RESUMO
Objectives: The study aimed to determine the effect of coffee intake on AGEs formation and platelet aggregation in diabetic Wistar rats. Methods: Coffee powder samples were used to prepare a 10% beverage. Diabetes mellitus was induced in the animals by administering 2% alloxan. All animal experiments were approved by the ethics committee for animal experiments under N°. 420/2012 and 536/2013. Diabetic and non-diabetic rats were divided into 6 groups treated and untreated with coffee (7.2 mL/Kg body weight) and aminoguanidine (AGE inhibiting agent) (100 mg/Kg body weight) for 50 days. After 50 days, the animals were fasted for 12 h and anesthetized (40 mg/Kg sodium pentobarbital) intraperitoneally. Blood samples were collected from the abdominal artery puncture. Hematological parameters (red cells, hemoglobin, hematocrit and leukocyte) and glycemic and HbA1c levels were measured. AGEs quantification (spectrofluorometric method) and the platelet aggregation test (aggregation of cuvettes in a four-channel platelet aggregometer) were also conducted. The rats' renal function was evaluated by measuring serum urea and creatinine. Results: Data showed that coffee intake had no effect on the hematological parameters. Fasting glucose and HbA1c dosage were significantly higher in diabetic animals compared to non-diabetic animals (confirmed the effectiveness of inducing and maintaining diabetic status). Results showed that coffee reduced AGE formation and platelet aggregation in our animal model, not altering the animals' renal function. Conclusions: These results suggest beneficial effects on vasculopathy, a common complication in diabetic patients.
RESUMO
Coffee is a mixture of substances with potential beneficial and adverse health effects. Several studies demonstrate the antioxidant effect of the phenolics compounds present in coffee. Neutrophils produce reactive oxygen species (ROS) by activating of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (NOX2), which plays a key role in organism defenseagainst microbial pathogens. Diabetes mellitus patients are more susceptible to bacterial and fungal infections. The present study evaluated the influence of coffee beverage on NOX2 activity and ROS generation and the impact of this effect on phagocytosis and killing of Candida albicansby neutrophils from diabetic and non-diabetic animals. Diabetes mellitus was induced in male Wistar rats using 2% alloxan. Diabetic and non-diabetic animals were divided into groups treated and untreated with coffee drink (7.2 mL/kg/day) or apocyanine (16 mg/kg/day) for 50 days. After 50 days, the animals' glycemic profile was measured by blood glucose and glycated hemoglobin (HbA1c) tests. The generation of ROS in neutrophilic cells was measured by chemiluminescence and cytochrome C reduction assays. C. albicans phagocytosis and death were evaluated by optical microscopy using the May-Grunwald-Giemsa staining method. The coffee drink has not altered the glycemic profile and NOX2 activity of the animals. However, coffee reduced the ROS pool in non-diabetic and diabetic animals, but this activity did not harm the phagocytosis or killing of neutrophils. Treatment with apocyanin decreased ROS production and killing capacity of neutrophils from non-diabetic animals against C. albicans. We suggest that the coffee drink intake prevents oxidative damage and does not impair response of the organism against opportunistic microorganism.