M.E. Figueira

Evaluation of cardiovascular protective effect of different apple varieties - Correlation of response with composition

Epidemiological evidence supports the concept that diets rich in fruits and vegetables promote health and attenuate or delay the onset of cardiovascular disease (CVD). In particular, a reduced risk of CVD has been associated with apple consumption, probably due to the cholesterol-lowering effect of the main bioactive compounds, namely fibre and polyphenols. In this work, the effect of diet supplementation with 20% of three Portuguese apple cultivars (Bravo de Esmolfe, Malápio Serra and Golden), containing distinct phenolic and fibre concentrations, on serum lipid profile and oxLDL of male Wistar rats fed a cholesterol-enriched diet (2%) was evaluated. After 30 days, only Bravo de Esmolfe apple was able to decrease significantly serum levels of triglycerides, total and LDL cholesterol concentrations (reductions of 27.2%, 21.0% and 20.4%, respectively, in relation to the cholesterol-enriched diet group, P<0.05). The levels of oxLDL were also significantly improved with the consumption of this apple variety (reductions of 20.0% and 11.9%, in relation to the cholesterol-enriched diet group and control group, respectively, P>0.05) as well as with Malapio da Serra apple (reductions of 9.8% in relation to the cholesterol-enriched diet group, P<0.05). Correlation of the bioactive response with chemical composition showed that catechin, epicatechin, procyanidin B1 and β-carotene are the major phytocompounds responsible for the cholesterol lowering ability of apples. The antioxidant potential may have also contributed to this beneficial effect.

Urinary metabolite profiling identifies novel colonic metabolites and conjugates of phenolics in healthy volunteers

SCOPE The colonic metabolism of dietary flavonoids, phenolic acids and their phenolic metabolites is complex and many metabolites and conjugates have not yet been unambiguously identified in humans. METHODS AND RESULTS Urine samples from nine healthy human volunteers obtained after the ingestion of a puree of five (poly)phenol-rich berry fruits were analysed using LC-Orbitrap MS to provide a preliminary indication of possible metabolites based on exact mass. In most cases, the identity of compounds was confirmed using standards produced either chemically or enzymically followed by analysis using LC-triple quadrupole MS. Sulphated, glucuronidated and methylated forms of catechol, pyrogallol and protocatechuic acid mostly appeared in urine after 8 h, suggesting colonic metabolism. Gallic acid and (-)-epicatechin conjugates appeared mainly before 4 h, indicative of absorption from the small intestine. Conjugates of ferulic, caffeic, and vanillic acid appeared at intermediate times. CONCLUSION We have positively identified metabolites and conjugates, some novel, in the urine of healthy volunteers after intake of multiple phenolics from a mixed puree from berry fruits, with each being excreted at specific and signature times. Some of these compounds could potentially be used as biomarkers of fruit intake. The possible biological activities of these colonic metabolites require further assessment.

Protective effects of hydroxytyrosol-supplemented refined olive oil in animal models of acute inflammation and rheumatoid arthritis

Virgin olive oil is the primary source of fat in the Mediterranean diet, and its beneficial health effects have been related with oleic acid and phenolic compounds content. Hydroxytyrosol, a typical virgin olive oil phenolic compound, has beneficial antioxidant and anti-inflammatory properties as previously reported. The aim of this study was to evaluate the effect of hydroxytyrosol-supplemented refined olive oil at 0.5 and 5 mg/kg in a rodent model of rheumatoid arthritis. Rheumatoid arthritis was induced by intradermic administration, in male Wistar rats, of Freunds adjuvant with collagen type II on days 1 and 21. Hydroxytyrosol-supplemented refined olive oils were administrated by gavage from day 23 until day 35. The treatment at 5-mg/kg dose significantly decreased paw edema (P<.01), histological damage, cyclooxygenase-2 and inducible nitric oxide synthase expression, and markedly reduced the degree of bone resorption, soft tissue swelling and osteophyte formation, improving articular function in treated animals. Acute inflammation, induced by carrageenan, was also evaluated for hydroxytyrosol-supplemented refined olive oils at 0.5 and 5 mg/kg. Both doses significantly reduced paw edema (P<.001). Our results suggest that the supplementation of refined olive oil with hydroxytyrosol may be advantageous in rheumatoid arthritis with significant impact not only on chronic inflammation but also on acute inflammatory processes.

Impact of a 6-wk olive oil supplementation in healthy adults on urinary proteomic biomarkers of coronary artery disease, chronic kidney disease, and diabetes (types 1 and 2): a randomized, parallel, controlled, double-blind study

BACKGROUND Olive oil (OO) consumption is associated with cardiovascular disease prevention because of both its oleic acid and phenolic contents. The capacity of OO phenolics to protect against low-density lipoprotein (LDL) oxidation is the basis for a health claim by the European Food Safety Authority. Proteomic biomarkers enable an early, presymptomatic diagnosis of disease, which makes them important and effective, but understudied, tools for primary prevention. OBJECTIVE We evaluated the impact of supplementation with OO, either low or high in phenolics, on urinary proteomic biomarkers of coronary artery disease (CAD), chronic kidney disease (CKD), and diabetes. DESIGN Self-reported healthy participants (n = 69) were randomly allocated (stratified block random assignment) according to age and body mass index to supplementation with a daily 20-mL dose of OO either low or high in phenolics (18 compared with 286 mg caffeic acid equivalents per kg, respectively) for 6 wk. Urinary proteomic biomarkers were measured at baseline and 3 and 6 wk alongside blood lipids, the antioxidant capacity, and glycation markers. RESULTS The consumption of both OOs improved the proteomic CAD score at endpoint compared with baseline (mean improvement: -0.3 for low-phenolic OO and -0.2 for high-phenolic OO; P < 0.01) but not CKD or diabetes proteomic biomarkers. However, there was no difference between groups for changes in proteomic biomarkers or any secondary outcomes including plasma triacylglycerols, oxidized LDL, and LDL cholesterol. CONCLUSION In comparison with low-phenolic OO, supplementation for 6 wk with high-phenolic OO does not lead to an improvement in cardiovascular health markers in a healthy cohort.

New perspectives on bioactivity of olive oil - evidence from animal models, human interventions and the use of urinary proteomic biomarkers

Olive oil (OO) is the primary source of fat in the Mediterranean diet and has been associated with longevity and a lower incidence of chronic diseases, particularly CHD. Cardioprotective effects of OO consumption have been widely related with improved lipoprotein profile, endothelial function and inflammation, linked to health claims of oleic acid and phenolic content of OO. With CVD being a leading cause of death worldwide, a review of the potential mechanisms underpinning the impact of OO in the prevention of disease is warranted. The current body of evidence relies on mechanistic studies involving animal and cell-based models, epidemiological studies of OO intake and risk factor, small- and large-scale human interventions, and the emerging use of novel biomarker techniques associated with disease risk. Although model systems are important for mechanistic research nutrition, methodologies and experimental designs with strong translational value are still lacking. The present review critically appraises the available evidence to date, with particular focus on emerging novel biomarkers for disease risk assessment. New perspectives on OO research are outlined, especially those with scope to clarify key mechanisms by which OO consumption exerts health benefits. The use of urinary proteomic biomarkers, as highly specific disease biomarkers, is highlighted towards a higher translational approach involving OO in nutritional recommendations.

Teor de fluoretos em infusões de chá verde (Camellia sinensis)

The aim of this work was to study the influence of green tea consumption on fluoride ingestion. The extraction conditions of fluorides from green tea infusions were defined and nine brands of green tea available in Portugal were analyzed. The quantification of fluorides in the green tea was preceded by the implementation and validation of the potentiometric method (commercial fluoride selective electrode). The concentration of fluorides in the samples ranged from 0. 8 to 2. 0 mg L-1.

Inhibition of glycogen synthase kinase-3β attenuates organ injury and dysfunction associated with liver ischemia-reperfusion and thermal injury in the rat.

ABSTRACT Glycogen synthase kinase 3 (GSK-3) is a serine-threonine kinase discovered decades ago to have an important role in glycogen metabolism. Today, we know that this kinase is involved in the regulation of many cell functions, including insulin signaling, specification of cell fate during embryonic development, and the control of cell division and apoptosis. Insulin and TDZD-8 (4-benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione) are inhibitors of GSK-3&bgr; that have been shown to possess organ-protective effects in inflammatory-mediated organ injury models. We aimed to evaluate the cytoprotective effect of GSK-3&bgr; inhibition on rat models of liver ischemia-reperfusion and thermal injury. In the liver ischemia-reperfusion model, TDZD-8 and insulin were administered at 5 mg/kg (i.v.) and 1.4 IU/kg (i.v.), respectively, 30 min before induction of ischemia and led to the significant reduction of the serum concentration of aspartate aminotransferase, alanine aminotransferase, &ggr;-glutamyltransferase, and lactate dehydrogenase. Beneficial effects were found to be independent from blood glucose levels. In the thermal injury model, TDZD-8 was administered at 5 mg/kg (i.v.) 5 min before induction of injury and significantly reduced multiple organ dysfunction markers (liver, neuromuscular, and lung). In the lung, TDZD-8 reduced the histological signs of tissue injury, inflammatory markers (cytokines), and neutrophil chemotaxis/infiltration; reduced GSK-3&bgr;, nuclear factor-&kgr;B, and Akt activation; reduced caspase-3 and metalloproteinase-9 activation. Our study provides a new insight on the beneficial effects of GSK-3&bgr; inhibition on systemic inflammation and further elucidates the mechanism and pathway crosstalks by which TDZD-8 reduces the multiple organ injury elicited by thermal injury.

Dyospiros kaki phenolics inhibit colitis and colon cancer cell proliferation, but not gelatinase activities

Polyphenols from persimmon (Diospyros kaki) have demonstrated radical-scavenging and antiinflammatory activities; however, little is known about the effects of persimmon phenolics on inflammatory bowel diseases (IBD) and colorectal cancer (CRC). Therefore, we aimed in this work to characterize the antiinflammatory and antiproliferative effects of a persimmon phenolic extract (80% acetone in water), using an in vivo model of experimental colitis and a model of cancer cell invasion. Our results show, for the first time, a beneficial effect of a persimmon phenolic extract in the attenuation of experimental colitis and a potential antiproliferative effect on cultured colon cancer cells. Administration of persimmon phenolic extract to mice with TNBS-induced colitis led to a reduction in several functional and histological markers of colon inflammation, namely: attenuation of colon length decrease, reduction of the extent of visible injury (ulcer formation), decrease in diarrhea severity, reduced mortality rate, reduction of mucosal hemorrhage and reduction of general histological features of colon inflammation. In vitro studies also showed that persimmon phenolic extract successfully impaired cell proliferation and invasion in HT-29 cells. Further investigation showed a decreased expression of COX-2 and iNOS in the colonic tissue of colitis mice, two important mediators of intestinal inflammation, but there was no inhibition of the gelatinase MMP-9 and MMP-2 activities. Given the role of inflammatory processes in the progression of CRC and the important link between inflammation and cancer, our results highlight the potential of persimmon polyphenols as a pharmacological tool in the treatment of patients with IBD.

Fluoride content of soft drinks, nectars, juices, juice drinks, concentrates, teas and infusions marketed in Portugal

A potentiometric method using a fluoride combination ion-selective electrode was validated and used to analyse 183 samples, including soft drinks, juices, nectars, juice drinks, concentrates, teas and infusions marketed in Portugal. The fluoride levels were higher in extract-based soft drinks, juice drinks and juice, with fluoride values of 0.86 ± 0.35, 0.40 ± 0.24 and 0.37 ± 0.11 mg l−1, respectively. The lowest fluoride concentration was found in infusion samples (0.12 ± 0.01 mg l−1), followed by teas and carbonated soft drinks with fluoride concentrations of 0.16 ± 0.12 and 0.18 ± 0.07 mg l−1, respectively. Nectars, concentrates and juice-based drinks had similar fluoride concentrations of 0.33 ± 0.16, 0.29 ± 0.12 and 0.25 ± 0.14 mg l−1, respectively. The fluoride concentrations in all these samples would only contribute intakes below the acceptable daily intake (ADI = 0.05 mg kg−1 body weight day−1), indicating that, individually, these beverages cannot induce fluoride toxicity in the population group of children.

Red Raspberry Phenols Inhibit Angiogenesis: A Morphological and Subcellular Analysis Upon Human Endothelial Cells

Polyphenols are a class of natural compounds whose potential as antioxidant, anti‐inflammatory, and anti‐angiogenesis has been reported in many pathological conditions. Red raspberry extract, rich in polyphenols, has been reported to exert anti‐inflammatory effects and prevent cell proliferation in distinct animal models. However, the signaling pathways involved remain unknown. Herein, we used human microvascular endothelial cells (HMVECs) to determine the influence of red raspberry phenolic compound extract concentrations, ranging from 10 to 250 µg gallic acid equivalents (GAE)/mL, on endothelium viability (MTS assay), proliferation (BrdU incorporation), migration (injury assay), and capillary‐like structures formation (Matrigel assay). Protein expression in cell lysates was determined by Western blot analysis. We showed that red raspberry extracts reduced cell viability (GI50 = 87,64 ± 6,59 μg GAE/mL) and proliferation in a dose‐dependent manner. A significant abrogation of cells ability to migrate to injured areas, even at low concentrations, was observed by injury assay. Cell assembly into capillary‐like structures on Matrigel also decreased in a dose dependent‐manner for higher extract concentrations, as well as the number of branching points per unit of area. Protein expression analysis showed a dose‐dependent decrease in Phospho‐VEGFR2 expression, implying abrogation of VEGF signaling activity. We also showed for the first time that red raspberry phenolic compounds induce the rearrangement of filamentous actin cytoskeleton, with an isotropy increase found for higher testing concentrations. Taken together, our findings corroborate the anti‐angiogenic potential of red raspberry phenolic compounds and provide new insights into their mode of action upon endothelium. J. Cell. Biochem. 117: 1604–1612, 2016.