RESUMO
Cystic echinococcosis is caused by the tissue-dwelling larva (hydatid) of Echinococcus granulosus sensu lato. A salient feature is that this larva is protected by the acellular laminated layer (LL). As the parasite grows, the LL sheds abundant particles that can accumulate in the parasite's vicinity. The potential of LL particles to induce inflammation in vivo has not been specifically analysed. It is not known how each of its two major components, namely highly glycosylated mucins and calcium inositol hexakisphosphate (InsP6) deposits, impacts inflammation induced by the LL as a whole. In this work, we show that LL particles injected intraperitoneally cause infiltration of eosinophils, neutrophils and monocytes/macrophages as well as the disappearance of resident (large peritoneal) macrophages. Strikingly, the absence of calcium InsP6 enhanced the recruitment of all the inflammatory cell types analysed. In contrast, oxidation of the mucin carbohydrates caused decreased recruitment of neutrophils. The carbohydrate-oxidised particles caused cell influx nonetheless, which may be explained by possible receptor-independent effects of LL particles on innate immune cells, as suggested by previous works from our group. In summary, LL particles can induce acute inflammatory cell recruitment partly dependent on its mucin glycans, and this recruitment is attenuated by the calcium InsP6 component.
Assuntos
Echinococcus granulosus , Ácido Fítico , Animais , Echinococcus granulosus/imunologia , Ácido Fítico/farmacologia , Ácido Fítico/metabolismo , Equinococose/imunologia , Equinococose/parasitologia , Inflamação , Neutrófilos/imunologia , Mucinas/metabolismo , Camundongos , Macrófagos/imunologia , Macrófagos/metabolismo , Eosinófilos/imunologia , Feminino , Larva/imunologiaRESUMO
The use of in vivo models to assess nephrotoxicity has faced ethical limitations. A viable alternative is the ex vivo model that combines the 3 R principles with the preservation of tissue histology. Here, we established a gentamicin nephrotoxicity model using pigs` kidney explants and investigated the effect of phytic acid (IP6) against gentamicin- induced nephrotoxicity. A total of 360 kidney explants were divided into control, gentamicin (10 mM), IP6 (5 mM), and gentamicin+IP6 groups. The activity of gammaglutamyltransferase (GGT), creatinine levels, histological assessment, oxidative stress, and inflammatory cytokine expression were analyzed. Exposure to gentamicin induced an increase in GGT activity, creatinine levels, lesion score, lipoperoxidation and IL-8 expression. Explants exposed to IP6 remained like the control. The addition of IP6 to gentamicin prevented tissue damage, increasing the antioxidant status and gene expression of IL-10. This model proved to be an adequate experimental approach for identifying nephrotoxins and potential products to modulate the toxicity.
Assuntos
Nefropatias , Insuficiência Renal , Animais , Suínos , Ácido Fítico/farmacologia , Ácido Fítico/uso terapêutico , Ácido Fítico/metabolismo , Creatinina , Rim , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Antioxidantes/metabolismo , Gentamicinas/toxicidade , Estresse Oxidativo , Nefropatias/patologiaRESUMO
The purpose of the present study was to investigate the effects of phytic acid (IP6) on morphological and immunohistochemical parameters and oxidative stress response in intestinal explants of pigs exposed to fumonisin B1 (FB1) and/or deoxynivalenol (DON). The jejunal explants were exposed to the following treatments: vehicle, IP6 5 mM, DON 10 µM, FB1 70 µM, DON 10 µM + FB1 70 µM, DON 10 µM + IP6 5 mM, FB1 70 µM + IP6 5 mM, and DON 10 µM + FB1 70 µM + IP6 5 mM. The decrease in villus height and goblet cell density was more evident in DON and DON + FB1 treatments. In addition, a significant increase in cell apoptosis and cell proliferation and a decrease in E-cadherin expression were observed in the same groups. DON and FB1 exposure increased cyclooxygenase-2 expression and decreased the cellular antioxidant capacity. An increase in lipid peroxidation was observed in DON- and FB1-treated groups. IP6 showed beneficial effects, such as a reduction in intestinal morphological changes, cell apoptosis, cell proliferation, and cyclooxygenase-2 expression, and an increase in E-cadherin expression when compared with DON, FB1 alone, or DON and FB1 in association. IP6 inhibited oxidative stress and increased the antioxidant capacity in the explants exposed to mycotoxins.
Assuntos
Fumonisinas/toxicidade , Intestinos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Ácido Fítico/farmacologia , Tricotecenos/toxicidade , Animais , Apoptose/efeitos dos fármacos , Contagem de Células , Proliferação de Células/efeitos dos fármacos , Células Caliciformes/efeitos dos fármacos , Intestinos/patologia , SuínosRESUMO
Bioavailability of food nutrients can be reduced in the presence of antinutrients such as phytates and tannins. This work aimed to study bovine serum albumin binding to phytic acid and tannic acid, and its influence on in vitro protein digestibility. The effect of autoclaving and boiling on protein digestibility and the microstructure of complexes was also evaluated. Results showed that high ionic strength promotes greater affinity between tannic acid and bovine serum albumin, and decreases in vitro protein digestibility. For phytic acid and bovine serum albumin, the opposite behavior is observed because interactions are governed by electrostatic forces. A rise in temperature above that causing denaturation of the protein favors its interaction with phytic acid, and disfavors that with tannic acid, probably due to different protein binding site exposure. For both antinutrients, heating treatment increased protein hydrolysis, the size of complexes and their fragility.
Assuntos
Digestão/efeitos dos fármacos , Temperatura Alta , Ácido Fítico/metabolismo , Ácido Fítico/farmacologia , Soroalbumina Bovina/metabolismo , Taninos/metabolismo , Taninos/farmacologia , Animais , Bovinos , Concentração Osmolar , Ligação ProteicaRESUMO
Human hemoglobin (Hb) Coimbra (ßAsp99Glu) is one of the seven ßAsp99 Hb variants described to date. All ßAsp99 substitutions result in increased affinity for O2 and decreased heme-heme cooperativity and their carriers are clinically characterized by erythrocytocis, caused by tissue hypoxia. Since ßAsp99 plays an important role in the allosteric α1ß2 interface and the mutation in Hb Coimbra only represents the insertion of a CH2 group in this interface, the present study of Hb Coimbra is important for a better understanding of the global impact of small modifications in this allosteric interface. We carried out functional, kinetic and dynamic characterization of this hemoglobin, focusing on the interpretation of these results in the context of a growth of the position 99 side chain length in the α1ß2 interface. Oxygen affinity was evaluated by measuring p50 values in distinct pHs (Bohr effect), and the heme-heme cooperativity was analyzed by determining the Hill coefficient (n), in addition to the effect of the allosteric effectors inositol hexaphosphate (IHP) and 2,3-bisphosphoglyceric acid (2,3-BPG). Computer simulations revealed a stabilization of the R state in the Coimbra variant with respect to the wild type, and consistently, the T-to-R quaternary transition was observed on the nanosecond time scale of classical molecular dynamics simulations.
Assuntos
Hemoglobinas Anormais/química , Hemoglobinas Anormais/metabolismo , 2,3-Difosfoglicerato/farmacologia , Regulação Alostérica , Heme/metabolismo , Hemoglobinas Anormais/genética , Humanos , Técnicas In Vitro , Cinética , Modelos Moleculares , Simulação de Dinâmica Molecular , Oxigênio/metabolismo , Ácido Fítico/farmacologia , Domínios e Motivos de Interação entre Proteínas , Estrutura Quaternária de ProteínaRESUMO
Inositol hexakisphosphate (IP6) and inositol both regulate insulin secretion, but their combined use in the management of diabetes deserves investigation. The combined effects of IP6 and inositol supplementation were investigated in streptozotocin-induced type 2 diabetic rats. The following groups of rats were studied for 8 weeks: non-diabetic control, non-diabetic high-fat diet control, diabetic untreated, diabetic rats treated with the combination of IP6 and inositol (650 mg/kg bw) and diabetic rats treated with glibenclamide (10 mg/kg bw). High-fat diet and streptozotocin were used to induce type 2 diabetes mellitus in Sprague-Dawley rats. Body weight, blood glucose, glycated haemoglobin, insulin, serum leptin, HOMA-insulin resistance scores, intestinal amylase activity, serum and faecal lipids and food and fluid consumption were measured. Treatment with the combination significantly reduced blood glucose (306 ± 53 mg/dl) and insulin resistance score (1.93 ± 0.45) compared with diabetic controls (522 ± 24 mg/dl and 5.1 ± 0.69 respectively). Serum leptin (2.8 ± 0.6 ng/dl) and faecal triglycerides (108 ± 8 mg/dl) were significantly increased in rats treated with the combination compared with the diabetic control (1.8 ± 0.06 ng/dl and 86 ± 4 mg/dl). Serum triglyceride (47 ± 5.1 mg/dl), total cholesterol (98 ± 3.2 mg/dl) and food intake (26 ± 0.3 g) were significantly reduced by 45%, 25% and 25%, respectively, in rats treated with the combination compared with the diabetic control. Inositol and IP6 combined supplementation may be effective in the management of type 2 diabetes mellitus and related metabolic disorders by regulating some aspects of lipid and carbohydrate metabolism.
Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Inositol/uso terapêutico , Ácido Fítico/uso terapêutico , Amilases/metabolismo , Animais , Glicemia/metabolismo , Peso Corporal/efeitos dos fármacos , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/fisiopatologia , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/fisiopatologia , Suplementos Nutricionais , Ingestão de Líquidos/efeitos dos fármacos , Ingestão de Líquidos/fisiologia , Avaliação Pré-Clínica de Medicamentos/métodos , Quimioterapia Combinada , Ingestão de Alimentos/efeitos dos fármacos , Ingestão de Alimentos/fisiologia , Fezes/química , Hipoglicemiantes/farmacologia , Inositol/farmacologia , Intestinos/enzimologia , Leptina/sangue , Metabolismo dos Lipídeos/efeitos dos fármacos , Lipídeos/sangue , Masculino , Ácido Fítico/farmacologia , Ratos Sprague-DawleyRESUMO
Several studies have shown the benefits of natural antioxidants on health and food preservation. Phytic acid (IP6) is a natural antioxidant that is found mainly in cereals and vegetables and, for a long period of time, was considered an antinutritional factor. However, in vitro and in vivo studies have demonstrated its beneficial effects in the prevention and treatment of several pathological conditions and cancer. Despite the numerous benefits of IP6, the signs and intracellular interactions mediated by this antioxidant remain poorly understood. This review describes the main chemical and biological aspects of IP6, as well as its actions in the prevention and treatment of various diseases.
Assuntos
Ácido Fítico/química , Ácido Fítico/farmacologia , Animais , Anticarcinógenos/farmacologia , Antioxidantes/farmacologia , Linhagem Celular Tumoral , Modelos Animais de Doenças , Grão Comestível/química , Humanos , Neoplasias/prevenção & controle , Verduras/químicaRESUMO
Inositol hexaphosphate (InsP6) is present in cereals, legumes, nuts and seed oils and is biologically active against some tumor and cancer cells. Herein, this study aimed at evaluating the cellular toxicity, antiproliferative activity and effects on cell cycle progression of free InsP6 and InsP6-Ni(II) of leukemic T (Jurkat) and normal human cells. Treatments with InsP6 at concentrations between 1.0 and 4.0mM significantly decreased the viability of Jurkat cells, but showed no cytotoxic effect on normal human lymphocytes. Treatment with InsP6-Ni(II) complex at concentrations between 0.05 and 0.30 mM showed an anti-proliferative dose and a time-dependent effect, with significantly reduced cell viability of Jurkat cells but showed no cytotoxic effect on normal human lymphocytes as compared to the control. Ni(II) free ion was toxic to normal cells while InsP6-Ni(II) had no cytotoxic effect. The InsP6-Ni(II) complex potentiated (up to 10×) the antiproliferative effect of free InsP6 on Jurkat cells. The cytometric flow assay showed that InsP6 led to an accumulation of cells in the G0/G1 phase of the cell cycle, accompanied by a decrease in the number of cells in S and G2/M phases, whereas InsP6-Ni(II) has led to an accumulation of cells in the S and G2/M phases. Our findings showed that InsP6-Ni(II) potentiates cytotoxic effects of InsP6 on Jurkat cells and may be a potential adjuvant in the treatment of cancer.
Assuntos
Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Níquel/química , Ácido Fítico/farmacologia , Antineoplásicos/química , Antineoplásicos/farmacologia , Ciclo Celular/efeitos dos fármacos , Humanos , Células Jurkat , Ácido Fítico/químicaRESUMO
OBJECTIVE: To determine the effect of phytic acid, tannic acid and pectin on fasting non-heme iron bioavailability in both the presence and absence of calcium. RESEARCH METHODS: Twenty-eight apparently healthy adult females participated in two iron absorption studies using radioactive iron isotopes ((59)Fe and (55)Fe). One group received 5mg of iron (as FeSO4) alone (control), together with 10mg of phytic acid, 100mg of tannic acid and 250mg of pectin (study A), on different days. The second group received the same iron doses and compounds as the other group, plus 800mg of calcium (CaCl2) (study B). The compounds were administered after an overnight fast, and no food or beverages were consumed for the following 3h. Iron status and circulating radioactivity were measured in venous blood samples. RESULTS: The geometric means of iron bioavailability (range±1SD) for iron alone, iron with phytic acid, iron with tannic acid, and iron with citrus pectin were 25.0% (11.9-52.0); 18.9% (9.9-35.8); 16.8% (8.7-32.3); and 21.1% (10.2-43.9), respectively (repeated-measures ANOVA, p<0.02 (Dunnett's post hoc: control vs tannic acid p<0.05). When 800mg of calcium was added (study B), iron bioavailability was 16.7% (10.1-27.5); 13.2% (7.1-24.6); 14.8% (8.8-25.1); and 12.6% (5.5-28.8), respectively (repeated-measures ANOVA, NS). CONCLUSIONS: Tannic acid decreases the fasting bioavailability of non-heme iron, however this effect did not exist in the presence of calcium. No effect was observed by phytic acid or citrus pectin on fasting non-heme iron bioavailability in both the presence and absence of calcium.
Assuntos
Cálcio/farmacologia , Jejum/metabolismo , Ferro/metabolismo , Pectinas/farmacologia , Ácido Fítico/farmacologia , Taninos/farmacologia , Adulto , Disponibilidade Biológica , Feminino , Heme/metabolismo , HumanosRESUMO
Calcium, phytic acid, polyphenols and fiber are major inhibitors of iron absorption and they could be found in excess in some diets, thereby altering or modifying the iron nutrition status. The purpose of this study is to evaluate the effect of calcium, tannic acid, phytic acid, and pectin over iron uptake, using an in vitro model of epithelial cells (Caco-2 cell line). Caco-2 cells were incubated with iron (10-30 µM) with or without CaCl2 (500 and 1,000 µM) for 24 h. Then, cells were challenged with phytic acid (50-150 µM); pectin (50-150 nM) or tannic acid (100-500 µM) for another 24 h. Finally, (55)Fe (10 µM) uptake was determined. Iron dialyzability was studied using an in vitro digestion method. Iron uptake in cells pre-incubated with 20 and 30 µM Fe was inhibited by CaCl2 (500 µM). Iron uptake decreased in cells cultured with tannic acid (300 µM) and CaCl2 (500-1,000 µM) (two-way ANOVA, p = 0.002). Phytic acid also decreased iron uptake mainly when cells were treated with CaCl2 (1,000 µM) (two-way ANOVA; p < 0.05). Pectin slightly decreased iron uptake (p = NS). Iron dialyzability decreased when iron was mixed with CaCl2 and phytic or tannic acid (T test p < 0.0001, for both) but not when mixed with pectin. Phytic acid combined with calcium is a strong iron uptake inhibitor. Pectin slightly decreased iron uptake with or without calcium. Tannic acid showed an unexpected behavior, inducing an increase on iron uptake, despite its low Fe dialyzability.