Leaf extract of Coffea arabica L. reduces lipid peroxidation and has anti-platelet effect in a rat dyslipidemia model

Abstract This study aimed to evaluate the antioxidant potential of the Coffea arabica Lineu (L.) leaf extract and its effects on platelet aggregation of dyslipidemic rats. The extract was obtained by the percolation of C. arabica L. leaves in hydroethanolic solution 70% (v/v). The mass spectrometry FIA-ESI-MS² suggested the presence of chlorogenic acid, rutin acid, and quinic acid. The DPPH• radicals scavenging capacity was demonstrated (IC50 = 0.06 mg/mL). The extract was administered to rats by gavage (300 mg/kg/day) for 56 days. Dyslipidemia was induced by administering Triton WR-1339 (300 mg/kg body weight) on the 54th day. On day 56, blood was collected by puncturing the abdominal aorta artery and the aortic artery was removed. Lipid profile, markers of renal and hepatic injury, lipid peroxidation, and platelet aggregation tests were carried out. The ingestion of extract reduced the lipid peroxidation (aorta and plasma) and platelet aggregation in dyslipidemic rats. The extract did not affect markers of renal and hepatic function as analyzed in this study, suggesting neither impaired liver nor kidney function in these animals. Therefore, our results demonstrate that the extract of leaves of C. arabica L. show antioxidant potential in vitro and in vivo as well as anti-platelet aggregation in dyslipidemic animals

Coffee intake (Coffea arabica L. ) reduces advanced glycation end product (AGEs) formation and platelet aggregation in diabetic rats

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.

Evaluation of cell biomarkers as in vitro photoprotective assays for sunscreen formulations

Objectives: The aim of this study was to evaluate cellular indicators, which change with exposure to ultraviolet (UV) radiation and can be used as parameters for measuring sunscreens efficiency. Methods: Commercial strains of L929 and HaCaT cells (skin dermis and epidermis, respectively), from the cell bank of Rio de Janeiro, were exposed to different doses of UVA (350 nm) and UVB (309 nm) radiation. The evaluation of the photoprotective potential of sunscreens was analyzed with cell viability, lipid peroxidation and ROS generation tests. Samples of sunscreen with SPF values ranging from 15 to 60 were applied to a quartz plate superimposed on the top of a microplate containing the cell culture, and then the system was irradiated. Results: The viability and lipid peroxidation of the two cell lines remained unchanged after exposure to UVA radiation. When exposed to UVB radiation, the reduction in viability and the increase in lipid peroxides were dose-dependent, that is, they varied from 3.15% to 95.4%, and from 1.2 to 42.7 nM MDA/pg protein, respectively, both for the L929 strain. The dose of 0.5 J/cm2 reduced by 41.4%±1.67 the number of viable cells, and the dose of 30 J/cm2 promoted the oxidation of 42.7 nM of MDA/pg protein. These doses were selected to evaluate the photoprotective effectiveness of commercial sunscreens. Sunscreens exposed to UVB rays could prevent the loss of cell viability (viability remained around 100% for higher SPF) and the formation of lipid peroxides (30 to 80% reduction of peroxide levels). None of the two cell strains, submitted to UVB radiation, formed amounts of intracellular ROS in a dose-dependent manner. Under exposure to UVA radiation, only the HaCaT cell line produced the largest amounts of ROS in a dose-dependent manner. After treating these cells with photoprotective formulations (20 J/cm2), the researchers observed a reduction in the amount of ROS formed. Conclusions: The parameters of cell viability and lipid peroxidation were promising to evaluate the photoprotective capacity of sunscreens against UVB radiation. The generation of ROS expressed in the HaCaT strain can discriminate the photoprotective potential of formulations against UVA radiation, as sunscreens reduced the formation of ROS. These results suggest that in vitro tests that evaluate the damage caused to cells can predict cellular indicators of the photoprotective effectiveness of sunscreens and contribute to minimize these tests in the initial phase of product research and development.

Coffee beverage reduces ROS production and does not affect the organism's response against Candida albicans

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.

Caffeinated instant coffee prevents an increase in exercise-mediated superoxide anion production in rat peritoneal neutrophils

The present study analyzed the in vivo effects of drinking caffeinated and decaffeinated instant coffee (8% w/v) by adult male Wistar rats submitted to high-intensity exercises. The parameters used in the evaluation were the determination of the activities of NADPH oxidase, myeloperoxidase and other antioxidant enzymes present in neutrophils of rats. It was observed that exercise-induced superoxide anion production depends on the NADPH oxidase activity (estimated by the cytochrome C reduction test) in peritoneal neutrophils (p < 0.05). The intake of caffeinated and decaffeinated instant coffee beverages and of a caffeine solution to 1.67% did not induced changes in the activities of the enzymes myeloperoxidase, superoxide dismutase and glutathione peroxidase (p < 0.05). But consumption of caffeinated instant coffee drink prevented an increase in NADPH oxidase-mediated superoxide production induced by highly intense exercise in rat neutrophils. While the decaffeinated instant coffee drink or caffeine solution alone did not affect NADPH oxidase-mediated superoxide production. We suggest that this activity is associated with the chemical composition and concentration of phenolic compounds and other antioxidant substances formed during roasting. From the obtained results, it was concluded that moderate intake of caffeinated instant coffee (equivalent to a daily human consumption of 4 50-mLcups of coffee) may have beneficial effects on health, contributing to a reduction in superoxide anion generation. Therefore, more research must be conducted to elucidate the mechanism of action of caffeinated coffee on NADPH oxidase in neutrophils.