Associations between red blood cells fatty acids, desaturases indices and metabolism of platelet activating factor in healthy volunteers.

INTRODUCTION: Platelet-activating-factor is an inflammatory lipid mediator. Key enzymes of its biosynthesis are CDP-choline:1-alkyl-2-acetyl-sn-glycerol-cholinephosphotransferase (PAF-CPT) and acetyl-CoA:lyso-PAF-acetyltransferases (Lyso-PAF-AT) while PAF-AH/Lp-PLA2 degrade PAF. The interplay between PAF and fatty acids metabolism was explored. MATERIAL AND METHODS: In a healthy population, PAF levels, its metabolic enzymes activity and RBC fatty acids were measured while desaturases indices (D) were estimated. A principal component analysis was also applied to assess patterns of RBC fatty acids. RESULTS: SFA were related to increased PAF biosynthesis and decreased Lp-PLA2 only in women. MUFA were inversely associated with PAF biosynthesis and positively with Lp-PLA2. Omega-6 fatty acids were positively correlated only with PAF-CPT while no significant correlations were observed with n3 fatty acids. D6 index was positively related with PAF biosynthetic enzymes and inversely with Lp-PLA2 while D9 correlated positively with Lp-PLA2. The pattern of high MUFA and low n6 was associated with reduced PAF biosynthesis and/or increased catabolism in both sexes. CONCLUSION: The role of fatty acids in amplifying or reducing inflammation seems to be also reflected in PAF metabolism.

Mediterranean diet is inversely associated with steatosis and fibrosis and decreases ten-year diabetes and cardiovascular risk in NAFLD subjects: Results from the ATTICA prospective cohort study.

BACKGROUND AND AIMS: We assessed the association of Mediterranean diet with NAFLD and their interaction in predicting ten-year diabetes onset and first fatal/non-fatal cardiovascular disease (CVD) incidence. METHODS: The ATTICA prospective observational study in Athens, Greece included 1,514 men and 1,528 women (>18 years old) free-of-CVD at baseline. Liver steatosis and fibrosis indices were calculated. Mediterranean diet adherence was assessed through MedDietScore. At the ten-year follow-up visit, CVD evaluation was performed in an a priori specified subgroup of n = 2,020 participants and diabetes onset in n = 1,485 free-of-diabetes participants. RESULTS: MedDietScore was inversely associated with steatosis and fibrosis; e.g. in the case of the TyG index the Odds Ratio (OR) of the 3rd vs. 1st MedDietScore tertile was = 0·53, [95% Confidence Interval (95% CI) (0·29, 0·95)] and the associations persisted in multi-adjusted models. NAFLD predicted incident diabetes prospectively over a ten year period [HR = 1·87, 95% CI (0·75, 4·61)] and the association remained significant only in subjects with low MedDietScore (below median) whereas diabetes onset among subjects with higher MedDietScore was not influenced by NAFLD. Similarly, NAFLD predicted CVD [Hazard Ratio (HR) = 3·01, 95%CI(2·28, 3·95)]; the effect remained significant only in subjects with MedDietScore below median [HR = 1·38, 95% CI (1·00, 1·93)] whereas it was essentially null [HR = 1·00,95% CI (0·38, 2·63)] among subjects with higher score. Mediation analysis revealed that adiponectin and adiponectin-to-leptin ratio were the strongest mediators. CONCLUSIONS: We report an inverse association between Mediterranean diet and NAFLD. Mediterranean diet protected against diabetes and CVD prospectively among subjects with NAFLD.

Mining possible associations of faecal A. muciniphila colonisation patterns with host adiposity and cardiometabolic markers in an adult population.

We aimed to evaluate colonisation patterns of Akkermansia muciniphila in a Greek adult population and to investigate model-adjusted associations of A. muciniphila with host adiposity and cardiometabolic markers. Participants (n=125) underwent anthropometric, dietary, physical activity and lifestyle evaluation. Blood sampling for determination of blood lipid indices, glucose metabolism, adiponectin, lipoprotein-associated phospholipase A2 (Lp-PLA2), inflammation and oxidative stress parameters was also performed. Stool A. muciniphila presence and levels were determined by quantitative PCR and subjects were grouped based on bimodal distribution of levels (Low vs High). A. muciniphila was detected in 88.6% of participants. Overweight/obese (OW/OB) subjects were more prone in low bimodal levels of A. muciniphila compared to normal-weight (NW) individuals (58.75 vs 27.59%, P=0.004), with a 4-time greater likelihood after multi-adjusted logistic regression analysis (P=0.016). Levels of A. muciniphila were negatively associated with total cholesterol/high-density lipoprotein cholesterol (TC/HDL-C) ratio (log10:-0.009±0.004, P=0.033), whereas detection of this bacterium was negatively associated with both TC/HDL-C ratio (log10: -0.049±0.023, P=0.036) and low-density lipoprotein cholesterol/HDL-C ratio (-0.407±0.176, P=0.023). Furthermore, low bimodal levels of A. muciniphila were positively associated with fasting blood glucose (log10: 0.018±0.009, P=0.037). In terms of inflammation markers, levels of A. muciniphila were positively associated with soluble cluster of differentiation-14 (sCD14) (log10: 0.012±0.004, P=0.003) and faecal detection of this bacterium had a positive association with anti-inflammatory interleukin 10 levels (log10: 0.325±0.131, P=0.015). In addition, A. muciniphila levels were positively associated with total adiponectin (log10: 0.046±0.015, P=0.002), whereas low bimodal levels of A. muciniphila had an inverse relationship with this blood marker (log10: -0.131±0.053, P=0.016). In conclusion, we confirmed the previously reported association of A. muciniphila with metabolic health for the first time in a Greek urban population; furthermore, we shed some light to novel atherosclerotic risk markers with rather unexplored connections with A. muciniphila colonisation patterns in human subjects.

Amino acid profile and metabolic syndrome in a male Mediterranean population: A cross-sectional study.

BACKGROUND AND AIMS: The metabolic syndrome (MetS) refers to a cluster of clinically relevant factors that increases the risk of cardiovascular diseases and all-cause mortality. Circulating levels of several amino acids and metabolites related to one-carbon metabolism have been associated with cardiometabolic risk factors and MetS. We aimed to identify the amino acid profile that is significantly associated with MetS among an all male Mediterranean population. METHODS AND RESULTS: One hundred middle-aged men (54.6 ± 8.9 years) participated in a cross-sectional study carried out during 2011-2012. The International Diabetes Federation (IDF) criteria were used to define MetS. Fasting plasma levels of 20 common amino acids and 15 metabolites related to amino acid and one-carbon metabolism were measured using gas chromatography (GC-MS/MS) and liquid chromatography tandem mass spectrometry (LC-MS/MS). Principal components analysis was applied. Fifty-six participants fulfilled the IDF criteria for defining MetS. Five factors were extracted from the 35 measured metabolites. The branched-chain amino acids/aromatic amino acids (BCAA/AAA) related pattern and the glutamine/glycine/serine/asparagine (Gln/Gly/Ser/Asn) related pattern were significantly associated with MetS (odds ratio, 95% confidence interval; 6.41, 2.43-16.91, and 0.47, 0.23-0.96, respectively) after adjustment for age, current smoking status, physical activity level and medical treatment for hypertension, dyslipidaemia, type 2 diabetes mellitus. Further adjustment for liver function markers (i.e. glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, and γ-glutamyltransferase), and plasma adiponectin levels did not significantly affect the associations. CONCLUSION: The BCAA/AAA pattern was positively associated, while the Gln/Gly/Ser/Asn pattern was inversely associated with established cardiometabolic risk factors and MetS. Plasma adiponectin levels or markers of liver function did not significantly affect these associations.

The effect of microablative fractional CO2 laser on vaginal flora of postmenopausal women.

OBJECTIVES: To assess the effect of microablative fractional CO2 laser (MFCO2-Laser) therapy on the vaginal microenvironment of postmenopausal women. METHODS: Three laser therapies at monthly intervals were applied in postmenopausal women with moderate to severe symptoms of genitourinary syndrome of menopause, pH of vaginal fluid >4.5 and superficial epithelial cells on vaginal smear <5%. Vaginal fluid pH values, fresh wet mount microscopy, Gram stain and aerobic and anaerobic cultures were evaluated at baseline and 1 month after each subsequent therapy. Nugent score and Hay-Ison criteria were used to evaluate vaginal flora. RESULTS: Fifty-three women (mean age 57.2 ± 5.4 years) participated and completed this study. MFCO2-Laser therapy increased Lactobacillus (p < 0.001) and normal flora (p < 0.001) after the completion of the therapeutic protocol, which decreased vaginal pH from a mean of 5.5 ± 0.8 (initial value) to 4.7 ± 0.5 (p < 0.001). The prevalence of Lactobacillus changed from 30% initially to 79% after the last treatment. Clinical signs and symptoms of bacterial vaginosis, aerobic vaginitis or candidiasis did not appear in any participant. CONCLUSION: MFCO2-Laser therapy is a promising treatment for improving the vaginal health of postmenopausal women by helping repopulate the vagina with normally existing Lactobacillus species and reconstituting the normal flora to premenopausal status.

The relation of diet with PAF and its metabolic enzymes in healthy volunteers.

PURPOSE: Platelet-activating factor (PAF), a potent inflammatory mediator, is implicated in atherosclerosis. Its key biosynthetic enzymes are lyso-PAF acetyltransferases (lyso-PAF-AT), responsible for PAF synthesis through the remodeling route and a specific CDP-choline:1-alkyl-2-acetyl-sn-glycerol cholinephosphotransferase (PAF-CPT), responsible for its de novo biosynthesis. PAF acetylhydrolase (PAF-AH) and its extracellular isoform lipoprotein-associated phospholipase A2 catabolize PAF. The impact of diet on PAF metabolism is ill-defined. The aim was to investigate associations between PAF, its enzymes and dietary factors. METHODS: One-hundred and six (n = 106) healthy volunteers were recruited. Food-frequency questionnaires, dietary recalls, lifestyle and biochemical variables were collected. Food groups, macronutrient intake, a priori (MedDietScore) and a posteriori defined food patterns with PCA analysis, dietary antioxidant capacity (DAC), glycemic index (GI) and glycemic load were assessed. RESULTS: PAF was inversely correlated with antioxidant-rich foods (herbal drinks and coffee), the DAC as well as a dietary pattern characterized by legumes, vegetables, poultry and fish (all Ps < 0.05). PAF was positively correlated to % fat intake. Lyso-PAF-AT was also negatively associated with healthy patterns (fruits, nuts and herbal drinks, and a pattern rich in olive oil and whole-wheat products), as well as the DAC and % monounsaturated fatty acids. PAF-CPT was negatively associated with GI and coffee intake and positively with dietary cholesterol. PAF-AH was negatively associated with coffee and positively associated with alcohol consumption (all Ps < 0.05). CONCLUSIONS: In conclusion, the DAC and healthy dietary patterns were inversely associated with PAF or its biosynthetic enzymes, suggesting potential new mechanisms of the diet-disease associations.

Gender-specific distribution of selenium to serum selenoproteins: associations with total selenium levels, age, smoking, body mass index, and physical activity.

The epidemiology of selenium (Se) is mainly based on the determination of total serum selenium levels (TSe) which by many aspects is an inadequate marker of Se status. In this study we applied a recently developed LC-ICP-MS method, for the determination of the selenium content of the three main serum selenium-containing proteins, in a subcohort of the ATTICA study. This enables us to investigate whether the selenium distribution to selenoproteins may correlate with demographic (age, gender) and lifestyle variables (smoking, physical activity) that are crucial for the development of chronic diseases. A sub-sample from the ATTICA Study, consisted of 236 males (40 ± 11 years) and 163 females (38 ± 12 years), was selected. The selenium content of glutathione peroxidase (GPx-3), selenoprotein P (SelP) and selenoalbumin (SeAlb) was determined in serum by LC-ICP/MS method. We found that 26% of TSe is found in GPx-3, 61% in SelP and 13% in SeAlb. We have assessed the different ratios of selenoproteins' selenium content (Se-GPX-3/Se-SelP, Se-GPX-3/Se-SeAlb, Se-SelP/Se-SeAlb), showing that people with similar TSe may have different distribution of this selenium to selenoproteins. Total selenium levels and gender are the variables that mostly affect selenium distribution to selenoproteins while age, smoking, physical activity and BMI do not significantly influence selenium distribution. In conclusion, the simultaneous determination of the selenium content of serum selenium-containing selenoproteins is necessary for a thorough estimation of selenium status. The ratio of the Se content between selenoproteins may be proven a novel, valid marker of selenium status.

Effect of Robola and Cabernet Sauvignon extracts on platelet activating factor enzymes activity on U937 cells.

A number of studies support the anti-atherogenic effect of wine compounds. The scope of this study was to examine the effect of a red (Cabernet Sauvignon-CS) and a white (Robola-R) wine, as well as resveratrol and quercetin, on the platelet activating factor (PAF) biosynthetic enzymes, acetyl-CoA:lyso-PAF acetyltransferase (lyso-PAF-AT) and DTT-insensitive CDP-choline 1-alkyl-2-acetyl-sn-glycerol cholinephosphotransferase (PAF-CPT), and its main catabolic enzyme (PAF acetylhydrolase; PAF-AH), on U937 cells, in cell free and in intact cell experiments. In cell free experiments, phenolic compounds and wine extracts inhibited PAF biosynthetic enzymes, however in higher concentrations than intact cell experiments. In the latter cases, polar lipids of both wines inhibited in the same order of magnitude the action of lyso-PAF-AT and of PAF-CPT. The water fractions possessed a dual action, in lower concentrations they activated both enzymes, while in higher concentrations only inhibited PAF-CPT. All fractions either did not affect or slightly activated PAF-AH activity. In conclusion, wine compounds may exert their anti-inflammatory activity by reducing PAF levels through modulation of the PAF metabolic enzymes.

Effects of highly active antiretroviral therapy on platelet activating factor metabolism in naive HIV-infected patients: ii) study of the abacavir/lamivudine/efavirenz HAART regimen.

Human Immunodeficiency Virus (HIV)-infected patients are at increased risk for cardiovascular diseases partly due to chronic inflammation. Some antiretroviral drugs and Highly Active Anti-Retroviral Therapy (HAART) regimens seem to be related and amplify this increased risk, especially the ones containing abacavir. Platelet-Activating-Factor (PAF) is a potent inflammatory mediator that is implicated in both cardiovascular diseases and HIV-related manifestations. Our objective is to study the in vivo effect of the abacavir/lamivudine/efavirenz first-line HAART regimen on PAF metabolism in HIV-infected patients. The specific activities of PAF basic biosynthetic enzymes in leukocytes and platelets, PAF-cholinephosphotransferase (PAF-CPT) and lyso-PAF-acetyltransferase (Lyso-PAF-AT), but also those of PAF-basic catabolic enzymes, PAF acetylhydrolase (PAF-AH) in leukocytes and platelets and Lipoprotein-associated-Phospholipase-A2 (LpPLA2) in plasma, were measured in blood samples of 10 asymptomatic naïve male HIV-infected patients just before and after 1, 3 and 6 months of treatment. CD4 cell counts, viral load and several biochemical markers were also measured in the same blood samples of these patients. The repeated ANOVA measures and the Pearson r criterion were used for studying statistical differences and correlations - partial correlations respectively. Even though viral load was decreased and CD4 cell counts were beneficially increased after treatment with the abacavir/lamivudine/efavirenz regimen, the main enzyme of the remodelling PAF-synthesis that is implicated in pro-atherogenic inflammatory procedures, Lyso-PAF-AT activity, was increased at 3 months of treatment in both leukocytes and platelets, while the main enzyme of PAF-degradation, PAF-AH, was increased as a response only in leukocytes at the 3rd month. Although the abacavir/lamivudine/efavirenz HAART regimen exhibits very efficient antiretroviral activities, on the other hand it induces an in vivo transient increase in the inflammation-related remodeling PAF-biosynthetic pathway. This finding supports the hypothesis of inflammation-mediated increased cardiovascular risk in HIV-infected patients during the first months of abacavir-containing HAART.

Osteoprotegerin and nuclear factor-kappaB ligand are associated with leptin and adiponectin levels, in apparently healthy women.

OBJECTIVES: We investigated the relationship between the major bone turnover markers, i.e., Osteoprotegerin (OPG) and Receptor activator of nuclear factor-kappaB ligand (RANKL) and serum adipokines (leptin, adiponectin) levels in a sample of apparently healthy women. METHODS: A random sample which consisted of 80 females (18-71 years) was studied. Elisa method was used to measure the OPG, RANKL and the leptin, adiponectin levels in females' serum. RESULTS: OPG values were inversely correlated with leptin (rho = -0.38, p = 0.002) and positively correlated with age (rho = 0.27, p=0.01) and body mass index (rho = 0.29, p=0.009). RANKL values were inversely correlated with adiponectin (rho = -0.23, p = 0.06) and age (rho = -0.30, p=0.01). Additionally, OPG was higher in post- as compared to pre-menopausal women. Further data analysis adjusting for potential confounders revealed that the OPG/RANKL ratio was positively associated with adiponectin and inversely associated with leptin levels independent of the effect of age, body mass index and menopausal status. CONCLUSIONS: These results reveal that leptin circulating levels are inversely associated with serum OPG/RANKL ratio among healthy women.

Dietary habits of Greek adults and serum total selenium concentration: the ATTICA study.

PURPOSE: The trace element selenium is an essential micronutrient for human health, and its low levels in serum are implicated in the pathogenesis of several chronic diseases. The determination of total serum selenium levels may contribute to the assessment of the health status of all populations. Since the serum selenium levels are highly affected by diet, we assessed its association with the dietary habits of Greek adults. METHODS: Serum selenium levels were determined with inductively coupled plasma mass spectrometry in a cohort of 506 participants (men: 296, women: 210) aged 18-75 from the ATTICA study. Food consumption was evaluated with a validated food-frequency questionnaire. RESULTS: Evaluation of the relationship between serum total selenium with major food groups and beverages by multi-adjusted analysis revealed that serum selenium was positively correlated with the consumption of red meat (2.37 ± 0.91, p = 0.01) while the consumption of other selenium-containing foods (i.e., fish, cereals, dairy products, vegetables) did not demonstrate such a relationship. Moreover, principal component analysis revealed that the adoption of a vegetarian type of diet is inversely correlated with total selenium (-3.94 ± 2.28, p = 0.08). CONCLUSIONS: Among the dietary habits that were examined, red meat seems to be the major determinant of serum selenium in Greek adults.

Dietary antioxidant capacity and concentration of adiponectin in apparently healthy adults: the ATTICA study.

BACKGROUND/OBJECTIVES: This study aimed at evaluating the relationship of adiponectin concentration with total dietary antioxidant capacity in free-living, apparently healthy adults from the ATTICA study. SUBJECTS/METHODS: A random subsample from the ATTICA study, consisting of 310 men (40+/-11 years) and 222 women (38+/-12 years), was selected. Adiponectin, along with other inflammatory markers, was measured in fasting participants. Dietary habits were evaluated using a food frequency questionnaire and the dietary antioxidant capacity was based on published values of Italian foods measured by three different assays: ferric-reducing antioxidant power (FRAP), total radical-trapping antioxidant parameters (TRAP) and trolox-equivalent antioxidant capacity (TEAC). RESULTS: Positive associations were observed between dietary antioxidant capacity and adiponectin concentration, as assessed with FRAP (b+/-s.e.=0.012+/-0.005, P=0.018 per 1 mmol Fe (II)/day), TRAP (b+/-s.e.=0.030+/-0.013, P=0.017 per 1 mmol trolox equivalent/day) and TEAC (b+/-s.e.=0.025+/-0.012, P=0.042, per 1 mmol trolox equivalent/day) in multiadjusted analysis. Moreover, a negative relation of dietary antioxidant indices with inflammatory markers was revealed. CONCLUSIONS: Diets with high antioxidant capacity are related to increased adiponectin levels. An adiponectin-mediated route through which antioxidant-rich foods exert beneficial effects against inflammation and cardiovascular diseases can be thus hypothesized.

Atherosclerosis regression study in rabbits upon olive pomace polar lipid extract administration.

BACKGROUND AND AIMS: Virgin olive oil polar lipid extract (OOPL) and olive pomace polar lipid extract (PPL) have similar antiatherosclerotic effects in cholesterol-fed rabbits. Our aim was to compare the effect of PPL with that of simvastatin on the progression of atherogenesis. METHODS AND RESULTS: Rabbits were fed an atherogenic diet for 6 weeks in order to develop dyslipidemia and atheromatous lesions. Following documentation of these events in random animals (group A, n=6), the remaining were fed for 3 weeks with: standard chow alone (group B, n=6), chow supplemented with PPL (group C, n=6), and chow supplemented with simvastatin (group D, n=6). Blood was collected at 0, 6 and 9 weeks, to determine plasma lipid levels, plasma PAF-AH activity, platelet aggregation (PAF-EC(50)), resistance of plasma to oxidation (RPO) and extent of atheromatous lesions in aortas. The atherogenic diet induced dyslipidemia and increased PAF-AH activity. Dyslipidemia and PAF-activity reduced more effectively in groups C and D. RPO decreased in group B only. PAF-EC(50) values decreased in group C only. Atherogenesis progression in group C was prevented to an extent indistinguishable from that in group D. PAF-AH activity was positively correlated, whereas RPO was negatively correlated with the extent of atheromatous lesions. CONCLUSION: PPL, as a dietary supplement, is equipotent to simvastatin in preventing the progression of atherogenesis.

Development, reliability and validity of a new motorized isometric dynamometer for measuring strength characteristics of elbow flexor muscles.

The aim of this study was to develop a new apparatus capable of accurately recording and analysing torque-time curve during isometric muscle contractions of the elbow flexors. A total of 25 (age 29.3+/-5.0 years) non-athlete male volunteers participated in this study. To establish the measurement precision of the new testing apparatus and to determine possible sources of error in the results, a series of tests was performed. Instrument validity was assessed by comparing each selected measure (lever arm angular position, torque and maximal isometric torque) to a criterion (external inclinometer, calibrated weights and isokinetic dynamometer, respectively), while trial-to-trial and day-to-day comparisons of measurements were made to estimate the reproducibility of the instrument. The statistical outcomes of validity tests demonstrated high agreement between measures and associated criteria (Pearson correlation coefficient's values >.97). Trial-to-trial correlations for maximal isometric torque in different elbow angles showed excellent reproducibility, as values of intraclass correlation coefficient (ICC([2,1])) ranged from 0.889 to 0.971, with higher value in the middle angle (90 degrees ). The value of ICC([2,1]) (day-to-day) for maximal isometric torque in 90 degrees was 0.986 and the respective standard error of measurement (SEM) was 1.5 Nm. Our results indicate that the isometric evaluation of elbow flexor muscles with the new dynamometer is accurate and reproducible.

Effects of baseline serum levels of Se on markers of eccentric exercise-induced muscle injury.

Inflammation and oxidative stress have been implicated in the mechanism of eccentric exercise-induced muscle injury. This study examined whether baseline serum levels of selenium (Se), a trace element that participates in both antioxidant and anti-inflammatory systems, affects the overall response to injury. Thirteen males performed 36 maximal eccentric actions with the elbow flexors of the non-dominant arm on a motorized dynamometer. Venous blood samples were collected immediately before and after exercise at 2, 24, 48, 72 and 96 hours. Established indicators of muscle damage such as maximum isometric torque (MIT), range of motion (ROM), relaxed arm angle (RANG), flexed arm angle (FANG), arm circumference (CIRC), muscle soreness and serum levels of creatine kinase (CK) and lactate dehydrogenase (LDH) were determined at the same time points. Baseline serum levels of Se were also measured. Complementary data regarding assessment of Se status were retrieved by the use of a semi-quantitative food frequency questionnaire. All measures changed significantly (p<0.05) after exercise. The main finding of this study was that baseline Se serum levels were associated inversely with CK, LDH and FANG and positively with MIT and ROM (p<0.05). These data suggest that beyond overt Se deficiency, suboptimal Se status possibly worsens muscle functional decrements subsequent to eccentric muscle contractions.

Dietary intake and biochemical risk factors for cardiovascular disease in two rural regions of Crete.

The aim of the present study was to identify any possible protective effects of wild greens on certain biochemical cardiovascular disease (CVD) risk factors in elderly women leaving in rural Crete. For the needs of the study a region with high consumption of wild greens (Avdou) and a region with low consumption (Anogia) were identified and a representative population from each area was recruited (n= 37 and n=35 respectively). Serum lipids and fibrinogen levels, total antioxidant capacity (TAC), soluble intercellular adhesion molucule-1 (sVCAM-1), soluble vascular adhesion molucule-1 (s-ICAM-1) and haematological factors were measured in both regions during winter and summer time when wild-green plants consumption is high and low, respectively. Regarding classic lipid risk factors for arteriosclerosis no significant different between the two regions were detected. TAC was found higher in Avdou compared to Anogia during winter screening, but null in both regions during summer. Fibrinogen was found higher in Avdou compared to Anogia while no differences between the two regions were detected for sVCAM-1 and s-ICAM-1 in both screenings. The significantly higher TAC and fibrinogen values detected in Avdou could be attributed to the higher wild green consumption in that region since recent data indicated that their content in vitamin C and E as well as flavonoids is particularly high.

Separation of biologically active lipids from red wine.

A number of lines of evidence suggest that red wine exerts a protective effect against coronary heart disease, but the nature of the protective compounds is unclear and the mechanism is incompletely understood. In this study, total lipids of a Greek red wine were separated into neutral and polar lipids. Polar lipids were further separated into glyco- and phospholipids, which were fractionated by HPLC. Each lipid fraction was tested in vitro for its ability to inhibit platelet-activating factor (PAF) and thrombin-induced washed rabbit platelet aggregation and/or to cause platelet aggregation. A significant number of glyco- and phospholipids that exerted the above biological activities were detected. Structural data of an active phosphoglycolipid are also provided. trans-Resveratrol demonstrated also a dose-dependent inhibition of PAF-induced platelet aggregation along with the already reported inhibitory activity against thrombin and adenosine-5'-diphosphate. Because it has already been reported that PAF is involved in atheromatosis generation, the existence of PAF inhibitors in red wine may contribute to the protective role of red wine against atherosclerosis.

Identification of a new endogenous platelet-activating factor-like molecule in gingival crevicular fluid.

Periodontal disease is an inflammatory disease and the major cause of tooth loss in adults. Bacteria and their products are the causative agents of this disease. Endogenous molecules mediate the inflammatory process and play a major role in its amplification and perpetuation as well as in the ensuing tissue destruction. The relationship between platelet-activating factor (PAF) and periodontal disease has not so far been examined thoroughly. We have isolated a phospholipid molecule with PAF-like activity from gingival crevicular fluid. This molecule, purified on HPLC, causes washed platelet aggregation with EC50 value 0.1 microM, based on phosphorus determination. It acts through PAF-receptors and is inactivated by PAF-acetylhydrolase. In addition, this phospholipid presents biological activity towards human platelets. The combination of the results obtained from the chemical and enzymic treatments, the biological assays as well as results from the electrospray analysis, leads to the conclusion that this phospholipid is a hydroxyl-PAF analogue with relative molecular mass 703. This PAF-like molecule may be implicated in periodontal disease.

Synthesis of a new phosphoglycolipid with biological activity towards platelets.

Various synthetic as well as naturally occurring compounds have been found to exhibit platelet-activating factor (PAF)-like activity or to act as specific PAF inhibitors. In this work we have synthesized a new phosphoglycolipid, methyl 2,3,4-tri-O-acetyl-6-(1'-O-stearoyl-2'-O- acetyl-DL-glycero-3'-phosphoryl)-alpha-D-glucopyranoside ammonium salt, using a combination of known synthetic steps. This phosphoglycolipid was first purified on TLC (Rf 0.7, using chloroform/methanol/water, 65:25:4, v/v/v as solvent system). It was further purified onto a high performance liquid chromatography silica column with an elution system that contained acetonitrile and methanol (retention time 13.5 min). Its identification was based on chemical determinations and electrospray mass spectrometry analysis. The above compound induced washed platelet aggregation with an EC50 value at 2 x 10(-4) M. The aggregation curve was biphasic, the first wave of which was through the PAF way while the second one was through the ADP way. Treatment with acetylhydrolase resulted in a rapid decrease of the first wave of aggregation and in a slow decrease of the second wave. In lower concentrations, the phosphoglycolipid inhibited PAF- and thrombin-induced aggregation with IC50 values of the order of 10(-7) M. In conclusion, this phosphoglycolipid has a diverse biological activity. The PAF-like activity of this new lipid enforces the conception that PAF is a member of a large family consisting of lipid mediators.

Blood cardiolipin in haemodialysis patients. Its implication in the biological action of platelet-activating factor.

Bovine heart cardiolipin specifically inhibits platelet aggregation induced by PAF in vitro. In the past we have reported that patients with primary glomerulonephritis have increased PAF levels in plasma (Iatrou et al., 1995b). In this work we investigate the existence of cardiolipin in the blood of end-stage renal patients due to primary glomerulonephritis and we study its implication in the biological study of PAF. Lipids from blood samples of end-stage renal patients were extracted, fractionated onto silicic acid column and onto High Performance Liquid Chromatography (HPLC) cation exchange column. PAF fraction was removed and phospholipids were separated from the rest lipid fraction with current counter distribution and furthermore fractionated onto HPLC silica column. The results show: 1. cardiolipin is present in the blood of end-stage renal patients. 2. Blood cardiolipin specifically inhibits PAF-induced aggregation in washed rabbit platelets. 3. Scatchard plot analysis of PAF binding, in the presence of unlabelled PAF and in the presence of cardiolipin, shows that rabbit platelets possess two different types of binding sites. One of which is saturable and of high affinity, kD = 0.103 +/- 0.03 nM (SEM, n = 3) with 337 +/- 94 binding sites per platelet for PAF and kD = 0.087 +/- 0.02 nM with 371 +/- 92.7 binding sites per platelet for cardiolipin while the other one has almost infinite binding capacity. 4. Blood cardiolipin competes [3H]PAF binding in rabbit platelets. This work shows that cardiolipin exists in the blood of end-stage renal patients and specifically inhibits PAF-induced aggregation as well as PAF binding in rabbit platelets. The possible implication of the biological actions of cardiolipin in the anticardiolipin-antiphospholipid syndrome is also discussed.