Fernanda Borges de Araújo Paula

Influence of Marolo (Annona crassiflora Mart.) Pulp Intake on the Modulation of Mutagenic/Antimutagenic Processes and Its Action on Oxidative Stress In Vivo

Brazilian savanna constitutes a valuable ecoregion that contributes to the supply of fruit known worldwide for its nutritional value and peculiar flavors. Among them, the Marolo (Annona crassiflora Mart.) fruit is known for its use in folk medicine. In order to establish the safety of Marolo for human consumption, this study evaluated the following: the chemical composition of Marolo pulp; its mutagenic and antimutagenic activities using micronucleus test; and the oxidative stress induced in the livers of mice fed a diet containing 1%, 10% or 20% pulp. It was observed that the chemical composition of marolo pulp was similar to that of common fruit; nevertheless, its lipidic content and energetic values were higher. In the mice fed experimental diets, the biochemical parameters of the blood serum showed normal levels of glucose, triglycerides, and cholesterol. The micronucleus test indicated neither mutagenic nor antimutagenic effects of Marolo consumption on bone marrow cells but showed potentialization of cyclophosphamide (CP). The oxidative stress levels observed indicated that CP was not exerting a great influence on the induction of reactive oxygen species. As the whole fruit is a complex matrix, the interactions between its components could be responsible for its negative and positive biological effects.

Neutrophil dysfunction induced by hyperglycemia: modulation of myeloperoxidase activity

Our data suggest that impaired activity of myeloperoxidase (MPO) may play an important role in the dysfunction of neutrophils from hyperglycemic rats. Neutrophil biochemical pathways include the NADPH oxidase system and the MPO enzyme. They both play important role in the killing function of neutrophils. The effect of hyperglycemia on the activity of these enzymes and the consequences with regard to Candida albicans phagocytosis and the microbicidal property of rat peritoneal neutrophils is evaluated here. The NADPH oxidase system activity was measured using chemiluminescence and cytochrome C reduction assays. MPO activity was measured by monitoring HOCl production, and MPO protein expression was analysed using Western blot and immunofluorescence. C. albicans phagocytosis and death were evaluated by optical microscopy using the May–Grunwald–Giemsa staining method. ROS generation kinetic was slightly delayed in the diabetic group. MPO expression levels were higher in diabetic neutrophils; however, MPO activity was decreased in these same neutrophils compared with the controls. C. albicans phagocytosis and killing were lower in the diabetic neutrophils. Based on our experimental model, the phagocytic and killing functions of neutrophil phagocytosis are impaired in diabetic rats because of the decreased production of HOCl, highlighting the importance of MPO in the microbicidal function of neutrophils. Copyright

Compostos bioativos do café: atividade antioxidante in vitro do café verde e torrado antes e após a descafeinação

This study aimed to evaluate the effect of coffee decaffeination with dichloromethane on the in vitro antioxidant activity of this matrix. It were determined the content of total phenolics, chlorogenic acid and caffeine of the coffee samples. The assessment of the antioxidant potential was investigated by DPPH radical scavenging method, reducer power and Fe2+chelation activity. The process of decaffeination and roasting caused changes in the levels of the compounds investigated. The results show that the decaffeination by the dichloromethane method reduces the in vitro antioxidant potential of coffee.

Effects of the Consumption of Caffeinated and Decaffeinated Instant Coffee Beverages on Oxidative Stress Induced by Strenuous Exercise in Rats

Many authors attribute the antioxidant activity of brewed coffee to its caffeine content. In addition, caffeine intake has been associated with increased performance during physical exercise. This study analyzed the in vivo effects of drinking caffeinated and decaffeinated instant coffee (8%, w/v) on oxidative stress and antioxidant enzyme activity in the anterior tibialis muscles of rats subjected to intense exercise. It was observed that exercise induced lipid peroxidation (estimated using malondialdehyde) and protein oxidation (evaluated by determining the formation of carbonyl groups) in the muscle (P < 0.05). Decaffeinated instant coffee and caffeine solution did not exhibit antioxidant activity in vivo. Caffeinated instant coffee beverage intake did not induce changes in superoxide dismutase and glutathione peroxidase activities but was able to diminish lipid and protein oxidation in the anterior tibialis muscles of rats after exercise (P < 0.05), contributing to a reduction in the oxidative stress triggered by exercise.

Aminoguanidine treatment increased NOX2 response in diabetic rats: Improved phagocytosis and killing of Candida albicans by neutrophils.

In this study, we show that aminoguanidine (AMG), an inhibitor of protein glycation, increases the NOX2 (phagocyte NADPH oxidase) response and microbicidal activity by neutrophils, regardless of diabetic status. The non-enzymatic glycation of proteins, yielding irreversible advanced glycation end products (AGEs), is involved in the development of diabetes complications, including alterations of signaling pathways and the generation of reactive oxygen species by phagocytes. The phagocytes produce ROS (reactive oxygen species) through activation of the NOX2 complex, which generates superoxide. The purpose of this study was to evaluate the effect of hyperglycemia and the glycation of proteins on the NOX2 activity of neutrophils and its implications for cellular physiology, with a focus on the microbicidal activity of these cells. We treated diabetic rats with AMG and evaluated neutrophil ROS generation and Candida albicans killing ability. We observed a large increase in the microbicidal activity of peritoneal neutrophils from AMG-treated rats. The increase was independent of diabetic status and myeloperoxidase activity. Collectively, our results suggest that AMG has an immunomodulator role that triggers an increase in the microbicidal response of neutrophils mainly related to reactive oxygen species production by NOX2.

Annona crassiflora Mart. fruit pulp effects on biochemical parameters and rat colon carcinogenesis

A. crassiflora Mart. a Brazilian savannah fruit, is a source of phytochemical compounds that possess a wide array of biological activities, including free radical scavenging. This native fruit proved to potentialize the mutagenic process in previous in vivo investigations. The aim of the present study was to investigate the effects of A. crassiflora Mart. pulp intake on colonic cell proliferation and on the development of Aberrant Crypt Foci (ACF) in male Wistar rats. The animals were fed with either a commercial diet or a diet supplemented with A. crassiflora Mart. pulp mixed in 1%, 10% or 20% (w/w) for 4 weeks or 20 weeks. The carcinogen 1,2-dimethylhydrazine dihydrochloride (4 doses, 40 mg kg-1 each) was used to induce colonic ACF. After euthanasia, the blood, liver and colon samples were collected for biochemical determinations, oxidative stress or ACF development analysis, respectively. Immunohistochemical analyses of the colonic mucosa were performed using antibodies against proliferating cell nuclear antigen (PCNA) in normal-appearing colonic crypt and β-catenin in ACF. There was no ACF development in the colon from groups treated with A. crassiflora Mart. pulp. Also, the biochemical and oxidative stress analysis, PCNA labeling and ACF development (number, multiplicity or cellular localization of β-catenin) were unchanged as a result of marolo pulp intake. Thus, the present results suggest that A. crassiflora Mart. pulp intake did not exert any protective effect in the colon carcinogenesis induced by DMH in rats.

Pharmacokinetics and pharmacodynamics of glimepiride polymorphs

&NA; Glimepiride (GLIM) is used as an oral antihyperglycemic agent for treatment of type 2 diabetes. The drug presents two polymorphic forms (GLIM form I and GLIM form II) described in the literature, and according to in vitro data, GLIM form II is about 3.5 times more soluble and releases 2 times the drug amount than GLIM form I in the physiological pH range. Considering the literature in vitro data and that the diabetes treatment demands glycemic control, avoiding abrupt fluctuations in the blood glucose levels, this work aimed to study the impact of GLIM polymorphism in the in vivo performance of GLIM solid oral dosages. For this, hard gelatin capsules with GLIM form I or II were prepared and orally administered in rats. After that, pharmacokinetic studies were performed by sampling animal blood at different times, and biochemical parameters (pharmacodynamic), such as glucose and insulin, were also evaluated. Our results showed that the in vitro data corroborate with our in vivo assays. GLIM form II provided higher plasma concentration of drug than form I (at baseline up to approximately 200 min after oral administration) and, consequently, increased insulin release and reduced levels of glucose, showing good correlation between pharmacokinetic and pharmacodynamics assays. Thus, this study demonstrated that GLIM polymorphs in oral dosages might alter the drug efficacy, which may expose the patients to risks, such as hypoglycemia.

Hepatoprotective and Antioxidant Activities of Oil from Baru Almonds (Dipteryx alata Vog.) in a Preclinical Model of Lipotoxicity and Dyslipidemia

The oil obtained from baru (Dipteryx alata Vog.) almonds exhibits high energy value and is reported in popular medicine for the treatment of rheumatic diseases and reproductive disturbances. Although baru oil is used in domestic cuisine, the chemical characterization of this oil and its effects on lipid metabolism are still poorly understood. Therefore, this study evaluated the fatty acid (FA) profile and the effects of baru oil on liver and aorta in a murine model of dyslipidemia. The chromatographic profile of baru oil showed high levels of unsaturated FAs, especially oleic acid. Saturated FAs, such as palmitic and lignoceric acids, were found in lower amounts. Hypercholesterolemia was induced in male Wistar rats by daily administration of a lipid emulsion by gavage for 15 weeks. Biochemical and histopathological analysis were performed on serum, aorta, and liver. The results demonstrated that animals developed marked hypercholesterolemia, liver steatosis, and increased lipid peroxidation in the aorta. Treatment with baru oil attenuated lipid peroxidation and drastically reduced liver damage, especially ballooning degeneration and steatosis. By restricting vascular and hepatic injury, this oil showed potential applicability as a functional food, reinforcing its use in popular medicine and domestic cuisine.

Ethanolic extract of Passiflora edulis Sims leaves inhibits protein glycation and restores the oxidative burst in diabetic rat macrophages after Candida albicans exposure

This study was conducted to evaluate the effects of the ethanolic extract of Passiflora edulis leaves on blood glucose, protein glycation, NADPH oxidase activity and macrophage phagocytic capacity after Candida albicans exposure in diabetic rats. The Passiflora edulis Sims leaves were dried to 40°C, powdered, extracted by maceration in 70% ethanol, evaporated under reduced pressure and lyophilised. The biochemical tests performed were total phenolic content (TP) as determined by the Folin-Ciocalteu assay, trapping potential DPPH assay and total iron-reducing potential. Diabetes was induced by alloxan injection. Protein glycation was determined by AGE and fructosamine serum concentrations. Extract-treated diabetic animals demonstrated lower fructosamine concentrations compared with the diabetic group. Our results suggest that ethanolic Passiflora edulis Sims leaf extraction may have beneficial effects on diabetes and may improve glycaemic control in diabetic rats.

Intervenções para a prevenção de condições crônicas: avaliação da prevalência de hemoglobinas variantes em população estudantil - Alfenas, MG doi: http://dx.doi.org/10.5892/ruvrv.2013.111.106113

As hemoglobinopatias sao doencas hereditarias, de comum ocorrencia na sociedade. Como exemplo, tem-se as hemoglobinas variantes, das quais a hemoglobina S e hemoglobina C sao consideradas as de maior incidencia na populacao. O presente estudo compreende a analise de uma populacao de estudantes da cidade de Alfenas, Minas Gerais, com relacao a presenca das hemoglobinas variantes HbS e HbC, seja em homozigose ou heterozigose. Este trabalho contou com a participacao de individuos voluntarios de ambos os sexos e variadas etnias, de idade igual ou superior a 18 anos, com a aplicacao do termo de consentimento livre e esclarecido. Foram analisadas 600 amostras sanguineas, sendo que 96,50% apresentaram resultados normais. Por outro lado, 3,50% da populacao estudada foram diagnosticados portadores de hemoglobinas variantes. Alem disso, dentre os individuos normais, verificou-se que 0,83% foram diagnosticados como heterozigotos para hemoglobina C e que 2,67% sao portadores do traco falcemico. Dessa forma, este estudo alerta e firma a necessidade do diagnostico antecipado das hemoglobinas variantes, alem da garantia do acompanhamento medico adequado e do aconselhamento genetico a populacao, conferindo maior seguranca e qualidade de vida as geracoes subsequentes.