Oxidative pathways of arachidonic acid as targets for regulation of platelet activation

Role of Helicobacter pylori Infection in Pathogenesis, Evolution, and Complication of Atherosclerotic Plaque

The therapeutic management of atherosclerosis focuses almost exclusively on the reduction of plasma cholesterol levels. An important role in the genesis and evolution of atherosclerosis is played by chronic inflammation in promoting thrombosis phenomena after atheroma rupture. This review aims to take stock of the knowledge so far accumulated on the role of endemic HP infection in atherosclerosis. The studies produced so far have demonstrated a causal relationship between Helicobacter pylori (HP) and CVD. In a previous study, we demonstrated in HP-positive patients that thrombin and plasma fragment 1 + 2 production was proportionally related to tumor necrosis factor-alpha levels and that eradication of the infection resulted in a reduction of inflammation. At the end of our review, we can state that HP slightly affects the risk of CVD, particularly if the infection is associated with cytotoxic damage, and HP screening could have a clinically significant role in patients with a high risk of CVD. Considering the high prevalence of HP infection, an infection screening could be of great clinical utility in patients at high risk of CVD.

Discovery and verification of Q-markers for promoting blood circulation and removing stasis of raw and wine-steamed Vaccaria segetalis based on pharmacological evaluation combined with chemometrics

ETHNOPHARMACOLOGICAL RELEVANCE

Dried and mature seeds of Vaccaria segetalis (Neck.) Garcke ex Asch. (VS) are known for their therapeutic effects, as they stimulate blood circulation, promote menstruation and diuresis and eliminate gonorrhoea. However, due to its hard shell, the dissolution of its active ingredients is often improved by steaming and frying in clinical applications. Among the processed products, wine-steamed Vaccaria segetalis (WVS) is one of the commonly used ones. Numerous historical records have shown that wine steaming can enhance the efficacy of drugs to promote blood circulation and remove blood stasis. However, the differences in the efficacy of VS and WVS in promoting blood circulation and removing blood stasis have not been thoroughly studied, and the possible reasons for these differences have not been reported.

AIM OF THE STUDY

The objective of this study was to identify quality markers (Q-markers) that could differentiate the efficacy of promoting blood circulation and removing blood stasis of VS and WVS, which could serve as a basis for the rational application of VS and WVS in clinical settings.

MATERIALS AND METHODS

A pharmacodynamic comparison between the water extracts of VS and WVS was carried out based on a mouse acute blood stasis model (ABS) and thrombus zebrafish model. The potential bioactive substances of WVS were screened by investigating the correlation between common peaks identified for 10 batches of WVS by ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS) and their rate of thrombosis inhibition in zebrafish. Furthermore, multivariate statistical analysis of chemical components between VS and WVS was conducted to speculate the Q-markers combined with the results of the bioactive components. Based on the efficacy verification of Q-markers, the content of Q-markers in 10 batches of WVS was evaluated.

RESULTS

The results of efficacy comparison assays demonstrated that the efficacy of WVS was more prominent than VS at the same dose. Five components were screened as effective components of WVS for promoting blood circulation and removing blood stasis by correlation analysis. Furthermore, a total of 24 common ingredients were identified in VS and WVS extracts, and 9 of them showed increased dissolution rate after wine steaming, including 4 active ingredients, Hypaphorine, Vaccarin, Saponarin, and Isovitexin-2″-O-arabinoside, which were screened out by correlation analysis. The monomer test suggested that these 4 components could activate blood circulation and remove blood stasis in a dose-dependent manner. Consequently, Hypaphorine, Vaccarin, Saponarin, and Isovitexin-2″-O-arabinoside were selected as Q-markers to distinguish between VS and WVS. The content determination showed that the total contents of 4 Q-markers of WVS from 10 batches with different origins ranged from 0.478% to 0.716%.

CONCLUSIONS

This study compared the efficacy of VS and WVS in promoting blood circulation and resolving stasis and revealed Q-markers that reflected the difference in efficacy between them for the first time, which laid the foundation for establishing quality standards for WVS.

Arachidonic acid metabolism in health and disease

Arachidonic acid (AA), an n-6 essential fatty acid, is a major component of mammalian cells and can be released by phospholipase A2. Accumulating evidence indicates that AA plays essential biochemical roles, as it is the direct precursor of bioactive lipid metabolites of eicosanoids such as prostaglandins, leukotrienes, and epoxyeicosatrienoic acid obtained from three distinct enzymatic metabolic pathways: the cyclooxygenase pathway, lipoxygenase pathway, and cytochrome P450 pathway. AA metabolism is involved not only in cell differentiation, tissue development, and organ function but also in the progression of diseases, such as hepatic fibrosis, neurodegeneration, obesity, diabetes, and cancers. These eicosanoids are generally considered proinflammatory molecules, as they can trigger oxidative stress and stimulate the immune response. Therefore, interventions in AA metabolic pathways are effective ways to manage inflammatory-related diseases in the clinic. Currently, inhibitors targeting enzymes related to AA metabolic pathways are an important area of drug discovery. Moreover, many advances have also been made in clinical studies of AA metabolic inhibitors in combination with chemotherapy and immunotherapy. Herein, we review the discovery of AA and focus on AA metabolism in relation to health and diseases. Furthermore, inhibitors targeting AA metabolism are summarized, and potential clinical applications are discussed.

Alterations in factors associated with diabetic retinopathy combined with thrombosis: A review

Diabetic retinopathy (DR) is one of the most common and serious microvascular complications of diabetes mellitus, the incidence of which has been increasing annually, and it is the main cause of vision loss in diabetic patients and a common cause of blindness. It is now found that thrombosis plays a crucial role in the disease progression in DR patients, and the final vision loss in DR may be related to the occurrence of thrombosis in the retinal vessels, which is dominated by abnormal endothelial cell function, together with platelet dysfunction, imbalance of coagulation and fibrinolytic function, and related alterations of inflammatory factors leading to the main cause of thrombotic disease in DR patients. In this review, we examine the role between DR and thrombosis and the association of each factor, including endothelial dysfunction; platelet dysfunction; coagulation-fibrinolytic imbalance; and alterations in inflammatory factors.

Preventive effect and mechanism of Tibetan tea extract on thrombosis in arachidonic acid-induced zebrafish determined via RNA-seq transcriptome profiles

Thrombosis is a key pathological event in cardiovascular diseases and is also the most important targeting process for their clinical management. In this study, arachidonic acid (AA) was used to induce thrombus formation in zebrafish larvae. Blood flow, red blood cell (RBCs) aggregation and cellular oxidative stress were measured to evaluate the antithrombotic effect of Tibetan tea (TT). Meanwhile, the potential molecular mechanism was further explored by transcriptome sequencing (RNA-seq). The results indicated that TT could significantly restore heart RBCs intensity of thrombotic zebrafish, whilst decreasing RBCs accumulation in the caudal vein. The transcriptome analysis revealed that the preventive effect of TT on thrombosis could be mostly attributed to changes in lipid metabolism related signaling pathways, such as fatty acid metabolism, glycerollipid metabolism, ECM-receptor interaction and steroid biosynthesis signaling pathway. This study demonstrated that Tibetan tea could alleviate thrombosis by reducing oxidative stress levels and regulating lipid metabolism.

Wuliangye Baijiu but not ethanol reduces cardiovascular disease risks in a zebrafish thrombosis model

Understanding how Baijiu facilitates blood circulation and prevents blood stasis is crucial for revealing the mechanism of Baijiu for cardiovascular disease (CVD) risk reduction. Here we established a zebrafish thrombosis model induced using arachidonic acid (AA) to quantitatively evaluate the antithrombotic effect of Wuliangye Baijiu. The prevention and reduction effects of aspirin, Wuliangye, and ethanol on thrombosis were compared using imaging and molecular characterization. Wuliangye Baijiu reduces thrombotic risks and oxidative stress in the AA-treated zebrafish, while ethanol with the same concentration has no similar effect. The prevention and reduction effects of Wuliangye on thrombosis are attributed to the change in the metabolic and signaling pathways related to platelet aggregation and adhesion, oxidative stress and inflammatory response.

Vitamin E supplementation improves post-transportation systemic antioxidant capacity in yak

This study was aimed to evaluate the effects of post-transportation vitamin E (VE) supplementation on health condition, blood biochemical parameters, blood antioxidant indices and blood metabolomics in yak. Five yaks were used in this study. After 2100 km of highway transportation from Riwoqe county to Rongchang County, Chongqing, blood was collected immediately after arrival and these samples served as the baseline (control, CON_VE). A VE injection (40 mg/kg) was then performed and blood samples were collected 10 days later. Injection of VE led to lower serum VE concentration. Relative to the CON_VE, VE injection led to greater concentrations of creatinine and lower concentrations of glutamate pyruvic transaminase, alkaline phosphatase, aspartate aminotransferase, total bilirubin, indirect bilirubin, direct bilirubin, UREA and glucose. Compared with CON_VE, VE injection led the lower serum level of malondialdehydeand greater serum level of glutathione s-transferase, glutathione peroxidase, glutathione reductase and glutathione peroxidase 4. Based on metabolomics analysis, 119 differentially altered serum metabolites (P<0.05 and VIP>1.0) were identified with VE injection relative to CON_VE. VE injection resulted in changes of lysophosphatidylethanolamine, lysophosphatidylcholine, phosphocholine, choline, malate, citrate, α-Oxo-glutarate, phenylalanine, 3-Phenylpropanoic acid and 3-(3-Hydroxyphenyl) propanoic acid. These metabolites are associated with lipid metabolism, tricarboxylic acid cycle and oxidative stress. Overall, our study indicates that VE injection can alleviate transportation stress in yak partly through protecting liver and kidney, and improving antioxidant defense systems.

INTERCEPT Pathogen Reduction in Platelet Concentrates, in Contrast to Gamma Irradiation, Induces the Formation of trans-Arachidonic Acids and Affects Eicosanoid Release during Storage

Pathogen inactivation techniques for blood products have been implemented to optimize clinically safe blood components supply. The INTERCEPT system uses amotosalen together with ultraviolet light wavelength A (UVA) irradiation. Irradiation-induced inactivation of nucleic acids may actually be accompanied by modifications of chemically reactive polyunsaturated fatty acids known to be important mediators of platelet functions. Thus, here, we investigated eicosanoids and the related fatty acids released upon treatment and during storage of platelet concentrates for 7 days, complemented by the analysis of functional and metabolic consequences of these treatments. Metabolic and functional issues like glucose consumption, lactate formation, platelet aggregation, and clot firmness hardly differed between the two treatment groups. In contrast to gamma irradiation, here, we demonstrated that INTERCEPT treatment immediately caused new formation of trans-arachidonic acid isoforms, while 11-hydroxyeicosatetraenoic acid (11-HETE) and 15-HETE were increased and two hydroperoxyoctadecadienoic acid (HpODE) isoforms decreased. During further storage, these alterations remained stable, while the release of 12-lipoxygenase (12-LOX) products such as 12-HETE and 12-hydroxyeicosapentaenoic acid (12-HEPE) was further attenuated. In vitro synthesis of trans-arachidonic acid isoforms suggested that thiol radicals formed by UVA treatment may be responsible for the INTERCEPT-specific effects observed in platelet concentrates. It is reasonable to assume that UVA-induced molecules may have specific biological effects which need to be further investigated.

Associations of Gut Microbiota and Fatty Metabolism With Immune Thrombocytopenia

Objective

To determine whether gut microbiota, fatty metabolism and cytokines were associated with immune thrombocytopenia (ITP).

Methods

In total, 29 preliminarily diagnosed ITP patients and 33 healthy volunteers were enrolled. Fecal bacterial were analyzed based on 16S rRNA sequencing. Plasma cytokines and motabolites were analyzed using flow cytometry and liquid chromatography-mass spectrometry (LC-MS), respectively.

Results

Bacteroides, Phascolarctobacterium, and Lactobacillus were enriched at the genus level in ITP patients, while Ruminococcaceae UCG-002, Eubacterium coprostanoligeues, Megamonas, and Lachnospiraceae NC2004 were depleted. At the phylum level, the relative abundance of Proteobacteria and Chloroflexi increased in ITP patients, while Firmicutes, Actinobacteria, and the Firmicutes/Bacteroidetes ratio decreased. Plasma levels of 5-hydroxyeicosatetraenoic acid (5-HETE), 6-trans-12-epi-leukotriene B4 (6t,12e-LTB₄), and resolvin D2 (RvD₂) were upregulated, and stachydrine, dowicide A, dodecanoylcarnitine were downregulated in ITP patients. Furthermore, RvD₂ is positively correlated with order Bacteroidetes VC2.1 Bac22, 5-HETE is positively correlated with genus Azospirillum, and 6t,12e-LTB₄ is positively correlated with genus Cupriavidus. In addition, stachydrine is positively correlated with family Planococcaceae, dowicide A is positively correlated with class MVP-15, and dodecanoylcarnitine is positively correlated with order WCHB1-41. Plasma levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were upregulated in ITP patients.

Conclusion

Our study revealed a relationship between microbiota and fatty metabolism in ITP. Gut microbiota may participate in the pathogenesis of ITP through affecting cytokine secretion, interfering with fatty metabolism.

Platelets, a Key Cell in Inflammation and Atherosclerosis Progression

Platelets play important roles in thrombosis-dependent obstructive cardiovascular diseases. In addition, it has now become evident that platelets also participate in the earliest stages of atherosclerosis, including the genesis of the atherosclerotic lesion. Moreover, while the link between platelet activity and hemostasis has been well established, the role of platelets as modulators of inflammation has only recently been recognized. Thus, through their secretory activities, platelets can chemically attract a diverse repertoire of cells to inflammatory foci. Although monocytes and lymphocytes act as key cells in the progression of an inflammatory event and play a central role in plaque formation and progression, there is also evidence that platelets can traverse the endothelium, and therefore be a direct mediator in the progression of atherosclerotic plaque. This review provides an overview of platelet interactions and regulation in atherosclerosis.

Metabolomics analysis of Semen Cuscutae protection of kidney deficient model rats using ultra high-performance liquid chromatography-quadrupole time-of-flight Mass Spectrometry

The traditional Chinese medicine syndrome "Kidney yang deficiency" is a kind of chronic kidney disease. With the development of society, the incidence of chronic kidney disease is increasing year by year, which also brings great economic pressure to people. Semen Cuscutae is an important traditional Chinese medicine to tonify liver and kidney, mainly used to tonify deficiency of liver and kidney, spleen and kidney deficiency and diarrhea. Although there are a lot of research at the molecular and cellular level to study the Semen Cuscutae on the treatment of Kidney yang deficiency syndrome, but there's no comprehensive research complete with metabolomics method from plasma, feces and urine metabolites aspects. The purpose of this study is to find the potential differential biomarkers of the Kidney yang deficiency model and blank group rats in plasma, urine and feces, and to investigate the mechanism of Semen Cuscutae in the treatment of Kidney yang deficiency syndrome. In this study, ultra high-performance liquid chromatography-quadrupole time-of-flight Mass Spectrometry (UPLC-QTOF/MS) was used to identify potential biomarkers. Through the analysis of metabolic profiles of plasma, urine, and feces, as well as multivariate statistical analysis and pathway analysis, the therapeutic mechanism of Semen Cuscutae for Kidney yang deficiency syndrome was described. The results showed that there were 69 differential metabolites in plasma, 93 differential metabolites in feces and 62 differential metabolites in urine, and the changes of the levels of these biomarkers showed that Semen Cuscutae had a good therapeutic effect on Kidney yang deficiency syndrome. Through the analysis of the channel, the metabolite changes mainly affected the steroid hormone biosynthesis, arachidonic acid metabolism, primary bile acid biosynthesis, sheath lipid metabolism and biosynthesis of tyrosine, phenylalanine metabolism, retinol metabolism,taurine and hypotaurine metabolism, lysine degradation and vitamin B6 metabolism, tryptophan metabolism, terpenoid backbone biosynthesis and starch and sucrose metabolism. Therefore, the results suggested that Semen Cuscutae could exert a good therapeutic effect by reversing the levels of some biomarkers.

Effects of Arachidonic Acid Metabolites on Cardiovascular Health and Disease

Arachidonic acid (AA) is an essential fatty acid that is released by phospholipids in cell membranes and metabolized by cyclooxygenase (COX), cytochrome P450 (CYP) enzymes, and lipid oxygenase (LOX) pathways to regulate complex cardiovascular function under physiological and pathological conditions. Various AA metabolites include prostaglandins, prostacyclin, thromboxanes, hydroxyeicosatetraenoic acids, leukotrienes, lipoxins, and epoxyeicosatrienoic acids. The AA metabolites play important and differential roles in the modulation of vascular tone, and cardiovascular complications including atherosclerosis, hypertension, and myocardial infarction upon actions to different receptors and vascular beds. This article reviews the roles of AA metabolism in cardiovascular health and disease as well as their potential therapeutic implication.

Role of Arachidonic Acid and Its Metabolites in the Biological and Clinical Manifestations of Idiopathic Nephrotic Syndrome

Studies concerning the role of arachidonic acid (AA) and its metabolites in kidney disease are scarce, and this applies in particular to idiopathic nephrotic syndrome (INS). INS is one of the most frequent glomerular diseases in childhood; it is characterized by T-lymphocyte dysfunction, alterations of pro- and anti-coagulant factor levels, and increased platelet count and aggregation, leading to thrombophilia. AA and its metabolites are involved in several biological processes. Herein, we describe the main fields where they may play a significant role, particularly as it pertains to their effects on the kidney and the mechanisms underlying INS. AA and its metabolites influence cell membrane fluidity and permeability, modulate platelet activity and coagulation, regulate lymphocyte activity and inflammation, preserve the permeability of the glomerular barrier, influence podocyte physiology, and play a role in renal fibrosis. We also provide suggestions regarding dietary measures that are able to prevent an imbalance between arachidonic acid and its parental compound linoleic acid, in order to counteract the inflammatory state which characterizes numerous kidney diseases. On this basis, studies of AA in kidney disease appear as an important field to explore, with possible relevant results at the biological, dietary, and pharmacological level, in the final perspective for AA to modulate INS clinical manifestations.

Epoprostenol up-regulates serum adiponectin level in patients with systemic sclerosis: therapeutic implications

INTRODUCTION

Adiponectin, resistin and leptin belong to adipokines, a group of molecules secreted mainly by the adipose tissue, which impaired expression may be a missing link between various manifestations of systemic sclerosis. Adiponectin, which is also released in small amounts by the endothelium, possesses anti-inflammatory, anti-fibrotic and protective against endothelial injury properties. Both leptin and resistin exhibit features which are contradictory to adiponectin, as they trigger inflammation and the activation of skin fibroblasts. Epoprostenol is a prostaglandin analogue with powerful vasodilator activity and inhibitory effect on platelet aggregation. The aim of the study was to evaluate whether epoprostenol may have an effect on serum adipokine levels in patients with systemic sclerosis.

METHODS

A total of 27 patients were included in the study and received epoprostenol intravenously (25 µg of per day for 3 consecutive days). Serum concentrations of total adiponectin, resistin and leptin were assessed with enzyme-linked immunosorbent essay (R&D Systems, Minneapolis, MN, USA).

RESULTS

In all SSc patients, the basal level of adiponectin was significantly lower compared to healthy controls (mean 6.00 [Formula: see text] 2.81 μg/ml vs. 8.8 [Formula: see text] 4.3 μg/ml, p = 0.02) and basal level of resistin (mean 11.12 [Formula: see text] 3.36 ng/ml vs. 8.54 [Formula: see text] 3.07 ng/ml p = 0.02) was significantly higher than in the control group. The serum concentration of adiponectin increased significantly after treatment with epoprostenol (6.00 [Formula: see text] 2.81 μg/ml vs 9.29 [Formula: see text] 6.05 μg/ml; P = 0.002). The level of resistin and leptin remained unchanged.

CONCLUSION

Epoprostenol infusions up-regulate the serum concentration of adiponectin in patients with systemic sclerosis. In our opinion, future studies on treatments in systemic sclerosis should address the issue of their effect on adipokine metabolism.

Ginsenosides Rb2 and Rd2 isolated from Panax notoginseng flowers attenuate platelet function through P2Y12-mediated cAMP/PKA and PI3K/Akt/Erk1/2 signaling

Saponins derived from Panax notoginseng root are widely used as herbal medicines and dietary supplements due to their wide range of health benefits. However, the effects of those from Panax notoginseng flowers (PNF) on platelet function and thrombus formation remain largely unknown. Using a series of platelet function assays, we found that G-Rb2 and G-Rd2, among the ten PNF saponin monomers, significantly inhibited human platelet aggregation and activation induced by adenosine diphosphate (ADP) in vitro. The 50% inhibitory concentration (IC50) of G-Rb2 and G-Rd2 against ADP-induced platelet aggregation was 85.5 ± 4.5 μg mL-1 and 51.4 ± 4.6 μg mL-1, respectively. Mechanistically, G-Rb2 and G-Rd2 could effectively modulate platelet P2Y12-mediated signaling by up-regulating cAMP/PKA signaling and down-regulating PI3K/Akt/Erk1/2 signaling pathways. Co-incubation of the P2Y12 antagonist cangrelor with either G-Rb2 or G-Rd2 did not show significant additive inhibitory effects. G-Rb2 and G-Rd2 also substantially suppressed thrombus growth in a FeCl3-induced murine arteriole thrombosis model in vivo. Interestingly, G-Rd2 generally exhibited more potent inhibitory effects on platelet function and thrombus formation than G-Rb2. Thus, our data suggest that PNF-derived G-Rb2 and G-Rd2 effectively attenuate platelet hyperactivity through modulating signaling pathways downstream of P2Y12, which indicates G-Rb2 and G-Rd2 may play important preventive roles in thrombotic diseases.

Artemisia plants, arachidonic and other polyunsaturated fatty acids

Arachidonic acid (AA or ARA) is an extremely important fatty acid involved in cell regulation. It is a polyunsaturated fatty acid (20:4n6) covalently bound in esterified form in membrane phospholipids of most body cells. Following irritation or injury, arachidonic acid is released and oxygenated by enzyme systems leading to the formation of an important group of inflammatory mediators, to the prostaglandins (PGE₂) by the cyclooxygenase enzyme. This paper describes the positive health effects of arachidonic acid on malaria and other tropical diseases.

Synthesis of antiplatelet ortho-carbonyl hydroquinones with differential action on platelet aggregation stimulated by collagen or TRAP-6

Cardiovascular diseases are the leading cause of death in the world. Platelets have a major role in cardiovascular events as they bind to the damaged endothelium activating and forming thrombi. Although some hydroquinone scaffold-containing compounds have known antiplatelet activities, currently there is a lack of evidence on the antiplatelet activity of hydroquinones carrying electron attractor groups. In this work, we evaluate the antiplatelet effect of a series of ortho-carbonyl hydroquinone derivatives on cytotoxicity and function of human platelets, using collagen and thrombin receptor activator peptide 6 (TRAP-6) as agonists. Our structure-activity relationship study shows that gem-diethyl/methyl substitutions and the addition/modifications of the third ring of ortho-carbonyl hydroquinone scaffold influence on the selective index (IC₅₀ TRAP-6/IC₅₀ Collagen) and the inhibitory capacity of platelet aggregation. Compounds 3 and 8 inhibit agonist-induced platelet aggregation in a non-competitive manner with IC₅₀ values of 1.77 ± 2.09 μM (collagen) and 11.88 ± 4.59 μM (TRAP-6), respectively and show no cytotoxicity. Both compounds do not affect intracellular calcium levels and mitochondrial bioenergetics. Consistently, they reduce the expression of P-selectin, activation of glycoprotein IIb/IIIa, and release of adenosine triphosphate and CD63 from platelet. Our findings may be used for further development of new drugs in platelet-related thrombosis diseases.