RESUMO
BACKGROUND: The current treatments for Chagas disease (CD) include benznidazole and nifurtimox, which have limited efficacy and cause numerous side effects. Triazoles are candidates for new CD treatments due to their ability to eliminate T. cruzi parasites by inhibiting ergosterol synthesis, thereby damaging the cell membranes of the parasite. METHODS: Eleven synthetic analogs of the kinase inhibitor SRPIN340 containing a triazole core (compounds 6A-6K) were screened in vitro against the Tulahuen strain transfected with ß-galactosidase, and their IC50, CC50, and selectivity indexes (SI) were calculated. Compounds with an SI > 50 were further evaluated in mice infected with the T. cruzi Y strain by rapid testing. RESULTS: Eight compounds were active in vitro with IC50 values ranging from 0.5-10.5 µg/mL. The most active compounds, 6E and 6H, had SI values of 125.2 and 69.6, respectively. These compounds also showed in vivo activity, leading to a reduction in parasitemia at doses of 10, 50, and 250 mg/kg/day. At doses of 50 and 250 mg/kg/day, parasitemia was significantly reduced compared to infected untreated animals, with no significant differences between the effects of 6E and 6H. CONCLUSIONS: This study identified two new promising compounds for CD chemotherapy and confirmed their activity against T. cruzi.
Assuntos
Doença de Chagas , Triazóis , Tripanossomicidas , Trypanosoma cruzi , Trypanosoma cruzi/efeitos dos fármacos , Animais , Triazóis/farmacologia , Doença de Chagas/tratamento farmacológico , Tripanossomicidas/farmacologia , Camundongos , Concentração Inibidora 50 , Testes de Sensibilidade Parasitária , TiazóisRESUMO
Chagas disease (CD) remains neglected and causes high morbidity and mortality. The great difficulty is the lack of effective treatment. The current drugs cause side effects and have limited therapeutic efficacy in the chronic phase. This study aims to fulfil some gaps in studies of the natural substance lychnopholide nanoencapsulated LYC-PLA-PEG-NC (LYC-NC) and free (Free-LYC): the activity in epimastigotes and amastigotes to determine its selectivity index (SI), the therapeutic efficacy in mice infected with Colombian Trypanosoma cruzi strain and insight of the mechanism of LYC-NC action on T. cruzi. The SI was obtained by calculation of the ratio between the IC50 value toward H9c2 cells divided by the IC50 value in the anti-T. cruzi test. Infected Swiss mice were treated with 2 and 12 mg/kg/day via intravenous and oral, respectively, and the therapeutic efficacy was determined. The IC50 of LYC-NC and Free-LYC for epimastigotes of T. cruzi were similar. Both were active against amastigotes in cell culture, particularly Free-LYC. The SI of LYC-NC and Free-LYC were 45.38 and 32.11, respectively. LYC-NC 2 and 12 mg/kg/day cured parasitologically, 62.5% and 80% of the animals, respectively, infected with a strain resistant to treatment. The fluorescent NC was distributed in the cardiomyocyte cytoplasm, infected or not, and interacted with the trypomastigotes. Together, these results represent advances in demonstrating LYC as a potent new therapeutic option for treating CD.
Assuntos
Doença de Chagas , Nanocápsulas , Nitroimidazóis , Tripanossomicidas , Trypanosoma cruzi , Animais , Camundongos , Nifurtimox/uso terapêutico , Nitroimidazóis/farmacologia , Nitroimidazóis/uso terapêutico , Doença de Chagas/tratamento farmacológico , Poliésteres/farmacologia , Poliésteres/uso terapêutico , Tripanossomicidas/farmacologia , Tripanossomicidas/uso terapêuticoRESUMO
Background: Chagas disease is a life-threatening illness caused by Trypanosoma cruzi. The involvement of serine-/arginine-rich protein kinase in the T. cruzi life cycle is significant. Aims: To synthesize, characterize and evaluate the trypanocidal activity of diamides inspired by kinase inhibitor, SRPIN340. Material & Methods: Synthesis using a three-step process and characterization by infrared, nuclear magnetic resonance and high-resolution mass spectrometry were conducted. The selectivity index was obtained by the ratio of CC50/IC50 in two in vitro models. The most active compound, 3j, was evaluated using in vitro cytokine assays and assessing in vivo trypanocidal activity. Results: 3j activity in the macrophage J774 lineage showed an anti-inflammatory profile, and mice showed significantly reduced parasitemia and morbidity at low compound dosages. Conclusion: Novel diamide is active against T. cruzi in vitro and in vivo.
RESUMO
Miconazole-loaded nanoparticles coated with hyaluronic acid (miconazole-loaded nanoparticles/HA) were developed to overcome the limitations of the conventional therapy of the vulvovaginal candidiasis (VVC). They were synthesized by emulsification and solvent evaporation techniques, characterized by diameter, polydispersity index, zeta potential, encapsulation efficiency, atomic force microscopy (AFM), evaluated in terms of efficacy against C. albicans in vitro, and tested in a murine VVC model. Nanoparticles showed 211nm of diameter with a 0.32 polydispersity index, -53mV of zeta potential, and 90% miconazole encapsulation efficiency. AFM evidenced nanoparticles with a spherical shape. They inhibited the proliferation of C. albicans in vitro and in vivo after a single administration. Nanoparticles released the miconazole directly in the site of action at low therapeutic doses, which was enough to eliminate the fungal burden in the murine VVC model. These systems were rationally designed since the existence of the HA induces their adhesion on the vaginal mucus and their internalization via CD44 receptors, inhibiting the C. albicans. Therefore, miconazole-loaded nanoparticles/HA represent an innovative non-conventional pharmaceutical dosage form to treat the VVC and recurrent VVC.
Assuntos
Candidíase Vulvovaginal , Nanopartículas , Humanos , Feminino , Camundongos , Animais , Miconazol/uso terapêutico , Candidíase Vulvovaginal/tratamento farmacológico , Ácido Hialurônico , Antifúngicos , Candida albicansRESUMO
Resveratrol is a polyphenolic compound whose antitumor activity has been demonstrated in several types of cancer. However, there are few studies on its molecular mechanisms of action in bladder cancer. Therefore, we aimed to evaluate resveratrol activity in bladder tumour cells with different TP53 gene status. Cytotoxicity, cell proliferation, reactive oxygen species (ROS) production, cell migration, mutagenicity, and CDH1, CTNNBIP1, HAT1, HDAC1, MYC, and SMAD4 gene expression were evaluated. An increase in ROS after resveratrol treatment was accompanied by reduced cell viability and proliferation in all cell lines. In TP53 wild-type cells, the inhibition of cell migration was accompanied by CDH1 and SMAD4 modulation. In TP53 mutated cells, cell migration inhibition with CDH1 and CTNNB1P1 upregulation was observed. In conclusion, resveratrol has antiproliferative effect in bladder tumour cells and its mechanism of action occurred through ROS production, interference with cell cycle, and inhibition of cell migration, independent of TP53 status.
RESUMO
Chagas disease, caused by the protozoan Trypanosoma cruzi, is an important public health problem in Latin America. Nanoencapsulation of anti-T. cruzi drugs has significantly improved their efficacy and reduced cardiotoxicity. Thus, we investigated the in vitro interaction of polyethylene glycol-block-poly(D,L-lactide) nanocapsules (PEG-PLA) with trypomastigotes and with intracellular amastigotes of the Y strain in cardiomyoblasts, which are the infective forms of T. cruzi, using fluorescence and confocal microscopy. Fluorescently labeled nanocapsules (NCs) were internalized by non-infected H9c2 cells toward the perinuclear region. The NCs did not induce significant cytotoxicity in the H9c2 cells, even at the highest concentrations and interacted equally with infected and non-infected cells. In infected cardiomyocytes, NCs were distributed in the cytoplasm and located near intracellular amastigote forms. PEG-PLA NCs and trypomastigote form interactions also occurred. Altogether, this study contributes to the development of engineered polymeric nanocarriers as a platform to encapsulate drugs and to improve their uptake by different intra- and extracellular forms of T. cruzi, paving the way to find new therapeutic strategies to fight the causative agent of Chagas disease.
Assuntos
Doença de Chagas , Nanocápsulas , Trypanosoma cruzi , Doença de Chagas/tratamento farmacológico , Humanos , Poliésteres , PolietilenoglicóisRESUMO
IR780 is a near-infrared fluorescent dye, which can be applied as a photosensitizer in photodynamic (PDT) and photothermal (PTT) therapies and as a biodistribution tracer in imaging techniques. We investigated the growth and migration inhibition and mechanism of death of breast tumor cells, MCF-7 and MDA-MB-231, exposed to polymeric nanocapsules (NC) comprising IR780 covalently linked to the biodegradable polymer PLA (IR-PLA) and IR780 physically encapsulated (IR780-NC) in vitro. Both types of NC had mean diameters around 120 nm and zeta potentials around -40 mV. IR-PLA-NC was less cytotoxic than IR780 NC to a non-tumorigenic mammary epithelial cell line, MCF-10A, which is an important aspect of selectivity. Free-IR780 was more cytotoxic than IR-PLA-NC for MCF-7 and MDA-MB-231 cells after illumination with a 808 nm laser. IR-PLA NC was effective to inhibit colony formation (50%) and migration (30-40%) for both cancer cell lines. MDA-MB-231 cells were less sensitive to all IR780 formulations compared to MCF-7 cells. Cell uptake was higher with IR-PLA-NC than with IR780-NC and free-IR780 in both cancer cell lines (p < 0.05). NC uptake was higher in MCF-7 than in MDA-MB-231 cells. IR-PLA-NC induced a higher percentage of apoptosis upon illumination in MDA-MB-231 than in MCF-7 cells. The necrosis mechanism of death predominated in treatments with free-IR780 and with encapsulated IR780 NC, suggestive of damages at the plasma membrane. IR780 conjugated with PLA increased the apoptotic pathway and demonstrated potential as a multifunctional theranostic agent for breast cancer treatment with increased cellular uptake, photodynamic activity and more reliable tracking in cell-image studies.
Assuntos
Neoplasias da Mama , Indóis/farmacologia , Nanocápsulas/química , Fotoquimioterapia/métodos , Polietilenoglicóis/farmacologia , Apoptose/efeitos dos fármacos , Plásticos Biodegradáveis/farmacologia , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/tratamento farmacológico , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Corantes Fluorescentes/farmacologia , Humanos , Células MCF-7 , Fármacos Fotossensibilizantes/farmacologia , Medicina de Precisão/métodos , Distribuição TecidualRESUMO
Caspofungin is an echinocandin, exhibiting efficacy against most Candida species invasive infection. Its cardiotoxicity was reported in isolated rat heart and ventricular myocytes, but in vivo and clinical studies are insufficient. Our objective was to evaluate caspofungin in vivo cardiac effects using an efficacious dose against Candida albicans. Female Swiss mice were infected with C. albicans, and treated with caspofungin, 5 or 10 mg/kg, intraperitoneal along 5 days. Survival rate and colony-forming units (CFU) into vital organs were determined. For cardiac effects study, mice were treated with caspofungin 10 mg/kg, and electrocardiogram (ECG) signal was obtained on C. albicans-infected mice, single dose-treated, and uninfected mice treated along 5 days, both groups to measure ECG intervals. Besides, ECG was also obtained by telemetry on uninfected mice to evaluate heart rate variability (HRV) parameters. The MIC for caspofungin on the wild-type C. albicans SC5314 strain was 0.3 µg/ml, indicating the susceptible. Survival rate increased significantly in infected mice treated with caspofungin compared to mice treated with vehicle. None of the survived infected mice presented positive CFU after treatment with 10 mg/kg. C. albicans infection induced prolongation of QRS, QT, and QTc intervals; caspofungin did not alter this effect. Caspofungin induced increase of PR and an additional increase of QRS after 24 h of a single dose in infected mice. No significant alterations occurred in ECG intervals and HRV parameters of uninfected mice, after caspofungin treatment. Caspofungin showed in vivo cardiac relative safety maintaining its antifungal efficacy against C. albicans.
Assuntos
Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Candidíase/tratamento farmacológico , Caspofungina/farmacologia , Frequência Cardíaca/efeitos dos fármacos , Coração/efeitos dos fármacos , Animais , Antifúngicos/toxicidade , Candida albicans/patogenicidade , Candidíase/microbiologia , Cardiotoxicidade , Caspofungina/toxicidade , Modelos Animais de Doenças , Eletrocardiografia , Feminino , Coração/fisiopatologia , Camundongos , Testes de Sensibilidade Microbiana , Medição de Risco , Testes de ToxicidadeRESUMO
Chagas disease (CD) is endemic in Latin America. Drugs available for its treatment are benznidazole (BZ)/nifurtimox (NF), both with low efficacy in the late infection and responsible for several side effects. Studies of new drugs for CD among natural products, and using drug combinations with BZ/NF are recommended. Silibinin (SLB) is a natural compound that inhibits the efflux pump (Pgp) of drugs in host cell membranes, causes death of trypanosomatids, has anti-inflammatory activity, and was never assayed against T. cruzi. Here, in vitro and in vivo activities of SLB, SLB+BZ, and BZ against T. cruzi Y strain were evaluated. Cytotoxicity of SLB in VERO cells by the MTT method revealed IC50 of 250.22 µM. The trypanocidal activity evaluated by resazurin method in epimastigotes showed that SLB 25 µM inhibited parasite growth. SLB IC50 and selectivity index (SI) for amastigote were 79.81 µM and 3.13, respectively. SLB100+BZ10 showed higher parasite inhibition (91.44%) than SLB or BZ. Swiss mice infected with Y strain were treated with SLB, SLB+BZ, and BZ. Parasitemia was evaluated daily and 90, 180, and 240 days after treatment in surviving animals by hemoculture, blood qPCR, and after euthanasia, by qPCR in heart tissue. SLB monotherapy was not able to control the parasitemia/mortality of the animals. Parasitological negativation of 85.7-100% was observed in the experimental groups treated with SLB+BZ. Although SLB had shown activity against T. cruzi in vitro, it was not active in mice. Thus, the results of the therapeutic effect observed with SLB+BZ may be interpreted as a result from BZ action.
Assuntos
Doença de Chagas/tratamento farmacológico , Nitroimidazóis/farmacologia , Silibina/farmacologia , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Animais , Doença de Chagas/parasitologia , Chlorocebus aethiops , Feminino , Coração/parasitologia , Concentração Inibidora 50 , Camundongos , Nitroimidazóis/uso terapêutico , Parasitemia/tratamento farmacológico , Parasitemia/parasitologia , Reação em Cadeia da Polimerase em Tempo Real , Silibina/química , Silibina/uso terapêutico , Tripanossomicidas/uso terapêutico , Células VeroRESUMO
Artemether (ART) was combined with triglyceride of docosahexaenoic acid (DHA) as the lipid-core in nanoemulsions (NE), nanostructured lipid carriers (NLC), and PEG-PLA nanocapsules (NC) formulations, and their effects on human breast cancer cells were evaluated. ART has been extensively used for malaria and has also therapeutic potential against different tumor cells in a repositioning strategy. The concentration-dependent cytotoxicity in vitro was determined in tumor lineages, MDA-MB-231 and MCF-7, and non-tumor MCF-10A cells for free-ART/DHA combination and its formulations. The cells were monitored for viability, effects on cell migration and clonogenicity, cell death mechanism, and qualitative and quantitative cell uptake of nanocarriers. The lipid-nanocarriers showed mean sizes over the range of 110 and 280 nm with monodisperse populations and zeta potential values ranging from -21 to -67 mV. The ART encapsulation efficiencies varied from 57 to 83 %. ART/DHA co-loaded in three different lipid nanocarriers reduced the MDA-MB-231 and MCF-7 viability in a dose-dependent manner with enhanced selectivity toward tumor cell lines. They also reduced clonogenicity and the ability of cells to migrate showing antimetastatic potential in both cell lines and triggered apoptosis in MCF-7 cells. Confocal microscopy and flow cytometry analysis showed that NC, NLC, and NE were rapidly internalized by cells, with higher interaction displayed by NE with MCF-7 cells compared to NC and NLC that was correlated with the strongest NE-fluorescence in cells. Therefore, this study not only demonstrated the value of this new combination of ART/DHA as a new strategy for breast cancer therapy but also showed enhanced cytotoxicity and potential metastatic activity of lipid-based formulations against human breast cancer cells that indicate great potential for pre-clinical and clinical translation.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/metabolismo , Artemeter/farmacologia , Neoplasias da Mama/tratamento farmacológico , Ácidos Docosa-Hexaenoicos/farmacologia , Portadores de Fármacos , Nanocápsulas , Triglicerídeos/química , Protocolos de Quimioterapia Combinada Antineoplásica/química , Apoptose/efeitos dos fármacos , Artemeter/química , Neoplasias da Mama/patologia , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ácidos Docosa-Hexaenoicos/química , Composição de Medicamentos , Emulsões , Feminino , Humanos , Células MCF-7 , Metástase NeoplásicaRESUMO
Malaria treatment is based on a reduced number of antimalarial drugs, and drug resistance has emerged, leading to the search for new antimalarial drugs incorporated into pharmaceutical formulations. In this study, 10-(4,5-dihydrothiazol-2-yl)thio)decan-1-ol) (thiazoline), a synthetic analog of 3-alkylpiridine marine alkaloid, and a potent antimalarial substance, was incorporated into O/W nanoemulsion. This formulation was prepared by a 23 factorial design. It was characterized by globule diameter, polydispersity index, zeta potential, encapsulation efficiency, in vitro thiazoline release at pH 2 and 6.86, and accelerated stability. In vitro and in vivo antimalarial activity was determined against P. falciparum and P. berghei, respectively. Thiazoline nanoemulsion showed 248.8 nm of globule diameter, 0.236 of polydispersity index, -38.5 mV of zeta potential, 96.92% encapsulation efficiency, and it was stable for 6 months. Thiazoline release profiles differed in acidic and neutral media, but in both cases, the nanoemulsion controlled and prolonged the thiazoline delivery. Thiazoline nanoemulsion exerted in vitro antimalarial activity against the parasite (IC50 = 1.32 µM), and it significantly reduced the in vivo parasitemia for 8 days without increasing the survival time of animals. Therefore, the thiazoline nanoemulsion represents a strategy to treat malaria combining an antimalarial candidate and a new nanocarrier.
Assuntos
Alcaloides , Antimaláricos , Malária , Alcaloides/farmacologia , Animais , Antimaláricos/farmacologia , Antimaláricos/uso terapêutico , Malária/tratamento farmacológico , Parasitemia/tratamento farmacológico , Plasmodium berghei , Plasmodium falciparumRESUMO
Chagas disease remains neglected, and current chemotherapeutics present severe limitations. Lychnopholide (LYC) at low doses loaded in polymeric poly(d,l-lactide)-block-polyethylene glycol (PLA-PEG) nanocapsules (LYC-PLA-PEG-NC) exhibits anti-Trypanosoma cruzi efficacy in mice infected with a partially drug-resistant strain. This study reports the efficacy of LYC-PLA-PEG-NC at higher doses in mice infected with a T. cruzi strain resistant to benznidazole (BZ) and nifurtimox (NF) treated at both the acute phase (AP) and the chronic phase (CP) of infection by the oral route. Mice infected with the T. cruzi VL-10 strain were treated by the oral route with free LYC (12 mg/kg of body weight/day), LYC-PLA-PEG-NC (8 or 12 mg/kg/day), or BZ at 100 mg/kg/day or were not treated (controls). Treatment efficacy was assessed by hemoculture (HC), PCR, enzyme-linked immunosorbent assay (ELISA), heart tissue quantitative PCR (qPCR), and histopathology. According to classical cure criteria, treatment with LYC-PLA-PEG-NC at 12 mg/kg/day cured 75% (AP) and 88% (CP) of the animals, while at a dose of 8 mg/kg/day, 43% (AP) and 43% (CP) were cured, showing dose-dependent efficacy. The negative qPCR results for heart tissue and the absence of inflammation/fibrosis agreed with the negative results obtained by HC and PCR. Thus, the mice treated with the highest dose could be considered 100% cured, in spite of a low ELISA reactivity in some animals. No cure was observed in animals treated with free LYC or BZ or the controls. These results are exceptional in terms of experimental Chagas disease chemotherapy and provide evidence of the outstanding contribution of nanotechnology in mice infected with a T. cruzi strain totally resistant to BZ and NF at both phases of infection. Therefore, LYC-PLA-PEG-NC has great potential as a new treatment for Chagas disease and deserves further investigations in clinical trials.
Assuntos
Doença de Chagas/tratamento farmacológico , Portadores de Fármacos/química , Lactonas/uso terapêutico , Sesquiterpenos/uso terapêutico , Tripanossomicidas/uso terapêutico , Trypanosoma cruzi/efeitos dos fármacos , Animais , Feminino , Camundongos , Nanocápsulas/uso terapêutico , Poliésteres/química , Polietilenoglicóis/químicaRESUMO
BACKGROUND: The current drugs for Chagas disease treatment present several limitations. METHODS: The sesquiterpene lactone goyazensolide (GZL) was evaluated regarding to cytotoxicity and trypanocidal activity against amastigotes, selectivity index (SI) in vitro, acute toxicity and anti-Trypanosoma cruzi activity in vivo. RESULTS: The in vitro cytotoxicity in H9c2 cells was observed at doses >250 ng mL-1 of GZL and the SI were of 52.82 and 4.85 (24 h) and of 915.00 and 41.00 (48 h) for GZL and BZ, respectively. Nephrotoxicity and hepatotoxicity were not verified. Treatment with GZL of mice infected with CL strain led to a significant decrease of parasitaemia and total survival at doses of 1 and 3 mg kg-1 day-1 by oral and IV, respectively. This last group cured 12.5% of the animals (negativation of HC, PCR, qPCR and ELISA). Animals infected with Y strain showed significant decrease of parasitaemia and higher negativation in all parasitological tests in comparison to BZ and control groups, but were ELISA reactive, as well as the BZ group, but mice treated with 5.0 mg kg-1 day-1 by oral were negative in parasitological tests and survived. CONCLUSION: GZL was more active against T. cruzi than benznidazole in vitro and presented important therapeutic activity in vivo in both T. cruzi strains.
Assuntos
Hidrocarbonetos Aromáticos com Pontes/farmacologia , Hidrocarbonetos Aromáticos com Pontes/uso terapêutico , Doença de Chagas/tratamento farmacológico , Furanos/farmacologia , Furanos/uso terapêutico , Sesquiterpenos/farmacologia , Sesquiterpenos/uso terapêutico , Sesterterpenos/farmacologia , Sesterterpenos/uso terapêutico , Trypanosoma cruzi/efeitos dos fármacos , Animais , Hidrocarbonetos Aromáticos com Pontes/toxicidade , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Modelos Animais de Doenças , Furanos/toxicidade , Camundongos , Nitroimidazóis/farmacologia , Nitroimidazóis/uso terapêutico , Sesquiterpenos/toxicidade , Sesterterpenos/toxicidade , Análise de Sobrevida , Tripanossomicidas/farmacologia , Tripanossomicidas/uso terapêutico , Tripanossomicidas/toxicidadeRESUMO
Chagas disease is a neglected parasitic disease caused by the protozoan Trypanosoma cruzi. New antitrypanosomal options are desirable to prevent complications, including a high rate of cardiomyopathy. Recently, a natural substance, lychnopholide, has shown therapeutic potential, especially when encapsulated in biodegradable polymeric nanocapsules. However, little is known regarding possible adverse effects of lychnopholide. Here we show that repeated-dose intravenous administration of free lychnopholide (2.0 mg/kg/day) for 20 days caused cardiopathy and mortality in healthy C57BL/6 mice. Echocardiography revealed concentric left ventricular hypertrophy with preserved ejection fraction, diastolic dysfunction and chamber dilatation at end-stage. Single cardiomyocytes presented altered contractility and Ca2+ handling, with spontaneous Ca2+ waves in diastole. Acute in vitro lychnopholide application on cardiomyocytes from healthy mice also induced Ca2+ handling alterations with abnormal RyR2-mediated diastolic Ca2+ release. Strikingly, the encapsulation of lychnopholide prevented the cardiac alterations induced in vivo by the free form repeated doses. Nanocapsules alone had no adverse cardiac effects. Altogether, our data establish lychnopholide presented in nanocapsule form more firmly as a promising new drug candidate to cure Chagas disease with minimal cardiotoxicity. Our study also highlights the potential of nanotechnology not only to improve the efficacy of a drug but also to protect against its adverse effects.
Assuntos
Materiais Biocompatíveis , Cardiotônicos/farmacologia , Lactonas/efeitos adversos , Nanocápsulas , Polímeros , Sesquiterpenos/efeitos adversos , Tripanossomicidas/efeitos adversos , Trypanosoma cruzi/efeitos dos fármacos , Animais , Materiais Biocompatíveis/química , Cálcio/metabolismo , Sinalização do Cálcio/efeitos dos fármacos , Cardiotônicos/química , Cardiotoxicidade , Doença de Chagas/diagnóstico , Doença de Chagas/tratamento farmacológico , Doença de Chagas/mortalidade , Doença de Chagas/parasitologia , Ecocardiografia , Masculino , Camundongos , Imagem Molecular , Mortalidade , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Nanocápsulas/química , Polímeros/químicaRESUMO
The clonal evolution of Trypanosoma cruzi sustains scientifically the hypothesis of association between parasite's genetic, biological behavior and possibly the clinical aspects of Chagas disease in patients from whom they were isolated. This study intended to characterize a range of biological properties of TcI, TcII and TcVI T. cruzi samples in order to verify the existence of these associations. Several biological features were evaluated, including in vitro epimastigote-growth, "Vero"cells infectivity and growth, along with in vivo studies of parasitemia, polymorphism of trypomastigotes, cardiac inflammation, fibrosis and response to treatment by nifurtimox during the acute and chronic murine infection. The global results showed that the in vitro essays (acellular and cellular cultures) TcII parasites showed higher values for all parameters (growth and infectivity) than TcVI, followed by TcI. In vivo TcII parasites were more virulent and originated from patients with severe disease. Two TcII isolates from patients with severe pathology were virulent in mice, while the isolate from a patient with the indeterminate form of the disease caused mild infection. The only TcVI sample, which displayed low values in all parameters evaluated, was also originated of an indeterminate case of Chagas disease. Response to nifurtimox was not associated to parasite genetic and biology, as well as to clinical aspects of human disease. Although few number of T. cruzi samples have been analyzed, a discreet correlation between parasite genetics, biological behavior in vitro and in vivo (murine model) and the clinical form of human disease from whom the samples were isolated was verified.
Assuntos
Doença de Chagas/parasitologia , Nifurtimox/farmacologia , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Trypanosoma cruzi/patogenicidade , Animais , Células Cultivadas , Modelos Animais de Doenças , Humanos , Camundongos , Trypanosoma cruzi/isolamento & purificação , VirulênciaRESUMO
The etiological treatment of Chagas disease remains neglected. The compounds available show several limitations, mainly during the chronic phase. Lychnopholide encapsulated in polymeric nanocapsules (LYC-NC) was efficacious in mice infected with Trypanosoma cruzi and treated by intravenous administration during the acute phase (AP). As the oral route is preferred for treatment of chronic infections, such as Chagas disease, this study evaluated the use of oral LYC-NC in the AP and also compared it with LYC-NC administered to mice by the oral and intravenous routes during the chronic phase (CP). The therapeutic efficacy was evaluated by fresh blood examination, hemoculture, PCR, and enzyme-linked immunosorbent assay (ELISA). The cure rates in the AP and CP were 62.5% and 55.6%, respectively, upon oral administration of LYC-poly(d,l-lactide)-polyethylene glycol nanocapsules (LYC-PLA-PEG-NC) and 57.0% and 30.0%, respectively, with LYC-poly-ε-caprolactone nanocapsules (LYC-PCL-NC). These cure rates were significantly higher than that of free LYC, which did not cure any animals. LYC-NC formulations administered orally during the AP showed cure rates similar to that of benznidazole, but only LYC-NC cured mice in the CP. Similar results were achieved with intravenous treatment during the CP. The higher cure rates obtained with LYC loaded in PLA-PEG-NC may be due to the smaller particle size of these NC and the presence of PEG, which influence tissue diffusion and the controlled release of LYC. Furthermore, PLA-PEG-NC may improve the stability of the drug in the gastrointestinal tract. This work is the first report of cure of experimental Chagas disease via oral administration during the CP. These findings represent a new and important perspective for oral treatment of Chagas disease.
Assuntos
Doença de Chagas/tratamento farmacológico , Preparações de Ação Retardada/farmacologia , Lactonas/farmacologia , Nanocápsulas/química , Sesquiterpenos/farmacologia , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Doença Aguda , Administração Intravenosa , Administração Oral , Animais , Doença de Chagas/mortalidade , Doença de Chagas/parasitologia , Doença de Chagas/patologia , Doença Crônica , Preparações de Ação Retardada/química , Modelos Animais de Doenças , Composição de Medicamentos/métodos , Humanos , Lactonas/química , Camundongos , Nanocápsulas/administração & dosagem , Nitroimidazóis/farmacologia , Polietilenoglicóis/química , Sesquiterpenos/química , Análise de Sobrevida , Resultado do Tratamento , Tripanossomicidas/química , Trypanosoma cruzi/crescimento & desenvolvimento , Trypanosoma cruzi/patogenicidadeRESUMO
The drugs available for Chagas disease treatment are toxic and ineffective. We studied the in vivo activity of a new drug, lychnopholide (LYC). LYC was loaded in nanocapsules (NC), and its effects were compared to free LYC and benznidazole against Trypanosoma cruzi. Infected mice were treated in the acute phase at 2.0 mg/kg/day with free LYC, LYC-poly-ε-caprolactone NC (LYC-PCL), and LYC-poly(lactic acid)-co-polyethylene glycol NC (LYC-PLA-PEG) or at 50 mg/kg/day with benznidazole solution by the intravenous route. Animals infected with the CL strain, treated 24 h after infection for 10 days, evaluated by hemoculture, PCR, and enzyme-linked immunosorbent assay exhibited a 50% parasitological cure when treated with LYC-PCL NC and 100% cure when treated with benznidazole, but 100% of the animals treated during the prepatent period for 20 days with these formulations or LYC-PLA-PEG NC were cured. In animals with the Y strain treated 24 h after infection for 10 days, only mice treated by LYC-PCL NC were cured, but animals treated in the prepatent period for 20 days exhibited 100, 75, and 62.5% cure when treated with LYC-PLA-PEG NC, benznidazole, and LYC-PCL NC, respectively. Free LYC reduced the parasitemia and improved mice survival, but no mice were cured. LYC-loaded NC showed higher cure rates, reduced parasitemia, and increased survival when used in doses 2five times lower than those used for benznidazole. This study confirms that LYC is a potential new treatment for Chagas disease. Furthermore, the long-circulating property of PLA-PEG NC and its ability to improve LYC efficacy showed that this formulation is more effective in reaching the parasite in vivo.
Assuntos
Doença de Chagas/tratamento farmacológico , Lactonas/uso terapêutico , Nanocápsulas/química , Nitroimidazóis/uso terapêutico , Sesquiterpenos/uso terapêutico , Animais , Modelos Animais de Doenças , Feminino , Lactonas/química , Lactonas/farmacocinética , Lactonas/farmacologia , Camundongos , Nitroimidazóis/química , Nitroimidazóis/farmacocinética , Nitroimidazóis/farmacologia , Sesquiterpenos/química , Sesquiterpenos/farmacocinética , Sesquiterpenos/farmacologia , Trypanosoma cruzi/efeitos dos fármacosRESUMO
Simple and sensitive methods using high-performance liquid chromatography-diode array detection (HPLC-DAD) and ultraviolet (UV)-spectrophotometry were developed and compared to quantify lychnopholide (LYC) in poly-ε-caprolactone nanocapsules and to study its release kinetics. Both methods were validated concerning their specificity, linearity, limits of detection and quantification, precision, accuracy and stability. HPLC-DAD analyses were conducted using an RP C18 column, isocratic elution with a methanol-water (60:40 v/v) mobile phase at 0.8 mL/min flow rate and detection at 265 nm. The linear response (r(2) > 0.999) was obtained within a concentration range of 2-25 µg/mL using HPLC-DAD and 5-40 µg/mL using spectrophotometry. Intra-day and inter-day precision were obtained with low relative standard deviation values. The accuracy of the methods was within the range 98-101% for HPLC-DAD and from 96-100% for UV-spectrophotometry. Both methods were suitable to be applied for the determination of drug loading percentage (>96%) and encapsulation efficiency (>90%). Furthermore, the sensitivity of HPLC-DAD method allows studies of LYC release/dissolution in sink conditions. LYC presented 100% dissolution after 24 h, whereas only 60% of LYC was released from the nanocapsule dosage form, with no burst effect. The methods fulfilled all validation parameters evaluated for LYC quantification in the polymeric nanocapsules and have proven to be accurate, selective and sensitive in the previously mentioned applications.