Effects of Hydroxytyrosol and Hydroxytyrosol Acetate Administration to Rats on Platelet Function Compared to Acetylsalicylic Acid (original) (raw)
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Inhibition of platelet aggregation and eicosanoid production by phenolic components of olive oil
Thrombosis Research, 1995
This study was designed to investigate the in vitro effects of phenolic compounds extracted from olive oil and from olive derived fractions. More specifically, we investigated the effects on platelets of 2-(3,4-di-hydroxyphenyl)-ethanol (DHPE), a phenol component of extra-virgin olive oil with potent antioxidant properties. The following variables were studied: aggregation of platelet rich plasma (PRP) induced by ADP or collagen, and thromboxane B2 production by collagen or thrombin-stimulated PRP. In addition, thromboxane B2 and 12-hydroxyeicosatetraenoic acid (12-HETE) produced during blood clotting were measured in serum. Preincubation of PRP with DHPE for at least 10 min resulted in maximal inhibition of the various measured variables. The IC50s (concentration resulting in 50% inhibition) of DHPE for ADP- or collagen-induced PRP aggregations were 23 and 67 μM, respectively. At 400 μM DHPE, a concentration which completely inhibited collagen-induced PRP aggregation, TxB2 production by collagen- or thrombin-stimulated PRP was inhibited by over 80 percent. At the same DHPE concentration, the accumulation of TxB2 and 12-HETE in serum was reduced by over 90 and 50 percent, respectively. We also tested the effects on PRP aggregation of oleuropein, another typical olive oil phenol, and of selected flavonoids (luteolin, apigenin, quercetin) and found them to be much less active. On the other hand a partially characterized phenol-enriched extract obtained from aqueous waste from olive oil showed rather potent activities. Our results are the first evidence that components of the phenolic fraction of olive oil can inhibit platelet function and eicosanoid formation in vitro, and that other, partially characterized, olive derivatives share these biological activities.
Journal of Functional Foods, 2017
The phenolic profiles of extra virgin olive oils (EVOOs) may influence their cardiovascular benefits. In a randomized crossover of acute EVOO intake on platelet function, participants (n=9) consumed 40 mL of EVOO weekly. EVOOs were matched for total phenolic content and were either tyrosol-poor with 1:2 oleacein/oleocanthal (D2 i 0.5), or 2:1 oleacein/oleocanthal (D2 i 2), or predominantly tyrosol (D2 i 0). Ibuprofen provided a platelet inhibition control. Blood was collected pre-and 2 hr post-EVOO intake. D2 i 0.5 and D2 i 2 reduced 1 µg/mL collagen-stimulated maximum platelet aggregation (Pmax), with effects best correlated to oleocanthal intake (R=0.56, P=0.002). Total phenolic intake was independently correlated to eicosanoid production inhibition, suggesting that cyclooxygenase blockade was not responsible for the Pmax inhibition. Five participants exhibited >25% ΔPmax declines with D2 i 0.5 and D2 i 2 intake and plasma metabolomic profiles discriminated subjects by oil responsivity. Platelet responses to acute EVOO intake are associated with oil phenolic composition and may be influenced by diet.
Inhibition of platelet aggregation by olive oil phenols via cAMP-phosphodiesterase
British Journal of Nutrition, 2008
The aim of the present study was to confirm that olive oil phenols reduce human platelet aggregability and to verify the hypothesis that cAMP-and cGMP-phosphodiesterases (PDE) could be one of the targets of the biological effect. Four extracts from oils characterized by a high phenol content (HPE), and low phenol levels (LPE) were prepared and analyzed quali-and quantitatively by HPLC-UV and electrospray ionization -MS/MS. Human washed platelets stimulated with thrombin were used for the aggregation assay. Human platelet cAMP-PDE and recombinant PDE5A1 were used as enzyme source. Platelet aggregation and enzyme activity were assayed in the presence of HPE, LPE and individual phenols. The phenol content of HPE ranged between 250 and 500 mg/kg, whereas the LPE content was 46 mg/kg. The compounds identified were hydroxytyrosol (HT), tyrosol (TY), oleuropein aglycone (OleA) and the flavonoids quercetin (QU), luteolin (LU) and apigenin (AP). OleA was the most abundant phenol (range 23·3 to 37·7 %) and LU was the most abundant flavonoid in the extracts. Oil extracts inhibited platelet aggregation with an 50% inhibitory concentration interval of 1·23 -11·2 mg/ml. The inhibitory effect of individual compounds (10 mM) including homovanillyl alcohol (HVA) followed this order: OleA . LU . HT ¼ TY ¼ QU ¼ HVA, while AP was inactive. All the extracts inhibited cAMP-PDE, while no significant inhibition of PDE5A1 (50mg/ml) was observed. All the flavonoids and OleA inhibited cAMP-PDE, whereas HT, TY, HVA (100 mM) were inactive. Olive oil extracts and part of its phenolic constituents inhibit platelet aggregation; cAMP-PDE inhibition is one mechanism through which olive oil phenols inhibit platelet aggregation.
The effects of polyphenols in olive leaves on platelet function
Nutrition Metabolism and Cardiovascular Diseases, 2008
Introduction: The phenolic compounds of olive leaves and olive oils in the Mediterranean diet have been associated with a reduced incidence of heart disease. Accordingly, antioxidant-rich diets may prevent the deleterious effects of oxidative metabolism by scavenging free radicals, thus inhibiting oxidation and delaying atherosclerosis. The process involves phospholipase C activation and arachidonic acid metabolism, and is thought to reduce hydrogen peroxide (H 2 O 2 ). In our study, an extract of Olea europaea L. leaves was used. The active phenolic compounds in this extract are part of the secoiridoid family, known for their capacity to scavenge H 2 O 2 . The results from this study will help to improve our understanding of effects of polyphenol antioxidants in olive leaf extract on platelet function. Methods: Full blood examination (FBE), platelet aggregation, and ATP release were performed on samples from fasting, normal, healthy male subjects. Platelet function at increasing concentrations of oleuropein was investigated through measures of platelet aggregation and ATP release from activated platelets. Results: Blood analysis (n [ 11) revealed a significant dose-dependant reduction in platelet activity with olive extract concentrations of 1.0% v/v (P < 0.001). ATP Release showed a similar pattern (P [ 0.02). Conclusions: Olive leaf polyphenols derived from O. europaea L. leaves inhibited in vitro platelet activation in healthy, non-smoking males. Further bioavailability studies need to be undertaken to determine the in vivo effect of extract on platelet function and to validate the present results. ª
American Journal of Therapeutics, 2016
The purpose of this study was to evaluate the effect of the consumption of seed oils from Vitis vinifera and Arachis hypogaea in platelet aggregation. The initial hypothesis suggested that subjects who have consumed these seed oils undergo modified platelet aggregation. This study was performed using a pre-post test design, with a control group, and double blind. The effects of the consumption of grape seed and peanut oils were measured for platelet aggregation in clinical and laboratory tests in 30 healthy subjects. In addition to this group, a control group of 4 health subjects received no treatment with oils, just 500 mg oral administration acetylsalicylic acid for 7 days. Platelet aggregation was assessed by the Born turbidimetric method, using 3 different concentrations of adenosine diphosphate as agonists (2, 54; 1, 17; and 0, 58 mM). The study subjects had very similar results; both oils were shown to have a significant reduction in platelet aggregation. Grape seed oil showed a decrease of 8.4 6 1% in aggregation, compared with peanut oil, which decreased aggregation by 10.4 6 1%. The control group, taking 500 mg OD aspirin for 7 days, showed a significant decrease in platelet aggregation, similar to that of oil ingestion. Each of the oils was analyzed for fatty acids, to determine which particular acids were presents in greater levels, which could explain the reduction in platelet aggregation. The oil found to be most abundant in grape seeds was linoleic acid (omega-6), and in peanuts, it was oleic acid (omega-9). However, in fact, both acids reduced platelet aggregation. Consumption of plant oils from grape seeds and peanuts had a lowering effect on platelet aggregation, in addition to containing a high content of unsaturated fatty acids. However, omega-3, omega-6, and omega-9 fatty acids were not specifically responsible for the reductions mentioned above.
1 The Effects of Polyphenols in Olive Leaves on Platelet Function
2016
Introduction The phenolic compounds of olives leaves and olive oils in the Mediterranean diet have been associated with a reduced incidence of heart disease. Accordingly, antioxidant-rich diets may prevent the deleterious effects of oxidative metabolism by scavenging free radicals, thus inhibiting oxidation and delaying atherosclerosis. The process involves phospholipase C activation and arachidonic acid metabolism, and is thought to reduce hydrogen peroxide (H 2 O 2). In our study, an extract of Olea europaea L. leaves was used. The active phenolic compounds in this extract are part of the secoiridoid family, known for their capacity to scavenge H 2 O 2. The results from this study will help to improve our understanding of effects of polyphenol antioxidants in olive leaf extract on platelet function. Methods Full blood examination (FBE), platelet aggregation, and ATP release were performed on samples from fasting, normal, healthy male subjects. Platelet function at increasing concentrations of oleuropein was investigated through measures of platelet aggregation and ATP release from activated platelets. Results Blood analysis (n=11) revealed a significant dose-dependant reduction in platelet activity with olive extract concentrations of 1.0% v/v (p<0.001). ATP Release showed a similar pattern (p=0.02).
2000
We investigated the effect of extra virgin olive oil (EVOO) on platelet aggregation and plasma concentrations of homocysteine (Hcy)redoxformsinratsinrelationtotheminorpolarcompound(MPC)concentrationofEVOO.Weused3oliveoilsampleswith similar fatty acid but different MPC concentrations: refined olive oil (RF) with traces of MPC (control oil), native EVOO with low MPC concentration (LC), and EVOO with high MPC concentration (HC) enriching LC with its own MPC. Oil samples were administeredtoratsbygavage(1.25mL/kgbodyweight)using2experimentaldesigns:acute(24-hfooddeprivationandkilled1h
The Journal of nutrition, 2008
We investigated the effect of extra virgin olive oil (EVOO) on platelet aggregation and plasma concentrations of homocysteine (Hcy) redox forms in rats in relation to the minor polar compound (MPC) concentration of EVOO. We used 3 olive oil samples with similar fatty acid but different MPC concentrations: refined olive oil (RF) with traces of MPC (control oil), native EVOO with low MPC concentration (LC), and EVOO with high MPC concentration (HC) enriching LC with its own MPC. Oil samples were administered to rats by gavage (1.25 mL/kg body weight) using 2 experimental designs: acute (24-h food deprivation and killed 1 h after EVOO administration) and subacute (12-d treatment, a daily dose of oil for 12 d, and killed after 24 h of food deprivation).
Olive oil isochromans inhibit human platelet reactivity
The Journal of nutrition, 2003
The effects of certain polyphenolic compounds in red wine, such as resveratrol and quercetin, have been widely investigated to determine the relationship between dietary phenolic compounds and the decreased risk of cardiovascular diseases. However, the effects of polyphenolic compounds contained in other foods, such as olive oil, have received less attention and little information exists regarding the biological activities of the phenol fraction in olive oil. The aim of this study was to evaluate the antiplatelet activity and antioxidant power of two isochromans [1-(3'-methoxy-4'-hydroxy-phenyl)-6,7-dihydroxy-isochroman (encoded L116) and 1-phenyl-6,7-dihydroxy-isochroman (encoded L137)] recently discovered in olive oil and synthesized in our laboratory from hydroxytyrosol. These compounds were effective free radical scavengers and inhibited platelet aggregation and thromboxane release evoked by agonists that induce reactive oxygen species-mediated platelet activation includ...
Postepy higieny i medycyny doswiadczalnej, 2006
INTRODUCTION Some compounds of herbal origin, such as Pycnogenol (PYC), have been considered as an aid in antiplatelet therapy. Pycnogenol, a French maritime pine bark extract, is a complex mixture of polyphenols that has the ability to reduce human smoking-induced platelet aggregation. The aim of this study was to evaluate the in vitro ability of PYC to improve the efficacy of acetylsalicylic acid (ASA) in the inhibition of platelet function. MATERIAL/METHODS Whole blood, anticoagulated with hirudin, was drawn from 38 volunteers (40.4+/-13.8 years old) and incubated with PYC (10, 50, 100 microg/ml) or/and ASA (25, 100 micromol/l) for 20 min at RT.PYC was dissolved in water (water-PYC group, n=20) or ethanol (ethanol-PYC group, n=18). To investigate platelet functions, PFA-100 closure-time determination, whole-blood electrical aggregation (WBEA), and PRP aggregation were employed. Collagen (1 microg/ml) and ADP (5 micromol/l) were used as platelet agonists. RESULTS A compounding eff...