RESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Schinus terebinthifolia Raddi is a plant broadly used in folk medicine and the use of its leaf extract as an antitumor agent has been reported. AIM OF THE STUDY: To evaluate the antitumor potential and the toxicity of saline extract (SE) and lectin (SteLL) from S. terebinthifolia leaves in sarcoma 180-bearing mice. MATERIALS AND METHODS: Cytotoxicity to sarcoma 180 cells was tested in vitro, and antitumor assay was performed using Swiss female mice. The treatments (0.15â¯M NaCl, negative control; methotrexate 1.5â¯mg/kg, positive control; SE 100â¯mg/kg; SteLL 1 and 5â¯mg/kg) by intraperitoneal injections started on the 8th day after tumor inoculation and lasted 7 days. It was analyzed: tumor weight; number and gauge of tumor vessels; hematological and biochemical parameters; histopathological changes; and occurrence of micronuclei in bone marrow cells. RESULTS: SE and SteLL showed IC50 values (concentrations that reduced cell viability to 50%) of 301.65 and 8.30⯵g/mL, respectively. The lectin was able to induce apoptosis. Treatments with the extract and lectin caused a 57.6-73.6% reduction in tumor weight, which was not significantly different from the reduction in the methotrexate group. Tumors of animals treated with SteLL at 5â¯mg/kg showed reduced number of secondary vessels while the gauge was lower in all treated groups. In the groups treated with SteLL, tumors showed reduced and slightly vascularized parenchyma, with necrosis in the center and at the periphery. No alterations in the blood levels of urea, creatine, and glucose were detected while serum AST level was moderately increased in the SE group. Histopathological analysis revealed vacuolization and steatosis in the liver of animals treated with the extract and lectin. In addition, the treatments with SE and SteLL resulted in the reduction of filtration space and alterations in tubular architecture in kidneys. In respect to hematological parameters, it was only detected increase in the number of monocytes in SE group. The extract and lectin did not induce the formation of micronuclei in the bone marrow cells. CONCLUSIONS: SE and SteLL had antitumor effect against sarcoma 180 without inducing hematological changes and genotoxic effects in mice; however, some degree of hepatic and renal toxicity was observed, suggesting the evaluation of drug delivery strategies in the future.
Assuntos
Anacardiaceae , Antineoplásicos/uso terapêutico , Extratos Vegetais/uso terapêutico , Lectinas de Plantas/uso terapêutico , Sarcoma 180/tratamento farmacológico , Animais , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Feminino , Rim/efeitos dos fármacos , Fígado/efeitos dos fármacos , Camundongos , Fitoterapia , Folhas de Planta , Lectinas de Plantas/farmacologiaRESUMO
With important carbohydrate binding properties, lectins are proteins able to decipher the glycocode, and as such, they can be used in bioassays involving cell-cell communication, protein targeting, inflammation, and hypernociception, among others. In this study, a new glucose/mannose-specific lectin from Canavalia villosa seeds (Cvill) was isolated by a single affinity chromatography step in a Sephadex® G-50 column, with a purification yield of 19.35mg of lectin per gram of powdered seed. Analysis of intact protein by mass spectrometry showed the lectin is composed of three polypeptide chains, including a 25.6kDa α chain, 12.9KDa ß, and 12.6 KDa γ fragments, similar to the profile of ConA-like glucose/mannose-specific lectins. Partial sequence of the protein was obtained by MS-MALDI TOF/TOF covering 41.7% of its primary structure. Cvill presented sugar specificity to d-glucose, α-methyl-d-mannoside, d-mannose, and glycoproteins fetuin and ovoalbumin. The lectin characterization showed that Cvill presents high stability within a broad range of pH and temperature, also showing average toxicity against Artemia nauplii. The proinflammatory effect of Cvill was observed by induction of paw edema and hypernociception in mice, with the participation of the carbohydrate binding site, showing its potential to be used as tool in inflammation studies.
Assuntos
Analgésicos/farmacologia , Canavalia/química , Glucose/metabolismo , Lectinas de Ligação a Manose/farmacologia , Manose/metabolismo , Lectinas de Plantas/farmacologia , Sementes/química , Sequência de Aminoácidos , Analgésicos/química , Analgésicos/metabolismo , Analgésicos/uso terapêutico , Animais , Artemia/efeitos dos fármacos , Edema/tratamento farmacológico , Concentração de Íons de Hidrogênio , Inflamação/tratamento farmacológico , Masculino , Lectinas de Ligação a Manose/química , Lectinas de Ligação a Manose/metabolismo , Lectinas de Ligação a Manose/uso terapêutico , Camundongos , Lectinas de Plantas/química , Lectinas de Plantas/metabolismo , Lectinas de Plantas/uso terapêutico , TemperaturaRESUMO
Digestive system cancers-those of the esophagus, stomach, small intestine, colon-rectum, liver, and pancreas-are highly related to genetics and lifestyle. Most are considered highly mortal due to the frequency of late diagnosis, usually in advanced stages, caused by the absence of symptoms or masked by other pathologies. Different tools are being investigated in the search of a more precise diagnosis and treatment. Plant lectins have been studied because of their ability to recognize and bind to carbohydrates, exerting a variety of biological activities on animal cells, including anticancer activities. The present report integrates existing information on the activity of plant lectins on various types of digestive system cancers, and surveys the current state of research into their properties for diagnosis and selective treatment.
Assuntos
Neoplasias do Sistema Digestório/tratamento farmacológico , Lectinas de Plantas/uso terapêutico , Animais , Antineoplásicos/uso terapêutico , Tecnologia Biomédica , HumanosRESUMO
Lectins are proteins that bind cellular glycans and can modulate various neuronal functions. We have evaluated the neuroprotective effect of ConBr, a lectin purified from the seeds of Canavalia brasiliensis in a model of rat organotypic hippocampal cultures (OHCs) exposed to oxygen and glucose deprivation (OGD). OGD for 15 min followed by 24 h re-oxygenation significantly increased cell death, caused mitochondrial depolarization and increased reactive oxygen species (ROS) in CA1 region of OHCs. ConBr (0.1 µg/mL) added during the re-oxygenation period counteracted cell death, mitochondrial depolarization and overproduction of ROS induced by OGD. Moreover, ConBr restored the levels of Akt and ERK1 phosphorylation that were reduced by OGD. Modulation of intracellular Ca2+ by ConBr was evaluated in isolated hippocampal neurons loaded with the fluorescent calcium dye Fluo-4/AM. ConBr (0.1 and 1 µg/mL) reduced by 25-30 % the Ca2+ increment induced by 70 mM K+. A sub effective concentration of ConBr (0.01 µg/mL) together with a sub effective concentration of the L-type calcium channel antagonist nifedipine (0.3 µM) conferred a synergic neuroprotective effect in OHCs subjected to OGD. In conclusion, ConBr provides OHCs neuroprotection against OGD. The mechanism was not fully addressed but it may involve modulation of L-type voltage-gated Ca2+ channels by ConBr.
Assuntos
Isquemia Encefálica/metabolismo , Canais de Cálcio/metabolismo , Canavalia , Hipocampo/metabolismo , Fármacos Neuroprotetores/uso terapêutico , Lectinas de Plantas/uso terapêutico , Animais , Isquemia Encefálica/prevenção & controle , Células Cultivadas , Relação Dose-Resposta a Droga , Hipocampo/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Fármacos Neuroprotetores/farmacologia , Técnicas de Cultura de Órgãos , Lectinas de Plantas/isolamento & purificação , Lectinas de Plantas/farmacologia , Ratos , Ratos Sprague-Dawley , SementesRESUMO
Lectins recognize and reversibly bind to carbohydrates attached to proteins and lipids modulating a variety of signaling pathways. We previously showed that ConBr, a lectin from Canavalia brasiliensis seeds, produced an antidepressant-like effect in mice by modulating the monoaminergic neurotransmitter systems. Moreover, ConBr blocked hippocampal neurotoxicity induced by quinolinic acid in vivo and by glutamate in vitro, suggesting a neuroprotective activity of ConBr via glutamatergic system modulation. Therefore, the present study was undertaken to investigate the involvement of the N-methyl-D-aspartate (NMDA) receptor and the L-arginine-nitric oxide (NO) pathway in the antidepressant-like action displayed by ConBr in the forced swimming test (FST). With the aim of verifying the involvement of NMDA receptors in the antidepressant-like effect of ConBr (10 µg/site, i.c.v.), an intracerebroventricular (i.c.v.) pretreatment with either NMDA (0.1 pmol/site) or D-serine (30 µg/site) was carried out. The results show that both treatments blocked the effect of ConBr. Furthermore, the coadministration of subeffective doses of the NMDA receptor antagonist MK-801 (0.001 mg/kg, i.p.) or ketamine (0.1 mg/kg, i.p.; NMDA receptor antagonist) and ConBr (0.1 µg/site, i.c.v.) caused a synergistic reduction in immobility time. In order to verify the dependence of the L-arginine-NO-cGMP pathway, on the effect of ConBr in the FST, a pretreatment with the NO precursor, L-arginine (750 mg/kg, i.p.), or the PDE5 inhibitor, sildenafil (5 mg/kg, i.p.), was performed. Both drugs abolished the antidepressant-like action of ConBr. Finally, the administration of subeffective doses of the soluble guanylate cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ; 30 pmol/site, i.c.v.) and ConBr (0.1 µg/site, i.c.v.) produced a synergistic antidepressant-like effect in the FST. Taken together, the results suggest that the antidepressant-like effect of ConBr in the FST involves NMDA receptor inhibition and reduction in NO and cGMP synthesis.
Assuntos
Antidepressivos/uso terapêutico , Canavalia , Ácido Glutâmico , Extratos Vegetais/uso terapêutico , Lectinas de Plantas/uso terapêutico , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Animais , Antidepressivos/isolamento & purificação , Relação Dose-Resposta a Droga , Ácido Glutâmico/fisiologia , Masculino , Camundongos , Extratos Vegetais/isolamento & purificação , Lectinas de Plantas/isolamento & purificação , Receptores de N-Metil-D-Aspartato/fisiologia , Sementes , Resultado do TratamentoRESUMO
Lectins are proteins or glycoproteins with the ability to link to carbohydrates at the cell surface in a specific and reversible manner. Studies have showed that lectins are demonstrate immunomodulatory and antitumor agents. This study aims to evaluate the effect of lectin extracted from the seeds of Canavalia brasiliensis (ConBr) on murine melanoma B16F10 cells by analyzing cell viability, apoptosis index, cell migration, production of cytokines and nitric oxide (NO). Results showed that ConBr was able to reduce cell viability and thwart apoptosis, which could be observed by decrease in cell migration. ConBr also induced NO and IL-12 synthesis. Altogether, these data demonstrate the potential of ConBr as a therapeutic agent for melanoma.
Assuntos
Apoptose/efeitos dos fármacos , Canavalia/imunologia , Melanoma/tratamento farmacológico , Lectinas de Plantas/farmacologia , Animais , Linhagem Celular Tumoral , Movimento Celular/imunologia , Sobrevivência Celular/imunologia , Citocinas/análise , Citometria de Fluxo , Melanoma/imunologia , Camundongos , Óxido Nítrico/análise , Lectinas de Plantas/uso terapêutico , Estatísticas não ParamétricasRESUMO
The anti-inflammatory activity of Canavalia seed lectins (Canavalia gladiata [CGL], Canavalia maritima [ConM] and Canavalia brasiliensis [ConBr]) was evaluated by intravenous administration in rats. In non-sensitized rats, cellular edema elicited by carrageenan was reduced (45-51 %) by ConM and (44-59 %) by CGL. Osmotic edema elicited by dextran was reduced by ConM and CGL in 27 % and 29 %. ConM and CGL reduced the edema elicited by L-arginine in 53 % and that of prostaglandin E2 in 48 % and 36 %. Leukocyte migration elicited by carrageenan was reduced in 49 % by ConM and in 55 % by CGL (attenuated in 4× by glucose) and peritoneal TNF-α content in 82 %. In rats sensitized, ConM inhibited the paw edema and leukocyte migration elicited by ovalbumin in 34 % and 70 %. ConM and CGL are anti-inflammatory, mainly in cellular events mediated by prostaglandin E2, nitric oxide and TNF-α in non-sensitized rats. However, only ConM is anti-inflammatory in sensitized rats. CGL effect involves the lectin domain.
Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Edema/tratamento farmacológico , Inflamação/tratamento farmacológico , Lectinas de Plantas/uso terapêutico , Animais , Arginina , Carragenina , Movimento Celular/efeitos dos fármacos , Dextranos , Dinoprostona , Edema/induzido quimicamente , Inflamação/induzido quimicamente , Leucócitos/efeitos dos fármacos , Leucócitos/metabolismo , Ovalbumina , Ratos , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Antiparasitic effect of a lectin isolated from Synadenium carinatum latex (ScLL) was evaluated against Leishmania (Leishmania) amazonensis promastigotes/amastigotes. Pretreatment of murine inflammatory peritoneal macrophages with ScLL reduced by 65.5% the association index of macrophages and L. (L) amazonensis promastigotes. Expression of cytokines (IL-12, IL-1 and TNF-α) was detected in infected macrophages pretreated with ScLL (10µg/mL). ScLL also reduced the growth of L. (L) amazonensis amastigote intracellular forms, showing no in vitro cytotoxic effects in mammalian host cells. ScLL treatment in infected murine inflammatory peritoneal macrophages did not induce nitric oxide production, suggesting that a nitric oxide independent pathway is activated to decrease the number of intracellular Leishmania.
Assuntos
Euphorbiaceae/química , Látex/farmacologia , Leishmania mexicana/efeitos dos fármacos , Leishmaniose Cutânea/tratamento farmacológico , Macrófagos Peritoneais/parasitologia , Lectinas de Plantas/farmacologia , Animais , Células Cultivadas , Citocinas/biossíntese , Citocinas/genética , Látex/uso terapêutico , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Óxido Nítrico/biossíntese , Óxido Nítrico/genética , Óxido Nítrico Sintase Tipo II/biossíntese , Óxido Nítrico Sintase Tipo II/genética , Lectinas de Plantas/uso terapêutico , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Neutrophil migration is responsible for tissue damage observed in inflammatory diseases and is also implicated in inflammatory nociception. The use of lectins has been demonstrated to be effective in different activities including anti-inflammatory, antimicrobial, and in cancer therapy. In this study, we addressed the potential use of a lectin from Canavalia grandiflora seeds (ConGF) to control neutrophil migration and inflammatory hypernociception. Pretreatment of the animals intravenously (15 min before) with ConGF inhibited neutrophil migration to the peritoneal cavity in a dose-dependent fashion confirmed by an inhibition of rolling and adhesion of leukocytes by intravital microscopy. Another set of experiments showed that pretreatment of the animals with ConGF inhibited the mechanical hypernociception in mice induced by the i.pl. injection of carrageenan or formalin. This anti-nociceptive effect correlated with an effective blockade of neutrophil influx, as assessed by the hind paw tissue myeloperoxidase levels. Furthermore, ConGF had important inhibitory effects on the mouse carrageenan-induced paw edema. In addition, animals treated with ConGF showed inhibition of cytokines release. In conclusion, we demonstrated that the lectin ConGF inhibits neutrophil migration and mechanical inflammatory hypernociception.
Assuntos
Analgésicos/farmacologia , Anti-Inflamatórios não Esteroides/farmacologia , Canavalia , Lectinas de Plantas/farmacologia , Sementes , Analgésicos/isolamento & purificação , Analgésicos/uso terapêutico , Animais , Anti-Inflamatórios não Esteroides/isolamento & purificação , Anti-Inflamatórios não Esteroides/uso terapêutico , Inflamação/tratamento farmacológico , Inflamação/patologia , Masculino , Camundongos , Dor/tratamento farmacológico , Dor/patologia , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Lectinas de Plantas/isolamento & purificação , Lectinas de Plantas/uso terapêuticoRESUMO
KM(+) is a mannose-binding lectin from Artocarpus integrifolia that induces interleukin (IL)-12 production by macrophages and protective T helper 1 immune response against Leishmania major infection. In this study, we performed experiments to evaluate the therapeutic activity of jackfruit KM(+) (jfKM(+)) and its recombinant counterpart (rKM(+)) in experimental paracoccidioidomycosis. To this end, jfKM(+) or rKM(+) was administered to BALB/c mice 10 days after infection with Paracoccidiodes brasiliensis. Thirty days postinfection, lungs from the KM(+)-treated mice contained significantly fewer colony-forming units and little to no organized granulomas compared to the controls. In addition, lung homogenates from the KM(+)-treated mice presented higher levels of nitric oxide, IL-12, interferon-gamma, and tumor necrosis factor-alpha, whereas higher levels of IL-4 and IL-10 were detected in the control group. With mice deficient in IL-12, Toll-like receptor (TLR) 2, TLR4, or TLR adaptor molecule MyD88, we demonstrated that KM(+) led to protection against P. brasiliensis infection through IL-12 production, which was dependent on TLR2. These results demonstrated a beneficial effect of KM(+) on the severity of P. brasiliensis infection and may expand its potential use as a novel immunotherapeutic molecule.
Assuntos
Interleucina-12/biossíntese , Lectinas Tipo C/metabolismo , Lectinas de Ligação a Manose/metabolismo , Paracoccidioides/efeitos dos fármacos , Paracoccidioidomicose/tratamento farmacológico , Lectinas de Plantas/uso terapêutico , Receptores de Superfície Celular/metabolismo , Receptor 2 Toll-Like/metabolismo , Animais , Artocarpus , Células Cultivadas , Contagem de Colônia Microbiana , Citocinas/biossíntese , Interleucina-12/genética , Pulmão/metabolismo , Pulmão/microbiologia , Pulmão/patologia , Masculino , Receptor de Manose , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fator 88 de Diferenciação Mieloide/metabolismo , Óxido Nítrico/metabolismo , Paracoccidioidomicose/metabolismo , Lectinas de Plantas/farmacologia , Proteínas Recombinantes/farmacologia , Proteínas Recombinantes/uso terapêutico , Receptor 4 Toll-Like/metabolismoRESUMO
This work investigated the potential use of an alternative adsorbent to anti-immunoglobulin E (IgE)-agarose for IgE selective adsorption therapy. A screening of several commercially available adsorbents (Concanavalin A, Lens culinaris[Lc], d-tryptophan, poly-l-lysine, and aminohexyl immobilized on agarose) was done through batch system assays, considering some criteria, such as adsorption capacity, selectivity, and biocompatibility. In the Lc-agarose adsorbent, total IgE, and specific IgE--for the airborne allergens Dermatophagoides pteronyssinus and Blomia tropicalis--were significantly better removed (63, 58, and 59%, respectively) than immunoglobulin G (19%), immunoglobulin A (33%), immunoglobulin M (9%), and albumin (18%). This adsorbent was packed into a column and the effect of superficial velocity, ratio of plasma volume to bed volume, number of perfusions, and temperature on IgE adsorption were evaluated. In vitro simulation of therapeutic adsorption (single perfusion) indicated that about 50% of total IgE could be eliminated.