ERIKA GRACIELLE PINTO
Projetos de Pesquisa
Unidades Organizacionais
16 resultados
Resultados de Busca
Agora exibindo 1 - 10 de 16
- Soulamarin Isolated from Calophyllum brasiliense (Clusiaceae) Induces Plasma Membrane Permeabilization of Trypanosoma cruzi and Mytochondrial Dysfunction(2013) REA, Alexandre; TEMPONE, Andre G.; PINTO, Erika G.; MESQUITA, Juliana T.; RODRIGUES, Eliana; SILVA, Luciana Grus M.; SARTORELLI, Patricia; LAGO, Joao Henrique G.Chagas disease is caused by the parasitic protozoan Trypanosoma cruzi. It has high mortality as well as morbidity rates and usually affects the poorer sections of the population. The development of new, less harmful and more effective drugs is a promising research target, since current standard treatments are highly toxic and administered for long periods. Fractioning of methanol (MeOH) extract of the stem bark of Calophyllum brasiliense (Clusiaceae) resulted in the isolation of the coumarin soulamarin, which was characterized by one- and two-dimensional H-1- and C-13 NMR spectroscopy as well as ESI mass spectrometry. All data obtained were consistent with a structure of 6-hydroxy-4-propyl-5-(3-hydroxy-2-methyl-1-oxobutyl)-6,6-dimethylpyrane-[2,3:8,7]-benzopyran-2-one for soulamarin. Colorimetric MTT assays showed that soulamarin induces trypanocidal effects, and is also active against trypomastigotes. Hemolytic activity tests showed that soulamarin is unable to induce any observable damage to erythrocytes (c(max.)=1,300 mu M). The lethal action of soulamarin against T. cruzi was investigated by using amino(4-(6-(amino(iminio)methyl)-1H-indol-2-yl)phenyl)methaniminium chloride (SYTOX Green and 1H,5H,11H,15H-Xantheno[2,3,4-ij:5,6,7-ij]diquinolizin-18-ium, 9-[4-(chloromethyl)phenyl]-2,3,6,7,12,13,16,17-octahydro-chloride (MitoTracker Red) as fluorimetric probes. With the former, soulamarin showed dose-dependent permeability of the plasma membrane, relative to fully permeable Triton X-100-treated parasites. Spectrofluorimetric and fluorescence microscopy with the latter revealed that soulamarin also induced a strong depolarization (ca. 97%) of the mitochondrial membrane potential. These data demonstrate that the lethal action of soulamarin towards T. cruzi involves damages to the plasma membrane of the parasite and mitochondrial dysfunction without the additional generation of reactive oxygen species, which may have also contributed to the death of the parasites. Considering the unique mitochondrion of T. cruzi, secondary metabolites of plants affecting the bioenergetic system as soulamarin may contribute as scaffolds for the design of novel and selective drug candidates for neglected diseases, mainly Chagas disease. Author Summary Chagas disease is a parasitic protozoan that affects the poorest population in the world, causing a high mortality and morbidity. As a result of highly toxic and long-term treatments, the discovery of novel, safe and more efficacious drugs is essential. Natural products isolated from plants are commonly used as drug prototypes or precursors to treat parasitic diseases. As part of our investigation of bioactive compounds from Brazilian flora, the present study was undertaken in order to determine the antitrypanosomal effects of the soulamarin, a coumarin isolated from the stem bark of Callophyllum brasiliense (Clusiaceae), against Trypanossoma cruzi. This study moreover investigated the lethal action of soulamarin towards the parasite. Considering the obtained results, secondary metabolites of plants affecting the bioenergetic system as soulamarin may contribute as scaffolds for the design of novel and selective drug candidates for neglected diseases, mainly Chagas disease.
- Antileishmanial and antitrypanosomal activity of the cutaneous secretion of Siphonops annulatus(2014) PINTO, Erika Gracielle; ANTONIAZZI, Marta Maria; JARED, Carlos; TEMPONE, Andre GustavoBackground: Among the tropical parasitic diseases, those caused by protozoans are considered a challenge to public health, being represented by leishmaniasis and Chagas disease. In view of the low effectiveness and toxicity of the current therapy, animal venoms such as amphibian secretions have been used as a promising source of new drug prototypes. The present work aimed to achieve bioguided fractionation of metabolites present in a cutaneous secretion of the caecilian Siphonops annulatus (Amphibia: Gymnophiona: Siphonopidae) with antileishmanial and antitrypanosomal activity. Methods: Through liquid-liquid partition and chromatographic techniques, the secretion was fractionated using bioguided assays. The 50% inhibitory concentration (IC50) of the main fraction (SaFr1) was studied against Leishmania (L.) infantum promastigotes and intracellular amastigotes, trypomastigotes of Trypanosoma cruzi and mammalian cells; viability was detected by the colorimetric MTT assay. By using a spectrofluorimetric assay with the probe SYTOX (R) Green and transmission electron microscopy (TEM), we also investigated the potential damage caused by SaFr1 in the plasma membrane and mitochondria of Leishmania. Results: The bioguided assay enabled isolation of a highly purified fraction (SaFr1) with an IC50 of 0.065 mu g/mL against promastigotes and 2.75 mu g/mL against trypomastigotes. Due to its high toxicity to peritoneal macrophages, SaFr1 showed no selectivity towards the intracellular forms of Leishmania. Ultrastructural studies with Leishmania demonstrated severe mitochondrial damage and the formation of large cytoplasmic vacuoles, leading to the parasite's death within a few hours. Nevertheless, it caused no alteration in the plasma membrane permeability as detected by the fluorescent probe and TEM. Conclusions: The present study demonstrated for the first time the antiparasitic activity of the skin secretion of the caecilian S. annulatus against Leishmania and T. cruzi, confirming that skin secretions of these amphibians, similarly to those of anurans and salamanders, are also potential tools for the development of new drug candidates against neglected diseases.
- Anti-parasitic Guanidine and Pyrimidine Alkaloids from the Marine Sponge Monanchora arbuscula(2015) SANTOS, Mario F. C.; HARPER, Philip M.; WILLIAMS, David E.; MESQUITA, Juliana T.; PINTO, Erika G.; COSTA-SILVA, Thais A. da; HAJDU, Eduardo; FERREIRA, Antonio G.; SANTOS, Raquel A.; MURPHY, Patrick J.; ANDERSEN, Raymond J.; TEMPONE, Andre G.; BERLINCK, Roberto G. S.HPLC-UV-ELSD-MS-guided fractionation of the anti-parasitic extract obtained from the marine sponge Monanchora arbuscula, collected off the southeastern coast of Brazil, led to the isolation of a series of guanidine and pyrimidine alkaloids. The pyrimidines monalidine A (1) and arbusculidine A (7), as well as the guanidine alkaloids batzellamide A (8) and hemibatzelladines 9-11, represent new minor constituents that were identified by analysis of spectroscopic data. The total synthesis of monalidine A confirmed its structure. Arbusculidine A (7), related to the ptilocaulin/mirabilin/netamine family of tricyclic guanidine alkaloids, is the first in this family to possess a benzene ring. Batzellamide A (8) and hemibatzelladines 9-11 represent new carbon skeletons that are related to the batzelladines. Evaluation of the anti-parasitic activity of the major known metabolites, batzelladines D (12), F (13), L (14), and nor-L (15), as well as of synthetic monalidine A (1), against Trypanosoma cruzi and Leishmania infantum is also reported, along with a detailed investigation of parasite cell-death pathways promoted by batzelladine L (14) and norbatzelladine L (15).
conferenceObject Soulamarin isolated from Calophyllum brasiliense (Clusiaceae) induces plasma membrane permeabilization of Trypanosoma cruzi and mytochondrial damage(2013) LAGO, J. H.; REA, A.; SILVA, L. G.; PINTO, E. G.; MESQUITA, J. T.; TEMPONE, A. G.- IN VITRO TRYPANOCIDAL EVALUATION OF PINANE DERIVATIVES FROM ESSENTIAL OILS OF RIPE FRUITS FROM Schinus terebinthifolius RADDI (ANACARDIACEAE)(2012) SARTORELLI, Patricia; SANTANA, Jefferson S.; GUADAGNIN, Rafael C.; LAGO, Joao Henrique G.; PINTO, Erika G.; TEMPONE, Andre G.; STEFANI, Helio A.; SOARES, Marisi G.; SILVA, Adalberto M. daEssential oils of ripe fruits from Schinus terebinthifolius (Anacardiaceae), obtained using a pilot extractor and a Clevenger apparatus were chemically characterized. Due the high amount of (-)-alpha-pinene in both oils, this monoterpene was tested against the protozoan parasite Trypanosoma cruzi, showing a moderate potential (IC50 63.56 mu g/mL) when compared to benznidazole (IC50 43.14 mu g/mL). Otherwise, (-)-alpha-pinene oxide did not showed anti-trypanosomal activity (IC50 > 400 mu g/mL) while (-)-pinane showed an IC50 of 56.50 mu g/mL. The obtained results indicated that the epoxydation of a-pinene results to the loss of the anti-parasitic activity while its hydrogenation product, contributed slightly to the increased activity.
- Lethal action of the nitrothiazolyl-salicylamide derivative nitazoxanide via induction of oxidative stress in Leishmania (L.) infantum(2013) MESQUITA, Juliana Tonini; PINTO, Erika Gracielle; TANIWAKI, Noemi Nosomi; GALISTEO JR., Andres Jimenez; TEMPONE, Andre GustavoStudying the cellular death pathways in Leishmania is an important aspect of discovering new antileishmanials. While using a drug repositioning approach, the lethal action of the nitrothiazolyl-salicylamide derivative nitazoxanide (NTZ) was investigated against Leishmania (L.) infantum. The in vitro antileishmanial activity and cytotoxicity were assessed using both parasite stages and mammalian NCTC cells, respectively. The lethal action of NTZ was investigated by detecting the phosphatidylserine (PS) exposure, reactive oxygen species (ROS) regulation, plasma membrane permeability, mitochondrial membrane potential and ultrastructural modifications by transmission electron microscopy. NTZ's activity against L. infantum was confirmed, producing IC50 values of 42.71 mu g/mL against promastigotes and 6.78 mu g/mL against intracellular amastigotes. NTZ rapidly altered the cellular metabolism of promastigotes by depolarising the mitochondrial membrane and up-regulating the reactive oxygen species (ROS). In addition, the flow cytometry data revealed an intense and time-dependent exposure of PS in promastigotes. When using SYTOX (R) Green as a fluorescent probe, NTZ demonstrated no interference in plasma membrane permeability. The ultrastructural alterations in promastigotes were time-dependent and caused chromatin condensation, plasma membrane blebbing and mitochondrial swelling. These data suggest that NTZ induced oxidative stress in L. (L.) infantum and might be a useful compound for investigating new therapeutic targets.
- Melittin induces in vitro death of Leishmania (Leishmania) infantum by triggering the cellular innate immune response(2016) PEREIRA, Andreia Vieira; BARROS, Gustavo de; PINTO, Erika Gracielle; TEMPONE, Andre Gustavo; ORSI, Ricardo de Oliveira; SANTOS, Lucilene Delazari dos; CALVI, Sueli; FERREIRA JR., Rui Seabra; PIMENTA, Daniel Carvalho; BARRAVIERA, BeneditoBackground: Apis mellifera venom, which has already been recommended as an alternative anti-inflammatory treatment, may be also considered an important source of candidate molecules for biotechnological and biomedical uses, such as the treatment of parasitic diseases. Methods: Africanized honeybee venom from Apis mellifera was fractionated by RP-C18-HPLC and the obtained melittin was incubated with promastigotes and intracellular amastigotes of Leishmania (L.) infantum. Cytotoxicity to mice peritoneal macrophages was evaluated through mitochondrial oxidative activity. The production of anti-and pro-inflammatory cytokines, NO and H2O2 by macrophages was determined. Results: Promastigotes and intracellular amastigotes were susceptible to melittin (IC50 28.3 mu g.mL(-1) and 1.4 mu g.mL(-1), respectively), but also showed mammalian cell cytotoxicity with an IC50 value of 5.7 mu g.mL(-1). Uninfected macrophages treated with melittin increased the production of IL-10, TNF-alpha, NO and H2O2. Infected melittin-treated macrophages increased IL-12 production, but decreased the levels of IL-10, TNF-alpha, NO and H2O2. Conclusions: The results showed that melittin acts in vitro against promastigotes and intracellular amastigotes of Leishmania (L.) infantum. Furthermore, they can act indirectly on intracellular amastigotes through a macrophage immunomodulatory effect.
- Histamine H1-receptor antagonists against Leishmania (L.) infantum: an in vitro and in vivo evaluation using phosphatidylserine-liposomes(2014) PINTO, Erika G.; COSTA-SILVA, Thais A. da; TEMPONE, Andre GustavoConsidering the limited and toxic therapeutic arsenal available for visceral leishmaniasis (VL), the drug repositioning approach could represent a promising tool to the introduction of alternative therapies. Histamine H1-receptor antagonists are drugs belonging to different therapeutic classes, including antiallergics and anxyolitics. In this work, we described for the first time the activity of H1-antagonists against L. (L) infantum and their potential effectiveness in an experimental hamster model. The evaluation against promastigotes demonstrated that chlorpheniramine, cinnarizine, hydroxyzine, ketotifen, loratadine, quetiapine and risperidone exerted a leishmanicidal effect against promastigotes, with IC50 values in the range of 13-84 mu M. The antihistaminic drug cinnarizine demonstrated effectiveness against the intracellular amastigotes, with an IC50 value of 21 mu M. The mammalian cytotoxicity was investigated in NCTC cells, resulting in IC50 values in the range of 57-229 mu M. Cinnarizine was in vivo studied as a free formulation and entrapped into phosphatidylserine-liposomes. The free drug was administered for eight consecutive days at 50 mg/kg by intraperitoneal route (i.p.) and at 100 mg/kg by oral route to L. infantum-infected hamsters, but showed lack of effectiveness in both regimens, as detected by real time PCR. The liposomal formulation was administered by i.p. route at 3 mg/kg for eight days and reduced the parasite burden to 54% in liver when compared to untreated group; no improvement was observed in the spleen of infected hamsters. Cinnarizine is the first antihistaminic drug with antileishmanial activity and could be used as scaffold for drug design studies for VL.
article 22 Citação(ões) na Scopus Anti-trypanosomal Phenolic Derivatives from Baccharis uncinella(2014) GREECO, Simone dos S.; FELIX, Maria Julia P.; LAGO, Joao Henrique G.; PINTO, Erika G.; TEMPONE, Andre G.; ROMOFF, Paulete; FERREIRA, Marcelo Jose P.; SARTORELLI, PatriciaBioassay-guided fractionation of the EtOH extract of the aerial parts of Baccharis uncinella C. DC. (Asteraceae) led to identification of two cinnamic acid derivatives (caffeic and ferulic acids), two flavones (hispidulin and pectolinaringenin) and a mixture of three chlorogenic acids (3,4-, 3,5- and 4,5-O-dicaffeoylquinic acids), which displayed in vitro anti-trypanosomal activity. Pectolinaringenin, hispidulin and caffeic acid showed activity against trypomastigotes of Trypanosoma cruzi, exhibiting 50% inhibitory concentration (IC50) values of 52, 81 and 56 mu g/mL, respectively, while the chlorogenic acid mixture showed an IC50 value of 61 mu g/mL. The flavonoids and cinnamic acid derivatives were evaluated for cytotoxicity against NCTC cells resulting in a 50% cytotoxic concentration (CC50) ranging from 33.82 to 129.1 mu g/mL while the chlorogenic acids did not display cytotoxicity (CC50 >150 mu g/mL). This is the first report of anti-trypanosomal activity of compounds from B. uncinella.- Conjugation to 4-aminoquinoline improves the anti-trypanosomal activity of Deferiprone-type iron chelators(2013) GEHRKE, Sebastian S.; PINTO, Erika G.; STEVERDING, Dietmar; PLEBAN, Karin; TEMPONE, Andre G.; HIDER, Robert C.; WAGNER, Gerd K.Iron is an essential growth component in all living organisms and plays a central role in numerous biochemical processes due to its redox potential and high affinity for oxygen. The use of iron chelators has been suggested as a novel therapeutic approach towards parasitic infections, such as malaria, sleeping sickness and leishmaniasis. Known iron chelating agents such as Deferoxamine and the 3-hydroxypyridin-4-one (HPO) Deferiprone possess anti-parasitic activity but suffer from mammalian toxicity, relatively modest potency, and/or poor oral availability. In this study, we have developed novel derivatives of Deferiprone with increased anti-parasitic activity and reduced cytotoxicity against human cell lines. Of particular interest are several new derivatives in which the HPO scaffold has been conjugated, via a linker, to the 4-aminoquinoline ring system present in the known anti-malaria drug Chloroquine. We report the inhibitory activity of these novel analogues against four parasitic protozoa, Trypanosoma brucei, Trypanosoma cruzi, Leishmania infantum and Plasmodium falciparum, and, for direct comparison, against human cells lines. We also present data, which support the hypothesis that iron starvation is the major cause of growth inhibition of these new Deferiprone-Chloroquine conjugates in T. brucei.