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The fish industry is now attempting to produce value-added fishery products with potential functional properties for consumers using agro-food by-products as healthy ingredients in aquafeed. Herein, microbial communities, microbial populations, sensory attributes and physicochemical e.g., Total Volatile Basic Nitrogen (TVB-N) and Thiobarbituric Acid Reactive Substances (TBARS) profile of fillets from gilthead seabream (Sparus aurata) previously fed with a fraction of polar lipids extracted from olive-oil industry by-products (enriched fish, hereafter) were examined during storage at 2 °C and compared with conventional sea bream fillets, in order to monitor quality changes and assess shelf-life. The end of the shelf-life was determined at 7 and 9 days of storage for the enriched and the conventional fillets, respectively. Results indicated no significant differences in any of the studied parameters between the enriched and conventional fish fillets. Based on the 16S metabarcoding analysis, Pseudomonas was the most dominant microorganism in both conventional and enriched fillets at the rejection time. TVB-N reached levels of ∼23.5 mg N / 100 g in both cases. Overall, the findings of the present work enhance the production of such fishery products, opening a new era in aquaculture industry that undoubtedly deserves further attention in the future.

Platelet aggregation and inflammation play a crucial role in atherothrombosis. Wine contains micro-constituents of proper quality and quantity that exert cardioprotective actions, partly through inhibiting platelet-activating factor (PAF), a potent inflammatory and thrombotic lipid mediator. However, wine cannot be consumed extensively due to the presence of ethanol. Alternatively, winery by-products are abundant in similar-to-wine micro-constituents that could be used in food fortification and dietary supplements. Also, the vinification process produces millions of tons of by-products worldwide, posing an environmental matter of waste management. Therefore, the purpose of this literature review is to update the existing data concerning the in vitro anti-platelet and anti-inflammatory properties of winery by-product extracts and their possible health effects through controlled clinical trials in humans, specifically focused on their effects on PAF’s actions. Data from in vitro studies report that winery by-product compounds are able to inhibit platelet aggregation against several aggregation factors, as well as to downregulate inflammatory markers. Among their actions, extracts or phenolic compounds present in winery by-products inhibit PAF’s actions, a potent inflammatory and thrombotic mediator. Similar conclusions have been drawn from human supplementation studies, which suggest that winery by-product extracts may have beneficial biological effects on the cardiovascular system. Evidence from long-term studies shows that consumption may lower total and low density lipoprotein (LDL) cholesterol, improve insulin sensitivity, decrease lipid and protein oxidative damage, enhance antioxidant capacity, and have mild anti-inflammatory action toward reducing cytokine expression and levels. Data from the limited postprandial studies report that the acute consumption of winery by-product extracts improves glycemic response and reduces platelet reactivity to aggregatory stimuli. Although wine extracts and phenolic compounds have been reported to inhibit PAF’s actions and reduce the activity of its biosynthetic enzymes, no data exist concerning the influence of winery by-product extracts. In the future, additional long-term randomized controlled trials or postprandial studies are needed to draw definitive conclusions and establish a viable cardioprotective strategy that incorporates the sustainable use of winery by-products.

Platelet-activating factor (PAF) is a potent lipid mediator, involved in thrombosis, inflammation, and atherosclerosis. The protective effect of wine and olive oil against atherosclerotic diseases is largely attributed to their phenolic compounds and mostly to resveratrol and tyrosol. Both compounds have been reported to inhibit PAF biosynthesis in interleukin-1β (IL-1β)-stimulated monocytes and also to attenuate PAF biosynthesis in cell lysates. The aim of this study was to investigate the effects of resveratrol, tyrosol, and their derivatives on unstimulated U937 cells and to explore the intracellular messaging pathways that participate in the activation of PAF biosynthesis in the same cell line. Tyrosol and its derivatives did not exert any substantial effect on PAF biosynthesis. Resveratrol (50 and 100 μM), as well as its methoxy derivative (5–20 μM), caused a reduction in the PAF biosynthetic enzymes’ activity by 20–43% after 24 h of incubation. On the other hand, lower resveratrol concentration (10 μM) and higher concentration of the methoxy derivative (50 μM) increased the Ca2+-dependent lyso–PAF acetyltransferase (LysoPAF-ATC) activity by 28–45% after half-hour incubation via p38 mitogen-activated protein kinase (p38-MAPK) action. IL-1β activated PAF biosynthetic pathways via different signaling pathways, with phospholipase C-β (PLC-β) being a key enzyme.

Lipid mediators are a class of signaling molecules that play important roles in various physiological processes, including inflammation, blood pressure regulation, and energy metabolism. Exercise has been shown to affect the production and metabolism of several types of lipid mediators, including prostaglandins, leukotrienes, sphingolipids, platelet-activating factors and endocannabinoids. Eicosanoids, which include prostaglandins and leukotrienes, are involved in the regulation of inflammation and immune function. Endocannabinoids, such as anandamide and 2-arachidonoylglycerol, are involved in the regulation of pain, mood, and appetite. Pro-resolving lipid mediators are involved in the resolution of inflammation. Sphingolipids have a role in the function of skeletal muscle during and after exercise. There are many studies that have examined the effects of exercise on the production and release of these and other lipid mediators. Some of these studies have focused on the effects of exercise on inflammation and immune function, while others have examined the effects on muscle function and metabolism. However, much less is known about their involvement in the phenomenon of exercise-induced muscle damage that follows after intense or unaccustomed exercise.

IntroductionPhase angle (PA) is derived from bioelectrical impedance analysis (BIA). It reflects cell membrane function and decreases in disease. It is affected by inflammation, oxidative stress, and diet. Platelet-activating factor (PAF) is a potent inflammatory lipid mediator. Its levels, along with the activity of its metabolic enzymes, including CDP-choline:1-alkyl-2-acetyl-sn-glycerol-cholinephosphotransferase, acetyl-CoA:lyso-PAF-acetyltransferases, and PAF-AH/Lp-PLA2 are also related to dietary factors, such as the dietary antioxidant capacity (DAC). The aim of the study was to estimate whether the PAF metabolic circuit and related dietary factors are associated with PA in healthy volunteers.MethodsIn healthy subjects, PAF, its metabolic enzyme activity, and erythrocyte fatty acids were measured, while desaturases were estimated. Food-frequency questionnaires and recalls were used, and food groups, macronutrient intake, MedDietScore, and DAC were assessed. Lifestyle and biochemical variables were collected. DXA and BIA measurements were performed.ResultsLp-PLA2 activity was positively associated with PA (rho = 0.651, p < 0.001, total population; rho = 0.780, p < 0.001, women), while PAF levels were negatively associated with PA only in men (partial rho = −0.627, p = 0.012) and inversely related to DAC. Estimated desaturase 6 was inversely associated with PA (rho = −0.404, p = 0.01, total sample). Moreover, the DAC correlated positively with PA (rho = 0.513, p = 0.03, women). All correlations were adjusted for age, body mass index, and sex (if applicable).ConclusionPA is associated with PAF levels and Lp-PLA2 activity in a gender-dependent fashion, indicating the involvement of PAF in cell membrane impairment. The relationship of PA with DAC suggests a protective effect of antioxidants on cellular health, considering that antioxidants may inhibit PAF generation.

Objective: The effect of the daily consumption of a low-fat yogurt (150 g) enriched with Platelet-Activating Factor receptor (PAF-R) antagonists, or the plain one, on gut microbiota and faecal metabolites was investigated in healthy overweight subjects. Methods: A randomized, three-arm, double-blind, placebo-controlled, parallel-group study was performed that lasted 8 weeks. Blood and stools were collected and analyzed before and after the intervention. Results: Our findings revealed that the intake of the enriched yogurt resulted in a significant increase in the levels of Bifidobacterium spp., Clostridium perfringens group and Firmicutes-to-Bacteroidetes (F/B) ratio. On the other hand, a significant increase in the levels of Lactobacillus and C. perfringens group was detected after the intake of the plain yogurt. The increase in the levels of C. perfringens group was inversely associated with the plasma catabolic enzyme of PAF, namely LpPLA2 (lipoprotein-associated phospholipase A2), a cardiovascular risk marker that has been linked with inflammation and atherosclerosis. Moreover, in the enriched with PAF-R antagonists yogurt group, the increased levels of C. perfringens group were also associated with lower PAF action assessed as ex vivo human platelet-rich plasma (PRP) aggregation. Additionally, a higher % increase in molar ratio of Branched Short Chain Fatty Acids (BSCFAs) was detected for both yogurt groups after the 8 week-intervention compared to control. The consumption of the enriched yogurt also resulted in a significant drop in faecal caproic levels and a trend for lower ratio of butyrate to total volatile fatty acids (VFAs) compared to baseline levels. Conclusion: Yogurt consumption seems to favorably affect gut microbiota while its enrichment with PAF-R antagonists from olive oil by-products, may provide further benefits in healthy overweight subjects. Clinical Trial Registration: ClinicalTrials.gov (NCT02259205).

Background and aims: Several studies have reported the positive cardio-metabolic effects of yogurt consumption. The addition of olive oil’s bioactive extracts into yogurt can result to a functional food with pleiotropic properties against cardiovascular diseases. A polar lipid extract of olive pomace (OOPLE) that contains platelet activating factor receptor (PAF-R) antagonists, has been stated not only to inhibit the development of atherosclerotic plaques in hypercholesterolemic rabbits but also to regress the already formed plaques. The present study aims to investigate the effect of the daily intake of an OOPLE-enriched low-fat yogurt, on the metabolic profile, ex vivo platelet aggregation and markers of thrombosis and inflammation, in healthy, mainly overweight volunteers. Methods and results: A randomized, three-arm, double-blind, placebo-controlled, parallel-group, 8 weeks duration, clinical trial was performed in apparently healthy adults (35–65 years old). Group A (control group) consumed at most one yogurt every two weeks, Group B (plain yogurt) consumed one serving of plain yogurt every day and Group C (enriched yogurt) consumed one serving of yogurt, enriched with OOPLE, daily. Enriched yogurt intake resulted in lower levels of IL-10 and to lower platelet sensitivity against PAF, compared to the other two groups (p-values

Atherosclerosis is a progressive vascular multifactorial process. The mechanisms underlining the initiating event of atheromatous plaque formation are inflammation and oxidation. Among the modifiable risk factors for cardiovascular diseases, diet and especially the Mediterranean diet (MedDiet), has been widely recognized as one of the healthiest dietary patterns. Olive oil (OO), the main source of the fatty components of the MedDiet is superior to the other “Mono-unsaturated fatty acids containing oils” due to the existence of specific microconstituents. In this review, the effects of OO microconstituents in atherosclerosis, based on data from in vitro and in vivo studies with special attention on their inhibitory activity against PAF (Platelet-Activating Factor) actions, are presented and critically discussed. In conclusion, we propose that the anti-atherogenic effect of OO is attributed to the synergistic action of its microconstituents, mainly polar lipids that act as PAF inhibitors, specific polyphenols and α-tocopherol that also exert anti-PAF activity. This beneficial effect, also mediated through anti-PAF action, can occur from microconstituents extracted from olive pomace, a toxic by-product of the OO production process that constitutes a significant ecological problem. Daily intake of moderate amounts of OO consumed in the context of a balanced diet is significant for healthy adults.

A fish-rich diet has a beneficial effect on cardiovascular health. The platelet activating factor (PAF) is involved in the development of atherosclerosis, and in vitro results support the regulating action of bioactive nutrients on PAF metabolism. The purpose of this study is to examine whether the consumption of farmed fish fed with an olive-pomace enriched diet (EF) affects PAF metabolism and the markers of inflammation and oxidative stress compared to the consumption of conventionally fed farmed fish (CF). Thirty apparently healthy adults completed a randomized double-blind crossover trial, during which they consumed both CF and EF twice a week for 8 weeks with a six-week washout period in between. The activities of PAF acetylhydrolase (PAF-AH), lysoPAF acetyltransferase (lysoPAF-AT), DTT-insensitive CDP-choline: 1-alkyl-2-acetyl-sn-glycerol-choline-phosphotransferase (PAF-CPT) in leukocytes, and lipoprotein-associated phospholipase A2 (LpPLA2) in serum were determined. The quantities of interleukin-6 (IL-6), high sensitivity C-reactive protein (hsCRP), oxidized LDL (ox-LDL), thiobarbituric acid-reactive substances (TBARS), and glutathione peroxidase (GPx), as well as the serum oxidation, were also determined. Both types of fish exerted similar effects as there were no statistically significant differences between the two interventions except for an elevated PAF-CPT and reduced arachidonic acid (AA) in the red blood cell (RBC) membrane lipids after the EF intake.

Abstract Background Excessive oxidative stress may impair bio-molecules and cellular function. Multi antioxidant supplementation is thought to be more effective than a single antioxidant probably through the synergistic or complementary action of natural substances that could enhance the prospective effect. Methods In order to estimate the effect of a plant extract based supplement in apparently healthy volunteers’ oxidative stress markers, a double-blind and placebo controlled intervention was performed. 62 apparently healthy volunteers, overweight with medium adherence to the Mediterranean diet, were recruited and randomly allocated into two intervention groups (supplement or placebo) for 8 weeks. Basic biochemical markers, oxidized LDL (oxLDL), resistance of serum in oxidation, protein carbonyls in serum and 8-isoprostane and DNA/RNA damage in urine were measured. Results No differentiation was observed in basic biochemical markers, in oxLDL levels as well as in serum resistance against oxidation, during intervention in the examined groups. A significant resistance regarding urine isoprostanes levels in the supplement group compared to the placebo one, was observed. Reduction on DNA/RNA damage and on protein carbonyls levels (almost 30% and 20% respectively, at 8 weeks) was detected in volunteers who consumed the supplement compared to the control group. Conclusion Consumption of plant extract based supplement seems to reduce DNA/RNA and protein oxidation and in less extent lipids peroxidation. Trial registration ClinicalTrials.gov Identifier for this study is: NCT02837107.

Platelet-activating factor (PAF), a proinflammatory lipid mediator, plays a crucial role in the formation of the atherosclerotic plaque. Therefore, the inhibition of endothelium inflammation by nutraceuticals, such as PAF inhibitors, is a promising alternative for preventing cardiovascular diseases. The aim of the present study was to evaluate the impact of a new functional yogurt enriched with PAF inhibitors of natural origin from olive oil by-products on PAF metabolism. Ninety-two apparently healthy, but mainly overweight volunteers (35–65 years) were randomly allocated into three groups by block-randomization. The activities of PAF’s biosynthetic and catabolic enzymes were measured, specifically two isoforms of acetyl-CoA:lyso-PAF acetyltransferase (LPCATs), cytidine 5′-diphospho-choline:1-alkyl-2-acetyl-sn-glycerol cholinephosphotransferase (PAF-CPT) and two isoforms of platelet activating factor acetylhydrolase in leucocytes (PAF-AH) and plasma (lipoprotein associated phospholipase-A2, LpPLA2). The intake of the enriched yogurt resulted in reduced PAF-CPT and LpPLA2 activities. No difference was observed in the activities of the two isoforms of lyso PAF-AT. In conclusion, intake of yogurt enriched in PAF inhibitors could favorably modulate PAF biosynthetic and catabolic pathways.

Subclinical, low-grade, inflammation is one of the main pathophysiological mechanisms underlying the majority of chronic and non-communicable diseases. Several methodological approaches have been applied for the assessment of the anti-inflammatory properties of nutrition, however, their impact in human body remains uncertain, because of the fact that the majority of the studies reporting anti-inflammatory effect of dietary patterns, have been performed under laboratory settings and/or in animal models. Thus, the extrapolation of these results to humans is risky. It is therefore obvious that the development of an inflammatory model in humans, by which we could induce inflammatory responses to humans in a regulated, specific, and non-harmful way, could greatly facilitate the estimation of the anti-inflammatory properties of diet in a more physiological way and mechanistically relevant way. We believe that exercise-induced muscle damage (EIMD) could serve as such a model, either in studies investigating the homeostatic responses of individuals under inflammatory stimuli or for the estimation of the anti-inflammatory or pro-inflammatory potential of dietary patterns, foods, supplements, nutrients, or phytochemicals. Thus, in this review we discuss the possibility of exercise-induced muscle damage being an inflammation model suitable for the assessment of the anti-inflammatory properties of diet in humans.

Cave Cyanobacteria - thriving in an ‘extreme’ environment with interesting species biodiversity - are supposed to be a potential source of bioactive compounds. Lipid extracts from pure cultures of two recently established Cyanobacteria from Greek caves, Toxopsis calypsus and Phormidium melanochroun, were used for antibacterial screening against human pathogenic bacteria (reference and clinical isolates). Antimicrobial Susceptibility testing for both taxa was carried out using the disc-diffusion (Kirby Bauer) method, while preliminary data applying the standard broth microdilution method for the determination of the Minimal Inhibitory Concentration (MIC) are given only for T. calypsus. Antibacterial activity was demonstrated against the Gram-positive clinical and reference bacteria, mostly pronounced in enterococci; no activity was observed against the Gram-negative bacteria. The above screening is the first record of antibacterial activity from lipid extracts of cave Cyanobacteria enhancing the importance of cave microbiota and the necessity for cave conservation.

Periodontal diseases are localized chronic inflammatory conditions of the gingival and underlying bone and connective tissue. Platelet-activating factor (PAF), a potent inflammatory phospholipid mediator that has been previously detected in elevated levels in inflamed gingival tissues, in gingival crevicular fluid and in saliva, is implicated in periodontal disease. Our results from previous studies showed that the biologically active phospholipid detected in gingival crevicular fluid is a hydroxyl-PAF analogue. In this study, hydroxyl-PAF analogue was detected for the first time in human blood derived from patients with chronic periodontitis as well as from periodontally healthy volunteers. The hydroxyl-PAF analogue was purified by high-performance liquid chromatography, detected by biological assays and identified by electrospray analysis. In addition, the quantitative determination of PAF and hydroxyl-PAF analogue (expressed as PAF-like activity) showed a statistically significant increase in the ratio of hydroxyl-PAF analogue levels to PAF levels in periodontal patients, suggesting that this bioactive lipid may play a role in oral inflammation.

Olive oil polar lipid (OOPL) extract has been reported to inhibit atherosclerosis development on rabbits. Olive pomace polar lipid (PPL) extract inhibits PAF activity in vitro and the most potent antagonist has been identified as a glycerylether-sn-2-acetyl glycolipid with common structural characteristics with the respective potent antagonist of OOPL. The aim of this study was to investigate the effect of PPL on early atherosclerosis development on rabbits and to compare it with the antiatherosclerotic effect of OOPL. OOPL and PPL inhibition potency, towards both PAF action and PAF binding, was tested in vitro on washed rabbit platelets. Consequently, rabbits were divided into three groups (A, B, and C). All groups were fed atherogenic diet for 22 days. Atherogenic diets in groups B and C were enriched with OOPL and PPL, respectively. At the end of the experimental time, rabbits were euthanized and aortic samples were examined histopathologically. OOPL and PPL inhibited PAF-induced aggregation, as well as specific PAF binding, with PPL being more potent. Free and bound PAF levels and PAF-AH activity were significantly elevated at the end of the experimental time. Plasma total cholesterol, HDL cholesterol, LDL cholesterol, and triglycerides levels were also found increased. Groups B and C exhibited significantly increased values of EC50 compared to group A. Histopathological examination revealed that the development of early atherosclerosis lesions in groups B and C were significantly inhibited compared to group A. Significant differences were noted in the early atherosclerosis lesions between groups B and C, thus indicating that PPL exhibit its anti-atherosclerotic activity by blocking PAF receptor. Specific PAF antagonists with similar in vitro and in vivo bioactivity to those that have been previously reported in OOPL exist in PPL.

Abstract  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. Therefore, the determination of total selenium in serum may contribute to the assessment of the health and nutritional status of certain populations. The objective of the present work was to determine total selenium in the serum of 506 healthy volunteers that participated in the ATTICA study. Selenium was determined in serum by using the technique of inductively coupled plasma mass spectrometry. The mean serum selenium concentration was determined to be 91.8 ± 33.7 μg/L (N = 506); 87.6% of women and 88.5% of men had serum selenium concentration below 125 μg/L, the cutoff considered to be required for optimal glutathione peroxidase activity. No association was found between serum selenium levels and the gender of the participants while a significant decline of selenium with age (p  [ABSTRACT FROM AUTHOR]

AbstractPlatelet-activating factor (PAF) is a potent inflammatory mediator, which seems to play a role in the pathogenesis of several AIDS manifestations such as AIDS dementia complex, Kaposi''s sarcoma, and HIV-related nephropathy. PAF antagonists have been studied in these conditions with promising results. In order to examine the possible interactions between PAF and antiretroviral therapy, we studied the effect of nucleoside reverse transcriptase inhibitors, non–nucleoside reverse transcriptase inhibitors, and protease inhibitors against PAF biological activities and its basic biosynthetic enzymes dithiothreitol-insensitive PAF-cholinephosphotransferase (PAF-CPT) and lyso-PAF-acetyltransferase (Lyso-PAF-AT), as well as its main degradative enzyme PAF-acetylhydrolase, of human mesangial cell line (HMC). We also studied the effect of several backbones and highly active antiretroviral therapy (HAART) regimens against PAF activity. Among the drugs tested, several inhibited PAF-induced platelet aggregation in a concentration-depended manner, with tenofovir, efavirenz, and ritonavir exhibiting the higher inhibitory effect. In addition, when these drugs were combined in backbones and HAART regimens based on American antiretroviral therapy proposals, they also synergistically exhibited an inhibitory effect against PAF-induced platelet aggregation. Several of these drugs have also inhibited in vitromicrosomal PAF-CPT activity, and concentrations of lopinavir-r or tenofovir-DF (similar to their IC50against PAF-induced platelet aggregation) exhibited the same effect against PAF-CPT and Lyso-PAF-AT when added in the cell medium of cultured HMC. In addition, in naïve patients treated with one of the most potent anti-PAF HAART regimens (efavirenz/emtricitabine/tenofovir-DF) for a period of 1 month, a significant reduction of the specific activity of PAF-CPT of washed human leukocytes of these patients was also observed, compared with its levels before the HAART treatment. These promising results need to be further studied and confirmed by additional in vivotests in order to optimize HAART efficacy. [ABSTRACT FROM AUTHOR]

Oxidation of lipoproteins, particularly of low-density lipoprotein (LDL), is of prime importance in the initiation and progression of atherosclerosis. The Mediterranean diet has been associated with an unexpectedly low rate of cardiovascular events. Type 2 diabetic patients are at high risk of developing atherosclerosis. Functional alterations in the endothelium, which lead to atherosclerosis, are stimulated by oxidized lipoproteins, particularly oxidized LDL. The present study investigated the effect of Greek quick casual Mediterranean-type diet (fast food Mediterranean-type diet) consumption on the resistance to oxidation in plasma from type 2 diabetic patients and healthy human subjects. Lipids from fast food Mediterranean-type foodstuffs were extracted and tested in vitrofor their ability to inhibit copper (Cu2)-induced LDL oxidation. Foodstuffs that exerted the most potent in vitroantioxidative activity were chosen for the diet of study groups. Eighteen type 2 diabetic patients (group A) and 10 healthy subjects (group B) were fed a 4-week diet contained the chosen foodstuffs, while 17 type 2 diabetic patients (group C) were kept on their regular diet that they were following before the study. Type 2 diabetic patients were treated with sulfonylureas or metformin and were under good glycemic control (hemoglobin A1C< 7). Serum lipoproteins, triglycerides, glucose, body mass index (BMI), and plasma resistance to Cu2-induced oxidation before and after the 4-week diet were monitored. At the beginning of the study, no statistical difference was detected in plasma resistance to Cu2-induced oxidation between type 2 diabetic patients (groups A and C) and healthy human subjects (group B), as this was detected at a time before the oxidation products become detectable, namely, lag time. After the 4-week period on the chosen diet the lag time in groups A and B significantly increased, while it was not changed in group C. In type 2 diabetic patients lag time was increased from 57.3 ± 13.3 minutes (mean ± SD) to 103.8 ± 21.8 minutes (mean ± SD) (P< .000), while in healthy human subjects there was an increase from 58.0 ± 8.5 minutes (mean ± SD) to 85.7 ± 21.8 minutes (mean ± SD) (P< .004). In all groups, total cholesterol, high-density lipoprotein-cholesterol, LDL-cholesterol, triglycerides, glucose, and BMI were not changed. Fast food Mediterranean foodstuffs exerted antioxidant activities both in vitroand in vivoafter consumption in type 2 diabetic patients and healthy human subjects. Therefore consumption of a fast food Mediterranean-type diet should contribute to prevention against cardiovascular diseases. [ABSTRACT FROM AUTHOR]

The most common causes of death in westernized societies remain heart disease and stroke. For this reason the prevention of atherosclerosis is a major objective of modern medicine. Platelet-Activating Factor (PAF, 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) is a crucial mediator in the inflammatory response. PAF is synthesized by several types of cells, including platelets, monocytes, macrophages, foam cells and endothelial cells upon activation. Many experimental data reveal that atherogenic activities of oxidized LDLs can be attributed to PAF and PAF-like lipids, which render these molecules the initiators of atherosclerosis. Several theories have been formulated for atherosclerosis. The purpose of this review is to highlight the significance of PAF and PAF-like lipids during the early stages of atherosclerosis. Secondly to link the biological action of PAF molecules to the most accepted, current hypotheses of atherosclerosis. Thirdly to propose a mechanism for the initiation and propagation of atherosclerosis by PAF. The mechanism we propose offers a new biochemical approach and may help to explains the beneficial effects of the Mediterranean diet. Mediterranean foods contain a significant number of lipid-like components with anti-PAF action in vitro. The comsumption of PAF antagonist from Mediterranian foods inhibits the development of atherosclerosis. Such observations suggest that our hypothesis serves as a sound basis for further research. [ABSTRACT FROM AUTHOR]