspergillosis in Iran. We aimed to perform molecular identification and AFST of 213 clinical Aspergillus isolates belonging to sections Flavi and Nigri. Molecular identification of isolates was performed using sequencing of the ß-tubulin gene and in vitro AFST was conducted according to the Clinical and Laboratory Standards Institute (CLSI) M38-A3 guidelines.Results. The most common isolates in sections Flavi and Nigri were Aspergillus flavus (110/113, 97.3 %) and Aspergillus tubingensis (49/100, 49.0 %), respectively. A total of 62/213 (29.1 %) isolates belonging to cryptic species were identified; among them, A. tubingensis was the most prevalent (49/62, 79.0%). Aspergillus flavus and A. niger isolates that responded to the minimum inhibitory concentrations (MICs) of itraconazole above the epidemiological cutoff values were the most frequently detected: 8/110 (7.3 %) and 3/41 (7.3 %), respectively. In section Flavi, Aspergillus alliaceus responded to amphotericin B at a high MIC (>16 µg mL-1) and in section Nigri, one of the three Aspergillus luchuensis/awamori isolates responded to itraconazole at an MIC >16 µg ml-1. Interestingly, for all Aspergillus welwitschiae isolates, the MIC50 and MIC90 of itraconazole were both 16 µg ml-1.Conclusion. A considerable presence of A. flavus and A. niger isolates showing non-wild-type responses to azoles in clinical cases of aspergillosis indicates the importance of classifying clinical Aspergillus isolates at the species level and performing antifungal susceptibility testing on the isolates, which would ensure appropriate treatment.


Assuntos
Antifúngicos , Aspergilose , Anfotericina B/farmacologia , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Aspergilose/microbiologia , Aspergillus/genética , Aspergillus flavus , Humanos , Itraconazol/farmacologia , Testes de Sensibilidade Microbiana
6.
Arch Oral Biol ; 138: 105415, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35390561

RESUMO

OBJECTIVE: As the emerging resistance of Candida species to common antifungals is a major global concern, we assessed the antifungal susceptibility of oral yeast isolates from a healthy, Thai adult cohort, and correlated the yeast prevalence with oral disease indices. METHODS: Oral rinse samples collected from 100 Thai adults were concentrated and cultured on CHROMagar Candida. The yeasts were then isolated, identified and finally speciated using Matrix Assisted Laser Desorption ionization-time of flight mass spectrometry. Their antifungal sensitivity against fluconazole, itraconazole, voriconazole, and amphotericin B were investigated using standard Etest strips. The decayed, missing, filled teeth (DMFT) and the periodontal health were recorded and correlated with mycological data. RESULTS: The overall oral yeast prevalence was 25%. C. albicans was the commonest species isolated, followed by C. tropicalis and C. dubliniensis. Non-albicans-Candida was noted in approximately one-third, and included C. lusitaniae and C. nivariensis; Trichosporon asahii, was also detected in one subject. A majority of C. albicans isolates, (> 54%), exhibited resistance to fluconazole and voriconazole, while approximately a quarter (27%) were resistant to itraconazole. The vast majority (92%) however, were susceptible to amphotericin B. Those with oral yeasts had a significantly higher DMFT score (p < 0.05). CONCLUSION: The resistance of a majority of Candida spp. to common azoles, described here for the first time in a Thai cohort, is disconcerting, and appear to confirm the creeping emergence of antifungal resistance globally. An incidental finding was the positive correlation between oral yeast carriage and DMFT score in Thai subjects.


Assuntos
Antifúngicos , Fluconazol , Adulto , Anfotericina B/farmacologia , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Candida , Candida albicans , Candida tropicalis , Farmacorresistência Fúngica , Fluconazol/farmacologia , Humanos , Itraconazol/farmacologia , Testes de Sensibilidade Microbiana , Filogenia , Prevalência , Tailândia/epidemiologia , Voriconazol/farmacologia
7.
Antimicrob Agents Chemother ; 66(4): e0227421, 2022 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-35254091

RESUMO

Aspergillus terreus is an opportunistic causative agent of invasive aspergillosis and, in most cases, it is refractory to amphotericin B (AMB) therapy. Notably, AMB-susceptible Aspergillus terreus sensu stricto (s.s.) representatives exist which are also associated with poor clinical outcomes. Such findings may be attributable to drug tolerance, which is not detectable by antifungal susceptibility testing. Here, we tested in vitro antifungal susceptibility (AFST) and the fungicidal activity of AMB against 100 clinical isolates of A. terreus species complex in RPMI 1640 and antibiotic medium 3 (AM3). MICs ranged from 0.5 to 16 µg/mL for RPMI 1640 and from 1 to >16 mg/L for AM3. AMB showed medium-dependent activity, with fungicidal effects only in antibiotic medium 3, not in RPMI 1640. Furthermore, the presence of AMB-tolerant phenotypes of A. terreus has been examined by assessing the minimum duration for killing 99% of the population (MDK99) and evaluating the data obtained in a Galleria mellonella infection model. A time-kill curve analysis revealed that A. terreus with AMB MICs of ≤1 mg/L (susceptible range) displayed AMB-tolerant phenotypes, exhibiting MDK99s at 18 and 36 h, respectively. Survival rates of infected G. mellonella highlighted that AMB was effective against susceptible A. terreus isolates, but not against tolerant or resistant isolates. Our analysis reveals that A. terreus isolates which are defined as susceptible based on MIC may comprise tolerant phenotypes, which may, in turn, explain the worse outcome of AMB therapy for phenotypically susceptible isolates.


Assuntos
Anfotericina B , Antifúngicos , Anfotericina B/farmacologia , Antibacterianos/uso terapêutico , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Aspergillus , Farmacorresistência Fúngica , Tolerância a Medicamentos , Testes de Sensibilidade Microbiana
8.
Rev Iberoam Micol ; 39(1): 21-24, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35256257

RESUMO

BACKGROUND: The prevalence of pulmonary aspergillosis and the importance of its early diagnosis are recognized. However, non-pulmonary involvement, including the sinuses region, is not frequently reported, and an infection in this area can affect all paranasal sinuses (pansinusopathy), being a rare pathology that affects immunocompromised hosts. Recent studies have highlighted the occurrence of Aspergillus flavus resistant to antifungal therapy. Therefore, a nasal sinus infection by resistant Aspergillus strains in immunocompromised patients may be linked to a high risk of lethality. CASE REPORT: We are reporting a resistant A. flavus infection in an allogeneic hematopoietic stem cell transplant recipient with episodes of febrile neutropenia, and prolonged use of various antibacterial drugs and antifungal prophylaxis. The patient underwent brain magnetic resonance, which showed the presence of pansinusopathy, and presented necrosis in the left nasal region. Direct microscopic examination of a sample taken from the nasal mucosa revealed the presence of septate hyphae and conidiophores resembling those of A. flavus, that species being the identification achieved with MALDI-TOF MS. Antifungigram was performed by microdilution in broth (EUCAST-E.DEF. 9.3.2) and E-test, and resistance to amphotericin B was shown in both tests. The patient died after septic shock and hemorrhage. CONCLUSIONS: Invasive fungal infections due to amphotericin-B resistant A. flavus may lead to the death of the patient due to an ineffective therapeutic management. Therefore, antifungal susceptibility testing are of utmost importance for administering the proper treatment.


Assuntos
Anfotericina B , Aspergilose , Anfotericina B/farmacologia , Anfotericina B/uso terapêutico , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Aspergilose/tratamento farmacológico , Aspergilose/microbiologia , Aspergillus flavus , Humanos , Testes de Sensibilidade Microbiana
9.
Biomater Sci ; 10(8): 1952-1967, 2022 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-35253814

RESUMO

The development of an effective amphotericin B (AmB) formulation to replace actual treatments available for leishmaniasis, which present serious drawbacks, is a challenge. Here we report the development of hyaluronic acid-amphotericin B self-assembled nanocomplexes (HA-AmB), processed by freeze-drying (FD) or nano spray-drying (SD), using a simple process that favors the non-covalent drug-polysaccharide association in an amorphous state. These water-soluble formulations, which presented a nanometric size (300-600 nm), high colloidal stability (zeta potential around -39 mV) and an AmB loading (15-18%) in aggregated and super aggregated states, demonstrated less in vitro cytotoxic and hemolytic effects compared to the free-drug. A significant decrease in the number of intramacrophagic L. infantum amastigotes upon treatment (IC50 of 0.026 and 0.030 µM for HA-AmB FD and HA-AmB SD, respectively) was also observed, and the best selectivity index (SI) was observed for the HA-AmB SD nanocomplex (SI of 651). Intravenous administration of the HA-AmB SD nanocomplex for 3 alternate days showed an effective parasite reduction in the spleen and liver of C57BL/6 mice without signs of toxicity commonly observed upon free-AmB treatment. Although lower than that achieved with AmBisome® in the liver, the observed parasite reduction for the nanocomplex was of a similar order of magnitude. The efficacy, stability, safety and low cost of the HA-AmB SD nanocomplex highlight its potential as an alternative treatment for leishmaniasis.


Assuntos
Anfotericina B , Leishmaniose , Anfotericina B/farmacologia , Animais , Sistemas de Liberação de Medicamentos , Ácido Hialurônico/uso terapêutico , Leishmaniose/tratamento farmacológico , Camundongos , Camundongos Endogâmicos C57BL
10.
Front Cell Infect Microbiol ; 12: 826287, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35141175

RESUMO

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 (SbV), 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.


Assuntos
Antiprotozoários , Leishmania , Leishmaniose , Anfotericina B/farmacologia , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Variação Genética , Humanos , Leishmaniose/tratamento farmacológico
11.
Molecules ; 27(3)2022 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-35164370

RESUMO

Fibrin-based systems offer promises in drug and gene delivery as well as tissue engineering. We established earlier a fibrin-based plasma beads (PB) system as an efficient carrier of drugs and antigens. In the present work, attempts were made to further improve its therapeutic efficacy exploiting innovative ideas, including the use of plasma alginate composite matrices, proteolytic inhibitors, cross linkers, and dual entrapment in various liposomal formulations. In vitro efficacy of the different formulations was examined. Pharmacokinetics of the formulations encapsulating Amphotericin B (AmpB), an antifungal compound, were investigated in Swiss albino mice. While administration of the free AmpB led to its rapid elimination (<72 h), PB/liposome-PB systems were significantly effective in sustaining AmpB release in the circulation (>144 h) and its gradual accumulation in the vital organs, also compared to the liposomal formulations alone. Interestingly, the slow release of AmpB from PB was unusual compared to other small molecules in our earlier findings, suggesting strong interaction with plasma proteins. Molecular interaction studies of bovine serum albumin constituting approximately 60% of plasma with AmpB using isothermal titration calorimetry and in silico docking verify these interactions, explaining the slow release of AmpB entrapped in PB alone. The above findings suggest that PB/liposome-PB could be used as safe and effective delivery systems to combat fungal infections in humans.


Assuntos
Anfotericina B/farmacologia , Antifúngicos/farmacologia , Sistemas de Liberação de Medicamentos , Fungos/efeitos dos fármacos , Lipossomos/administração & dosagem , Micoses/tratamento farmacológico , Plasma/química , Alginatos/química , Anfotericina B/química , Animais , Antifúngicos/química , Feminino , Lipossomos/química , Camundongos , Coelhos
12.
Med Mycol ; 60(3)2022 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-35099003

RESUMO

Oropharyngeal candidiasis (OPC) is an oral infection mainly caused by Candida albicans, a dimorphic human opportunistic pathogen that can proliferate and invade the superficial oral epithelium using its hyphae. The filamentation of C. albicans is a hallmark of biofilm formation, accompanied by the occurrence of a hypoxic microenvironment. Paeonol (PAE) is a traditional medicine with multiple properties. In a previous study, we demonstrated the synergism of PAE plus Fluconazole (FLU) or Amphotericin B (AmB) against C. albicans in vitro and in vivo. This study aimed to explore the therapeutic mechanisms of drug combinations on OPC. In an established OPC mouse model, the culture of hypoxia was observed by calcofluor white and hypoxyprobe staining. The expression and levels of IL-17 signaling-associated genes and proteins (IL-17A and IL-23) were evaluated in tissue homogenates and EC109 cells. The results show that compared with the single therapy, PAE plus FLU or AmB can decrease fungal burden, restore mucosal integrity, and reduce the hypoxic microenvironment and inflammation in the OPC mice. Relative to infected mice, the drug combinations can also rectify the abnormal expression of hypoxia inducible factor (hif)-1α, il-17a, and il-23 mRNA. Meanwhile, compared with the infected EC109 cells treated with a single drug, PAE plus FLU or AmB significantly inhibited the mRNA and protein expression of HIF-1α, IL-17A, and IL-23. Taken together, the possible mechanism of PAE plus FLU or AmB can be attributed to the regulation of hypoxia-associated IL-17 signaling in OPC treatment.


Assuntos
Acetofenonas , Anfotericina B , Candidíase Bucal , Fluconazol , Acetofenonas/farmacologia , Acetofenonas/uso terapêutico , Anfotericina B/farmacologia , Anfotericina B/uso terapêutico , Animais , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Candida albicans/efeitos dos fármacos , Candidíase Bucal/tratamento farmacológico , Fluconazol/farmacologia , Fluconazol/uso terapêutico , Interleucina-17/genética , Camundongos , Testes de Sensibilidade Microbiana
13.
Biochim Biophys Acta Biomembr ; 1864(5): 183872, 2022 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-35085568

RESUMO

Spin label electron paramagnetic resonance (EPR) spectroscopy was used to characterize the components of the Mycobacterium abscessus massiliense cell envelope and their interactions with amphotericin B (AmB), miltefosine (MIL), and nerolidol (NER). Spin labels analogous to stearic acid and phosphatidylcholine (PC) were distributed on an envelope layer with fluidity comparable to other biological membranes, probably the mycobacterial cell wall, because after treatment with AmB a highly rigid spectral component was evident in the EPR spectra. Methyl stearate analogue spin labels found a much more fluid membrane and did not detect the presence of AmB, except for at very high drug concentrations. Unlike other spin-labeled PCs, the TEMPO-PC spin probe, with the nitroxide moiety attached to the choline of the PC headgroup, also did not detect the presence of AmB. On the other hand, the steroid spin labels were not distributed across the membranes of M. abscessus and, instead, were concentrated in some other location of the cell envelope. Both MIL and NER compounds at 10 µM caused increased fluidity in the cell wall and plasma membrane. Furthermore, NER was shown to have a remarkable ability to extract lipids from the mycobacterial cell wall. The EPR results suggest that the resistance of mycobacteria to the action of AmB must be related to the fact that this drug does not reach the bacterial plasma membrane.


Assuntos
Anfotericina B/farmacologia , Antibacterianos/farmacologia , Espectroscopia de Ressonância de Spin Eletrônica , Mycobacterium abscessus/efeitos dos fármacos , Fosforilcolina/análogos & derivados , Sesquiterpenos/farmacologia , Membrana Celular/química , Membrana Celular/efeitos dos fármacos , Parede Celular/química , Parede Celular/efeitos dos fármacos , Óxidos N-Cíclicos/química , Testes de Sensibilidade Microbiana , Mycobacterium abscessus/química , Mycobacterium abscessus/metabolismo , Fosfatidilcolinas/química , Fosforilcolina/farmacologia , Marcadores de Spin , Ácidos Esteáricos/química
14.
Life Sci ; 291: 120271, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34974077

RESUMO

INTRODUCTION: Amphotericin B (AmB), used for systemic fungal infections, has a limited clinical application because of its high nephrotoxicity. Natural antioxidant and anti-inflammatory substances have been widely studied for protection against drug-induced nephrotoxicity. α-Bisabolol (BIS) has demonstrated a nephroprotective effect on both in vitro and in vivo models. AIMS: The aim of this work was to evaluate the effect of BIS against AmB-induced nephrotoxicity in vitro. MATERIAL AND METHODS: LLC-MK2 cells were pre- and post-treated with non-toxic BIS concentrations and/or AmB IC50 (13.97 µM). Cell viability was assessed by MTT [(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide)] assay. Flow cytometry analyses were used to assess cell death mechanism, production of reactive oxidative stress (ROS) and mitochondrial transmembrane potential. Kidney Injury Molecule-1 (KIM-1) levels were measured via ELISA. KEY FINDINGS: The present work showed that BIS pretreatment (125; 62.5 and 31.25 µM) increased cell viability when compared to the group treated only with AmB IC50. AmB treatment induced both necrosis (7-AAD-labeled cells) and late apoptosis (AnxV-labeled). BIS was able to prevent the occurrence of these events. These effects were associated with a decrease of ROS accumulation, improving transmembrane mitochondrial potential and protecting against tubular cell damage, highlighted by the inhibition of KIM-1 release after BIS treatment. SIGNIFICANCE: BIS presented a potential effect on model of renal cytotoxicity induced by AmB, bringing perspectives for the research of new nephroprotective agents.


Assuntos
Sobrevivência Celular/efeitos dos fármacos , Túbulos Renais Proximais/efeitos dos fármacos , Sesquiterpenos Monocíclicos/farmacologia , Anfotericina B/farmacologia , Anfotericina B/toxicidade , Animais , Antifúngicos/farmacologia , Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular , Receptor Celular 1 do Vírus da Hepatite A/metabolismo , Rim/metabolismo , Túbulos Renais Proximais/metabolismo , Macaca mulatta , Sesquiterpenos Monocíclicos/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Substâncias Protetoras/farmacologia
15.
Biomacromolecules ; 23(3): 1169-1182, 2022 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-35025509

RESUMO

Amphotericin B (AmB) is a highly hydrophobic drug with significant leishmanicidal activity whose use is limited by its poor water solubility and adverse effects. Polymer-drug conjugates are proposed as a delivery system designed to overcome those limitations while improving drug bioavailability, safety, and activity. Here, AmB was covalently linked to periodate-oxidized hyaluronic acid (HA) (oxidation degree of 30.1 ± 5.6%) via a Schiff base (HA-AmB imine). The conjugate presents high water solubility and self-assembles into particles with a mean size of 88.2 ± 17.6 nm, a negative charge (-28.3 ± 0.9 mV), and a drug content of 17.8 ± 1.4%. Spectroscopic studies revealed the presence of AmB in aggregate and super-aggregated forms in the conjugate, which could explain the significant reduction of the in vitro cytotoxicity and hemolytic activity. The formulation showed not only in vitro anti-leishmanial activity against L. infantum-infected macrophages (IC50 = 0.023 µM) but also against an in vivo infected mouse model, promoting a 1.32- and a 4.98-log10 suppression of the L. infantum burden in the spleens and liver, respectively, without toxic effects. In summary, this study describes the safe and effective use of water-soluble HA-AmB imine conjugates for leishmaniasis treatment.


Assuntos
Anfotericina B , Ácido Hialurônico , Anfotericina B/química , Anfotericina B/farmacologia , Animais , Antifúngicos/química , Iminas , Camundongos , Água
16.
J Investig Med ; 70(4): 914-918, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35078866

RESUMO

An epidemic of mucormycosis followed the second wave of COVID 19 in the state of Uttar Pradesh, India in May 2021. This epidemic, however, had additional challenges to offer in the form of acute shortage of all forms of amphotericin B, posaconazole and isavuconazole. It was, therefore, planned to assess the trends in minimum inhibitory concentration (MIC) of antifungal agents, viz itraconazole and terbinafine, and provide a template for personalized therapy to see whether the results could be translated clinically. This is an observational, single-center study. Samples comprising nasal swab, nasal and paranasal sinus tissue, brain tissue, brain abscess and orbital content, derived from 322 patients from northern India with mucormycosis, of whom 215 were male and 107 were female, were used for analysis. Cultures were identified both by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and conventional methods of identification. Antifungal susceptibility was done for amphotericin B, posaconazole, isavuconazole, itraconazole and terbinafine as per Clinical Laboratory Standard Institute M38-A2. The outcome was identification of the species of mucormycosis and susceptibility to itraconazole and terbinafine besides other primary antifungal agents. Patients or the public were not involved in the design, or conduct, or reporting or in the dissemination plans of our research. Of 322 patients, 203 were culture-positive, of whom 173 were positive by both MALDI-TOF and conventional methods of identification. Final antifungal susceptibility testing was available for 150 patients. The most common Mucorales found to cause this epidemic was Rhizopus oryzae, followed by R. microsporus Amphotericin B, posaconazole and isavuconazole had low MIC values in 98.8% of all Mucorales identified. The MIC of itraconazole was species-dependent. 97.7% of R oryzae had MIC ≤2 µg/mL. However, only 36.5% of R microsporus had MIC ≤2 µg/mL. For terbinafine, 85.2% of R. microsporus had MIC ≤2 µg/mL. We conclude that identification at the species level is required as antifungal susceptibilities seem to be species-dependent. Assessment of the efficacy of itraconazole and terbinafine warrants further studies with clinical assessment and therapeutic drug monitoring as they seem to be potential candidates especially when the primary agents are not available.


Assuntos
COVID-19 , Mucormicose , Anfotericina B/farmacologia , Anfotericina B/uso terapêutico , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Feminino , Humanos , Itraconazol/farmacologia , Itraconazol/uso terapêutico , Masculino , Mucormicose/tratamento farmacológico , Mucormicose/epidemiologia , Mucormicose/microbiologia , Terbinafina/farmacologia , Terbinafina/uso terapêutico
17.
J Prosthet Dent ; 127(2): 320-330, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33279153

RESUMO

STATEMENT OF PROBLEM: The use of antifungals has been suggested during the treatment of denture stomatitis associated with Candida albicans biofilms. However, how time, material surface, and substrates present during adhesion and biofilm development can influence clinical treatment is unclear. PURPOSE: The purpose of this in vitro study was to investigate the growth kinetics of C. albicans biofilms on surfaces of specimens under the influence of adsorbed films and to evaluate the antibiofilm efficacy of antifungal agents: amphotericin B, fluconazole, and nystatin. MATERIAL AND METHODS: Specimens of Silagum-Comfort Soft Relining were submerged in preconditioning systems: phosphate-buffered saline, artificial saliva, fetal bovine serum, and artificial saliva+fetal bovine serum. Planktonic cells were incubated (phosphate-buffered saline+specimens) for 1.5 hours (adhesion phase) and washed with phosphate-buffered saline solution. The specimens were then incubated (YNB+glucose) for 8, 24, and 48 hours (initial, intermediate, and maturation phases). The biofilm sessile minimum inhibitory concentration was determined by the broth microdilution method (7.81 to 500 µg/mL). The metabolic activity of the biofilms was tested by colorimetric assay (cell metabolic activity). Cell viability, relative biomass (µm3), and the thickness of the biofilm (µm) were evaluated by confocal laser scanning microscopy. RESULTS: The highest bioactivity was recorded in the presence of fetal bovine serum. Biofilms treated with fluconazole and amphotericin B were partially inhibited in a dose-dependent manner. Nystatin inhibited metabolic activity mainly from ≥15.63 or 62.5 µg/mL. Variations in magnitude parameters (relative biomass and thickness) were observed depending on the development phases of biofilms, whereas biological parameters (percentage of nonviable cells) were constant throughout the formation of C. albicans biofilms. CONCLUSIONS: The data suggest that partial (fluconazole and amphotericin B) or more effective (nystatin) reduction of metabolic activity of C. albicans biofilms occurred depending on the time and the antifungal and its concentrations.


Assuntos
Prótese Dentária , Fluconazol , Anfotericina B/farmacologia , Anfotericina B/uso terapêutico , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Biofilmes , Candida albicans , Fluconazol/farmacologia , Nistatina/farmacologia
18.
Br J Ophthalmol ; 106(2): 184-189, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-33172862

RESUMO

BACKGROUND/AIM: We compared the quality of human donor corneas stored in a cold storage medium containing 2.5 µg/ml of amphotericin B (Kerasave, AL.CHI.MI.A. S.R.L., Ponte San Nicolò, Italy) and Optisol-GS (Bausch & Lomb Inc., Bridgewater, NJ, USA) for 14 days. METHODS: Sixteen pairs of human donor corneas were collected in Eusol-C (AL.CHI.MI.A. S.R.L., Ponte San Nicolò, Italy). Next, all tissues underwent the first evaluation that included the assessments of central corneal thickness (CCT), endothelial cell density (ECD) measured using both trypan blue staining and specular microscopy, endothelial cell (EC) mortality and morphology, and corneal transparency within 24 hours from recovery (Day 1). Afterwards, one cornea of each pair was transferred into Kerasave or Optisol-GS. ECD and CCT were also assessed at Day 7, and all the metrics were evaluated again at the end of the storage period (Day 14). RESULTS: At all tested time points, no differences were found in the qualitative (corneal transparency, EC morphology) and quantitative metrics (ECD, CCT, EC mortality) between the Kerasave and the Optisol-GS storage groups. At Day 14, the corneas stored in Kerasave and Optisol-GS showed ECD of 2312±98 and 2335±128 cells/mm2 (p=0.886), CCT of 717±17 and 697±19 µm (p=0.454) and central EC mortality of 0.54%±0.40% and 0.14%±0.14% (p=0.719), respectively. CONCLUSIONS: The new amphotericin B-containing medium Kerasave was comparable to Optisol-GS in terms of preservation of corneal characteristics at 2-8°C for 14 days.


Assuntos
Anfotericina B , Preservação de Órgãos , Anfotericina B/farmacologia , Sulfatos de Condroitina , Misturas Complexas , Córnea , Meios de Cultura Livres de Soro , Dextranos , Endotélio Corneano , Gentamicinas , Humanos
19.
Exp Eye Res ; 214: 108881, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34871569

RESUMO

Corneal ulcers, a leading cause of blindness in the developing world are treated inappropriately without prior microbiology assessment because of issues related to availability or cost of accessing these services. In this work we aimed to develop a device for identifying the presence of Gram-positive or Gram-negative bacteria or fungi that can be used by someone without the need for a microbiology laboratory. Working with branched poly (N-isopropyl acrylamide) (PNIPAM) tagged with Vancomycin, Polymyxin B, or Amphotericin B to bind Gram-positive bacteria, Gram-negative bacteria and fungi respectively, grafted onto a single hydrogel we demonstrated specific binding of the organisms. The limit of detection of the microbes by these polymers was between 10 and 4 organisms per high power field (100X) for bacteria and fungi binding polymers respectively. Using ex vivo and animal cornea infection models infected with bacteria, fungi or both we than demonstrated that the triple functionalised hydrogel could pick up all 3 organisms after being in place for 30 min. To confirm the presence of bacteria and fungi we used conventional microbiology techniques and fluorescently labelled ligands or dyes. While we need to develop an easy-to-use either a colorimetric or an imaging system to detect the fluorescent signals, this study presents for the first time a simple to use hydrogel system, which can be applied to infected eyes and specifically binds different classes of infecting agents within a short space of time. Ultimately this diagnostic system will not require trained microbiologists for its use and will be used at the point-of-care.


Assuntos
Resinas Acrílicas/metabolismo , Úlcera da Córnea/diagnóstico , Infecções Oculares Bacterianas/diagnóstico , Infecções Oculares Fúngicas/diagnóstico , Hidrogéis/metabolismo , Ligantes , Resinas Acrílicas/química , Anfotericina B/farmacologia , Animais , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/metabolismo , Candidíase/diagnóstico , Candidíase/microbiologia , Úlcera da Córnea/microbiologia , Infecções Oculares Bacterianas/microbiologia , Infecções Oculares Fúngicas/microbiologia , Fungos/efeitos dos fármacos , Fungos/metabolismo , Humanos , Hidrogéis/química , Testes de Sensibilidade Microbiana , Polimixina B/farmacologia , Infecções por Pseudomonas/diagnóstico , Infecções por Pseudomonas/microbiologia , Coelhos , Infecções Estafilocócicas/diagnóstico , Infecções Estafilocócicas/microbiologia , Vancomicina/farmacologia
20.
Acta Trop ; 226: 106260, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34848183

RESUMO

Leishmaniasis is an emerging disease in several countries over the world, especially in tropical regions. In Thailand, Leishmania (Mundinia) martiniquensis is the most frequent cause of visceral leishmaniasis and disseminated cutaneous leishmaniasis among HIV/AIDs patients. Amphotericin B (AmB) is the only drug currently available for the treatment of leishmaniasis in Thailand, but has some limitations like high renal toxicity and the prolonged hospitalization required for the treatment. Moreover, recurrence of the disease has been reported in several cases, indicating that new drugs or treatment strategies should be improved. In this study, Artesunate (ARS) was determined for anti-Leishmania activity against L. martiniquensis in promastigotes and amastigotes. In addition, the combination effects of ARS and AmB against intracellular amastigotes on THP-1 derived macrophages were also investigated for the first time. The result showed that L. martiniquensis was susceptible to ARS in both stages of the parasite. ARS was effective against intracellular amastigotes and safe to macrophage host cells, showing a SI value of 1,065. Furthermore, combination effects of ARS and AmB showed five synergistic combinations with a combination index (CI) value less than 1.0 (0.28-0.92) for intracellular amastigotes ranging from slight synergism to strong synergism. The strong synergistic combination had the highest dose reduction index (DRI), approximately a 9.7-fold reduction in AmB used. None of the treatments in combination had noticeable toxicity to THP-1 derived macrophages in the concentration range examined. The data provided in this study lead to further study in vivo and to develop a novel formulation of drug combinations to improve the outcome of leishmaniasis treatment.


Assuntos
Antiprotozoários , Leishmania , Leishmaniose Cutânea , Leishmaniose Visceral , Anfotericina B/farmacologia , Anfotericina B/uso terapêutico , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Artesunato/uso terapêutico , Humanos , Leishmaniose Cutânea/tratamento farmacológico , Leishmaniose Visceral/tratamento farmacológico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...