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1.
J Agric Food Chem ; 67(34): 9630-9642, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31365255

RESUMO

Six series of (+)-usnic acid derivatives were synthesized. The IC50 values of these compounds were determined in T. gondii infected HeLa cells (µM) and in HeLa cells (µM), and their selectivity indexes (SI) were calculated. In vitro, most of the derivatives tested in this study exhibited more anti activity than that of the parent compound (+)-usnic acid and the positive control drugs. Among these derivatives, methyl (E)-(1-(6-acetyl-7,9-dihydroxy-8,9b-dimethyl-1,3-dioxo-3,9b-dihydrodibenzo[b,d]furan-2(1H)-ylidene)ethyl)phenylalaninate (D3) showed the most effective anti-T. gondii activity (selectivity >2.77). In comparison with the clinically used positive control drugs sulfadiazine (selectivity 1.15), pyrimethamine (selectivity 0.89), spiramycin (selectivity 0.72), and the lead compound (+)-usnic acid (selectivity 0.96), D3 showed better results in vitro. Furthermore, D3 and (E)-6-acetyl-7,9-dihydroxy-8,9b-dimethyl-2-(1-(quinolin-6-ylamino)ethylidene)dibenzo[b,d]furan-1,3(2H,9bH)-dione (F3) had greater inhibitory effects on T. gondii (inhibition rates 76.0% and 64.6%) in vivo in comparison to spiramycin (inhibition rate 55.2%); in the peritoneal cavity of mice, the number of tachyzoites was significantly reduced (p < 0.001) in vivo. Additionally, some biochemical parameters were measured and spleen indexes were comprehensively evaluated, and the results indicated that mice treated with both compound D3 and compound F3 showed reduced hepatotoxicity and significantly enhanced antioxidative effects in comparison to the normal group. Granuloma and cyst formation were effected by the inhibition of compound D3 and compound F3 in liver sections. Overall, these results indicated that D3 and F3 for use as anti-T. gondii agents are promising lead compounds.


Assuntos
Antiprotozoários/administração & dosagem , Benzofuranos/administração & dosagem , Toxoplasma/efeitos dos fármacos , Toxoplasmose/tratamento farmacológico , Animais , Antiprotozoários/síntese química , Antiprotozoários/química , Benzofuranos/síntese química , Benzofuranos/química , Avaliação Pré-Clínica de Medicamentos , Feminino , Células HeLa , Humanos , Camundongos , Estrutura Molecular , Toxoplasma/crescimento & desenvolvimento , Toxoplasmose/parasitologia
2.
Chem Biodivers ; 16(8): e1900318, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31364803

RESUMO

Sponges from freshwater environments, unlike marine's, are poorly known producers of natural compounds with medicinal purposes. Amazonian sponges produce massive large specimens and are widely spread, taxonomically diverse and their metabolites could represent a new frontier on unusual natural products to treat diseases such as Alzheimer's and Malaria. Species of Metania and Drulia (Metaniidae) genera are major contributors to the fauna of Amazonian freshwater sponges. Methanolic extracts from several species from these genera had their inhibitory activities evaluated in vitro, for parasite Plasmodium falciparum and acetyl and butyrylcholinesterase enzymes (AChE and BChE). All extracts were able to inhibit AChE, although no activity was observed towards BChE. Drulia uruguayensis extract was the most potent, inhibiting AChE with IC50 =1.04 mg/mL. For antiplasmodial activity, all species showed inhibition to P. falciparum, but Metania reticulata being the most efficient with IC50 =2.7 µg/mL. Mass spectrometry analyses evidenced the presence of fatty acids and sterols in active extracts.


Assuntos
Antiprotozoários/química , Inibidores da Colinesterase/química , Poríferos/química , Acetilcolinesterase/química , Acetilcolinesterase/metabolismo , Animais , Antiprotozoários/isolamento & purificação , Antiprotozoários/farmacologia , Butirilcolinesterase/química , Butirilcolinesterase/metabolismo , Inibidores da Colinesterase/metabolismo , Ácidos Graxos/análise , Ácidos Graxos/química , Plasmodium falciparum/efeitos dos fármacos , Poríferos/metabolismo , Espectrometria de Massas por Ionização por Electrospray , Esteróis/química
3.
Eur J Med Chem ; 179: 335-346, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31260888

RESUMO

Herein we introduce new compounds as conjugates of arylnicotinic acids with aryl (thio)semicarbazide derivatives. Based on a structure-guided approach, they were designed to possess anti-leishmanial activity through anti-folate mechanism, via targeting Leishmania major pteridine reductase 1 (Lm-PTR1). The in vitro anti-promastigote and anti-amastigote activity were promising for many thiosemicarbazide derivatives and superior to the reference miltefosine. The most active compounds 8i and 8j exhibited their anti-amastigote activity with IC50 values of 4.2 and 3.3 µM, respectively, compared to reference miltefosine (IC50 value of 7.3). Their anti-folate mechanism was confirmed via the ability of folic and folinic acids to reverse the anti-leishmanial activity of these compounds, comparably to Lm-PTR1 inhibitor trimethoprim. Interestingly, the in vitro cytotoxicity test of the most active compounds displayed higher selectivity indices than that of miltefosine emphasizing their safety on mammalian cells. Furthermore, the docking experiments on Lm-PTR1 as a putative target rationalized the in vitro anti-leishmanial activity. The in silico predictions exhibited promising pharmacokinetics and drug-likeness profiles of the most active compounds. Generally, this work introduces a fruitful matrix for new anti-leishmanial chemotype which would extend the chemical space for the anti-leishmanial activity.


Assuntos
Antiprotozoários/farmacologia , Leishmania major/efeitos dos fármacos , Ácidos Nicotínicos/farmacologia , Semicarbazidas/farmacologia , Animais , Antiprotozoários/síntese química , Antiprotozoários/química , Sobrevivência Celular/efeitos dos fármacos , Cercopithecus aethiops , Relação Dose-Resposta a Droga , Leishmania major/crescimento & desenvolvimento , Modelos Moleculares , Estrutura Molecular , Ácidos Nicotínicos/síntese química , Ácidos Nicotínicos/química , Testes de Sensibilidade Parasitária , Semicarbazidas/química , Relação Estrutura-Atividade , Células Vero
4.
Chem Pharm Bull (Tokyo) ; 67(7): 654-665, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31257321

RESUMO

Quassinoids, one kind of triterpenoids with multiple bioactivities such as anti-cancer, anti-malarial, anti-oxidative, anti-microbial, anti-diabetic, anti-viral, and anti-inflammatory effects, have drawn much attention in recent years. Between 2004 and 2018, the structural characteristics and plant sources of 190 quassinoids were reported. Herein, the structure-activity relationships (SARs) of quassinoids along with the anti-cancer mechanisms of four representative quassinoids, eurycomanone, bruceine D, dehydrobruceine B, and brusatol are discussed. This review might be useful for further research and development of quassinoids.


Assuntos
Antineoplásicos Fitogênicos/química , Quassinas/química , Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/farmacologia , Antiprotozoários/química , Antiprotozoários/isolamento & purificação , Antiprotozoários/farmacologia , Antivirais/química , Antivirais/isolamento & purificação , Antivirais/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Humanos , Plantas/química , Plantas/metabolismo , Plasmodium falciparum/efeitos dos fármacos , Quassinas/isolamento & purificação , Quassinas/farmacologia , Relação Estrutura-Atividade , Vírus do Mosaico do Tabaco/efeitos dos fármacos
5.
Analyst ; 144(17): 5232-5244, 2019 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-31360935

RESUMO

Leishmaniasis comprises a group of infectious diseases with worldwide distribution, of which both the visceral and cutaneous forms are caused by Leishmania parasites. In the absence of vaccines, efficacious chemotherapy remains the basis for leishmaniasis control. The available drugs are expensive and associated with several secondary adverse effects. Due to these limitations, the development of new antileishmanial compounds is imperative, and plants offer various perspectives in this regard. The present study evaluated the in vitro leishmanicidal activity of flavonoids isolated from Solanum paludosum Moric. and investigated the mechanisms of cell death induced by them. These compounds were evaluated in vitro for their antileishmanial activity against Leishmania amazonensis promastigotes and they showed prominent leishmanicidal activity. The EtOAc fraction, gossypetin 3,7,8,4'-tetra-O-methyl ether (1), and kaempferol 3,7-di-O-methyl ether (3) were selected to be used in an in vitro assay against L. amazonensis amastigotes and cell death assays. The flavonoids (1) and (3) presented significant activity against L. amazonensis amastigotes, exhibiting the IC50 values of 23.3 ± 4.5 µM, 34.0 ± 9.6 µM, and 10.5 ± 2.5 µM for the EtOAc fraction, (1), and (3), respectively, without toxic effects to the host cells. Moreover, (1) and (3) induced blocked cell cycle progression at the G1/S transition, ultimately leading to G1/G0 arrest. Flavonoid (3) also induced autophagy. Using Raman spectroscopy in conjunction with principal component analysis, the biochemical changes in the cellular components induced by flavonoids (1) and (3) were presented. The obtained results indicated that the mechanisms of action of (1) and (3) occurred through different routes. The results support that the flavonoids derived from S. paludosum can become lead molecules for the design of antileishmanial prototypes.


Assuntos
Antiprotozoários/farmacologia , Morte Celular/efeitos dos fármacos , Flavonoides/farmacologia , Citometria de Fluxo/métodos , Leishmania/efeitos dos fármacos , Animais , Antiprotozoários/química , Autofagia/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos , Flavonoides/química , Quempferóis/química , Quempferóis/farmacologia , Leishmania/citologia , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Camundongos , Análise Espectral Raman , Estreptófitas/química
6.
Nat Commun ; 10(1): 2816, 2019 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-31249291

RESUMO

Cryptosporidiosis is a leading cause of life-threatening diarrhea in young children and causes chronic diarrhea in AIDS patients, but the only approved treatment is ineffective in malnourished children and immunocompromised people. We here use a drug repositioning strategy and identify a promising anticryptosporidial drug candidate. Screening a library of benzoxaboroles comprised of analogs to four antiprotozoal chemical scaffolds under pre-clinical development for neglected tropical diseases for Cryptosporidium growth inhibitors identifies the 6-carboxamide benzoxaborole AN7973. AN7973 blocks intracellular parasite development, appears to be parasiticidal, and potently inhibits the two Cryptosporidium species most relevant to human health, C. parvum and C. hominis. It is efficacious in murine models of both acute and established infection, and in a neonatal dairy calf model of cryptosporidiosis. AN7973 also possesses favorable safety, stability, and PK parameters, and therefore, is an exciting drug candidate for treating cryptosporidiosis.


Assuntos
Antiprotozoários/administração & dosagem , Compostos de Boro/administração & dosagem , Criptosporidiose/tratamento farmacológico , Isoxazóis/administração & dosagem , Animais , Antiprotozoários/efeitos adversos , Antiprotozoários/química , Compostos de Boro/efeitos adversos , Compostos de Boro/química , Criptosporidiose/parasitologia , Cryptosporidium/efeitos dos fármacos , Cryptosporidium/crescimento & desenvolvimento , Avaliação Pré-Clínica de Medicamentos , Feminino , Humanos , Isoxazóis/efeitos adversos , Isoxazóis/química , Masculino , Camundongos , Ratos
7.
J Enzyme Inhib Med Chem ; 34(1): 1164-1171, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31219348

RESUMO

Chagas disease and leishmaniasis are neglected tropical disorders caused by the protozoans Trypanosoma cruzi and Leishmania spp. Carbonic anhydrases (CAs, EC 4.2.1.1) from these protozoans (α-TcCA and ß-LdcCA) have been validated as promising targets for chemotherapic interventions. Many anti-protozoan agents, such as nitroimidazoles, nifurtimox, and benznidazole possess a nitro aromatic group in their structure which is crucial for their activity. As a continuation of our previous work on N-nitrosulfonamides as anti-protozoan agents, we investigated benzenesulfonamides bearing a nitro aromatic moiety against TcCA and LdcCA, observing selective inhibitions over human off-target CAs. Selected derivatives were assessed in vitro in different developmental stages of T. cruzi and Leishmania spp. A lack of significant growth inhibition has been found, which has been connected to the low permeability of this class of derivatives through cell membranes. Further strategies necessarily need to be designed for targeting Chagas disease and leishmaniasis with nitro-containing CA inhibitors.


Assuntos
Antiprotozoários/farmacologia , Inibidores da Anidrase Carbônica/farmacologia , Anidrases Carbônicas/metabolismo , Leishmania donovani/efeitos dos fármacos , Trypanosoma cruzi/efeitos dos fármacos , Antiprotozoários/síntese química , Antiprotozoários/química , Inibidores da Anidrase Carbônica/síntese química , Inibidores da Anidrase Carbônica/química , Relação Dose-Resposta a Droga , Humanos , Isoenzimas/antagonistas & inibidores , Isoenzimas/metabolismo , Leishmania donovani/enzimologia , Estrutura Molecular , Testes de Sensibilidade Parasitária , Relação Estrutura-Atividade , Trypanosoma cruzi/enzimologia
8.
PLoS Negl Trop Dis ; 13(5): e0007030, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31125333

RESUMO

BACKGROUND: Chemotherapy is a principle tool for the control and prevention of piroplasmosis. The search for a new chemotherapy against Babesia and Theileria parasites has become increasingly urgent due to the toxic side effects of and developed resistance to the current drugs. Chalcones have attracted much attention due to their diverse biological activities. With the aim to discover new drugs and drug targets, in vitro and in vivo antibabesial activity of trans-chalcone (TC) and chalcone 4 hydrate (CH) alone and combined with diminazene aceturate (DA), clofazimine (CF) and atovaquone (AQ) were investigated. METHODOLOGY/PRINCIPAL FINDINGS: The fluorescence-based assay was used for evaluating the inhibitory effect of TC and CH on four Babesia species, including B. bovis, B. bigemina, B. divergens, B. caballi, and T. equi, the combination with DA, CF, and AQ on in vitro cultures, and on the multiplication of a B. microti-infected mouse model. The cytotoxicity of compounds was tested on Madin-Darby bovine kidney (MDBK), mouse embryonic fibroblast (NIH/3T3), and human foreskin fibroblast (HFF) cell lines. The half maximal inhibitory concentration (IC50) values of TC and CH against B. bovis, B. bigemina, B. divergens, B. caballi, and T. equi were 69.6 ± 2.3, 33.3 ± 1.2, 64.8 ± 2.5, 18.9 ± 1.7, and 14.3 ± 1.6 µM and 138.4 ± 4.4, 60.9 ± 1.1, 82.3 ± 2.3, 27.9 ± 1.2, and 19.2 ± 1.5 µM, respectively. In toxicity assays, TC and CH affected the viability of MDBK, NIH/3T3, and HFF cell lines the with half maximum effective concentration (EC50) values of 293.9 ± 2.9, 434.4 ± 2.7, and 498 ± 3.1 µM and 252.7 ± 1.7, 406.3 ± 9.7, and 466 ± 5.7 µM, respectively. In the mouse experiment, TC reduced the peak parasitemia of B. microti by 71.8% when administered intraperitoneally at 25 mg/kg. Combination therapies of TC-DA and TC-CF were more potent against B. microti infection in mice than their monotherapies. CONCLUSIONS/SIGNIFICANCE: In conclusion, both TC and CH inhibited the growth of Babesia and Theileria in vitro, and TC inhibited the growth of B. microti in vivo. Therefore, TC and CH could be candidates for the treatment of piroplasmosis after further studies.


Assuntos
Antiprotozoários/administração & dosagem , Babesia/efeitos dos fármacos , Babesia/crescimento & desenvolvimento , Babesiose/tratamento farmacológico , Chalconas/administração & dosagem , Theileria/efeitos dos fármacos , Theileria/crescimento & desenvolvimento , Theileriose/tratamento farmacológico , Animais , Antiprotozoários/química , Babesia/genética , Babesiose/parasitologia , Linhagem Celular , Chalconas/química , Avaliação Pré-Clínica de Medicamentos , Feminino , Humanos , Concentração Inibidora 50 , Camundongos Endogâmicos BALB C , Theileria/genética , Theileriose/parasitologia
9.
Parasitol Res ; 118(8): 2443-2454, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31144032

RESUMO

Acanthamoeba keratitis (AK) is a devastating, painful corneal infection, which may lead to loss of vision. The development of resistance and failure of the currently used drugs represent a therapeutic predicament. Thus, novel therapies with lethal effects on resistant Acanthamoeba are necessary to combat AK. In the present study, the curative effect of Nigella sativa aqueous extract (N. sativa) and chitosan nanoparticles (nCs) and both agents combined were assessed in experimentally induced AK. All inoculated corneas developed varying grades of AK. The study medications were applied on the 5th day postinoculation and were evaluated by clinical examination of the cornea and cultivation of corneal scraps. On the 10th day posttreatment, a 100% cure of AK was obtained with nCs (100 µg/ml) in grades 1 and 2 of corneal opacity as well as with N. sativa 60 mg/ml-nCs 100 µg/ml in grades 1, 2, and 3 of corneal opacity, highlighting a possible synergistic effect. On the 15th day posttreatment, a 100% cure was reached with N. sativa aqueous extract (60 mg/ml). Moreover, on the 20th day posttreatment, N. sativa (30 mg/ml) provided a cure rate of 87.5%, while nCs (50 µg/ml) as well as N. sativa 30 mg/ml-nCs 50 µg/ml yielded a cure rate of 75%; the lowest percentage of cure (25%) was obtained with chlorhexidine (0.02%), showing a non-significant difference compared to the parasite control. The clinical outcomes were in agreement with the results of corneal scrap cultivation. The results of the present study demonstrate the effectiveness of N. sativa aqueous extract and nCs (singly or combined) when used against AK, and these agents show potential for the development of new, effective, and safe therapeutic alternatives.


Assuntos
Ceratite por Acanthamoeba/tratamento farmacológico , Antiprotozoários/administração & dosagem , Nigella sativa/química , Extratos Vegetais/administração & dosagem , Acanthamoeba/efeitos dos fármacos , Acanthamoeba/fisiologia , Ceratite por Acanthamoeba/parasitologia , Adulto , Animais , Antiprotozoários/química , Quitosana/química , Quitosana/farmacologia , Quitosana/uso terapêutico , Clorexidina/farmacologia , Córnea/parasitologia , Feminino , Humanos , Masculino , Nanopartículas/química , Extratos Vegetais/química , Ratos , Resultado do Tratamento
10.
PLoS Negl Trop Dis ; 13(5): e0007373, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31120889

RESUMO

Infections of humans and livestock with African trypanosomes are treated with drugs introduced decades ago that are not always fully effective and often have severe side effects. Here, the trypanosome haptoglobin-haemoglobin receptor (HpHbR) has been exploited as a route of uptake for an antibody-drug conjugate (ADC) that is completely effective against Trypanosoma brucei in the standard mouse model of infection. Recombinant human anti-HpHbR monoclonal antibodies were isolated and shown to be internalised in a receptor-dependent manner. Antibodies were conjugated to a pyrrolobenzodiazepine (PBD) toxin and killed T. brucei in vitro at picomolar concentrations. A single therapeutic dose (0.25 mg/kg) of a HpHbR antibody-PBD conjugate completely cured a T. brucei mouse infection within 2 days with no re-emergence of infection over a subsequent time course of 77 days. These experiments provide a demonstration of how ADCs can be exploited to treat protozoal diseases that desperately require new therapeutics.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Antiprotozoários/administração & dosagem , Benzodiazepinas/administração & dosagem , Pirróis/administração & dosagem , Tripanossomíase Africana/tratamento farmacológico , Animais , Anticorpos Monoclonais/química , Antiprotozoários/química , Benzodiazepinas/química , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Pirróis/química , Trypanosoma brucei brucei/efeitos dos fármacos , Tripanossomíase Africana/parasitologia
11.
PLoS Negl Trop Dis ; 13(5): e0007388, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31042710

RESUMO

Most treatments of leishmaniasis require hospitalization and present side effects or parasite resistance; innovations in drug formulation/reposition can overcome these barriers and must be pursued to increase therapeutic alternatives. Therefore, we tested polymyxin B (polB) potential to kill Leishmania amazonensis, adsorbed or not in PBCA nanoparticles (PBCAnp), which could augment polB internalization in infected macrophages. PBCAnps were fabricated by anionic polymerization and analyzed by Dynamic Light Scattering (size, ζ potential), Nanoparticle Tracking Analysis (size/concentration), vertical diffusion cell (release rate), drug incorporation (indirect method, protein determination) and in vitro cell viability. Nanoparticles coated with polB (PBCAnp-polB) presented an adequate size of 261.5 ± 25.9 nm, low PDI and ζ of 1.79 ± 0.17 mV (stable for 45 days, at least). The 50% drug release from PBCAnp-polB was 6-7 times slower than the free polB, which favors a prolonged and desired release profile. Concerning in vitro evaluations, polB alone reduced in vitro amastigote infection of macrophages (10 µg/mL) without complete parasite elimination, even at higher concentrations. This behavior limits its future application to adjuvant leishmanicidal therapy or antimicrobial coating of carriers. The nanocarrier PBCAnp also presented leishmanicidal effect and surpassed polB activity; however, no antimicrobial activity was detected. PolB maintained its activity against E. coli, Pseudomonas and Klebsiella, adding antimicrobial properties to the nanoparticles. Thus, this coated drug delivery system, described for the first time, demonstrated antileishmanial and antimicrobial properties. The bactericidal feature helps with concomitant prevention/treatment of secondary infections that worst ulcers induced by cutaneous L. amazonensis, ultimately ending in disfiguring or disabling lesions.


Assuntos
Antibacterianos/farmacologia , Antiprotozoários/farmacologia , Sistemas de Liberação de Medicamentos/métodos , Leishmania/efeitos dos fármacos , Polimixina B/farmacologia , Antibacterianos/química , Antiprotozoários/química , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Infecções Bacterianas/tratamento farmacológico , Infecções Bacterianas/microbiologia , Sistemas de Liberação de Medicamentos/instrumentação , Avaliação Pré-Clínica de Medicamentos , Leishmania/crescimento & desenvolvimento , Leishmaniose/tratamento farmacológico , Leishmaniose/parasitologia , Macrófagos/parasitologia , Nanopartículas/química , Polimixina B/química
12.
J Enzyme Inhib Med Chem ; 34(1): 1100-1109, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31124384

RESUMO

Inhibition of Leishmania arginase leads to a decrease in parasite growth and infectivity and thus represents an attractive therapeutic strategy. We evaluated the inhibitory potential of selected naturally occurring phenolic substances on Leishmania infantum arginase (ARGLi) and investigated their antileishmanial activity in vivo. ARGLi exhibited a Vmax of 0.28 ± 0.016 mM/min and a Km of 5.1 ± 1.1 mM for L-arginine. The phenylpropanoids rosmarinic acid and caffeic acid (100 µM) showed percentages of inhibition of 71.48 ± 0.85% and 56.98 ± 5.51%, respectively. Moreover, rosmarinic acid and caffeic acid displayed the greatest effects against L. infantum with IC50 values of 57.3 ± 2.65 and 60.8 ± 11 µM for promastigotes, and 7.9 ± 1.7 and 21.9 ± 5.0 µM for intracellular amastigotes, respectively. Only caffeic acid significantly increased nitric oxide production by infected macrophages. Altogether, our results broaden the current spectrum of known arginase inhibitors and revealed promising drug candidates for the therapy of visceral leishmaniasis.


Assuntos
Antiprotozoários/farmacologia , Arginase/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Leishmania infantum/efeitos dos fármacos , Fenóis/farmacologia , Animais , Antiprotozoários/química , Arginase/metabolismo , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/química , Leishmania infantum/enzimologia , Leishmania infantum/crescimento & desenvolvimento , Macrófagos/efeitos dos fármacos , Macrófagos/parasitologia , Camundongos , Camundongos Endogâmicos BALB C , Modelos Moleculares , Estrutura Molecular , Testes de Sensibilidade Parasitária , Fenóis/química , Células RAW 264.7 , Relação Estrutura-Atividade
13.
Chem Commun (Camb) ; 55(49): 7009-7012, 2019 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-31119221

RESUMO

Expanding the chemical space of quinolones led to a tandem quinolone-alkyne-cyclisation reaction allowing chemoselective control of the synthesis of tricyclic pyrrolo[1,2-a]quinolin-5-ones. Importantly, we discovered anti-protozoal activity against Plasmodium and Toxoplasma with specific potency of one of the compounds against the liver stage of the malaria parasite in the nanomolar range.


Assuntos
Alquinos/farmacologia , Antiprotozoários/farmacologia , Plasmodium/efeitos dos fármacos , Quinolonas/farmacologia , Toxoplasma/efeitos dos fármacos , Alquinos/química , Antiprotozoários/síntese química , Antiprotozoários/química , Linhagem Celular , Ciclização , Relação Dose-Resposta a Droga , Humanos , Estrutura Molecular , Testes de Sensibilidade Parasitária , Quinolonas/química , Relação Estrutura-Atividade
14.
Exp Parasitol ; 201: 57-66, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31004571

RESUMO

In the present study, we investigated the in vitro and in vivo leishmanicidal activity of synthetic compounds, containing a semicarbazone scaffold as a peptide mimetic framework. The leishmanicidal effect against amastigotes of Leishmania amazonensis was also evaluated at concentration of 100 µM-0.01 nM. The derivatives 2e, 2f, 2g and 1g, beyond the standards miltefosine and pentamidine, significantly diminished the number of L. amazonensis amastigotes in macrophages. These derivatives were also active against amastigotes of L. braziliensis. As 2g presented potent leishmanicidal activity against the amastigotes of L. amazonensis in macrophages, we also investigated the in vivo leishmanicidal activity of this compound against L. amazonensis. Approximately 105L. amazonensis promastigotes were subcutaneously inoculated into the dermis of the right ear of BALB/c mice, which were subsequently treated with 2g (p.o. or i.p.), miltefosine (p.o.) or glucantime (i.p.) at 30 µmol/kg/day x 28 days. Thus, a similar reduction in the lesion size was observed after the administration of 2g through oral (63.7 ±â€¯10.1%) and intraperitoneal (61.8 ±â€¯3.7%) routes. A larger effect was observed after treatment with miltefosine (97.7 ±â€¯0.4%), and glucantime did not exhibit activity at the dose administered. With respect to the ear parasite load, 2g diminished the number of parasites by p.o. (30.5 ±â€¯5.1%) and i.p. (33.3 ±â€¯4.3%) administration. In addition, 2g induced in vitro apoptosis, autophagy and cell cycle alterations on L. amazonensis promastigotes. In summary, the derivative 2g might represent a lead candidate for antileishmanial drugs, as this compound displayed pronounced leishmanicidal activity.


Assuntos
Antiprotozoários/uso terapêutico , Leishmania mexicana/efeitos dos fármacos , Leishmaniose Cutânea/tratamento farmacológico , Semicarbazonas/uso terapêutico , Análise de Variância , Animais , Antiprotozoários/química , Antiprotozoários/farmacologia , Caspases/análise , Ciclo Celular , Linhagem Celular , Membrana Celular/metabolismo , Permeabilidade da Membrana Celular , Feminino , Citometria de Fluxo , Concentração Inibidora 50 , Macrófagos/parasitologia , Potencial da Membrana Mitocondrial , Camundongos , Camundongos Endogâmicos BALB C , Pentamidina/química , Pentamidina/farmacologia , Pentamidina/uso terapêutico , Fosfolipídeos/metabolismo , Fosforilcolina/análogos & derivados , Fosforilcolina/química , Fosforilcolina/farmacologia , Fosforilcolina/uso terapêutico , Semicarbazonas/química , Semicarbazonas/farmacologia
15.
Exp Parasitol ; 200: 84-91, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30954455

RESUMO

Cysteine proteases are involved in critical cell processes to the protozoa from Leishmania genus, and their inhibition is a therapeutic alternative to treat the disease. In this work, derivatives of dipeptidyl nitriles acting as reversible covalent inhibitors of cysteine proteases were studied as cytostatic agents. The proteolytic activity inside the living and lysed parasite cells was quantified using a selective substrate for cysteine proteases (Z-FR-MCA) from Leishmania amazonensis and L. infantum. The overall proteolytic activity of intact cells and even cell extracts was only marginally affected at high concentrations, with the observation of cytostatic activity and cell cycle arrest of promastigotes. However, the cytotoxic effects were only observed for infected J774 macrophages, which impaired further analysis of the amastigote infection. Therefore, the proteolytic inhibition in intact L. amazonensis and L. infantum promastigotes had no relationship to the cytostatic activity, which emphasizes that these dipeptidyl nitriles act through another mechanism of action.


Assuntos
Antiprotozoários/farmacologia , Inibidores de Cisteína Proteinase/farmacologia , Citostáticos/farmacologia , Leishmania infantum/efeitos dos fármacos , Leishmania mexicana/efeitos dos fármacos , Nitrilos/farmacologia , Animais , Antiprotozoários/química , Linhagem Celular , Inibidores de Cisteína Proteinase/química , Citostáticos/química , Fibroblastos/efeitos dos fármacos , Citometria de Fluxo , Leishmania infantum/enzimologia , Leishmania mexicana/enzimologia , Macrófagos/efeitos dos fármacos , Camundongos , Nitrilos/química
16.
Artif Cells Nanomed Biotechnol ; 47(1): 1122-1131, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30942629

RESUMO

Clinically, available synthetic chemotherapeutics in the treatment for leishmaniasis are associated with serious complications, such as toxicity and emergence of resistance. Natural products from plants can provide better remedies against the Leishmania parasite and can possibly minimize the associated side effects. In this study, various extracts of the callus cultures of Artimisia scoparia established in response to different plant growth regulators (PGRs) were evaluated for their anti-leishmanial effects against Leishmania tropica promastigotes, followed by an investigation of the possible mechanism of action through reactive apoptosis assay using fluorescent microscopy. Amongst the different callus extracts, higher anti-leishmanial activity (IC50:19.13 µg/mL) was observed in the callus raised in-vitro in the presence of 6-Benzylaminopurine (BA) plus 2,4-Dichlorophenoxyacetic Acid (2,4-D) at the concentration of 1.5 mg/L, each. Further, the results of apoptosis assay showed a large number of early-stage apoptotic (EA) and late-stage apoptotic (LA) cells in the Leishmania under the effect of callus extract grown in-vitro at BA plus 2,4-D. For the determination of the potent natural products in the callus extracts responsible for the anti-leishmanial activity, extracts were subjected to Gas chromatography-mass spectrometry (GC-MS) for the metabolite analysis. Nonetheless, higher levels of the metabolites, such as nerolidol (22%), pelletierine (18%), aspidin (15%) and ascaridole (11%) were detected in the callus grown in vitro at BA plus 2,4-D (1.5 mg/L, each). This protocol determines a novel method of production of anti-leishmanial natural products through callus cultures of A. scoparia, a medicinal plant.


Assuntos
Artemisia/crescimento & desenvolvimento , Artemisia/metabolismo , Produtos Biológicos/metabolismo , Produtos Biológicos/farmacologia , Leishmania tropica/efeitos dos fármacos , Extratos Vegetais/biossíntese , Extratos Vegetais/farmacologia , Antioxidantes/química , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Antiprotozoários/química , Antiprotozoários/metabolismo , Antiprotozoários/farmacologia , Apoptose/efeitos dos fármacos , Produtos Biológicos/química , Linhagem Celular , Flavonoides/análise , Depuradores de Radicais Livres/química , Depuradores de Radicais Livres/metabolismo , Depuradores de Radicais Livres/farmacologia , Leishmania tropica/citologia , Extratos Vegetais/química , Polifenóis/análise
17.
Molecules ; 24(7)2019 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-30986947

RESUMO

Due to the lack of approved vaccines against human leishmaniasis and the limitations of the current chemotherapy inducing side effects and drug resistance, development of new, effective chemotherapeutic agents is essential. This study describes the synthesis of a series of novel oxadiazoles and indolizine-containing compounds. The compounds were screened in silico using an EIIP/AQVN filter followed by ligand-based virtual screening and molecular docking to parasite arginase. Top hits were further screened versus human arginase and finally against an anti-target battery to tag their possible interactions with proteins essential for the metabolism and clearance of many substances. Eight candidate compounds were selected for further experimental testing. The results show measurable in vitro anti-leishmanial activity for three compounds. One compound with an IC50 value of 2.18 µM on Leishmania donovani intramacrophage amastigotes is clearly better positioned than the others as an interesting molecular template for further development of new anti-leishmanial agents.


Assuntos
Antiprotozoários/farmacologia , Indolizinas/farmacologia , Leishmania donovani/efeitos dos fármacos , Oxidiazóis/farmacologia , Animais , Antiprotozoários/química , Arginase/metabolismo , Indolizinas/química , Leishmania donovani/metabolismo , Camundongos , Simulação de Acoplamento Molecular , Estrutura Molecular , Oxidiazóis/química , Células RAW 264.7
18.
Phytomedicine ; 58: 152748, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31005722

RESUMO

BACKGROUND: Several species of Salvia are used as medicinal plants around the world. Biological activities of isolated compounds have been described, being diterpenes frequently responsible for the effects. PURPOSE: Isolation of diterpenes from Salvia uliginosa Benth. and evaluation of the antichemotactic and leishmanicidal activities of the isolated compounds. STUDY DESIGN: To isolate diterpenes from S. uliginosa and evaluate their antichemotactic and leishmanicidal activities in vitro. METHODS: The exudate of S. uliginosa was obtained by rapidly dipping the aerial parts in dichloromethane. The compounds were isolated by repeated column chromatography over silica gel. The effects on L. amazonensis growth, survival, DNA degradation, ROS generation, as well as the antichemotactic activity and cytotoxicity of the compounds towards human erythrocytes and macrophages were evaluated. RESULTS: A novel icetexane diterpene, isoicetexone (IsoICT) along with the known diterpenes icetexone (ICT), and 7-acetoxy-6,7-dihydroicetexone were isolated from the dichloromethane surface exudate of S. uliginosa. The structures were elucidated using NMR and MS experiments, and by comparison with previously reported data. IsoICT and ICT at low concentrations caused completely inhibition of neutrophils migration in vitro. In addition, IsoICT and ICT showed high leishmanicidal activity against L. amazonensis, induced ROS production in parasites and presented low cytotoxicity against macrophages and human erythrocytes, and moderate to high selectivity index. CONCLUSION: These data indicated that IsoICT and ICT exhibit potent antichemotactic and leishmanicidal effects. Further studies are needed in order to evaluate the in vivo activities as well as the toxicity of the compounds.


Assuntos
Antiprotozoários/química , Quimiotaxia/efeitos dos fármacos , Diterpenos/química , Salvia/química , Antiprotozoários/farmacologia , Células Cultivadas , Diterpenos/farmacologia , Avaliação Pré-Clínica de Medicamentos/métodos , Eritrócitos/efeitos dos fármacos , Humanos , Leishmania/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Estrutura Molecular , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Espécies Reativas de Oxigênio/metabolismo
19.
Chem Biodivers ; 16(5): e1800644, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30843651

RESUMO

The phytochemical investigation of Grazielia gaudichaudeana aerial parts yielded 15 compounds, including diterpenes, triterpenes, sterols and flavonoids. With exception to ent-kaurenoic acid diterpenes, the compounds isolated are being described for the first time in this species. Some unusual 1 H-NMR chemical shifts of 18-nor-ent-labdane (7-9) led us carry out a conformational analysis by theoretical calculations in order to support the experimental data. Moreover, due to the limitation of studies focused on pharmacological potential of Grazielia gaudichaudeana, the present study was carried out to investigate the antioxidant, antiproliferative, antiviral, antileishmanial and antimicrobial activities from the extract, fractions and isolated compounds obtained from this species. Ethyl acetate fraction showed significant activity in the antiproliferative assay, with GI50 range of 3.9 to 27.2 µg mL-1 . Dichloromethane fraction, rich in diterpenoids, inhibited all human tumor cell lines tested, and the nor-labdane 7 showed potent cytotoxic activity against glioma and ovary cancer cell lines.


Assuntos
Asteraceae/química , Diterpenos/química , Anti-Infecciosos/química , Anti-Infecciosos/isolamento & purificação , Anti-Infecciosos/farmacologia , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/farmacologia , Antioxidantes/química , Antiprotozoários/química , Antiprotozoários/isolamento & purificação , Antiprotozoários/farmacologia , Asteraceae/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cristalografia por Raios X , Diterpenos/isolamento & purificação , Diterpenos/farmacologia , Fungos/efeitos dos fármacos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Humanos , Leishmania/efeitos dos fármacos , Espectroscopia de Ressonância Magnética , Conformação Molecular , Extratos Vegetais/química
20.
Malar J ; 18(1): 65, 2019 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-30849984

RESUMO

BACKGROUND: Optimal adoption of the malaria transmission-blocking strategy is currently limited by lack of safe and efficacious drugs. This has sparked the exploration of different sources of drugs in search of transmission-blocking agents. While plant species have been extensively investigated in search of malaria chemotherapeutic agents, comparatively less effort has been channelled towards exploring them in search of transmission-blocking drugs. Artemisia afra (Asteraceae), a prominent feature of South African folk medicine, is used for the treatment of a number of diseases, including malaria. In search of transmission-blocking compounds aimed against Plasmodium parasites, the current study endeavoured to isolate and identify gametocytocidal compounds from A. afra. METHODS: A bioassay-guided isolation approach was adopted wherein a combination of solvent-solvent partitioning and gravity column chromatography was used. Collected fractions were continuously screened in vitro for their ability to inhibit the viability of primarily late-stage gametocytes of Plasmodium falciparum (NF54 strain), using a parasite lactate dehydrogenase assay. Chemical structures of isolated compounds were elucidated using UPLC-MS/MS and NMR data analysis. RESULTS: Two guaianolide sesquiterpene lactones, 1α,4α-dihydroxybishopsolicepolide and yomogiartemin, were isolated and shown to be active (IC50 < 10 µg/ml; ~ 10 µM) against both gametocytes and intra-erythrocytic asexual P. falciparum parasites. Interestingly, 1α,4α-dihydroxybishopsolicepolide was significantly more potent against late-stage gametocytes than to early-stage gametocytes and intra-erythrocytic asexual P. falciparum parasites. Additionally, both isolated compounds were not overly cytotoxic against HepG2 cells in vitro. CONCLUSION: This study provides the first instance of isolated compounds from A. afra against P. falciparum gametocytes as a starting point for further investigations on more plant species in search of transmission-blocking compounds.


Assuntos
Antiprotozoários/farmacologia , Artemisia/química , Extratos Vegetais/farmacologia , Plasmodium falciparum/efeitos dos fármacos , Antiprotozoários/química , Antiprotozoários/isolamento & purificação , Sobrevivência Celular/efeitos dos fármacos , Cromatografia Líquida , Concentração Inibidora 50 , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Parasitária , Extratos Vegetais/isolamento & purificação , Espectrometria de Massas em Tandem
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