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1.
Acta Trop ; 252: 107143, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38331084

ABSTRACT

Leishmaniasis is an endemic disease in more than 90 countries, constituting a relevant public health problem. Limited treatment options, increase in resistance, and therapeutic failure are important aspects for the discovery of new treatment options. Drug repurposing may accelerate the discovery of antiLeishmanial drugs. Recent tests indicating the in vitro potential of antimalarials Leishmania resulted in the design of this study. This study aimed at evaluating the susceptibility of Leishmania (L.) amazonensis to chloroquine (CQ) and quinine (QN), alone or in combination with amphotericin B (AFT) and pentamidine (PTN). In the in vitro tests, first, we evaluated the growth inhibition of 50 % of promastigotes (IC50) and cytotoxicity for HepG2 and THP-1 cells (CC50). The IC50 values of AFT and PNT were below 1 µM, while the IC50 values of CQ and QN ranged between 4 and 13 µM. Concerning cytotoxicity, CC50 values ranged between 7 and 30 µM for AFT and PNT, and between 22 and 157 µM for the antimalarials. We also calculated the Selectivity Index (SI), where AFT and PTN obtained the highest values, while the antimalarias obtained values between 5 and 12. Both antimalarials were additive (Æ©FIC 1.05-1.8) in combination with AFT and PTN. For anti-amastigote activity, the drugs obtained the following ICA50 values: AFT (0.26 µM), PNT (2.09 µM), CQ (3.77 µM) and QN (24.5 µM). In the in vivo tests, we observed that the effective dose for the death of 50 % of parasites (ED50) of AFT and CQ were 0.63 mg/kg and 27.29 mg/kg, respectively. When combining CQ with AFT, a decrease in parasitemia was observed, being statistically equal to the naive group. For cytokine quantification, it was observed that CQ, despite presenting anti-inflammatory activity was effective at increasing the production of IFN-γ. Overall, our data indicate that chloroquine will probably be a candidate for repurposing and use in drug combination therapy.


Subject(s)
Antimalarials , Leishmania , Leishmaniasis , Humans , Chloroquine/pharmacology , Chloroquine/therapeutic use , Quinine/pharmacology , Quinine/therapeutic use , Antimalarials/pharmacology , Antimalarials/therapeutic use , Leishmaniasis/drug therapy , Plasmodium falciparum
2.
BMC Psychiatry ; 23(1): 227, 2023 04 04.
Article in English | MEDLINE | ID: mdl-37016319

ABSTRACT

BACKGROUND: Major Depressive Disorder (MDD) is a leading cause of disability worldwide. Approximately one-third of patients with MDD do not respond to treatment, and often exhibit elevated inflammation biomarkers, which are associated with worse prognosis. Previous research has linked healthier dietary patterns, such as the Mediterranean Diet (MedDiet), with a lower risk of MDD and symptoms of depression, potentially due to their anti-inflammatory properties. The aim of this study is to evaluate the effectiveness of a nutritional counselling intervention promoting MedDiet to alleviate symptoms of depression in adults recently diagnosed with MDD and presenting with elevated inflammation biomarkers. METHODS: This study is a randomized controlled trial (RCT) that will recruit adults from outpatient clinics, between the ages of 18 and 70 years who have been diagnosed with MDD and are currently receiving treatment with the first prescribed antidepressant, and who exhibit elevated inflammation biomarkers (interleukin-6 and/or C-reactive protein). The control group will receive treatment-as-usual (TAU) only. The primary outcome of the study will be the change in symptoms of depression, as measured by the Beck Depression Inventory 2 (BDI-II), after 12 weeks of intervention. Data analysis will follow an intention-to-treat approach. Secondary outcomes will include changes in inflammation biomarkers, quality of life, adherence to the MedDiet, and cost-effectiveness of nutritional counselling. All outcomes will be assessed at baseline, after the 12-week intervention, and at 6- and 12-months post-baseline. DISCUSSION: This study will be the first RCT to evaluate the effect of a nutritional intervention with anti-inflammatory properties, as an adjuvant in the treatment of MDD, in individuals diagnosed with MDD and elevated inflammation biomarkers. The results of this study may contribute to the development of more effective and personalized interventions for MDD patients with elevated inflammation biomarkers.


Subject(s)
Depressive Disorder, Major , Diet, Mediterranean , Adult , Humans , Adolescent , Young Adult , Middle Aged , Aged , Depressive Disorder, Major/therapy , Counseling , Quality of Life , Biomarkers , Inflammation/therapy , Treatment Outcome , Randomized Controlled Trials as Topic
3.
Toxicon ; 217: 96-106, 2022 Oct 15.
Article in English | MEDLINE | ID: mdl-35977615

ABSTRACT

OBJECTIVE: To investigate the in vitro activity, synergism, cytotoxicity and cellular immunological response, as well as the molecular affinity between amphotericin B (AmB) and crotamine (CTA), derived from Crotalus durissus terrificus venom against Leishmania amazonensis. METHODS: This study performed the inhibition of promastigotes and amastigotes' growth under different concentrations of the drug and pharmacological combinations (AmB + CTA) based on the Berimbaum method (synergism study). The lactate dehydrogenase (LDH) quantification method was used to determine the cytotoxicity of the drug and combinations employing four cell lines (J774, HepG2, VERO, and C2C12). Following, the levels of Tumour Necrose Factor-alpha (TNF-α) and Interleukin-12 (IL-12) cytokines, using enzyme-linked immunosorbent assay (ELISA) and nitrites, as an indirect measure of Nitric Oxide (NO), using the Griess reaction were assessed in the supernatants of infected macrophages. In silico approach (molecular docking and dynamics) and binding affinity (surface plasmon resonance) between the drug and toxin were also investigated. RESULTS: CTA enhanced AmB effect against promastigote and amastigote forms of L. amazonensis, decreased the drug toxicity in different cell lines and induced the production of important Th1-like cytokines and NO by infected macrophages. The pharmacological combination also displayed consistent molecular interactions with low energy of coupling and a concentration-dependent profile. CONCLUSION: Our data suggest that this pharmacological approach is a promising alternative treatment against L. amazonensis infection due to the improved activity (synergistic effect) achieved against the parasites' forms and to the decreased cytotoxic effect.


Subject(s)
Antiprotozoal Agents , Crotalid Venoms , Amphotericin B/metabolism , Amphotericin B/toxicity , Animals , Antiprotozoal Agents/pharmacology , Crotalid Venoms/chemistry , Crotalus/metabolism , Cytokines/metabolism , Molecular Docking Simulation , Nitric Oxide/metabolism
4.
Exp Parasitol ; 217: 107934, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32698075

ABSTRACT

The inadequacy of available treatments for leishmaniasis has presented up to 40% therapeutic failure. This fact suggests an urgency in the discovery of new drugs or alternative approaches for treating this disease. The objective of this study was to evaluate the antileishmanial activity of combined therapy between crotamine (CTA) from Crotalus durissus terrificus and the pentavalent antimonial Glucantime® (GLU). The assays were in vitro performed measuring the inhibition of Leishmania amazonensis amastigotes, followed by the evaluation of cellular production of cytokines and nitrites. After that, analytical methods were performed in order to characterize the molecules involved in the study by Mass Spectrometry, molecular affinity through an in silico assay and Surface Plasmon Resonance. In vivo experiments with BALB/c mice were performed by analyzing parasitemia, lesion size and immunological mediators. In the in vitro experiments, the pharmacological association improved the inhibition of the amastigotes, modulated the production of cytokines and nitric oxide. The therapy improved the effectiveness of the GLU, demonstrating a decreased parasitemia in the infected tissues. Altogether, the results suggest that the combined approach with CTA and GLU may be a promising alternative for the treatment of cutaneous leishmaniasis.


Subject(s)
Antiprotozoal Agents/therapeutic use , Crotalid Venoms/therapeutic use , Crotalus , Leishmania mexicana/drug effects , Leishmaniasis, Cutaneous/drug therapy , Meglumine Antimoniate/therapeutic use , Animals , Antiprotozoal Agents/pharmacology , Crotalid Venoms/pharmacology , Drug Combinations , Interleukin-12/blood , Interleukin-12/metabolism , Leishmania mexicana/isolation & purification , Lymph Nodes/parasitology , Macrophages, Peritoneal , Mass Spectrometry , Meglumine Antimoniate/pharmacology , Mice , Mice, Inbred BALB C , Molecular Docking Simulation , Nitric Oxide/metabolism , Nitrites/analysis , Tumor Necrosis Factor-alpha/blood , Tumor Necrosis Factor-alpha/metabolism
5.
Int Immunopharmacol ; 85: 106640, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32470884

ABSTRACT

The activation of proinflammatory cellular processes and signals such as those linked to NF-kB in macrophages are involved in the control of infection by Leishmania ssp. However, little is known about the influence of the drugs used in the treatment on the host cellular inflammatory signaling pathways. This study aimed to evaluate the effects of different drugs used in the treatment of leishmaniasis on inflammatory profile related to Toll-like receptors (TLRs) from L. amazonensis-infected macrophages. J774 macrophage-like cells were infected with the promastigote forms (5:1) and 24 hs incubated with Amphotericin B (AmB), Glucantime® (GLU) or Pentamidine (Pent). The following inflammatory pathways were evaluated: NF-κB p65, NF-κB p65 phosphorylated (Ser536), stress-activated protein kinase/c-Jun NH(2)-terminal kinase (SAPK/JNK) phosphorylated (Thr183/Tyr185), p38 mitogen activated protein kinase (MAPK p38) phosphorylated (Thr180/Tyr182), signal transducer and activator of transcription-3 (Stat3) phosphorylated (Tyr705) and inhibitor kappa B-α (IκB-α) phosphorylated (Ser32). In silico tests were performed to evaluate the molecular affinity between TLRs and antileishmanial drugs. Molecular docking showed that affinities varied significantly among the binders evaluated. The lowest affinity (-8.6 Kcal/Mol) was calculated for AmB in complex with TLR4. Pent showed higher values for TLR1, TLR2 and TLR3, while for TLR4 the affinity value was lower (5.5 Kcal/Mol). The values obtained for GLU were the highest for the set of binders tested. From the infected macrophages, treatments inhibited NF-kB p65 for GLU (65.44%), for Pent (46.43%) and for AmB (54.07%) compared to untreated infected macrophages. The activation of the signaling pathway of NF-kB, SAPK/JNK and IκB-α caused by AmB and Pent may potentiate the microbicidal mechanisms of the infected macrophages.


Subject(s)
Antiprotozoal Agents/pharmacology , Leishmania , Macrophages/drug effects , Toll-Like Receptors/metabolism , Amphotericin B/pharmacology , Animals , Cell Line , Inflammation/immunology , Leishmaniasis/immunology , Macrophages/metabolism , Meglumine Antimoniate/pharmacology , Mice , Mitogen-Activated Protein Kinases/metabolism , Molecular Docking Simulation , Pentamidine/pharmacology , Signal Transduction/drug effects , Transcription Factor RelA/metabolism
6.
J Parasit Dis ; 44(1): 79-87, 2020 Mar.
Article in English | MEDLINE | ID: mdl-32174708

ABSTRACT

Cutaneous leishmaniasis (CL), a clinical condition caused mainly by Leishmania amazonensis in Brazil, is characterized by topical, painless ulcers. The current treatment, based on intravenous administration of pentavalent antimonials, presents low adherence by patients and may cause serious adverse effects, leading to the need for searching new therapeutic options. Thus, this study aimed at evaluating a topical administration of "intelligent dressings" as an alternative treatment for CL. BALB/c mice were infected with L. amazonensis promastigotes. Afterward, lesions were treated with hydrophobic dressings incorporated with clinically used drugs. After lesion development, the following analyses were carried out: measurement of lesion diameters, biochemical analyses of serum, evaluation of the recovery of amastigote forms and histological analyses. No significant clinical changes in serum parameters were observed. The group that was treated with dressings impregnated with Glucantime® displayed the lowest number of amastigotes recovered from tissues (parasite load). Conventional treatment with Glucantime® (i.p.) was also able to reduce parasite load. After 6 weeks from the measurement of the lesions mice treated with dressings impregnated with Pentamidine displayed the smallest values. Representative histological aspects of the lesions showed the absence or few amastigotes inside the macrophages when mice were treated with dressings impregnated with Glucantime® and Pentamidine, respectively. The findings presented here indicate that the topical treatments may constitute an alternative treatment option for CL.

7.
Exp Parasitol ; 205: 107738, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31442456

ABSTRACT

Leishmaniases, caused by Leishmania spp., are among the most prevalent infectious diseases in the world and their treatment may present high toxicity and side/adverse effects. This study evaluated the antileishmanial activity of the Hexanic Eluate subfraction from Maytenus guianensis bark (HEMg) incorporated in microparticles of PLGA. One batch of microparticles produced contained HEMg (HEMgP) and another contained the PLGA polymer alone (PCTE). The microparticles were characterized in regards to diameter, Zeta potential, encapsulation rate and morphology and their cytotoxicity was evaluated against J774 macrophages. The infection assay employing peritoneal macrophages witth L. amazonensis and cytokine dosages were performed on the cell supernatants. The groups of infected BALB/C mice were treated, euthanized and the parasite load and cytokine production were evaluated. The diameters and zeta potential were: 4 µm and -11.6 mV (PCTE) and 7.8 µm and -26.7 mV (HEMgP). The encapsulation rate was ≅ 15% and the morphology of the particles was spherical and homogeneous. In the infection assay, HEMgP inhibited the amastigotes by 70% (24 h) and 59% (48 h) and induced IL-12 and TNF-α production. HEMg in solution reduced the number of parasites in the lymph nodes by 50% and HEMgP administration increased the levels of IL-12 and TNF-α cytokines in lymph nodes and in the lesion site. When encapsulated, HEMg maintained its antileishmanial activity, but in a more attenuated and sustained form over time, showing promise as complementary/alternative therapy against cutaneous leishmaniasis.


Subject(s)
Antiprotozoal Agents/pharmacology , Leishmania mexicana/drug effects , Maytenus/chemistry , Plant Bark/chemistry , Plant Extracts/pharmacology , Animals , Biodegradation, Environmental , Cell Line , Cell-Derived Microparticles/chemistry , Cell-Derived Microparticles/ultrastructure , Inhibitory Concentration 50 , Lymph Nodes/parasitology , Macrophages, Peritoneal/drug effects , Macrophages, Peritoneal/parasitology , Male , Mice , Mice, Inbred BALB C , Microscopy, Electron, Scanning
8.
Int Immunopharmacol ; 55: 128-132, 2018 Feb.
Article in English | MEDLINE | ID: mdl-29253818

ABSTRACT

This study aimed to evaluate the in vivo anti-Leishmania amazonensis activity of a Phospholipase A2 (Asp49-PLA2), isolated from Bothrops jararacussu venom, encapsulated in liposomes as a modified toxin release system. The activity of the liposomes was evaluated in BALB/c mice, previously infected with 1×105 of the parasite's promastigotes. The size of the paw lesion in Asp49-PLA2-liposomal-treated animals, after 21days, was observed as decreasing by 16% relative to the untreated control group and 12% by the Glucantime®-treated animals, which was used as a reference drug. At the end of the treatment, the animals were sacrificed and the paw and lymph node tissues were collected. Part of the collection was used to recover amastigotes and another to quantify cytokines and nitrites. In the group treated with Asp49-PLA2-liposomes the parasitic load was observed to be reduced by 73.5% in the macerated lymph node, compared to the control group. Comparatively, in the paw tissue was observed a reduction of 57.1%. The infected groups treated with Asp49-PLA2-liposomes showed significant production in TNF-α measured in lymph nodes and paw (43.73pg/mL±2.25 and 81.03pg/mL±5.52, respectively) and nitrite levels (31.28µM±0.58 and 35.64µM±5.08) also measured in lymph nodes and paw tissues, respectively, compared to untreated groups. These results indicate that the Asp49-PLA2-loaded liposomes were able to activate the production of some cellular components of the protective TH1 response during the infection, constituting a promising tool for inducing the microbicidal activity of the Leishmania-infected macrophages.


Subject(s)
Crotalid Venoms/metabolism , Leishmania/physiology , Leishmaniasis, Cutaneous/therapy , Liposomes/metabolism , Lymph Nodes/immunology , Macrophages/immunology , Phospholipases A2/metabolism , Reptilian Proteins/metabolism , Animals , Anti-Infective Agents/metabolism , Bothrops , Disease Models, Animal , Humans , Liposomes/therapeutic use , Lymph Nodes/parasitology , Macrophages/parasitology , Male , Mice , Mice, Inbred BALB C , Nitrites/metabolism , Parasite Load , Phospholipases A2/therapeutic use , Reptilian Proteins/therapeutic use , Th1 Cells/immunology , Therapies, Investigational , Tumor Necrosis Factor-alpha/metabolism
9.
Int Immunopharmacol ; 47: 227-230, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28433944

ABSTRACT

American tegumentary leishmaniasis (ATL) is considered a neglected disease, for which an effective vaccine or an efficient diagnosis is not yet available and whose chemotherapeutic arsenal is threatened by the emergence of resistance by etiological agents such as Leishmania amazonensis. ATL is endemic in poor countries and has a high incidence in Brazil. Vaccines developed from native parasite fractions have led to the identification of defined antigenic subunits and the development of vaccine adjuvant technology. The purpose of the present study was to develop and compare preparations based on membrane antigens from L. amazonensis, as a biotechnological prototype for the immunoprophylaxis of the disease in a murine experimental model. For this purpose, batches of biodegradable polymeric micro/nanoparticles were produced, characterized and compared with other parasite's antigens in solution. All preparations containing membrane antigens presented low toxicity on murine macrophages. The in vivo evaluation of immunization efficacy was performed against a challenge with L. amazonensis, along with an evaluation of the immune response profile generated in BALB/C mice. The animals were followed for sample processing and quantification of serum-specific cytokines, nitrites and antibodies. The sera of animals immunized with the non-encapsulated antigen formulations showed higher intensities of nitrites and total IgGs. This approach evidenced the importance of the biological studies involving the immune response of the host against the parasite being interconnected and related to the subfractionation of its proteins in the search for more effective vaccine candidates.


Subject(s)
Antigens, Protozoan/immunology , Leishmania/immunology , Leishmaniasis Vaccines/immunology , Leishmaniasis, Cutaneous/immunology , Leishmaniasis/immunology , Macrophages/immunology , Membrane Proteins/immunology , Animals , Antibodies, Protozoan/blood , Cells, Cultured , Cytokines/blood , Humans , Male , Mice , Mice, Inbred BALB C , Models, Animal , Nanoparticles , Nitric Oxide/metabolism
10.
Rev Soc Bras Med Trop ; 49(5): 579-585, 2016.
Article in English | MEDLINE | ID: mdl-27812652

ABSTRACT

INTRODUCTION: Maytenus guianensis is a member of the Celastraceae family that is used in traditional medicine, particularly for its anti-parasitic and anti-cancer effects. To explore the ethnopharmacological potential of this plant, the present study was designed to screen the in vitro antileishmanial activities of extracts and compounds isolated from M. guianensis. METHODS: Maytenus guianensis stems and leaves were extracted in acetone, followed by the preparation of eluates and isolation of secondary metabolites using chromatography on a glass column with silica gel as the fixed phase. The chemical components were identified using spectroscopic methods, including one- and two-dimensional nuclear magnetic resonance of hydrogen-1 and carbon-13, mass spectroscopy, and infrared spectroscopy. The anti-Leishmania amazonensis activities of these eluates and compounds were evaluated by direct promastigote counting and viability assays. RESULTS: It was found that the hexane bark eluate produced the strongest anti-L. amazonensis effect, with 90-100% inhibition of the promastigote form. The isolated metabolite that produced the best result was tingenone B, followed by a compound formed by the union of tingenone and tingenone B (80-90% inhibition). CONCLUSIONS: Maytenus guianensis shows anti-parasite activity that warrants further investigation to determine the mechanisms underlying this antileishmanial effect and to evaluate the pharmacological potential of these eluates and isolated secondary metabolites, while minimizing any adverse effects.


Subject(s)
Antiprotozoal Agents/pharmacology , Leishmania braziliensis/drug effects , Maytenus/chemistry , Plant Extracts/pharmacology , Antiprotozoal Agents/isolation & purification , Parasitic Sensitivity Tests
11.
Rev. Soc. Bras. Med. Trop ; 49(5): 579-585, Sept.-Oct. 2016. tab, graf
Article in English | LILACS | ID: lil-798123

ABSTRACT

Abstract INTRODUCTION Maytenus guianensis is a member of the Celastraceae family that is used in traditional medicine, particularly for its anti-parasitic and anti-cancer effects. To explore the ethnopharmacological potential of this plant, the present study was designed to screen the in vitro antileishmanial activities of extracts and compounds isolated from M. guianensis. METHODS Maytenus guianensis stems and leaves were extracted in acetone, followed by the preparation of eluates and isolation of secondary metabolites using chromatography on a glass column with silica gel as the fixed phase. The chemical components were identified using spectroscopic methods, including one- and two-dimensional nuclear magnetic resonance of hydrogen-1 and carbon-13, mass spectroscopy, and infrared spectroscopy. The anti-Leishmania amazonensis activities of these eluates and compounds were evaluated by direct promastigote counting and viability assays. RESULTS It was found that the hexane bark eluate produced the strongest anti-L. amazonensis effect, with 90-100% inhibition of the promastigote form. The isolated metabolite that produced the best result was tingenone B, followed by a compound formed by the union of tingenone and tingenone B (80-90% inhibition). CONCLUSIONS Maytenus guianensis shows anti-parasite activity that warrants further investigation to determine the mechanisms underlying this antileishmanial effect and to evaluate the pharmacological potential of these eluates and isolated secondary metabolites, while minimizing any adverse effects.


Subject(s)
Leishmania braziliensis/drug effects , Plant Extracts/pharmacology , Maytenus/chemistry , Antiprotozoal Agents/pharmacology , Parasitic Sensitivity Tests , Antiprotozoal Agents/isolation & purification
13.
Rev. patol. trop ; 44(4): 359-374, dez. 2015. tab, ilus
Article in Portuguese | LILACS | ID: biblio-912261

ABSTRACT

A preocupação em buscar novos fármacos para o tratamento da leishmaniose é cada vez maior em virtude da toxicidade dos existentes e do aumento da resistência do parasito, o que representa uma ameaça ao controle da doença. O presente estudo apresenta uma revisão bibliográfica sobre as plantas da Amazônia brasileira com potencial atividade leishmanicida in vitro. Constatouse uma grande diversidade de espécies vegetais da Amazônia brasileira com potencial para a investigação de novos fitoterápicos e metabólitos secundários com ação leishmanicida, além do tratamento de outras parasitoses negligenciadas. A presente revisão demonstrou que as espécies dos gêneros Casearia, Croton e Physalis são fortes candidatas para busca de novos fármacos, visto que apresentaram um IC50 menor que 1µg/mL em testes in vitro contra as formas promastigotas ou amastigotas de Leishmania spp. Ressalta-se a importância de estudos futuros sobre espécies que apresentem metabólitos terpenoides ou esteroides em virtude do potencial leishmanicida que têm demonstrado.


Subject(s)
Leishmaniasis , Ethnopharmacology , Drug Therapy
14.
Int Immunopharmacol ; 28(1): 554-9, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26218282

ABSTRACT

During Leishmania infection, host immune response is important to prevent the growth/survival of intracellular amastigotes. In this study, we evaluated in vitro and in vivo whether or not during Leishmania amazonensis infection, pentavalent antimonial treatment/therapy could be more effective under TNF-α inhibition. Both L. amazonensis-infected macrophages (in vitro model) and mice (in vivo model) were treated with a nuclear factor-κB (NF-κB) inhibitor and with Glucantime®, alone and in combined administrations. The in vitro amastigote counts, cytokines and nitrites' production were assessed after 48h incubation with the drugs. Paw lesion sizes and amastigote counts were also evaluated in vivo. Quantification of IL-1ß from the infected tissue was performed. In vitro results show that when infected macrophages were incubated with QNZ+Glucantime®, a greater clearance was observed for the amastigotes' growth and this was related to greater nitrite production compared to the group that was only infected. In vivo results show that mice that received the combined treatment had their paw lesion sizes and amastigote nests inside the macrophages greatly diminished, correlating with increased IL-1ß levels.


Subject(s)
Antiprotozoal Agents/therapeutic use , Leishmania mexicana , Leishmaniasis, Cutaneous/drug therapy , Meglumine/therapeutic use , NF-kappa B/antagonists & inhibitors , Organometallic Compounds/therapeutic use , Phenyl Ethers/therapeutic use , Quinazolines/therapeutic use , Animals , Antiprotozoal Agents/pharmacology , Drug Therapy, Combination , Interleukin-10/immunology , Interleukin-12/immunology , Interleukin-1beta/immunology , Leishmaniasis, Cutaneous/immunology , Leishmaniasis, Cutaneous/parasitology , Macrophages, Peritoneal/immunology , Meglumine/pharmacology , Meglumine Antimoniate , Mice, Inbred BALB C , NF-kappa B/immunology , Organometallic Compounds/pharmacology , Phenyl Ethers/pharmacology , Quinazolines/pharmacology , Signal Transduction
15.
Toxicon ; 103: 1-11, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26095535

ABSTRACT

The Micrurus genus is the American representative of Elapidae family. Micrurus spixii is endemic of South America and northern states of Brazil. Elapidic venoms contain neurotoxins that promote curare-mimetic neuromuscular blockage. In this study, biochemical and functional characterizations of M. spixii crude venom were performed and a new neurotoxic phospholipase A2 called MsPLA2-I was isolated. M. spixii crude venom caused severe swelling in the legs of tested mice and significant release of creatine kinase (CK) showing its myotoxic activity. Leishmanicidal activity against Leishmania amazonensis (IC50 1.24 µg/mL) was also observed, along with antiplasmodial activity against Plasmodium falciparum, which are unprecedented for Micrurus venoms. MsPLA2-I with a Mr 12,809.4 Da was isolated from the crude venom of M. spixii. The N-terminal sequencing of a fragment of 60 amino acids showed 80% similarity with another PLA2 from Micrurus altirostris. This toxin and the crude venom showed phospholipase activity. In a mouse phrenic nerve-diaphragm preparation, M. spixii venom and MsPLA2-I induced the blockage of both direct and indirect twitches. While the venom presented a pronounced myotoxic activity, MsPLA2-I expressed a summation of neurotoxic activity. The results of this study make M. spixii crude venom promising compounds in the exploration of molecules with microbicidal potential.


Subject(s)
Elapid Venoms/chemistry , Elapidae/metabolism , Neurotoxins/toxicity , Phospholipases A2/toxicity , Amino Acid Sequence , Animals , Antiparasitic Agents/pharmacology , Brazil , Creatine Kinase/metabolism , Inhibitory Concentration 50 , Leishmania/drug effects , Leishmania/growth & development , Mice , Molecular Sequence Data , Neurotoxins/isolation & purification , Phospholipases A2/isolation & purification , Plasmodium falciparum/drug effects , Plasmodium falciparum/growth & development , Protein Conformation , Toxins, Biological
16.
Pharmacology ; 95(1-2): 78-86, 2015.
Article in English | MEDLINE | ID: mdl-25633844

ABSTRACT

BACKGROUND/AIMS: To evaluate antileishmanial activity of crotamine, a toxin isolated from Crotalus durissus terrificus, in solution form and encapsulated in biodegradable microparticles in vitro. METHODS: Particles were analyzed on-chip by surface plasmon resonance and characterized by testing their diameters, zeta potential and encapsulation rate. The viability of promastigotes as well as murine macrophages was assessed. Furthermore, the phagocytic index was determined for macrophages, and cell supernatants were collected for the determination of TNF-α levels. An infection assay using Leishmania amazonensis-infected macrophages was also conducted. RESULTS: The diameters and zeta potential of control particles (1.35 µm; -12.3 mV) and of those containing crotamine (3.09 µm; -20.9 mV) were adequate for the assays conducted. Crotamine-loaded particles were better captured by macrophages than control particles (increase of 12% in the phagocytic index), leading to increased TNF-α levels (196 pg/ml), and they also induced a significant decrease in the numbers of amastigotes compared to infected macrophages only. CONCLUSION: The approach presented here opens the possibility of working with safe concentrations of encapsulated toxins to reach antileishmanial effects.


Subject(s)
Antiprotozoal Agents/pharmacology , Crotalid Venoms/pharmacology , Leishmania/drug effects , Macrophages, Peritoneal/drug effects , Animals , Antiprotozoal Agents/administration & dosage , Crotalid Venoms/administration & dosage , Crotalus , Drug Carriers/administration & dosage , Drug Carriers/pharmacology , Lactic Acid/chemistry , Macrophages, Peritoneal/metabolism , Macrophages, Peritoneal/microbiology , Male , Mice, Inbred BALB C , Polyglycolic Acid/chemistry , Polylactic Acid-Polyglycolic Acid Copolymer , Tumor Necrosis Factor-alpha/metabolism
17.
Biomed Res Int ; 2014: 195356, 2014.
Article in English | MEDLINE | ID: mdl-24724078

ABSTRACT

Bothrops mattogrossensis snake is widely distributed throughout eastern South America and is responsible for snakebites in this region. This paper reports the purification and biochemical characterization of three new phospholipases A2 (PLA2s), one of which is presumably an enzymatically active Asp49 and two are very likely enzymatically inactive Lys49 PLA2 homologues. The purification was obtained after two chromatographic steps on ion exchange and reverse phase column. The 2D SDS-PAGE analysis revealed that the proteins have pI values around 10, are each made of a single chain, and have molecular masses near 13 kDa, which was confirmed by MALDI-TOF mass spectrometry. The N-terminal similarity analysis of the sequences showed that the proteins are highly homologous with other Lys49 and Asp49 PLA2s from Bothrops species. The PLA2s isolated were named BmatTX-I (Lys49 PLA2-like), BmatTX-II (Lys49 PLA2-like), and BmatTX-III (Asp49 PLA2). The PLA2s induced cytokine release from mouse neutrophils and showed cytotoxicity towards JURKAT (leukemia T) and SK-BR-3 (breast adenocarcinoma) cell lines and promastigote forms of Leishmania amazonensis. The structural and functional elucidation of snake venoms components may contribute to a better understanding of the mechanism of action of these proteins during envenomation and their potential pharmacological and therapeutic applications.


Subject(s)
Bothrops/metabolism , Leishmania/drug effects , Mycotoxins/chemistry , Mycotoxins/pharmacology , Neoplasms, Experimental/drug therapy , Snake Venoms/chemistry , Snake Venoms/pharmacology , Animals , Cell Line, Tumor , Cell Survival/drug effects , Male , Mice , Mycotoxins/isolation & purification , Neoplasms, Experimental/pathology , Snake Venoms/isolation & purification , Survival Rate , Treatment Outcome
18.
Exp Parasitol ; 135(2): 337-43, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23933281

ABSTRACT

Leishmania amazonensis causes human diseases that range from self-healing to diffusion cutaneous lesions. The chemotherapy of leishmaniasis requires long-term treatment and has been based on the use of pentavalent antimonials. Liposomes have been used as antileishmanial drug carries and have adjuvant activity in vaccines against several microorganisms, representing an important option to the development of new therapeutics for the disease. In this study, we developed a liposomal formulation containing lupane [3ß,6ß,16ß-trihydroxylup-20(29)-ene], isolated from fruits of Combretum leprosum with pharmacological properties as antinociceptive, anti-inflammatory, antiulcerogenic and antileishmanial activities. The aim of the present study was to evaluate the efficacy of liposomal-lupane in L. amazonensis-infection model. Liposomes were prepared by the extrusion method with DPPC, DPPS and cholesterol at 5:1:4 weight ratio. The lupane (2 mg/mL) was added to the lipid mixture, solubilized in chloroform and dried under nitrogen flow. The activity of liposomal-lupane was conducted in vitro with mouse peritoneal infected macrophages. Furthermore, mice were infected in the right hind footpad with 10(5) stationary growth phase of L. amazonensis promastigotes. After 6 weeks, animals were treated with liposomal-lupane for 15 days by intraperitoneal injection. The evolution of disease was monitored weekly by measuring footpad thickness with a caliper. Three days after the treatment, peritoneal macrophages were collected, plated and production of the cytokines IL-10 and IL-12 was evaluated in supernatants of the cultures after 24 h. The results indicate that the liposomal system containing lupane achieved here is a promising tool to confer antileishmanial activity to infected macrophages.


Subject(s)
Antiprotozoal Agents/administration & dosage , Leishmania mexicana/drug effects , Leishmaniasis, Cutaneous/drug therapy , Macrophages, Peritoneal/parasitology , Triterpenes/administration & dosage , Animals , Combretum/chemistry , Disease Models, Animal , Interleukin-10/metabolism , Interleukin-12/metabolism , Leishmania mexicana/growth & development , Leishmaniasis, Cutaneous/pathology , Liposomes , Macrophages, Peritoneal/drug effects , Macrophages, Peritoneal/immunology , Male , Mice , Mice, Inbred BALB C , Pentamidine/administration & dosage , Plant Extracts/administration & dosage
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