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2.
Parasit Vectors ; 12(1): 280, 2019 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-31159839

RESUMO

BACKGROUND: Species of Acanthamoeba are facultative pathogens which can cause sight threatening Acanthamoeba keratitis and a rare but deadly brain infection, granulomatous amoebic encephalitis. Due to conversion of Acanthamoeba trophozoites to resistant cyst stage, most drugs are found to be ineffective at preventing recurrence of infection. This study was designed to test the antiacanthamoebic effects of different cobalt nanoparticles (CoNPs) against trophozoites and cysts, as well as parasite-mediated host cell cytotoxicity. METHODS: Three different varieties of CoNPs were synthesized by utilizing hydrothermal and ultrasonication methods and were thoroughly characterized by X-ray diffraction and field emission scanning electron microscopy. Amoebicidal, encystation, excystation, and host cell cytopathogenicity assays were conducted to study the antiacanthamoebic effects of CoNPs. RESULTS: The results of the antimicrobial evaluation revealed that cobalt phosphate Co3(PO4)2 hexagonal microflakes, and 100 nm large cobalt hydroxide (Co(OH)2) nanoflakes showed potent amoebicidal activity at 100 and 10 µg/ml against Acanthamoeba castellanii as compared to granular cobalt oxide (Co3O4) of size 35-40 nm. Furthermore, encystation and excystation assays also showed consistent inhibition at 100 µg/ml. CoNPs also inhibited amoebae-mediated host cell cytotoxicity as determined by lactate dehydrogenase release without causing significant damage to human cells when treated alone. CONCLUSIONS: To our knowledge, these findings determined, for the first time, the effects of composition, size and morphology of CoNPs against A. castellanii. Co3(PO4)2 hexagonal microflakes showed the most promising antiamoebic effects as compared to Co(OH)2 nanoflakes and granular Co3O4. The results reported in the present study hold potential for the development of antiamoebic nanomedicine.


Assuntos
Acanthamoeba castellanii/efeitos dos fármacos , Amebicidas/farmacologia , Cobalto/farmacologia , Nanopartículas/química , Amebíase/tratamento farmacológico , Células Cultivadas , Microscopia Eletrônica de Varredura , Trofozoítos/efeitos dos fármacos
3.
Parasitol Res ; 118(6): 1953-1961, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31069536

RESUMO

The genus Acanthamoeba can cause Acanthamoeba keratitis (AK) and granulomatous amoebic encephalitis (GAE). The treatment of these illnesses is hampered by the existence of a resistance stage that many times causes infection relapses. In an attempt to add new agents to our chemotherapeutic arsenal against acanthamebiasis, two Acanthamoeba isolates were treated in vitro with newly synthesized biguanide dendrimers. Trophozoite viability analysis and ultrastructural studies showed that dendrimers prevent encystment by lysing the cellular membrane of the amoeba. Moreover, one of the dendrimers showed low toxicity when tested on mammalian cell cultures, which suggest that it might be eventually used as an amoebicidal drug or as a disinfection compound in contact lens solutions.


Assuntos
Ceratite por Acanthamoeba/tratamento farmacológico , Acanthamoeba/efeitos dos fármacos , Amebicidas/farmacologia , Biguanidas/farmacologia , Clorexidina/análogos & derivados , Dendrímeros/farmacologia , Encefalite/tratamento farmacológico , Acanthamoeba/classificação , Acanthamoeba/isolamento & purificação , Animais , Linhagem Celular Tumoral , Clorexidina/farmacologia , Soluções para Lentes de Contato , Encefalite/parasitologia , Células HeLa , Humanos , Trofozoítos/efeitos dos fármacos
4.
Exp Parasitol ; 201: 90-92, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31059693

RESUMO

Acanthamoeba are free living amoeba that have been isolated from different environments like soil, water, air dust. Moreover, they are also able to act as opportunist pathogens, mainly causing a fatal encephalitis and also keratitis in both human and animals. This study was aimed to evaluate the activity of the Medicines for Malaria Venture (MMV) compounds against the trophozoite stage of Acanthamoeba castellanii Neff. Sixteen compounds showed ≥90% inhibition of parasite growth in the initial screen (10 µM). Those set were further evaluated to determine the inhibitor concentration that inhibit the 50% of the initial population and cytotoxicity against murine macrophages. Among the compounds included in the pathogen box, pentamidine and posaconazole were the most effective against this parasite with an of IC50 of 0.567 ±â€¯0.04 and 0.630 ±â€¯0.11, respectively.


Assuntos
Acanthamoeba castellanii/efeitos dos fármacos , Amebicidas/farmacologia , Amebicidas/classificação , Animais , Linhagem Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Concentração Inibidora 50 , Camundongos , Pentamidina/farmacologia , Triazóis/farmacologia , Trofozoítos/efeitos dos fármacos
5.
Molecules ; 24(10)2019 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-31137574

RESUMO

Malaria is an infectious disease caused by Plasmodium group. The mechanisms of antimalarial drugs DHA/CQ are still unclear today. The inhibitory effects (IC50) of single treatments with DHA/CQ or V-ATPase inhibitor Baf-A1 or combination treatments by DHA/CQ combined with Baf-A1 on the growth of Plasmodium falciparum strain 3D7 was investigated. Intracellular cytoplasmic pH and labile iron pool (LIP) were labeled by pH probe BCECF, AM and iron probe calcein, AM, the fluorescence of the probes was measured by FCM. The effects of low doses of DHA (0.2 nM, 0.4 nM, 0.8 nM) on gene expression of V-ATPases (vapE, vapA, vapG) located in the membrane of DV were tested by RT-qPCR. DHA combined with Baf-A1 showed a synergism effect (CI = 0.524) on the parasite growth in the concentration of IC50. Intracellular pH and irons were effected significantly by different doses of DHA/Baf-A1. Intracellular pH was decreased by CQ combined with Baf-A1 in the concentration of IC50. Intracellular LIP was increased by DHA combined with Baf-A1 in the concentration of 20 IC50. The expression of gene vapA was down-regulated by all low doses of DHA (0.2/0.4/0.8 nM) significantly (p < 0.001) and the expression of vapG/vapE were up-regulated by 0.8 nM DHA significantly (p < 0.001). Interacting with ferrous irons, affecting the DV membrane proton pumping and acidic pH or cytoplasmic irons homeostasis may be the antimalarial mechanism of DHA while CQ showed an effect on cytoplasmic pH of parasite in vitro. Lastly, this article provides us preliminary results and a new idea for antimalarial drugs combination and new potential antimalarial combination therapies.


Assuntos
Artemisininas/farmacologia , Cloroquina/farmacologia , Eritrócitos/parasitologia , Homeostase , Estágios do Ciclo de Vida/efeitos dos fármacos , Plasmodium falciparum/crescimento & desenvolvimento , Animais , Antimaláricos/farmacologia , Membrana Celular/efeitos dos fármacos , Membrana Celular/parasitologia , Quimioterapia Combinada , Eritrócitos/efeitos dos fármacos , Fluorescência , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Homeostase/efeitos dos fármacos , Humanos , Concentração de Íons de Hidrogênio , Concentração Inibidora 50 , Ferro/metabolismo , Macrolídeos/farmacologia , Parasitos/efeitos dos fármacos , Parasitos/crescimento & desenvolvimento , Testes de Sensibilidade Parasitária , Plasmodium falciparum/efeitos dos fármacos , Trofozoítos/efeitos dos fármacos , ATPases Vacuolares Próton-Translocadoras/genética , ATPases Vacuolares Próton-Translocadoras/metabolismo
6.
Parasitol Res ; 118(7): 2295-2304, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31093751

RESUMO

Acanthamoeba castellanii belonging to the T4 genotype is an opportunistic pathogen which is associated with blinding eye keratitis and rare but fatal central nervous system infection. A. castellanii pose serious challenges in antimicrobial chemotherapy due to its ability to convert into resistant, hardy shell-protected cyst form that leads to infection recurrence. The fatty acid composition of A. castellanii trophozoites is known to be most abundant in oleic acid which chemically is an unsaturated cis-9-Octadecanoic acid and naturally found in animal and vegetable fats and oils. This study was designed to evaluate antiacanthamoebic effects of oleic acid against trophozoites, cysts as well as parasite-mediated host cell cytotoxicity. Moreover, oleic acid-conjugated silver nanoparticles (AgNPs) were also synthesized and tested against A. castellanii. Oleic acid-AgNPs were synthesized by chemical reduction method and characterized by ultraviolet-visible spectrophotometry, atomic force microscopy, dynamic light scattering analysis, and Fourier transform infrared spectroscopy. Viability, growth inhibition, encystation, and excystation assays were performed with 10 and 5 µM concentration of oleic acid alone and oleic acid-conjugated AgNPs. Bioassays revealed that oleic acid alone and oleic acid-conjugated AgNPs exhibited significant antiamoebic properties, whereas nanoparticle conjugation further enhanced the efficacy of oleic acid. Phenotype differentiation assays also showed significant inhibition of encystation and excystation at 5 µM. Furthermore, oleic acid and oleic acid-conjugated AgNPs also inhibited amoebae-mediated host cell cytotoxicity as determined by lactate dehydrogenase release. These findings for the first time suggest that oleic acid-conjugated AgNPs exhibit antiacanthamoebic activity that hold potential for therapeutic applications against A. castellanii.


Assuntos
Ceratite por Acanthamoeba/tratamento farmacológico , Acanthamoeba castellanii/efeitos dos fármacos , Amebicidas/farmacologia , Nanopartículas Metálicas/química , Ácido Oleico/farmacologia , Ceratite por Acanthamoeba/parasitologia , Amebicidas/química , Animais , Olho/parasitologia , Humanos , Microscopia de Força Atômica , Ácido Oleico/química , Prata/química , Espectrofotometria Ultravioleta , Trofozoítos/efeitos dos fármacos
7.
Artigo em Inglês | MEDLINE | ID: mdl-31015151

RESUMO

Giardia duodenalis is an ubiquitous parasitic pathogen that causes significant morbidity and mortality worldwide. Failures in drug therapy are commonly due to poor patient compliance as a result of the need for repeated administration, off target drug effects and increasing parasite drug resistance. In this study the in vitro efficacy and selectivity of the aminoguanidine compound robenidine and 2 structural analogues against Giardia were determined. After 5 h exposure to each compound the IC50 was as low as 0.2 µM with corresponding MLCs as low as 2.8 µM. This is in contrast to metronidazole which required 24 h to exhibit inhibitory activity. A modified adherence assay, developed for this study, demonstrated that three of the compounds inhibited in vitro adherence of the parasite. The lead compound exhibited rapid giardicidal activity (<5hr). In addition, microscopy studies demonstrated damage to the plasma membrane of trophozoites. In conclusion, a class of aminoguanidines, represented by robenidine, has shown antigiardial activity warranting further investigation.


Assuntos
Antiprotozoários/farmacologia , Giardia lamblia/efeitos dos fármacos , Giardíase/tratamento farmacológico , Guanidinas/farmacologia , Animais , Antiprotozoários/química , Membrana Celular/efeitos dos fármacos , Membrana Celular/ultraestrutura , Giardia lamblia/crescimento & desenvolvimento , Giardia lamblia/fisiologia , Giardia lamblia/ultraestrutura , Giardíase/parasitologia , Guanidinas/química , Humanos , Testes de Sensibilidade Parasitária , Trofozoítos/efeitos dos fármacos , Trofozoítos/crescimento & desenvolvimento , Trofozoítos/ultraestrutura
8.
Ann Agric Environ Med ; 26(1): 198-202, 2019 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-30922053

RESUMO

INTRODUCTION: Various Acanthamoeba species are free-living organisms widely distributed in the human environment. Amphizoic amoebae as facultative parasites may cause vision-threatening eye disease - Acanthamoeba keratitis, mostly among contact lens wearers. As the number of cases is increasing, and applied therapy often unsuccessful, proper hygienic measures and effective contact lenses disinfection are crucial for the prevention of this disease. Available contact lens solutions are not fully effective against amphizoic amoebae; there is a need to enhance their disinfecting activity to prevent amoebic infections. The use of developing nanotechnology methods already applied with success in the prevention, diagnostic and therapy of other infectious diseases might be helpful regarding amoebic keratitis. This study assesses the in vitro effect of selected contact lens solutions conjugated with nanoparticles against Acanthamoeba trophozoites. MATERIAL AND METHODS: Three selected contact lens solutions conjugated with silver and gold nanoparticles in concentration of 0.25-2.5 ppm were used in vitro against the axenically cultured ATCC 30010 type Acanthamoeba castellanii strain. The anti-amoebic efficacy was examined based on the oxido-reduction of AlamarBlue. The cytotoxicity tests based on the measurement of lactate dehydrogenase (LDH) activity were performed using a fibroblast HS-5 cell line. RESULTS: Enhancement of the anti-amoebic activity of contact lens solutions conjugated with selected nanoparticles expressed in the dose dependent amoebic growth inhibition with a low cytotoxicity profile was observed. CONCLUSIONS: Results of the study showed that conjugation of selected contact lens solutions with silver nanoparticles might be a promising approach to prevent Acanthamoeba keratitis among contact lens users.


Assuntos
Acanthamoeba castellanii/efeitos dos fármacos , Soluções para Lentes de Contato/farmacologia , Nanopartículas Metálicas/uso terapêutico , Ceratite por Acanthamoeba/prevenção & controle , Linhagem Celular Tumoral , Soluções para Lentes de Contato/toxicidade , Ouro/farmacologia , Ouro/toxicidade , Humanos , L-Lactato Desidrogenase/metabolismo , Nanopartículas Metálicas/toxicidade , Prata/farmacologia , Prata/toxicidade , Trofozoítos/efeitos dos fármacos
9.
PLoS One ; 14(3): e0213385, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30845190

RESUMO

The effects on Giardia duodenalis of Slab51 probiotic supernatants were evaluated in vitro and ex vivo. In vitro, Slab51 (101 UFC) was cultured and the obtained supernatant was filtered, adjusted at pH 7, and added (100µl/ml) as such (Slab51 FS) or after heat-treatment, to G. duodenalis cultures to evaluate its effects on G. duodenalis trophozoites growth and adherence. For comparison, negative and metronidazole (20µg/ml) treated controls were used. The morphological and ultrastructural alterations of G. duodenals trophozoites following treatment with Slab51 FS supernatant were investigated by transmission electron microscopy. Ex vivo, mice duodenal portions were cultivated in standard conditions with 5x105 G. duodenalis trophozoites/ml, while to further five duodenal portions similarly cultured and infected, Slab51 FS 200µl was added. After 12 and 18h, samples were fixed in 10% buffered formalin and histologically processed to score Giardia infection and cell damage. Cell proliferation/apoptosis was scored by Ki67, TUNEL and Caspase-3 tests. All experiments were conducted in triplicate throughout the study. All data were statistically evaluated (P< 0.05). Results showed that Slab51 FS significantly reduced Giardia growth and adherence respect to negative controls, but its efficacy was overall lower than that of metronidazole. Moreover, the effects of Slab51 FS were significantly lowered by heat-treatment and this reduction was statistically higher at 90°C than at 56°C, indicating a heat-sensitive nature of active Slab51 FS compounds. At the ultrastructural level, Slab51 FS treated Giardia trophozoites were swelling, increased in size and showed alterations of their cellular membrane and vacuole patterns, loss of the nuclear envelope and nuclear architecture. In ex vivo trials, viable G. duodenalis trophozoites and enterocyte TUNEL+ and Caspase-3 expression were significantly reduced in intestinal sections added with Slab51 FS, while enterocyte Ki67 expression was significantly increased, confirming the anti-G. duodenalis activity of Slab51 FS observed in vitro. In conclusion, results from this study showed that the fresh culture supernatant of the commercial probiotic Slab51 has anti-G. duodenalis properties both in vitro and ex vivo in a mouse model.


Assuntos
Giardia lamblia/efeitos dos fármacos , Giardíase/tratamento farmacológico , Probióticos/farmacologia , Trofozoítos/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Proliferação de Células/efeitos dos fármacos , Duodeno/parasitologia , Giardíase/metabolismo , Antígeno Ki-67/metabolismo , Camundongos , Camundongos Endogâmicos ICR
11.
Nat Commun ; 10(1): 371, 2019 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-30670687

RESUMO

Studies of Plasmodium vivax gene expression are complicated by the lack of in vitro culture system and the difficulties associated with studying clinical infections that often contain multiple clones and a mixture of parasite stages. Here, we characterize the transcriptomes of P. vivax parasites from 26 malaria patients. We show that most parasite mRNAs derive from trophozoites and that the asynchronicity of P. vivax infections is therefore unlikely to confound gene expression studies. Analyses of gametocyte genes reveal two distinct clusters of co-regulated genes, suggesting that male and female gametocytes are independently regulated. Finally, we analyze gene expression changes induced by chloroquine and show that this antimalarial drug efficiently eliminates most P. vivax parasite stages but, in contrast to P. falciparum, does not affect trophozoites.


Assuntos
Cloroquina/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Plasmodium vivax/efeitos dos fármacos , Plasmodium vivax/genética , Transcriptoma/efeitos dos fármacos , Antimaláricos/farmacologia , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/genética , Feminino , Genes de Protozoários/efeitos dos fármacos , Genes de Protozoários/genética , Genoma de Protozoário/efeitos dos fármacos , Genoma de Protozoário/genética , Humanos , Malária/tratamento farmacológico , Malária Falciparum/tratamento farmacológico , Malária Vivax/tratamento farmacológico , Masculino , Família Multigênica , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/genética , Plasmodium vivax/patogenicidade , RNA Mensageiro/metabolismo , Trofozoítos/efeitos dos fármacos , Trofozoítos/genética
12.
Int J Med Microbiol ; 309(2): 130-142, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30665874

RESUMO

Giardia trophozoites have developed resistance mechanisms to currently available compounds, leading to treatment failures. In this context, the development of new additional agents is mandatory. Sirtuins, which are class III NAD+-dependent histone deacetylases, have been considered important targets for the development of new anti-parasitic drugs. Here, we evaluated the activity of KH-TFMDI, a novel 3-arylideneindolin-2-one-type sirtuin inhibitor, on G. intestinalis trophozoites. This compound decreased the trophozoite growth presenting an IC50 value lower than nicotinamide, a moderately active inhibitor of yeast and human sirtuins. Light and electron microscopy analysis showed the presence of multinucleated cell clusters suggesting that the cytokinesis could be compromised in treated trophozoites. Cell rounding, concomitantly with the folding of the ventro-lateral flange and flagella internalization, was also observed. These cells eventually died by a mechanism which lead to DNA/nuclear damage, formation of multi-lamellar bodies and annexin V binding on the parasite surface. Taken together, these data show that KH-TFMDI has significant effects against G. intestinalis trophozoites proliferation and structural organization and suggest that histone deacetylation pathway should be explored on this protozoon as target for chemotherapy.


Assuntos
Antiprotozoários/farmacologia , Giardia lamblia/efeitos dos fármacos , Inibidores de Histona Desacetilases/farmacologia , Trofozoítos/efeitos dos fármacos , Células CACO-2 , Citocinese/efeitos dos fármacos , Giardia lamblia/citologia , Giardia lamblia/crescimento & desenvolvimento , Humanos , Concentração Inibidora 50 , Microscopia , Microscopia Eletrônica , Testes de Sensibilidade Parasitária , Trofozoítos/citologia , Trofozoítos/crescimento & desenvolvimento
13.
Malar J ; 18(1): 8, 2019 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-30642330

RESUMO

BACKGROUND: The erythrocytic stage of Plasmodium falciparum parasites in humans is clinically important, as the parasites at this growth stage causes malarial symptoms. Most of the currently available anti-malarial drugs target this stage, but the emergence and spread of parasites resistant to anti-malarial drugs are a major challenge to global eradication efforts; therefore, the development of novel medicines is urgently required. In this study, the in vitro anti-malarial activity of five current anti-malarial drugs (artemisinin, atovaquone, chloroquine, mefloquine, and pyrimethamine) and 400 compounds from the Pathogen Box provided by the Medicines for Malaria Venture on P. falciparum parasites was characterized using the XN-30 analyzer. Furthermore, the outcomes obtained using the analyser were classified according to the parasitaemias of total and each developmental stages. RESULTS: The growth inhibition rate and the half-maximal (50%) inhibitory concentration (IC50) of the five current anti-malarial drugs were calculated from the parasitaemia detected using the XN-30 analyzer. Respective strains and drugs presented strongly fitted sigmoidal curves, and the median SD at all tested concentrations was 1.6, suggesting that the variation in values measured with the analyser was acceptably low for the comparison of drug efficacy. Furthermore, the anti-malarial activity of the 400 compounds from the Pathogen Box was tested, and 141 drugs were found to be effective. In addition, the efficacy was classified into 4 types (Type I, parasites were arrested or killed without DNA replication; Type II, parasites were arrested or killed similar to Type I, and the parasitaemia was apparently decreased; Type III, parasites progressed to trophozoite without sufficient DNA replication; and Type IV, parasites were arrested at late trophozoite or schizont after DNA replication). CONCLUSION: The current study demonstrates that the XN-30 analyzer objectively, reproducibly, and easily evaluated and characterized the anti-malarial efficacy of various compounds. The results indicate the potential of the XN-30 analyzer as a powerful tool for drug discovery and development in addition to its use as an important diagnostic tool.


Assuntos
Antimaláricos/farmacologia , Automação Laboratorial/instrumentação , Descoberta de Drogas/instrumentação , Hematologia/instrumentação , Antimaláricos/isolamento & purificação , Atovaquona/farmacologia , Automação Laboratorial/métodos , Cloroquina/farmacologia , Descoberta de Drogas/métodos , Hematologia/métodos , Humanos , Concentração Inibidora 50 , Malária Falciparum/tratamento farmacológico , Mefloquina/farmacologia , Plasmodium falciparum/efeitos dos fármacos , Esquizontes/efeitos dos fármacos , Trofozoítos/efeitos dos fármacos
14.
Acta Parasitol ; 64(1): 63-70, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30689190

RESUMO

PURPOSE : The present study aimed to investigate the amoebicidal and amoebistatic efects of Artemisia argyi leaf methanolic extract by testing the effects on trophozoites and on cysts. We also determined cytotoxic effect, enzymatic and non-enzymatic antioxidant activities, total phenolic, lavonoid and antioxidative contents of A. argyi. METHODS: A. argyi was harvested from various geographic sites in Ordu province in Turkey. The fresh leaves were subjected to methanolic extraction. In 100 µl culture, different concentrations of A. argyi methanolic extract (in quantities from 1.2, 2.3, 4.7, 9.4, 18.7, 37.4, 74.8 mg/ml) and the same volume of trophozoite/cyst suspension were mixed for the determination of the amoebicidal activity of the plant extract. Human bronchial epithelial cells were treated with the same concentrations of Artemisia extracts to determine cytotoxic potential. RESULTS: Total phenolic and lavonoid contents of the extract were calculated as 261 mg gallic acid/g dry extract and 29 mg quercetin/g dry extract, respectively. Total antioxidant activity was also calculated as 367 mg ascorbic acid/g dry extract. The growth of trophozoites stopped in A. argyi methanolic extract with 50% inhibitory concentrations (IC50)/8 h for 37.4 mg/ ml and 74.8 mg/ml extract solution and had stronger amoebicidal activity on the cysts with IC50/72 h. Artemisia showed stronger inhibitory effects on bronchial epithelial cells at the concentrations of 9.4, 18.7, 37.4 and 74.8 mg/ml. CONCLUSION: The study indicated that A. argyi leaf extract has cytotoxic and anti-amoebic activities.


Assuntos
Acanthamoeba castellanii/efeitos dos fármacos , Amebicidas/farmacologia , Artemisia/química , Extratos Vegetais/farmacologia , Trofozoítos/efeitos dos fármacos , Amebicidas/isolamento & purificação , Amebicidas/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Humanos , Testes de Sensibilidade Parasitária , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/toxicidade , Folhas de Planta/química , Turquia
15.
Eye Contact Lens ; 45(3): 164-170, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30138250

RESUMO

PURPOSE: To compare the antimicrobial effects of CLEAR CARE, a 3% hydrogen peroxide (H2O2) solution formulated for simultaneous cleaning, daily protein removal, disinfection, and storage of soft (hydrophilic) hydrogel, silicone hydrogel, and gas-permeable contact lenses, and CLEAR CARE PLUS, consisting of the 3% H2O2 solution plus a novel wetting agent, polyoxyethylene-polyoxybutylene (EOBO-21). METHODS: Three lots each of the 2 solutions were incubated with 5 compendial microorganisms required by the Food and Drug Administration (FDA) 510(k) and International Organization for Standardization (ISO) 14729 stand-alone procedures, 4 clinical isolates of Gram-positive and Gram-negative bacteria, and trophozoites and cysts of 2 Acanthamoeba strains that are associated with microbial keratitis. Microbial loads were evaluated after disinfection and neutralization. RESULTS: Both solutions exceeded the FDA/ISO stand-alone primary criteria against Gram-positive and Gram-negative compendial bacteria, yeast, and mold after only 1.5-hr disinfection/neutralization. At the recommended minimum disinfection time, bacteria were reduced by 4.4 to 5.1 logs, yeast by 4.4 to 4.9 logs, and mold by 2.9 to 3.5 logs with and without organic soil. In addition, both solutions eliminated or effectively reduced populations of clinically relevant ocular bacterial isolates (4.5-5.0 logs), Acanthamoeba trophozoites (3.4-4.2 logs), and cysts (1.5-2.1 logs). CONCLUSION: Both solutions eliminated or reduced populations of FDA/ISO compendial bacteria and fungi as well as clinically relevant microorganisms and Acanthamoeba trophozoites and cysts. The addition of EOBO-21 to the 3% H2O2 lens care solution had no impact on antimicrobial activity.


Assuntos
Acanthamoeba/efeitos dos fármacos , Antibacterianos/farmacologia , Soluções para Lentes de Contato/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Peróxido de Hidrogênio/farmacologia , Agentes Molhantes/farmacologia , Lentes de Contato Hidrofílicas/microbiologia , Desinfetantes , Fungos/efeitos dos fármacos , Polienos/farmacologia , Polietilenoglicóis/farmacologia , Trofozoítos/efeitos dos fármacos
16.
Nat Prod Res ; 33(4): 606-611, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29117746

RESUMO

Several species of the genus Acanthamoeba cause human diseases. Treatment of infections involves various problems, emphasising the need to develop alternative antiprotozoal agents. We studied the anti-amoebic activity of Essential Oils (EOs), derived from rosemary (Rosmarinus officinalis L.) and cloves (Syzygium aromaticum L. Merr. & Perry), against Acanthamoeba polyphaga strain. The amoebicidal activity of cloves and rosemary EOs was preliminary demonstrated by the morphology change (modifications in the cell shape, the presence of precipitates in the cytoplasm, autophagic vesicles, membrane blends) of the treated trophozoites. The cell-counts, carried out after staining trophozoites with a Trypan blue solution, revealed that both EOs were active in a dose-dependent manner and in relation to the exposure time. This activity was evident after few hours, with encouraging results obtained in particular with cloves EO, able to act at the lower concentrations and after 1 h, probably for its high eugenol content (65.30%).


Assuntos
Acanthamoeba/efeitos dos fármacos , Óleos Voláteis/farmacologia , Rosmarinus/química , Syzygium/química , Amebicidas/isolamento & purificação , Amebicidas/farmacologia , Animais , Eugenol/análise , Humanos , Trofozoítos/efeitos dos fármacos
17.
Biosci Rep ; 39(1)2019 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-30429239

RESUMO

Amoebiasis caused by the protozoan parasite Entamoeba histolytica remains a public health problem in developing countries, making the identification of new anti-amoebic compounds a continuing priority. Previously, we have shown that lactoferrin (Lf) and several Lf-derived peptides exhibit in vitro anti-amoebic activity independently of their iron-binding activity. Here, we evaluated the amoebicidal effect of synthetic Lf-derived peptides Lfcin-B, Lfcin 17-30, and Lfampin, analyzed the mechanism of death induced by the peptides and determined their therapeutic effects on murine intestinal amoebiasis. MTT assays in trophozoite cultures of E. histolytica exposed to each peptide (1-1000 µM) showed that Lfampin is far more amoebicidal than Lfcins. Lfampin killed 80% of trophozoites at doses higher than 100 µM in 24 h, and FACs analysis using Annexin V/propidium iodide showed that death occurred mainly by necrosis. In contrast, Lfcin-B and Lfcin 17-30 appeared to have no significant effect on amoebic viability. FACs and confocal microscopy analysis using FITC-labeled peptides showed that all three peptides are internalized by the amoeba mainly using receptor (PI3K signaling) and actin-dependent pathways but independent of clathrin. Docking studies identified cholesterol in the amoeba's plasma membrane as a possible target of Lfampin. Oral treatment of intracecally infected mice with the abovementioned peptides at 10 mg/kg for 4 days showed that Lfampin resolved 100% of the cases of intestinal amoebiasis, whereas Lfcin 17-30 and Lfcin-B were effective in resolving infection in 80 and 70% of cases, respectively. These data show that although synthetic bovine Lf-derived peptides exhibit varying amoebicidal potentials in vitro, they do resolve murine intestinal amoebiasis efficiently, suggesting that they may be useful as a therapeutic treatment.


Assuntos
Antiprotozoários/farmacologia , Entamoeba histolytica/efeitos dos fármacos , Entamebíase/tratamento farmacológico , Lactoferrina/farmacologia , Necrose/tratamento farmacológico , Peptídeos/farmacologia , Trofozoítos/efeitos dos fármacos , Animais , Bovinos , Entamebíase/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C3H , Fosfatidilinositol 3-Quinases/metabolismo
18.
Parasitol Res ; 118(2): 607-615, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30535524

RESUMO

Trichomoniasis is the most common non-viral sexually transmitted disease worldwide and can lead to serious consequences in reproductive health, cancer, and HIV acquisition. The current approved treatment present adverse effects and drug resistance data on this neglected parasitic infection is underestimated. Chalcones are a family of molecules that present biological applications, such as activity against many pathogenic organisms including protozoan pathogens. Chalcone (1) and three amino-analogues (2-4) were synthesized by Claisen-Schmidt condensation reaction and had their activity evaluated against the parasitic protozoan Trichomonas vaginalis. This bioassay indicated the presence and position of the amino group on ring A was crucial for anti-T. vaginalis activity. Among these, 3'-aminochalcone (3) presented the most potent effect and showed high cytotoxicity against human vaginal cells. On the other hand, 3 was not able to exhibit toxicity against Galleria mellonella larvae, as well as the hemolytic effect on human erythrocytes. Trophozoites of T. vaginalis were treated with 3, and did not present significant reactive oxygen species (ROS) accumulation, but induced a significantly higher ROS accumulation in human neutrophils after co-incubation. T. vaginalis pyruvate:ferredoxin oxidoreductase (PFOR) and ß-tubulin gene expression was not affected by 3.


Assuntos
Antiprotozoários/farmacologia , Chalconas/farmacologia , Doenças Sexualmente Transmissíveis/tratamento farmacológico , Tricomoníase/tratamento farmacológico , Trichomonas vaginalis/efeitos dos fármacos , Animais , Antiprotozoários/síntese química , Chalconas/síntese química , Resistência a Medicamentos , Feminino , Humanos , Testes de Sensibilidade Parasitária , Doenças Sexualmente Transmissíveis/parasitologia , Tricomoníase/parasitologia , Trofozoítos/efeitos dos fármacos
19.
Biochem Biophys Res Commun ; 508(4): 1031-1037, 2019 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-30545628

RESUMO

Entamoeba invadens is a protozoan, which causes multiple damages in reptiles and is considered a prototype for the study of the Entamoeba encystment in vitro. Here we report for the first time the role of the de novo synthesis pathway of sphingolipids during the encystment of E. invadens. In silico analysis showed that this parasite has six putative genes coding for ceramide synthases (CerS), all of them coding for proteins containing the Lag1p motif, a region conserved in the ceramide synthases of multiple organisms, suggesting that they might be bona fide CerS. The six genes of E. invadens are differentially expressed at different time intervals in both stages trophozoite and cyst, based on the results obtained through qRT-PCR assays, the genes involved in the synthesis of sphingolipids with long-chain fatty acids CerS 2,3,4 (EIN_046610, EIN_097030, EIN_130350) have maximum points of relative expression in both stages of the E. invadens life cycle, which strongly suggest that the signaling exerted from the synthesis pathway of sphingolipids is essential for the encystment of E. invadens, since the generation of the more abundant sphingomyelin (SM) subspecies with long-chain fatty acids are fundamental for the parasite to reach its conversion from trophozoite to cyst. When myriocin was used as an inhibitor of serine palmitoyl CoA transferase (SPT), first enzyme in the de novo biosynthesis of sphingolipids, the trophozoites of E. invadens were unable to reach the encystment. Since the effect of myriocin was reversed with exogenous d-erythrosphingosine (DHS), it was demonstrated that the inhibition was specific and it was confirmed that the synthesis of sphingolipids play an essential role during the encystment process of E. invadens.


Assuntos
Entamoeba/metabolismo , Encistamento de Parasitas , Esfingolipídeos/metabolismo , Entamoeba/efeitos dos fármacos , Entamoeba/enzimologia , Entamoeba/genética , Ácidos Graxos Monoinsaturados/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Cinética , Estágios do Ciclo de Vida/efeitos dos fármacos , Oxirredutases/genética , Oxirredutases/metabolismo , Encistamento de Parasitas/efeitos dos fármacos , Filogenia , Esfingolipídeos/biossíntese , Esfingomielinas/metabolismo , Esfingosina/análogos & derivados , Esfingosina/farmacologia , Trofozoítos/efeitos dos fármacos , Trofozoítos/genética
20.
Colloids Surf B Biointerfaces ; 173: 725-732, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30384269

RESUMO

Acanthamoeba keratitis is an ophthalmic disease with no specific treatment that specially affects contact lens users. The silencing of serine phosphatase (SP) and glycogen phosphorylase (GP) proteins produced by Acanthamoeba has been shown to significantly reduce the cytopathic effect, although no vehicle was proposed yet to deliver the siRNA sequences to the trophozoites. In this study, PEGylated cationic liposomes were proposed and optimized using Box-Behnken design. The influence of DOTAP:DOPE ratio, DSPE-PEG concentration, and siRNA/DOTAP charge ratio were evaluated over both biological response and physicochemical properties of liposomes. The ratio of DOTAP:DOPE had an effect in the trophozoite activity whereas the charge ratio influenced both size and protease activity. The predicted values were very close to the observed values, yielding a formulation with good activity and toxicity profile, which was used in the following experiments. A murine model of ocular keratitis was treated with siGP + siSP-loaded liposomes, as well as their respective controls, and combined treatment of liposomes and chlorhexidine. After 15 days of eight daily administrations, the liposomal complex combined with chlorhexidine was the only treatment able to reverse the more severe lesions associated with keratitis. There was 60% complete regression in corneal damage, with histological sections demonstrating the presence of an integral epithelium, without lymphocytic infiltrate. The set of results demonstrate the efficacy of a combined therapy based on siRNA with classical drugs for a better prognosis of keratitis caused by Acanthamoeba.


Assuntos
Ceratite por Acanthamoeba/terapia , Acanthamoeba/efeitos dos fármacos , Clorexidina/farmacologia , Sistemas de Liberação de Medicamentos/métodos , Lipossomos/química , Proteínas de Protozoários/antagonistas & inibidores , Trofozoítos/efeitos dos fármacos , Acanthamoeba/enzimologia , Acanthamoeba/patogenicidade , Ceratite por Acanthamoeba/parasitologia , Ceratite por Acanthamoeba/patologia , Animais , Córnea/efeitos dos fármacos , Córnea/parasitologia , Córnea/patologia , Modelos Animais de Doenças , Esquema de Medicação , Composição de Medicamentos/métodos , Quimioterapia Combinada , Análise Fatorial , Ácidos Graxos Monoinsaturados/química , Regulação da Expressão Gênica , Glicogênio Fosforilase/antagonistas & inibidores , Glicogênio Fosforilase/genética , Glicogênio Fosforilase/metabolismo , Humanos , Lipossomos/metabolismo , Fosfatidiletanolaminas/química , Monoéster Fosfórico Hidrolases/antagonistas & inibidores , Monoéster Fosfórico Hidrolases/genética , Monoéster Fosfórico Hidrolases/metabolismo , Polietilenoglicóis/química , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Compostos de Amônio Quaternário/química , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Ratos , Ratos Wistar , Trofozoítos/enzimologia , Trofozoítos/patogenicidade
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