Antithrombotic effects of (n-3) polyunsaturated fatty acids in rat models of arterial and venous thrombosis

Metabolomic Profile in Venous Thromboembolism (VTE)

Venous thromboembolism (VTE) is a condition comprising deep venous thrombosis (DVT) and pulmonary embolism (PE). The prevalence of this disease is constantly increasing and it is also a chief reason for morbidity. Therefore, the primary prevention of VTE remains a highly important public health issue. At present, its diagnosis generally relies on subjective clinical examination and ultrasound imaging. D-dimer is also used as a biomarker, but it is considered to be poorly specific and only moderately sensitive. There are also no reliable methods that could accurately guide the type of treatment and potentially identify patients who may benefit from more aggressive therapies without the risk of bleeding. The application of metabolomics profiling in the area of vascular diseases may become a turning point in early diagnosis and patient management. Among the most described metabolites possibly related to VTE are carnitine species, glucose, phenylalanine, 3-hydroxybutarate, lactic acid, tryptophan and some monounsaturated and polyunsaturated fatty acids. The cell response to acute PE was suggested to involve the uncoupling between glycolysis and oxidative phosphorylation. Despite technological advancement in the identification of metabolites and their alteration in thrombosis, we still do not understand the mechanisms and pathways responsible for the occurrence of observed alterations.

DHA 12-LOX-derived oxylipins regulate platelet activation and thrombus formation through a PKA-dependent signaling pathway

BACKGROUND

The effects of docosahexaenoic acid (DHA) on cardiovascular disease are controversial and a mechanistic understanding of how this omega-3 polyunsaturated fatty acid (ω-3 PUFA) regulates platelet reactivity and the subsequent risk of a thrombotic event is warranted. In platelets, DHA is oxidized by 12-lipoxygenase (12-LOX) producing the oxidized lipids (oxylipins) 11-HDHA and 14-HDHA. We hypothesized that 12-LOX DHA-oxylipins may be involved in the beneficial effects observed in dietary supplemental treatment with ω-3 PUFAs or DHA itself.

OBJECTIVES

To determine the effects of DHA, 11-HDHA, and 14-HDHA on platelet function and thrombus formation, and to elucidate the mechanism by which these ω-3 PUFAs regulate platelet activation.

METHODS AND RESULTS

DHA, 11-HDHA, and 14-HDHA attenuated collagen-induced human platelet aggregation, but only the oxylipins inhibited ⍺IIbβ3 activation and decreased ⍺-granule secretion. Furthermore, treatment of whole blood with DHA and its oxylipins impaired platelet adhesion and accumulation to a collagen-coated surface. Interestingly, thrombus formation was only diminished in mice treated with 11-HDHA or 14-HDHA, and mouse platelet activation was inhibited following acute treatment with these oxylipins or chronic treatment with DHA, suggesting that under physiologic conditions, the effects of DHA are mediated through its oxylipins. Finally, the protective mechanism of DHA oxylipins was shown to be mediated via activation of protein kinase A.

CONCLUSIONS

This study provides the first mechanistic evidence of how DHA and its 12-LOX oxylipins inhibit platelet activity and thrombus formation. These findings support the beneficial effects of DHA as therapeutic intervention in atherothrombotic diseases.

Associations of Fish and Omega-3 Fatty Acids Consumption With the Risk of Venous Thromboembolism. A Meta-Analysis of Prospective Cohort Studies

Objective: This study aims to investigate the effect of fish and omega-3 fatty acids consumption on the risk of VTE. Methods: A comprehensive literature search in the databases of PubMed, Web of Science, and Embase (up to September 2020), was conducted to identify the prospective cohort studies concerning the associations of fish and omega-3 fatty acids consumption with the risk of VTE. The pooled relative risk (RR) of VTE for the highest vs. lowest category of fish and omega-3 fatty acids consumption, as well as their corresponding 95% confidence interval (CI) were calculated. Results: A total of seven articles with eight prospective cohort studies were included. Specifically, six studies were related to fish consumption, and the overall multi-variable adjusted RR showed no significant relationship between fish consumption and the risk of VTE (RR = 1.02, 95% CI: 0.93-1.11; P = 0.709). In the four studies related to omega-3 fatty acids consumption, the overall multi-variable adjusted RR suggested that omega-3 fatty acids consumption was associated with a lower risk of VTE (RR = 0.89, 95% CI: 0.80-0.98; P = 0.024). Moreover, two studies were related to recurrent VTE, and the overall multi-variable adjusted RR demonstrated a significant inverse association between omega-3 fatty acids consumption and the risk of recurrent VTE (RR = 0.45, 95% CI: 0.25-0.81; P = 0.008). Conclusion: Although current evidence is still insufficient to demonstrate any relationship between fish consumption and the risk of VTE, omega-3 fatty acids consumption seems to be associated with a lower risk of both VTE and recurrent VTE. Further large well-designed prospective cohort studies are warranted to elaborate the issues examined in this study.

Plasma Biomarkers and Identification of Resilient Metabolic Disruptions in Patients With Venous Thromboembolism Using a Metabolic Systems Approach

OBJECTIVE

Deep vein thrombosis and pulmonary embolism referred as venous thromboembolism (VTE) are a common cause of morbidity and mortality. Plasma from healthy controls or individuals who have experienced a VTE were analyzed using metabolomics to characterize biomarkers and metabolic systems of patients with VTE. Approach and Results: Polar metabolite and lipidomic profiles from plasma collected 3 months after an incident VTE were obtained using liquid chromatography mass spectrometry. Fasting-state plasma samples from 42 patients with VTE and 42 healthy controls were measured. Plasma metabolomic profiling identified 512 metabolites forming 62 biological clusters. Multivariate analysis revealed a panel of 21 metabolites altogether capable of predicting VTE status with an area under the curve of 0.92 (P=0.00174, selectivity=0.857, sensitivity=0.971). Multiblock systems analysis revealed 25 of the 62 functional biological groups as significantly affected in the VTE group (P<0.05 to control). Complementary correlation network analysis of the dysregulated functions highlighted a subset of the lipidome composed mainly of n-3 long-chain polyunsaturated fatty acids within the predominant triglycerides as a potential regulator of the post-VTE event biological response, possibly controlling oxidative and inflammatory defence systems, and metabolic disorder associated dysregulations. Of interest was microbiota metabolites including trimethylamine N-oxide that remained associated to post incident VTE patients, highlighting a possible involvement of gut microbiota on VTE risk and relapse.

CONCLUSIONS

These findings show promise for the elucidation of underlying mechanisms and the design of a diagnostic test to assess the likely efficacy of clinical care in patients with VTE.

Carriers of an apolipoprotein E epsilon 4 allele are more vulnerable to a dietary deficiency in omega-3 fatty acids and cognitive decline

Carriers of an epsilon 4 allele (E4) of apolipoprotein E (APOE) develop Alzheimer's disease (AD) earlier than carriers of other APOE alleles. The metabolism of plasma docosahexaenoic acid (DHA, 22:6n-3), an omega-3 fatty acid (n-3 FA), taken up by the brain and concentrated in neurons, is disrupted in E4 carriers, resulting in lower levels of brain DHA. Behavioural and cognitive impairments have been observed in animals with lower brain DHA levels, with emphasis on loss of spatial memory and increased anxiety. E4 mice provided a diet deficient in n-3 FA had a greater depletion of n-3 FA levels in organs and tissues than mice carrying other APOE alleles. However, providing n-3 FA can restore levels of brain DHA in E4 animals and in other models of n-3 FA deficiency. In E4 carriers, supplementation with DHA as early as possible might help to prevent the onset of AD and could halt the progression of, and reverse some of the neurological and behavioural consequences of their higher vulnerability to n-3 FA deficiency.

Omega-3 fatty acids predict recurrent venous thromboembolism or total mortality in elderly patients with acute venous thromboembolism

Essentials The role of omega-3 fatty acids (n-3 FAs) in recurrent venous thromboembolism (VTE) is unknown. Association of n-3 FAs with recurrent VTE or total mortality was investigated in 826 patients. Whole blood n-3 FAs were inversely correlated with recurrent VTE or total mortality. Major and non-major bleeding was not increased in patients with higher levels of n-3 FAs.

SUMMARY

Background The role of omega-3 fatty acids (n-3 FAs) in recurrent venous thromboembolism (VTE) remains unknown. Objectives To investigate the association of n-3 FAs with recurrent VTE or total mortality at 6 months and 3 years. Methods N-3 FAs were assessed in 826 patients aged ≥ 65 years, categorized into low, medium and high based on the 25th and 75th percentile. Mean follow-up was 29 months. Results At 6 months, subjects with medium (adjusted hazard ratio [HR], 0.37; 95% confidence interval [CI], 0.22-0.62) and high n-3 FA levels (adjusted HR, 0.36; 95% CI, 0.20-0.67) were less likely to develop recurrent VTE or total mortality, compared with those with low n-3 FAs. At 3 years, medium levels (adjusted HR, 0.67; 95% CI, 0.47-0.96) were associated with lower risk of recurrent VTE or total mortality. As compared with low n-3 FAs, the adjusted sub-hazard ratio [SHR] of recurrent VTE was 0.39 (95% CI, 0.15-0.99) in patients with medium and 0.17 (95% CI, 0.03-0.82) in patients with high n-3 FAs. The cumulative incidence of recurrent VTE was lower in the medium and high n-3 FA groups as compared with the low n-3 FA groups, but seems to have worn off after 3 years. The incidence of major and non-major bleeding was not greater in the high n-3 FA group. Conclusion Higher levels of n-3 FAs were associated with a lower risk of recurrent VTE or total mortality in elderly patients with VTE, but not with greater bleeding risk.

Fish oil attenuates neurologic severity of antiphospholipid syndrome in a mice experimental model

INTRODUCTION

Murine experimental models of antiphospholipid syndrome (eAPLS) showed neurologic dysfunction and therapeutic effect of the anticoagulant enoxaparin is well established. Omega-3 fatty acids and curcumin, tested in neuroinflammation and auto-immunity diseases, might be interesting therapeutic candidates. The aim of this study was to evaluate the effects of these candidates on neurologic severity in eAPLS.

METHODS

One month after immunization of BALB/c mice with beta-2-glycoprotein I, daily treatments were initiated with enoxaparin (1 mg/kg), omega-3 fatty acids (0.5 g/kg), and curcumin (200 mg/kg) for 3 months.

RESULTS

Mortality was significantly decreased by enoxaparin and omega-3 treatments. Fish oil and curcumin group exhibited the highest mean of swimming behavior in forced swim test in surviving mice. Mice under omega-3 fatty acids or curcumin presented low anxiety-like behavior in the elevated plus-maze test. Cerebral histopathology revealed heavy inflammatory infiltrates in cortical and subcortical regions with vacuolization, swelling, and degeneration of astrocytes in the control group, with aggravation under curcumin; no infiltrate was retrieved in enoxaparin and omega-3 groups.

CONCLUSION

Our study is the first to demonstrate a potential therapeutic effect of omega-3 fatty acids in eAPLS. Enoxaparin and omega-3 fatty acids combination would be interesting for further investigation.

Fish Intake and Venous Thromboembolism: A Systematic Literature Review

Diet plays an important role in modulating the risk of arterial and venous thrombosis. Several lines of evidence attest that consumption of fish and its compounds, especially omega-3 fatty acids, may be effective to decrease the cardiovascular risk. Since the pathogenesis of arterial and venous thrombosis share some common aspects, we performed a systematic review of published clinical studies that investigated the association between fish intake and venous thrombosis. An electronic search was carried out in Medline, Scopus, and ISI Web of Science using the key words "fish" OR "seafood" AND "venous thromboembolism" OR "deep vein thrombosis" OR "pulmonary embolism", with no language or date restriction. Overall, 6 studies (5 prospective and 1 case-control) were finally identified. In only 1 small case-control study, a larger intake of total fish was found to be negatively associated with the risk of venous thromboembolism. No association was found in 4 large prospective studies, whereas a positive association was observed in the remaining. No substantial difference was also noticed between intake of fatty or lean fish. Taken together, the current epidemiological evidence does not support the existence of a significant effect of total fish consumption on the risk of venous thromboembolism.

Investigation into the anti-thrombosis effect and contents of total saponins and flavonoids in the bioactive fraction of Naodesheng prescription

ETHNOPHARMACOLOGICAL RELEVANCE

Naodesheng prescription is a widely used traditional Chinese medicine (TCM), and mainly applied in clinics to treat cerebral arteriosclerosis, ischemic stroke, sequelae of cerebral hemorrhage etc.

AIM OF THE STUDY

The present study was designed to investigate the anti-thrombosis effects of this prescription, and to search its bioactive fraction.

MATERIALS AND METHODS

We evaluated the anti-thrombotic effects by measuring platelet aggregation in rats, and the clotting time and protection rate in mice. The contents of total saponins and flavonoids in the bioactive fraction were determined by UV-vis spectrophotometry.

RESULTS

The results showed that Naodesheng has significant anti-thrombotic and anticoagulation effects. The contents of total saponins and flavonoids in the bioactive fraction were 7.885% and 8.434%, respectively.

CONCLUSIONS

Such study will contribute to further exploration of Naodesheng in the therapy of thrombosis diseases and to its re-development based on the bioactive fraction and ingredients.

Dietary fats and dietary cholesterol and risk of stroke in women

BACKGROUND

Whether intakes of dietary fat and cholesterol are associated with risk of stroke remain unclear. We examined the associations between intakes of total fat, specific types of fat, and cholesterol and risk of stroke in a prospective cohort of women.

METHODS

The study population consisted of 34,670 women, aged 49-83 years, in the Swedish Mammography Cohort who were free of cardiovascular disease and completed a food-frequency questionnaire in 1997. Cox proportional hazard regression models were used to estimate relative risks (RR) with 95% confidence intervals (CI).

RESULTS

During a mean follow-up of 10.4 years, we ascertained 1680 stroke events, including 1310 cerebral infarctions, 233 hemorrhagic strokes, and 137 unspecified strokes. After adjustment for other stroke risk factors, intake of long-chain omega-3 polyunsaturated fatty acids (PUFA) was inversely associated with risk of total stroke. The multivariable RR of total stroke for the highest compared with the lowest quintile of long-chain omega-3 PUFA intake was 0.84 (95% CI, 0.72-0.99; P for trend=0.04). Dietary cholesterol was positively associated with risk of total stroke (highest versus lowest quintile: RR=1.20; 95% CI, 1.00-1.44; P for trend=0.01) and cerebral infarction (corresponding RR=1.29; 95% CI, 1.05-1.58; P for trend=0.004). Total fat, saturated fat, monounsaturated fat, polyunsaturated fat, α-linolenic acid, and omega-6 PUFA intakes were not associated with stroke.

CONCLUSIONS

These findings suggest that intake of long-chain omega-3 PUFAs is inversely associated with risk of stroke, whereas dietary cholesterol is positively associated with risk.

Dietary α-Linolenic Acid Inhibits Arterial Thrombus Formation, Tissue Factor Expression, and Platelet Activation

Objective—

Plant-derived α-linolenic acid (ALA) may constitute an attractive cardioprotective alternative to fish-derived n -3 fatty acids. However, the effect of dietary ALA on arterial thrombus formation remains unknown.

Methods and Results—

Male C57Bl/6 mice were fed a high-ALA or low-ALA diet for 2 weeks. Arterial thrombus formation was delayed in mice fed a high-ALA diet compared with those on a low-ALA diet (n=7; P <0.005). Dietary ALA impaired platelet aggregation to collagen and thrombin (n=5; P <0.005) and decreased p38 mitogen-activated protein kinase activation in platelets. Dietary ALA impaired arterial tissue factor (TF) expression, TF activity, and nuclear factor-κB activity (n=7; P <0.05); plasma clotting times and plasma thrombin generation did not differ (n=5; P =not significant). In cultured human vascular smooth muscle and endothelial cells, ALA inhibited TF expression and activity (n=4; P <0.01). Inhibition of TF expression occurred at the transcriptional level via the mitogen-activated protein kinase p38 in smooth muscle cells and p38, extracellular signal-regulated kinases 1 and 2, and c-Jun N-terminal kinases 1 and 2 in endothelial cells.

Conclusion—

ALA impairs arterial thrombus formation, TF expression, and platelet activation and thereby represents an attractive nutritional intervention with direct dual antithrombotic effects.

Anti-thrombosis effect of diosgenin extract from Dioscorea zingiberensis C.H. Wright in vitro and in vivo

Thrombus formation in blood vessel plays an important role in the pathogenesis and progression of atherosclerosis and cardiovascular diseases. Extract of Dioscorea zingiberensis C.H. Wright (D. zingiberensis) is demonstrated to posses activities for curing cardiovascular diseases such as coronary heart disease and angina pectoris. However, there were few studies on anti-thrombosis activity of it. We investigated the anti-thrombosis effect of diosgenin from D. zingiberensis (Dio) in vitro and in vivo on inferior vena cava ligation thrombosis rat model and pulmonary thrombosis mice model. We evaluated the protective effect of Dio by measuring the platelet aggregation, activated partial thromboplastin time (APTT), thrombin time (TT), prothrombin time (PT) and the venous thrombosis in rats and the bleeding time, clotting time and protection rate in mice. Results showed that Dio inhibited platelet aggregation, thrombosis and prolonged APTT, PT and TT in rats in a dose-dependent manner. They also prolonged the bleeding time, clotting time and increased protection rate in mice in a dose-dependent manner. Taken together, these findings suggested that Dio which contained 95% diosgenin had anti-thrombosis activity. Dio executives the anti-thrombosis activity through improving the anticoagulation function, inhibiting platelet aggregation and thrombosis.

Anti-thrombotic activity and chemical characterization of steroidal saponins from Dioscorea zingiberensis C.H. Wright

Steroidal saponins have long attracted scientific attention, due to their structural diversity and significant biological activities. Total steroidal saponins (TSS) extracted from the rhizomes of Dioscorea zingiberensis C.H. Wright (DZW) constitute an effective treatment for cardiovascular disease. However, the active constituents contained in DZW rhizomes and their pharmacological properties are not fully understood. The aim of this work is to determine and quantify the active constituents in DZW rhizomes using fingerprint technique, and evaluate its anti-thrombotic activity using inferior vena cava ligation thrombosis rat model and pulmonary thrombosis mice model after being gavaged with TSS for 1 or 2weeks. In the study, a chemical fingerprint method was firstly established and validated to quantify and standardize TSS from DZW rhizomes including parvifloside, protodeltonin, protodioscin, protogracillin, zingiberensis saponin, deltonin, dioscin and trillin. TSS extracted from DZW rhizomes were showed to have the inhibitions on platelet aggregation (PAG) and thrombosis, and prolong activated partial thromboplastin time (APTT), thrombin time (TT), and prothrombin time (PT) in a dose-dependent manner in rats. TSS also prolonged the bleeding time and clotting time in a dose-dependent manner in mice. The results indicate that TSS could inhibit thrombosis by both improving the anticoagulation activity and inhibiting PAG action, suggesting that TSS from DZW rhizomes have the potential to reduce the risk of cardiovascular diseases by anti-thrombotic action.

Fatty acids, lipid metabolism and Alzheimer pathology

Alzheimer's disease is the most common form of dementia in the elderly. The cause of Alzheimer's disease is still unknown and there is no cure for the disease yet despite 100 years of extensive research. Cardiovascular risk factors such as high serum cholesterol, presence of the Apolipoprotein epsilon4 (APOE epsilon4) allele and hypertension, play important roles in the development of Alzheimer's disease. We postulate that a combination of diet, lifestyle, vascular, genetic, and amyloid related factors, which enhance each other's contribution in the onset and course of Alzheimer's disease, will be more likely the cause of the disease instead of one sole mechanism. The possibility that the risk for Alzheimer's disease can be reduced by diet or lifestyle is of great importance and suggests a preventative treatment in Alzheimer's disease. Because of the great importance of lipid diets and metabolism in preventative treatment against both Alzheimer's disease and cardiovascular disease, long-chain polyunsaturated fatty acids from fish oil, ApoE genotype and cholesterol metabolism in correlation with Alzheimer's disease will be reviewed.

Fish oil inhibits photochemically induced thrombosis in the guinea pig in a dose dependent manner

The dose-response effect of dietary fish oil was investigated in the photochemically induced thrombosis model in guinea pigs. In this arterial thrombosis model thrombus formation was evaluated by determination of different occlusion parameters (percentage of occlusion, area under the blood flow curve, time to first occlusion, spontaneous reflow). Sixty guinea pigs (7 weeks old) were randomly assigned to and fed a 40 energy % diet containing increasing amounts (0, 5.5, 17 and 36 energy %) of fish oil for four weeks. Arterial thrombosis was induced in the femoral artery by free radical damage and subsequent thrombus formation. Increasing fish oil concentrations in the diet were associated with a linear decrease (p<0.001) in the percentage of occlusion (calculated as a decrease in blood flow) and a linear increase in area under the blood flow curve/begin flow (p<0.001). The time to thrombus formation was not significantly prolonged in any group. However the frequency of animals in which complete occlusion of the femoral artery was not obtained during the thrombosis induction and subsequent observation period was higher in the groups receiving the two highest doses of fish oil. Spontaneous reflow correlated positively (p<0.013) with increasing dietary fish oil content. In conclusion, our data indicates that dietary fish oil inhibits photochemically induced thrombosis in this animal model of arterial thrombosis in a dose dependent manner.

Vitamin K-dependent and vitamin K-independent hypocoagulant effects of dietary fish oil in rats

In rats, dietary fish oil causes a plasma triglyceride-lowering as well as hypocoagulant effect. The latter is apparent from reduced levels of vitamin K-dependent coagulation factors and a decreased thrombin-forming potential of the coagulating plasma. Here, we describe that intervention with low levels of n-3 polyunsaturated fatty acids (n-3 PUFAs, about 2.5% of digestible energy, en%) resulted in no more than a small reduction in coagulation factors, when supplied as part of a high-fat diet relatively rich in vitamin K. Plasma triglycerides also remained unchanged. On the other hand, when feeding rats with low- or high-fat diets restricted in vitamin K, intervention with 3 en% of n-3 PUFAs acids (fish oil) caused only a lowering in triglycerides in combination with high fat. The fish caused a reduction in coagulation potential and levels vitamin K-dependent coagulation factors (prothrombin and factor VII) that was most prominent with the low-fat diet. Fish oil, in combination with low fat but not with high fat, reduced the vitamin K levels in the liver of the animals. In addition, regardless of the fat content, the vitamin K-independent coagulation factor V was decreased in the fish oil groups. Taken together, these results indicate that, in the rat, the hypocoagulant effect of a low dose of n-3 PUFAs is most apparent at low intakes of both vitamin K and fat, is not linked to the triglyceride plasma level, but involves modulation of both vitamin K-dependent and -independent coagulation factors.