Thromboelastography with platelet mapping: Limited predictive ability in detecting preinjury antiplatelet agent use.

BACKGROUND: Preinjury antiplatelet agent (APA) use in trauma patients can increase traumatic hemorrhage and worsen outcomes. Thromboelastography with platelet mapping (TEGPM) has characterized platelet function via arachidonic acid (AA) and adenosine diphosphate (ADP) inhibition in nontrauma settings, but limited data exist in the acute trauma population. METHODS: A prospective observational study of adult trauma patients with suspected preinjury APA use who received TEGPM testing from 2017 to 2020 was performed. Patients on anticoagulants were excluded. Patients were grouped according to preinjury APA regimen: 81 mg or 325 mg of aspirin daily, 81 mg of aspirin and 75 mg of clopidrogrel daily, 75 mg of clopidrogrel daily, or no antiplatelet. Ability of TEGPM to detect APA use was assessed using predictive statistics and area under receiver operating characteristic curves (AUROCs). RESULTS: A total of 824 patients were included with most patients taking 81 mg of aspirin (n = 558). Patients on no antiplatelet were younger and had higher baseline platelet counts, while patients on 75 mg of clopidrogrel were more likely to be admitted after ground level fall. All other baseline characteristics were balanced. Admission TEG values were similar between groups. Median AA inhibition was higher in patients on aspirin containing regimens (p < 0.0001). Median ADP inhibition was higher in patients on clopidogrel containing regimens and those taking 325 mg of aspirin (p < 0.0001). Arachidonic acid inhibition accurately detected preinjury APA use and aspirin use (AUROC, 0.89 and 0.84, respectively); however, ADP inhibition performed poorly (AUROC, 0.58). Neither AA nor ADP inhibition was able to discern specific APA regimens or rule out APA use entirely. CONCLUSION: High AA inhibition accurately detects preinjury APA use in trauma patients. High ADP inhibition after trauma is common, limiting its utility to accurately identify preinjury APA use. Further study is needed to identify assays that can reliably detect and further characterize preinjury APA use in trauma populations. LEVEL OF EVIDENCE: Diagnostic test, level II.

Assessment of the anti-rheumatoid arthritis activity of Gastrodia elata (tian-ma) and Radix aconitic lateralis preparata (fu-zi) via network pharmacology and untargeted metabolomics analyses.

AIM: Gastrodia elata and Radix aconiti lateralis preparrata are respectively named as Tian-Ma and Fu-Zi (TF) in Chinese. We explored the active components against rheumatoid arthritis (RA) from an extensively used couplet of Chinese herbs, Gastrodia elata and Radix aconiti lateralis preparata (TF) via untargeted metabolomics and network pharmacological approaches. METHODS: Water extracts of TF were mixed at ratios 1:1, 3:2 and 2:3 (w/w). Ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) was then utilized as metabolomics screening. Human Metabolome (http://www.hmdb.ca/) and Lipidmaps (http://www.lipidmaps.org/) databases were used to annotate detected compounds. Further identification of vital genes and important pathways associated with the anti-RA properties of the TF preparations was done via network pharmacology, and verified by real-time quantitative polymerase chain reaction (RT-qPCR). RESULTS: Four key compounds involved in unsaturated fatty acid biosynthesis and isoflavonoid biosynthesis were identified through metabolomics analyses. Three key components of TF associated with anti-RA activity were linoleic acid, daidzein, and daidzin. Results of RT-qPCR revealed that all 3 tested TF couplets (1:1, 3:2, and 2:3) markedly suppressed the transcription of PTGS2. These results were consistent with our network pharmacological predictions. CONCLUSIONS: The anti-RA properties of Tian-Ma and Fu-Zi are associated with the inhibition of arachidonic acid metabolism pathway.

Nitrate and nitrite exposure leads to mild anxiogenic-like behavior and alters brain metabolomic profile in zebrafish.

Dietary nitrate lowers blood pressure and improves athletic performance in humans, yet data supporting observations that it may increase cerebral blood flow and improve cognitive performance are mixed. We tested the hypothesis that nitrate and nitrite treatment would improve indicators of learning and cognitive performance in a zebrafish (Danio rerio) model. We utilized targeted and untargeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis to examine the extent to which treatment resulted in changes in nitrate or nitrite concentrations in the brain and altered the brain metabolome. Fish were exposed to sodium nitrate (606.9 mg/L), sodium nitrite (19.5 mg/L), or control water for 2-4 weeks and free swim, startle response, and shuttle box assays were performed. Nitrate and nitrite treatment did not change fish weight, length, predator avoidance, or distance and velocity traveled in an unstressed environment. Nitrate- and nitrite-treated fish initially experienced more negative reinforcement and increased time to decision in the shuttle box assay, which is consistent with a decrease in associative learning or executive function however, over multiple trials, all treatment groups demonstrated behaviors associated with learning. Nitrate and nitrite treatment was associated with mild anxiogenic-like behavior but did not alter epinephrine, norepinephrine or dopamine levels. Targeted metabolomics analysis revealed no significant increase in brain nitrate or nitrite concentrations with treatment. Untargeted metabolomics analysis found 47 metabolites whose abundance was significantly altered in the brain with nitrate and nitrite treatment. Overall, the depletion in brain metabolites is plausibly associated with the regulation of neuronal activity including statistically significant reductions in the inhibitory neurotransmitter γ-aminobutyric acid (GABA; 18-19%), and its precursor, glutamine (17-22%). Nitrate treatment caused significant depletion in the brain concentration of fatty acids including linoleic acid (LA) by 50% and arachidonic acid (ARA) by 80%; nitrite treatment caused depletion of LA by ~90% and ARA by 60%, change which could alter the function of dopaminergic neurons and affect behavior. Nitrate and nitrite treatment did not adversely affect multiple parameters of zebrafish health. It is plausible that indirect NO-mediated mechanisms may be responsible for the nitrate and nitrite-mediated effects on the brain metabolome and behavior in zebrafish.

α-Conotoxins Enhance both the In Vivo Suppression of Ehrlich carcinoma Growth and In Vitro Reduction in Cell Viability Elicited by Cyclooxygenase and Lipoxygenase Inhibitors.

Several biochemical mechanisms, including the arachidonic acid cascade and activation of nicotinic acetylcholine receptors (nAChRs), are involved in increased tumor survival. Combined application of inhibitors acting on these two pathways may result in a more pronounced antitumor effect. Here, we show that baicalein (selective 12-lipoxygenase inhibitor), nordihydroguaiaretic acid (non-selective lipoxygenase inhibitor), and indomethacin (non-selective cyclooxygenase inhibitor) are cytotoxic to Ehrlich carcinoma cells in vitro. Marine snail α-conotoxins PnIA, RgIA and ArIB11L16D, blockers of α3ß2/α6ß2, α9α10 and α7 nAChR subtypes, respectively, as well as α-cobratoxin, a blocker of α7 and muscle subtype nAChRs, exhibit low cytotoxicity, but enhance the antitumor effect of baicalein 1.4-fold after 24 h and that of nordihydroguaiaretic acid 1.8-3.9-fold after 48 h of cell cultivation. α-Conotoxin MII, a blocker of α6-containing and α3ß2 nAChR subtypes, increases the cytotoxic effect of indomethacin 1.9-fold after 48 h of cultivation. In vivo, baicalein, α-conotoxins MII and PnIA inhibit Ehrlich carcinoma growth and increase mouse survival; these effects are greatly enhanced by the combined application of α-conotoxin MII with indomethacin or conotoxin PnIA with baicalein. Thus, we show, for the first time, antitumor synergism of α-conotoxins and arachidonic acid cascade inhibitors.

Study on coagulation profiles and platelet function in trauma-induced coagulopathy caused by three types of injury.

BACKGROUND: Traumatic coagulopathy is a major public health issue globally with undefined mechanisms. We established rat models of hemorrhagic shock (HS), multiple injury (MI) and traumatic brain injury (TBI) to investigate the diversity of traumatic coagulopathy, especially platelet dysfunction. METHODS: Seventy male SD rats were divided randomly into seven groups(n = 10): control, HS30min, HS3h, MI30min, MI3h, TBI30min and TBI3h. Plasma or whole blood was collected for conventional coagulation tests, thromboelastography and platelet mapping. X-ray, 7T magnetic resonance imaging and hematoxylin-eosin staining of injured tissues were conducted to confirm the injuries of rats model. RESULTS: The activated partial thromboplastin time (aPTT) prolonged significantly in HS30min and MI3h groups, compared with those in control (P = 0.0403 and P = 0.0076, respectively). R values decreased in HS30min and HS3h groups, compared with those in control (P < 0.0001 and P < 0.0001, respectively). The maximum amplitude (MA) were 71.8 ± 0.6 mm, 71.9 ± 0.5 mm, 71.8 ± 0.7 mm, 70.0 ± 0.7 mm, 72.6 ± 0.9 mm, 70.4 ± 0.9 mm in HS30min, HS3h, MI30min, MI3h, TBI30min and TBI3h groups respectively, which were lower than those in control (P = 0.0304, P = 0.0205, P = 0.0431, P = 0.0007 and P = 0.0066, respectively). The platelet counts were 539±46 × 109/L, 523±31 × 109/L, 629 ± 18 × 109/L and 636±20 × 109/L in HS30min, HS3h, MI3h and TBI3h groups respectively, which were lower than those in control (P = 0.0040, P = 0.0001, P = 0.0127 and P = 0.0232, respectively). The adenosine diphosphate (ADP) inhibition rate decreased in HS30min group, compared with that in control (P = 0.0355). While, ADP inhibition rate increased in HS3h and TBI3h groups (P = 0.0041 and P = 0.0433 vs. control, respectively). The arachidonic acid (AA) inhibition rate increased in MI30min and MI3h groups, compared with control (P = 0.0029 and P = 0.0185, respectively). CONCLUSION: These results demonstrated that it might be the failure of forming a strong clot instead of the prolonged clot time, which contributed to traumatic coagulopathy. The platelet dysfunctions might contribute to trauma-induced coagulopathy in different ways. The loss of platelets might be the main reason for HS-induced coagulopathy. While, AA-dependent pathway inhibition might account for MI-induced coagulopathy. ADP-dependent pathway inhibition might be the major contributor for TBI-induced coagulopathy.

Transcriptomic studies provide insights into the tumor suppressive role of miR-146a-5p in non-small cell lung cancer (NSCLC) cells.

Non-small cell lung cancer (NSCLC) is a complex disease in need of new methods of therapeutic intervention. Recent interest has focused on using microRNAs (miRNAs) as a novel treatment method for various cancers. miRNAs negatively regulate gene expression post-transcriptionally, and have become attractive candidates for cancer treatment because they often simultaneously target multiple genes of similar biological function. One such miRNA is miR-146a-5p, which has been described as a tumor suppressive miRNA in NSCLC cell lines and tissues. In this study, we performed RNA-Sequencing (RNA-Seq) analysis following transfection of synthetic miR-146a-5p in an NSCLC cell line, A549, and validated our data with Gene Ontology and qRT-PCR analysis of known miR-146a-5p target genes. Our transcriptomic data revealed that miR-146a-5p exerts its tumor suppressive function beyond previously reported targeting of EGFR and NF-κB signaling. miR-146a-5p mimic transfection downregulated arachidonic acid metabolism genes, the RNA-binding protein HuR, and many HuR-stabilized pro-cancer mRNAs, including TGF-ß, HIF-1α, and various cyclins. miR-146a-5p transfection also reduced expression and cellular release of the chemokine CCL2, and this effect was mediated through the 3' untranslated region of its mRNA. Taken together, our work reveals that miR-146a-5p functions as a tumor suppressor in NSCLC by controlling various metabolic and signaling pathways through direct and indirect mechanisms.

Duchenne muscular dystrophy: Focus on arachidonic acid metabolites.

Duchenne muscular dystrophy (DMD) is an incurable disease, characterized by the muscle inflammation and progressive deterioration of muscle function. We discuss and review the role of arachidonic acid (AA) metabolites in DMD in muscle fiber degeneration and regeneration and new opportunities for developing new drugs by targeting the AA pathway, providing evidence that the AA pathway could represent an efficacious strategy to ameliorate the treatment of DMD patients. Currently a series of DMD care recommendations regarding management of rehabilitation, orthopedic, respiratory, cardiovascular, gastroenterology exist and the therapy is restricted to corticosteroids for muscle dysfunction with serious side effects. Nowadays there are still no effective cures for the disease. The alternative pharmacological strategies targeting the AA metabolites may yield favorable outcomes in DMD. 5-LOX inhibition might be important for the survival of myofibers. Moreover H-PGDS inhibitors, cyclooxygenase (COX)-inhibiting NO donors (CINODs), inhibitors of Ca2+-independent PLA2, are some of the different pathways which can bring to further development of new drugs.

Two-pronged approach to anti-inflammatory therapy through the modulation of the arachidonic acid cascade.

Chronic inflammation and pain is a major global health problem, and nonsteroidal anti-inflammatory drugs (NSAIDs) remain the most frequently prescribed drugs and common option for the treatment of inflammatory pain. However, they have the potential to cause serious complications, such as gastrointestinal (GI) lesions, bleeding and cardiovascular (CV) problems. NSAIDs exert their anti-inflammatory, analgesic and anti-pyretic actions by inhibiting the cyclooxygenases (COX)-1 and COX-2, key enzymes of the arachidonic acid (AA) cascade. However, not all the AA products or their receptors are pro-inflammatory. Therefore, given the multifaceted interactions of these lipid mediators where a single precursor can trigger multiple events with synergic or opposed function, it is easy to predict that any perturbation of this interplay will cause several unavoidable side effects. Today, we do not have a truly safe NSAID that minimizes GI damage and CV toxicity. One possibility to interfere with this intricate network, while trying to keep its fine balance, is to develop molecules affecting several targets. Different strategies have been proposed for a multitargeted intervention at different levels of the AA cascade, like inhibition of multiple upstream enzymes, such as COX, 5-lipoxygenase, or even soluble epoxide hydrolase and prostaglandin E synthase. Alternative strategies are more focused in the inhibition of targets downstream in the metabolic pathway, such as thromboxane synthase and/or blocking selective receptors. In this review we will briefly summarize the new strategies that have been proposed for a multitargeted pharmacological intervention on this metabolic cascade aimed at developing novel anti-inflammatory therapeutics.

HPLC profile and antiedematogenic activity of Ximenia americana L. (Olacaceae) in mice models of skin inflammation.

The aim of this study was to evaluate the anti-edematogenic activity of X. americana L. (HEXA) hydroethanolic extract in ear edema models (acute and chronic) induced by croton oil and by different phlogistic agents (arachidonic acid, capsaicin, phenol and histamine), identifying the possible anti-edematogenic mechanism. HEXA demonstrated a significant anti-edematogenic effect at concentrations of 100-500 µg/ear in ear edema induced by croton oil with higher inhibition of edema of 39.37. However, the concentrations of 100 and 200 µg/ear were taken as a standard, demonstrating the effect in the chronic model induced by croton oil with inhibition of 61.62% and 48.74%. In the AA-induced ear edema model, HEXA showed inhibition of: 24.45% and 32.31%; capsaicin inhibition of 72.72% and 47.57%; phenol inhibition of 34% and 20.1%; and histamine inhibition of 31.8% and 21.62%. Then, the results were showed that HEXA demonstrated an anti-edematogenic effect in acute and chronic inflammation models, demonstrating a probable mechanism of action by the inhibition or modulation of key mediators of the inflammatory process. The chemical profile and presence of flavonoids guaranteeing a profile of activity similar to natural drugs that act or modulate the production of mediators of inflammations.

Anti-platelet effects of vitamin supplements in age-related macular degeneration: an in vitro study.

OBJECTIVE: The purpose of this experimental study was to investigate the role of vitamin supplements (Ocuvite, Vitalux Omega, and Nutrof Total) as possible inhibitors of the onset of age-related macular degeneration (AMD). MATERIALS AND METHODS: The anti-aggregating effect of each vitamin was determined against four accumulative factors namely, platelet activating factor (PAF), adenosine diphosphate (ADP), thrombin receptor-activating peptide (TRAP), and arachidonic acid (AA) in the platelet rich plasma (PRP) of healthy volunteers. RESULTS: Ocuvite, Vitalux Omega, and Nutrof Total were more potent inhibitors against PAF and ADP compared to TRAP and AA. Among the three vitamins, Nutrof Total displayed more potent inhibitions against TRAP and AA, while against PAF and ADP all the three vitamins revealed similar IC50 values. CONCLUSIONS: The vitamins Ocuvite, Vitalux Omega, and Nutrof Total have anti-aggregating effects and therefore can be used against AMD in healthy volunteers.

In vivo anti-inflammatory and anti-platelet aggregation activities of longissiminone A, isolated from Usnea longissima.

Secondary metabolite, longissiminone A (1) was isolated from a lichen, Usnea longissima. It was screened for its' in vivo anti-inflammatroy and anti-platelet aggregation activities. Compound 1 showed moderate in vivo anti-inflammatory activity as well as moderately active against the aggregation induced by arachidonic acid at different doses.

Surfactant Protein B Suppresses Lung Cancer Progression by Inhibiting Secretory Phospholipase A2 Activity and Arachidonic Acid Production.

BACKGROUND/AIMS: Radiotherapy is applied to patients with inoperable cancer types including advanced stage non-small cell lung cancer (NSCLC) and radioresistance functions as a critical obstacle in radiotherapy. This study was aimed to investigate the mechanism of radioresistance regulated by surfactant protein B (SP-B). METHODS: To investigate the role of SP-B in radioresistance, ΔSFTPB A549 cell line was established and SP-B expression was analyzed. In response to ionizing radiation (IR), the change of SP-B expression was analyzed in A549 and NCI-H441 cell lines. Conditioned media (CM) from NSCLC cells were utilized to evaluate the downstream signaling pathway. The in vivo effects of SP-B were assessed through mouse xenograft model with intratumoral injection of CM. RESULTS: In response to IR, NSCLC cell lines showed decreased SP-B regulated by the TGF-ß signaling and decreased SP-B stimulated cell survival and epithelial-mesenchymal transition. Treatment with CM from irradiated cells activated sPLA2, enhanced protein kinase Cδ-MAPKs signaling pathway, and increased arachidonic acid production. We confirmed the in vivo roles of SP-B through mouse xenograft model. CONCLUSION: Our results revealed that down-regulation of SP-B was involved in the radiation-induced metastatic conversion of NSCLC and provided evidence that SP-B acted as a suppressor of NSCLC progression.

Valnoctamide, which reduces rat brain arachidonic acid turnover, is a potential non-teratogenic valproate substitute to treat bipolar disorder.

BACKGROUND: Valproic acid (VPA), used for treating bipolar disorder (BD), is teratogenic by inhibiting histone deacetylase. In unanaesthetized rats, chronic VPA, like other mood stabilizers, reduces arachidonic acid (AA) turnover in brain phospholipids, and inhibits AA activation to AA-CoA by recombinant acyl-CoA synthetase-4 (Acsl-4) in vitro. Valnoctamide (VCD), a non-teratogenic constitutional isomer of VPA amide, reported effective in BD, also inhibits recombinant Acsl-4 in vitro. HYPOTHESIS: VCD like VPA will reduce brain AA turnover in unanaesthetized rats. METHODS: A therapeutically relevant (50mg/kg i.p.) dose of VCD or vehicle was administered daily for 30 days to male rats. AA turnover and related parameters were determined using our kinetic model, following intravenous [1-14C]AA in unanaesthetized rats for 10min, and measuring labeled and unlabeled lipids in plasma and high-energy microwaved brain. RESULTS: VCD, compared with vehicle, increased λ, the ratio of brain AA-CoA to unesterified plasma AA specific activities; and decreased turnover of AA in individual and total brain phospholipids. CONCLUSIONS: VCD's ability like VPA to reduce rat brain AA turnover and inhibit recombinant Acsl-4, and its efficacy in BD, suggest that VCD be further considered as a non-teratogenic VPA substitute for treating BD.

2,3-Diarylxanthones as Potential Inhibitors of Arachidonic Acid Metabolic Pathways.

In response to an inflammatory stimulus, arachidonic acid (AA), the main polyunsaturated fatty acid present in the phospholipid layer of cell membranes, is released and metabolized to a series of eicosanoids. These bioactive lipid mediators of inflammation arise physiologically through the action of the enzymes 5-lipoxygenase (5-LOX) and cyclooxygenases (constitutive COX-1 and inducible COX-2). It is believed that dual inhibition of 5-LOX and COXs may have a higher beneficial impact in the treatment of inflammatory disorders rather than the inhibition of each enzyme. With this demand for new dual-acting anti-inflammatory agents, a range of 2,3-diarylxanthones were tested through their ability to interact in the AA metabolism. In vitro anti-inflammatory activity was evaluated through the inhibition of 5-LOX-catalyzed leukotriene B4 (LTB4) formation in human neutrophils and inhibition of COX-1- and COX-2-catalyzed prostaglandin E2 (PGE2) formation in human whole blood. The results showed that some of the studied arylxanthones were able to prevent LTB4 production in human neutrophils, in a concentration-dependent manner. The xanthone with a 2-catechol was the most active one (IC50 ∼ 9 µM). The more effective arylxanthones in preventing COX-1-catalyzed PGE2 production presented IC50 values from 1 to 7 µM, exhibiting a structural feature with at least one non-substituted aryl group. All the studied arylxanthones were ineffective to prevent the formation of PGE2 catalyzed by COX-2, up to the maximum concentration of 100 µM. The ability of the tested 2,3-diarylxanthones to interact with both 5-LOX and COX-1 pathways constitutes an important step in the research of novel dual-acting anti-inflammatory drugs.

Developing anti-inflammatory therapeutics for patients with osteoarthritis.

OA is the most common joint disorder in the world, but there are no approved therapeutics to prevent disease progression. Historically, OA has been considered a wear-and-tear joint disease, and efforts to identify and develop disease-modifying therapeutics have predominantly focused on direct inhibition of cartilage degeneration. However, there is now increasing evidence that inflammation is a key mediator of OA joint pathology, and also that the link between obesity and OA is not solely due to excessive load-bearing, suggesting therefore that targeting inflammation in OA could be a rewarding therapeutic strategy. In this review we therefore re-evaluate historical clinical trial data on anti-inflammatory therapeutics in OA patients, highlight some of the more promising emerging therapeutic targets and discuss the implications for future clinical trial design.

Five New Triterpenoid Saponins from the Rhizomes of Panacis majoris and Their Antiplatelet Aggregation Activity.

Five new triterpenoid saponins (1-5) and four known triterpenoid saponins, ginsenoside Re5 (6), majonoside R1 (7), 24(R)-majonoside R1 (8), and ginsenoside Rf (9), were isolated from the rhizomes of Panacis majoris. The structures of new compounds were elucidated as (20S,24S,25R*)-6-O-[ß-D-glucopyranosyl-(1 → 2)-ß-D-glucopyranosyl]-dammar-20,24-epoxy-3ß,6α,12ß,25,26-pentaol (1), (20S,24R,25R)-6-O-[ß-D-glucopyranosyl-(1 → 2)-ß-D-glucopyranosyl]-dammar-20,24-epoxy-3ß,6α,12ß,25,26-pentaol (2), (20S)-6-O-[ß-D-glucopyranosyl-(1 → 2)-ß-D-glucopyranosyl]-dammar-20,25-epoxy-3ß,6α,12ß,24α-tetraol (3), 6-O-[ß-D-glucopyranosyl-(1 → 2)-ß-D-glucopyranosyl]-dammar-3ß,6α,12ß,20S,24R,25-hexaol (4), and 6-O-[ß-D-glucop-yranosyl-(1 → 2)-ß-D-glucopyranosyl]-dammar-25(26)-ene-3ß,6α,12ß,20S,24R-pentaol (5) on the basis of extensive spectral analysis and chemical methods. Ginsenoside Re5 was isolated from the plant for the first time. The similarities of the nine compounds lie in the fact that their aglycones are conjoined with the same glucopyranose moieties, the same linkage of the glycosyl chains, and the same glycosylation sites, while they have a varied C-17 side chain. Compounds 3 and 5 exhibited moderate antiplatelet aggregation activities induced by adenosine diphosphate with IC50 values of 23.24 and 18.43 µM, respectively. Compound 5 displayed moderate inhibition of arachidonic acid-induced platelet aggregation with an IC50 value of 30.11 µM.

Oxidized arachidonic and adrenic PEs navigate cells to ferroptosis.

Enigmatic lipid peroxidation products have been claimed as the proximate executioners of ferroptosis-a specialized death program triggered by insufficiency of glutathione peroxidase 4 (GPX4). Using quantitative redox lipidomics, reverse genetics, bioinformatics and systems biology, we discovered that ferroptosis involves a highly organized oxygenation center, wherein oxidation in endoplasmic-reticulum-associated compartments occurs on only one class of phospholipids (phosphatidylethanolamines (PEs)) and is specific toward two fatty acyls-arachidonoyl (AA) and adrenoyl (AdA). Suppression of AA or AdA esterification into PE by genetic or pharmacological inhibition of acyl-CoA synthase 4 (ACSL4) acts as a specific antiferroptotic rescue pathway. Lipoxygenase (LOX) generates doubly and triply-oxygenated (15-hydroperoxy)-diacylated PE species, which act as death signals, and tocopherols and tocotrienols (vitamin E) suppress LOX and protect against ferroptosis, suggesting a homeostatic physiological role for vitamin E. This oxidative PE death pathway may also represent a target for drug discovery.

Effects of atorvastatin on ADP-, arachidonic acid-, collagen-, and epinephrine-induced platelet aggregation.

Objective Atorvastatin reduces the incidence of cardiovascular events. However, the effects of atorvastatin on platelet aggregation are unknown. Methods Blood samples were obtained from 126 healthy volunteers. Prepared isolated platelet suspensions were adjusted with saline to three different concentrations of 100 × 109, 300 × 109, and 600 × 109 platelets/L. Platelet samples were incubated with atorvastatin (10-7 mol/L, 10-6 mol/L or 10-5 mol/L), and stimulated with ADP (10 µmol/L), arachidonic acid (0.5 mmol/L), collagen (2 µg/mL), and epinephrine (1 mg/mL). The maximal amplitude of aggregation and the curve slope were measured by electric impedance aggregometry. Results Atorvastatin inhibited platelet aggregation at moderate (300 × 109/L) and high (600 × 109/L) concentrations. However, an inhibitory effect of atorvastatin at low concentrations (100 × 109/L) was not observed. Conclusions The study shows that atorvastatin inhibits platelet aggregation in vitro, and this inhibitory effect is related to platelet concentrations.

Bioactive chemical constituents from the root bark of Morus australis.

Two new pyranoflavonoids, morustralins A (1) and B (2), a new natural benzene derivative, one benzenoid (Z)-1-hydroxy-4-(2-nitroethenyl)benzene (3), and thirty known compounds were isolated and characterized from the root bark of Morus australis. The structures of the new compounds were established from spectroscopic and spectrometric analyses. Ten isolates (1-10) were examined for inhibitory effects on adenosine diphosphate (ADP)-, arachidonic acid (AA)-, and platelet-aggregating factor (PAF)-induced platelet aggregation. Among the tested compounds, compound 3 displayed the most significant inhibition of ADP- and AA-induced platelet aggregation with IC50 values of 9.76±5.54 and 9.81±2.7µM, respectively. In addition, eight purified compounds (3-10) were examined for inhibition of nitric oxide (NO) production in RAW 264.7 cells and six compounds (3-8) displayed significant inhibitory effects with IC50 values ranging from 2.1±0.3 to 6.3±0.6µM.

Arachidonic Acid Metabolite as a Novel Therapeutic Target in Breast Cancer Metastasis.

Metastatic breast cancer (BC) (also referred to as stage IV) spreads beyond the breast to the bones, lungs, liver, or brain and is a major contributor to the deaths of cancer patients. Interestingly, metastasis is a result of stroma-coordinated hallmarks such as invasion and migration of the tumor cells from the primary niche, regrowth of the invading tumor cells in the distant organs, proliferation, vascularization, and immune suppression. Targeted therapies, when used as monotherapies or combination therapies, have shown limited success in decreasing the established metastatic growth and improving survival. Thus, novel therapeutic targets are warranted to improve the metastasis outcomes. We have been actively investigating the cytochrome P450 4 (CYP4) family of enzymes that can biosynthesize 20-hydroxyeicosatetraenoic acid (20-HETE), an important signaling eicosanoid involved in the regulation of vascular tone and angiogenesis. We have shown that 20-HETE can activate several intracellular protein kinases, pro-inflammatory mediators, and chemokines in cancer. This review article is focused on understanding the role of the arachidonic acid metabolic pathway in BC metastasis with an emphasis on 20-HETE as a novel therapeutic target to decrease BC metastasis. We have discussed all the significant investigational mechanisms and put forward studies showing how 20-HETE can promote angiogenesis and metastasis, and how its inhibition could affect the metastatic niches. Potential adjuvant therapies targeting the tumor microenvironment showing anti-tumor properties against BC and its lung metastasis are discussed at the end. This review will highlight the importance of exploring tumor-inherent and stromal-inherent metabolic pathways in the development of novel therapeutics for treating BC metastasis.