Nick Kalogeropoulos

Unsaturated fatty acids are inversely associated and n-6/n-3 ratios are positively related to inflammation and coagulation markers in plasma of apparently healthy adults.

BACKGROUND Blood lipids and inflammatory markers levels have been associated with the development and progression of atherosclerosis. As the association of inflammatory markers with plasma fatty acids has not been extensively evaluated and understood, we sought to investigate the associations between dietary and plasma fatty acids with various inflammation and coagulation markers. METHODS High sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), fibrinogen, and homocysteine were measured in serum of 374 free-living, healthy men and women, randomly selected from the ATTICAs study database. Total plasma fatty acids were determined by gas chromatography. Dietary fatty acids were assessed through a semi-quantitative FFQ. RESULTS Multi-adjusted regression analyses revealed that plasma n-3 fatty acids were inversely associated with CRP, IL-6 and TNF-alpha; plasma n-6 fatty acids were inversely associated with CRP, IL-6 and fibrinogen; monounsaturated fatty acids were inversely associated with CRP and IL-6 (all p-values<0.05). Interestingly, the n-6/n-3 ratios exhibited the strongest positive correlations with all the markers studied. No associations were observed between dietary fatty acids and the investigated markers. CONCLUSIONS Measurements of total plasma fatty acids could provide insights into the relationships between diet and atherosclerotic disease. Moreover, the n-6/n-3 ratio may constitute a predictor of low-grade inflammation and coagulation.

Deterioration of natural antioxidant species of vegetable edible oils during the domestic deep-frying and pan-frying of potatoes

In the present work, virgin olive oil, sunflower oil and a vegetable shortening were used as cooking oils for the deep-frying and pan-frying of potatoes, for eight successive sessions, under the usual domestic practice. Several chemical and physicochemical parameters (acidic value, peroxide value, total polar artefacts, total phenol content and triglyceride fatty acyl moiety composition) were assayed during frying operations in order to evaluate the status of the frying oils, which were found within expected ranges similar to those previously reported. The oil fatty acids were effectively protected from oxidation by the natural antioxidants. The frying oil absorption by the potatoes was quantitated within 6.1-12.8%, depending on the oil type and the frying process. The retention of α - and (β + γ)-tocopherols during the eight fryings ranged from 85-90% (first frying) to 15-40% (eighth frying), except for the (β + γ)-tocopherols of sunflower oil, which almost disappeared after the sixth frying. The deterioration during the successive frying of several phenolic species present in virgin olive oil is reported for the first time. The retention of total phenolics ranged from 70-80% (first frying) to 20-30% (eighth frying). Tannic acid, oleuropein and hydroxytyrosol-elenolic acid dialdeydic form showed remarkable resistance in all frying sessions in both frying methods, while hydroxytyrosol and hydroxytyrosol-elenolic acid were the faster eliminated. The deterioration of the other phenolic species account for 40-50% and 20-30% for deep-frying and pan-frying, respectively, after three to four frying sessions, which are the most usual in the household kitchen. Deep-frying resulted in better recoveries of all the parameters examined. The correlation of the deterioration rate of the phenolic compounds and tocopherols during frying is discussed and the nutritional aspects of the natural antioxidant intake, through the oil absorbed by the potatoes, are evaluated.

Thermal Stability of Anthocyanin Extract of Hibiscus sabdariffa L. in the Presence of β-Cyclodextrin

The thermal stability of anthocyanin extract isolated from the dry calyces of Hibiscus sabdariffa L. was studied over the temperature range 60-90 degrees C in aqueous solutions in the presence or absence of beta-cyclodextrin (beta-CD). The results indicated that the thermal degradation of anthocyanins followed first-order reaction kinetics. The temperature-dependent degradation was adequately modeled by the Arrhenius equation, and the activation energy for the degradation of H. sabdariffa L. anthocyanins during heating was found to be approximately 54 kJ/mol. In the presence of beta-CD, anthocyanins degraded at a decreased rate, evidently due to their complexation with beta-CD, having the same activation energy. The formation of complexes in solution was confirmed by nuclear magnetic resonance studies of beta-CD solutions in the presence of the extract. Moreover, differential scanning calorimetry revealed that the inclusion complex of H. sabdariffa L. extract with beta-CD in the solid state was more stable against oxidation as compared to the free extract, as the complex remained intact at temperatures 100-250 degrees C where the free extract was oxidized. The results obtained clearly indicated that the presence of beta-CD improved the thermal stability of nutraceutical antioxidants present in H. sabdariffa L. extract, both in solution and in solid state.

Bioactive microconstituents and antioxidant properties of wild edible mushrooms from the island of Lesvos, Greece

Crude composition, fatty acids, sterols, total phenolic content (TPC), individual polyphenols and terpenic acids were determined in five wild edible mushrooms species (Lactarius deliciosus, Lactarius sanguifluus, Lactarius semisanguifluus, Russula delica, Suillus bellinii) from Lesvos Island, Greece. In addition, the DPPH scavenging capacity, the ferric ion reducing power (FRAP) and the ferrous ion chelating activity of mushroom methanolic extracts were assessed. Among sterols, ergosterol predominated at concentrations 9.2-18.0mg/100g fw. Total phenolic content of mushroom extracts ranged from 6.0 to 20.8mg GAE/100g fw. Up to 19 simple polyphenols were determined in mushrooms extracts, the more abundant being p-OH-benzoic acid, p-OH-phenylacetic acid, o-coumaric acid, ferulic acid and chrysin. In addition, the triterpenic acids oleanolic and ursolic were detected for the first time in mushrooms. All species exerted antioxidant activity and ferrous ion chelating capacity. Principal component analysis revealed good correlations between TPC, DPPH and FRAP but not with metal chelating activity. It seems that mushrooms polyphenols exert antiradical and reducing activities, but they are not strong metal chelators, the observed chelating ability being probably due to other classes of compounds. To our knowledge, this is the first report on the bioactive microconstituents and antioxidant activity of wild Greek edible mushrooms.

Depression and long chain n-3 fatty acids in adipose tissue in adults from Crete

Background:Only one study has investigated the relationship of essential fatty acids in the adipose tissue with depression in adults and suggested an inverse relationship between docosahexaenoic acid (22:6 n-3) (DHA) and depression.Objective:To examine the relation between adipose tissue polyunsaturated fatty acids especially n-3 and n-6 fatty acids, an index of long-term or habitual fatty acid intake, and depression in adults.Design:Cross-sectional study of healthy adults from the island of Crete.Setting:The Preventive Medicine and Nutrition Clinic, University of Crete, Greece.Subjects:A total of 130 healthy adults (59 males, 71 females) aged 22—58 years. The sample was a sub-sample of the Greek ApoEurope study group.Methods:Fatty acids were determined by gas chromatography in adipose tissue. Information about depression was obtained through the Zung Self-rating Depression Scale.Results:Adipose tissue DHA was inversely related with depression. Multiple linear regression analysis taking into account the possible confounding effect of age, gender, body mass index, smoking and educational level confirmed this association.Conclusions:The inverse relationship between adipose DHA and depression in adults, replicates findings of a previous study. This relationship indicates that a low long-term dietary intake of DHA is associated with an increased risk for depression in adults.Funding:The International Olive Oil Council and the DG XII of the European Union.

Heavy metals in raw, fried and grilled Mediterranean finfish and shellfish.

The effect of domestic pan-frying and grilling on Cd, Cr, Cu, Fe, Hg, Ni, Pb and Zn content of popular small Mediterranean finfish and shellfish was studied. The species selected -namely anchovy, bogue, hake, picarel, sardine, sand smelt, stripped mullet, Mediterranean mussel, shrimp and squid- are among the most commonly marketed and consumed in Greece and most of the Mediterranean countries. Both culinary practices examined resulted in increased metals concentrations compared to those of raw samples, the increment being inversely related to fish size and -in most cases- being more extended in pan-frying. The consumption of cooked seafood is expected to provide significant amounts of Fe and Zn followed, in decreasing order, by Cr, Cu and Ni. In addition, the estimation of (a) weekly intakes and (b) target hazard quotients for the toxic elements Cd, Hg and Pb revealed that the cooked fish and shellfish do not pose any health risk for the consumers.

Deployment of response surface methodology to optimise recovery of grape (Vitis vinifera) stem polyphenols

A 2(3)-full factorial design and response surface methodology were deployed to assess some basic factors (time, % ethanol and pH) affecting profoundly the extractability of polyphenolic phytochemicals from grape (Vitis vinifera) stems. In an effort to obtain a thorough insight into the applicability of the models established, stem extracts from three different varieties were tested, by determining several indices of the polyphenolic composition, such as total polyphenol (TP), total flavanol (TFl), total flavone (TFn) and proanthocyanidin (PC) concentration. It was shown that the models generated can adequately predict the recovery levels for each polyphenol group, but the optimal conditions predicted for TP, TFl, TFn and PC recovery varied significantly. Notable differences were also seen among the different varieties. Correlation of the polyphenol indices with the antiradical activity and reducing power of the extracts indicated that the PC fraction might exert strong effects, while the influence of other groups was not apparent. Examination of the optimally obtained extracts using liquid chromatography-mass spectrometry revealed that the most prominent compounds were caftaric acid, flavanols and derivatives thereof, as well as dehydroflavonols and flavonols.

Herbal infusions; their phenolic profile, antioxidant and anti-inflammatory effects in HT29 and PC3 cells.

In this survey, we analyzed the phenolic profile of six herbal infusions namely Cretan marjoram, pink savory, oregano, mountain tea, pennyroyal and chamomile by LCDAD-MS and by GC-MS. Further, we investigated their anticarcinogenic effect as to their ability to (a) scavenge free radicals (b) inhibit proliferation (c) decrease IL-8 levels and (d) regulate nuclear factor-kappa B in epithelial colon cancer (HT29) and prostate (PC3) cancer cells. All herbal infusions exhibited antiradical activity correlated positevely with total phenolic content. Further, infusions exhibited the potential to inhibit cell proliferation and to reduce IL-8 levels in HT29 colon and PC3 prostate cancer cells. The molecular target for chamomile in HT29 seemed to be the NF-κB, while for the other herbal infusions needs to be identified. This study is the first to show the potential chemopreventive activity of infusions prepared from the examined herbs.

Validation of the MedDietScore via the determination of plasma fatty acids.

Background The purpose of the present work was to validate the MedDietScore by means of plasma fatty acid levels. Methods The study sample consisted of 189 men (44±13 years old) and 185 women (40±15 years old), randomly selected from the ATTICA study database. All participants completed a food frequency questionnaire (the EPIC-Greek FFQ), and a modified version of the MedDietScore (using weights) was then calculated to evaluate the level of adherence to the Mediterranean diet. Plasma and dietary fatty acids were measured. Results Correlation analysis revealed a strong positive relationship between the MedDietScore, monounsaturated fatty acids (P <0.001), monounsaturated fatty acids to saturated fatty acids (P <0.001), docosahexaenoic acid (22:6 n-3) (P <0.05) and n-3 fatty acids (P <0.001), and inverse correlations between the diet score and polyunsaturated fatty acids (comprised of the sum of n-3 and n-6 fatty acids) (P <0.001), saturated fatty acids (P <0.01), and total n-6 fatty acids (P <0.001). The effect size of the relationships between the weighted-MedDietScore and fatty acids was better than the relationships with the initial version of the diet score. Conclusions Our findings suggest that the modified MedDietScore is a valid measure of various plasma fatty acids, and may prove a useful tool in assessing diet quality of adults.

Phenolic profiles and antioxidant and anticarcinogenic activities of Greek herbal infusions; balancing delight and chemoprevention?

Total phenolic content, antioxidant activity and phenolic profiles of six herbal infusions - namely rosemary, Cretan dittany, St. Johns Wort, sage, marjoram and thyme were assayed. Additionally, the infusion anticarcinogenic effect as to their ability to (a) scavenge free radicals, (b) inhibit cell growth, (c) decrease IL-8 levels and (d) regulate p65 subunit in epithelial colon cancer (HT29) and prostate (PC3) cancer cells was investigated. LC-DAD-MS and GC-MS analyses showed major qualitative and quantitative differences in phenolic profiles of the infusions. All herbal infusions exhibited antiradical activity which correlated strongly with their total phenolic content. Infusions exhibited the potential to inhibit cell growth and to reduce IL-8 levels in HT29 colon and PC3 prostate cancer cells. The regulation reported in p65 subunit in HT29 treated with St Johns Wort and in PC3 treated with thyme might point to the NF-κB as the molecular target underlying the effect of these infusions.