Antitcoagulant and antiplatelet activities of scolymoside

Xanthine oxidase inhibition study of isolated secondary metabolites from Dolichandrone spathacea (Bignoniaceae): In vitro and in silico approach

Xanthine oxidase (XO) has been widely recognized as a pivotal enzyme in developing hyperuricemia, primarily contributing to the excessive production of uric acid during purine metabolism in the liver. One of the standard treatment approaches involves reducing uric acid levels by inhibiting XO activity. In this study, the leaf extract of Dolichandrone spathacea, traditionally used in folk medicine, was found to inhibit XO activity in the ethyl acetate and butanol fractions at a concentration of 100 µg/mL, their values were 78.57 ± 3.85 % (IC50 = 55.93 ± 5.73 µg/ml) and 69.43 ± 8.68 % (IC50 = 70.17 ± 7.98 µg/ml), respectively. The potential XO inhibitory components were isolated by bioactivity assays and the HR-ESI-MS and NMR spectra system. The main constituents of leaf extracts of Dolichandrone spathacea, six compounds, namely trans-4-methoxycinnamic acid (3), trans-3,4-dimethoxycinnamic acid (4), p-coumaric acid (5), martynoside (6), 6-O-(p-methoxy-E-cinnamoyl)-ajugol (7), and scolymoside (17), were identified as potent XO inhibitors with IC50 values ranging from 19.34 ± 1.63 μM to 64.50 ± 0.94 μM. The enzyme kinetics indicated that compounds 3-5, 7, and 17 displayed competitive inhibition like allopurinol, while compound 6 displayed a mixed-type inhibition. Computational studies corroborated these experimental results, highlighting the interactions between potential metabolites and XO enzyme. The hydrogen bonds played crucial roles in the binding interaction, especially, scolymoside (17) forms a hydrogen bond with Mos3004, exhibited the lowest binding energy (-18.3286 kcal/mol) corresponding to the lowest IC50 (19.34 ± 1.63 μM). Furthermore, nine compounds were isolated for the first time from this plant. In conclusion, Dolichandrone spathacea and its constituents possess the potential to modulate the xanthine oxidase enzyme involved in metabolism.

Comparative Metabolomics Analysis of Stigmas and Petals in Chinese Saffron (Crocus sativus) by Widely Targeted Metabolomics

The dried stigmas of Crocus sativus, commonly known as saffron, are consumed largely worldwide because it is highly valuable in foods and has biological activities beneficial for health. Saffron has important economic and medicinal value, and thus, its planting area and global production are increasing. Petals, which are a by-product of the stigmas, have not been fully utilized at present. We compared the metabolites between the stigmas and petals of C. sativus using a non-targeted metabolomics method. In total, over 800 metabolites were detected and categorized into 35 classes, including alkaloids, flavonoids, amino acids and derivatives, phenols and phenol esters, phenylpropanoids, fatty acyls, steroids and steroid derivatives, vitamins, and other metabolites. The metabolite composition in the petals and stigmas was basically similar. The results of the study showed that the petals contained flavonoids, alkaloids, coumarins, and other medicinal components, as well as amino acids, carbohydrates, vitamins, and other nutritional components. A principal components analysis (PCA) and an orthogonal partial least-squares discriminant analysis (OPLS-DA) were performed to screen the different metabolic components. A total of 339 differential metabolites were identified, with 55 metabolites up-regulated and 284 down-regulated. The up-regulated metabolites, including rutin, delphinidin-3-O-glucoside, isoquercitrin, syringaresinol-di-O-glucoside, dihydrorobinetin, quercetin, and gallocatechin, were detected in the petals. The down-regulated metabolites were mainly glucofrangulin B, acetovanillone, daidzein, guaiazulene, hypaphorine, indolin-2-one, and pseudouridine. KEGG annotation and enrichment analyses of the differential metabolites revealed that flavonoid biosynthesis, amino acids biosynthesis, and arginine and proline metabolism were the main differentially regulated pathways. In conclusion, the petals of C. sativus are valuable for medicine and foods and have potential utility in multiple areas such as the natural spice, cosmetic, health drink, and natural health product industries.

Formulation of Isopropyl Isothiocyanate Loaded Nano Vesicles Delivery Systems: In Vitro Characterization and In Vivo Assessment

Isopropyl Isothiocyanate (IPI) is a poorly water-soluble drug used in different biological activities. So, the present work was designed to prepare and evaluate IPI loaded vesicles and evaluated for vesicle size, polydispersity index (PDI) and zeta potential, encapsulation efficiency, drug release, and drug permeation. The selected formulation was coated with chitosan and further assessed for the anti-platelet and anti-thrombotic activity. The prepared IPI vesicles (F3) exhibited a vesicle size of 298 nm ± 5.1, the zeta potential of −18.7 mV, encapsulation efficiency of 86.2 ± 5.3% and PDI of 0.33. The chitosan-coated IPI vesicles (F3C) exhibited an increased size of 379 ± 4.5 nm, a positive zeta potential of 23.5 ± 2.8 mV and encapsulation efficiency of 77.3 ± 4.1%. IPI chitosan vesicle (F3C) showed enhanced mucoadhesive property (2.7 folds) and intestinal permeation (~1.8-fold) higher than IPI vesicles (F3). There was a significant (p < 0.05) enhancement in size, muco-adhesion, and permeation flux achieved after coating with chitosan. The IPI chitosan vesicle (F3C) demonstrated an enhanced bleeding time of 525.33 ± 12.43 s, anti-thrombin activity of 59.72 ± 4.21, and inhibition of platelet aggregation 68.64 ± 3.99%, and anti-platelet activity of 99.47%. The results of the study suggest that IPI chitosan vesicles showed promising in vitro results, as well as improved anti-platelet and anti-thrombotic activity compared to pure IPI and IPI vesicles.

The Quantitative Trait Loci Mapping of Rice Plant and the Components of Its Extract Confirmed the Anti-Inflammatory and Platelet Aggregation Effects In Vitro and In Vivo

Unpredictable climate change might cause serious lack of food in the world. Therefore, in the present world, it is urgent to prepare countermeasures to solve problems in terms of human survival. In this research, quantitative trait loci (QTLs) were analyzed when rice attacked by white backed planthopper (WBPH) were analyzed using 120 Cheongcheong/Nagdong double haploid lines. Moreover, from the detected QTLs, WBPH resistance-related genes were screened in large candidate genes. Among them, OsCM, a major gene in the synthesis of Cochlioquinone-9 (cq-9), was screened. OsCM has high homology with the sequence of chorismate mutase, and exists in various functional and structural forms in plants that produce aromatic amino acids. It also induces resistance to biotic stress through the synthesis of secondary metabolites in plants. The WBPH resistance was improved in rice overexpressed through map-based cloning of the WBPH resistance-related gene OsCM, which was finally detected by QTL mapping. In addition, cq-9 increased the survival rate of caecal ligation puncture (CLP)-surgery mice by 60%. Moreover, the aorta of rat treated with cq-9 was effective in vasodilation response and significantly reduced the aggregation of rat platelets induced by collagen treatment. A cq-9, which is strongly associated with resistance to WBPH in rice, is also associated with positive effect of CLP surgery mice survival rate, vasodilation, and significantly reduced rat platelet aggregation induced by collagen treatment. Therefore, cq-9 presents research possibilities as a substance in a new paradigm that can act on both Plant-Insect in response to the present unpredictable future.

Screening of plant-based natural compounds as a potential COVID-19 main protease inhibitor: an in silico docking and molecular dynamics simulation approach

A new strain of coronavirus (CoV) has been identified as SARS-CoV-2, which is responsible for the recent COVID-19 pandemic. Currently, there is no approved vaccine or drug available to combat the pandemic. COVID-19 main protease (M^pro) is a key CoV enzyme, which plays an important role in triggering viral replication and transcription, turns it into an attractive target. Therefore, we aim to screen natural products library to find out potential COVID-19 M^pro inhibitors. Plant-based natural compounds from Sigma-Aldrich plant profiler chemical library have been screened through virtual molecular docking and molecular dynamics simulation to identify potential inhibitors of COVID M^pro. Our virtual molecular docking results have shown that there are twenty-eight natural compounds with a greater binding affinity toward the COVID-19 M^pro inhibition site as compared to the co-crystal native ligand Inhibitor N3 (-7.9 kcal/mol). Also, molecular dynamics simulation results have confirmed that Peonidin 3-O-glucoside, Kaempferol 3-O-β–rutinoside, 4-(3,4-Dihydroxyphenyl)-7-methoxy-5-[(6-O-β-D-xylopyranosyl-β-D-glucopyranosyl)oxy]-2H-1-benzopyran-2-one, Quercetin-3-D-xyloside, and Quercetin 3-O-α-L-arabinopyranoside (selected based on the docking score) possess a significant amount of dynamic properties such as stability, flexibility and binding energy. Our In silco results suggests that all the above mention natural compounds have the potential to be developed as a COVID-19 M^pro inhibitor. But before that, it must go through under the proper preclinical and clinical trials for further scientific validation.

Communicated by Ramaswamy H. Sarma

Novel Anticoagulant Peptide from Lactoferrin Binding Thrombin at the Active Site and Exosite-I

Thrombin is currently one of the important targets for the treatment and prevention of thrombosis. At present, there are few reports on the application of lactoferrin peptides in anticoagulation. In this study, a peptide with the amino acid sequence of LRPVAAEIY (LF-LR) derived from lactoferrin was shown to possess antithrombotic activity. LF-LR (5 mM) significantly prolonged activated partial thromboplastin time, prothrombin time, and thrombin time for 13.4, 1.7, and 5.1 s, respectively. It prolonged the coagulation time of fibrinogen from 15.3 ± 0.4 to 20.2 ± 0.5 s by affecting the conformation of thrombin. Using circular dichroism analysis, LF-LR can increase the α-helix content of thrombin from 25.6 to 56.7% and made the β-sheet disappear. In addition, LF-LR also quenched fluorescence of thrombin at about 346 nm (λ_Ex = 280 nm). By means of molecular docking, it was found that LF-LR could bind to both the active site and the exosite-I of thrombin, and the combined LYS60F, TRP60D, ASP189, LYS36, and ARG77A are typical amino acids in the two domains, respectively.

Antithrombotic activity of flavonoids and polyphenols rich plant species

Cardiovascular diseases represent one of the most notable health problems of the modern civilization. Stroke and heart attack often lead to lethal outcome; essential problem underneath being thrombus formation. Prophylactic approaches include acetylsalicylic acid and clopidogrel therapy on the level of primary hemostasis, i.e., primary clot formation. In the last five years, in the USA, health care expenses related to cardiovascular diseases have increased 50 %, to over 350 billion dollars. Thus, application of plant species and medicinal plants rich in polyphenols in prevention of thrombus formation are of interest. This is supported by the fact that the number of publications on antiaggregatory effect of polyphenols has doubled in the last decade. In this review we focus on antiaggregatory effect of most abundant polyphenols - flavonoids, the effect of plant extracts rich in polyphenols (propolis, species Salvia sp., Calamintha nepeta L., Lavandula angustifolia Mill., Melissa officinalis L, Mentha x piperita L., Ocimum basilicum L., Origanum vulgare L., Rosmarinus officinalis L.) on platelet aggregation, association of chemical composition and antioxidant properties with the observed biological effect, and possible clinical significance of the published results.

Antithrombotic Effect of Artemisia princeps Pampanini Extracts in Vitro and in FeCl3 -Induced Thrombosis Rats

Extracts of several plants possess antithrombotic effects. Herein, we examined the antithrombotic effects of different extracts of Artemisia princeps Pampanini prepared using distilled water, hot distilled water, 70% ethanol, or subcritical water. The antithrombotic effects were determined using a co-culture system consisting of tumor necrosis factor-alpha (TNF-α)-treated EA.hy926 cells and THP-1 cells. In addition, the coagulation time of plasma collected from healthy volunteers was evaluated in terms of the prothrombin time and activated partial thromboplastin time. A carotid arterial thrombosis model was induced by ferric chloride in Sprague Dawley rats. The rats were treated with either sterile water or three different doses of the subcritical water extract for 2 weeks. The thrombus weight, gene expression of cell adhesion molecules, and histological characteristics were assessed. The results of in vitro studies revealed a significant inhibition in the adhesion of monocytes to EA.hy926 cells stimulated by TNF-α in the subcritical water extract-treated group. We also observed considerable suppression of the occlusion and mRNA expression of cell adhesion molecules in the in vivo experiments. This study suggests that Artemisia princeps Pampanini may have the potential to improve blood coagulation.

Hepatoprotective effects of vicenin-2 and scolymoside through the modulation of inflammatory pathways

The aim of this study was to investigate the effects of two structurally related flavonoids found in Cyclopia subternata, vicenin-2 (VCN) and scolymoside (SCL) on lipopolysaccharide (LPS)-induced liver failure in mice and to elucidate underlying mechanisms. Mice were treated intravenously with VCN or SCL at 12 h after LPS treatment. LPS significantly increased mortality, serum levels of alanine transaminase, aspartate transaminase, and inflammatory cytokines, and toll-like receptor 4 (TLR4) protein expression; these effects of LPS were inhibited by VCN or SCL. It also attenuated the LPS-induced activation of myeloid differentiation primary response gene 88 and TLR-associated activator of interferon-dependent signaling pathways of the TLR system. Our results suggest that VCN or SCL protects against LPS-induced liver damage by inhibiting the TLR-mediated inflammatory pathway, indicating its potential to treat liver diseases.

Identification and characterization of a novel casein anticoagulant peptide derived from in vivo digestion

A novel anticoagulant casein peptide has been identified by in vivo digestion.

Pelargonidin Protects Against Renal Injury in a Mouse Model of Sepsis

Pelargonidin (PEL) is a well-known red pigment found in plants, and it has been reported to have important biological activities that are potentially beneficial for human health. This study was initiated to determine whether PEL could modulate renal functional damage in a mouse model of sepsis, and to elucidate the underlying mechanisms. The potential of PEL treatment to reduce renal damage induced by cecal ligation and puncture (CLP) surgery in mice was measured by assessment of serum creatinine, blood urea nitrogen (BUN), lipid peroxidation, total glutathione, glutathione peroxidase (GSH-Px) activity, catalase activity, and superoxide dismutase (SOD) activity. Treatment with PEL resulted in elevated plasma levels of BUN and creatinine, and of protein in urine in mice with CLP-induced renal damage. Moreover, PEL inhibited nuclear factor-κB activation and reduced the induction of nitric oxide synthase and excessive production of nitric acid. PEL treatment also reduced the plasma levels of interleukin-6 and tumor necrosis factor-α reduced lethality due to CLP-induced sepsis, increased lipid peroxidation, and markedly enhanced the antioxidant defense system by restoring the levels of SOD, GSH-Px, and catalase in kidney tissues. These results suggested that PEL protects mice against sepsis-triggered renal injury.

Antiseptic effects of dabrafenib on TGFBIp-induced septic responses

Transforming growth factor-β-induced protein (TGFBIp), an extracellular protein, is expressed on several cell types in response to TGF-β stimulation. Human umbilical vein endothelial cell (HUVEC)-derived TGFBIp functions as a mediator of sepsis. Screening of bioactive compound libraries is an effective approach for repositioning FDA-approved drugs or discovering new treatments for human diseases (drug repositioning). Dabrafenib (DAB), a B-Raf inhibitor, was initially used for treating metastatic melanoma. The present study determined whether DAB modulated TGFBIp-mediated septic responses in HUVECs and in mice. Antiseptic functions of DAB were examined by measuring permeability, leukocyte adhesion and migration, and proinflammatory protein activation in TGFBIp-stimulated HUVECs and mice. In addition, beneficial effects of DAB on survival rate were examined using a mouse model of sepsis. We found that DAB inhibited TGFBIp-induced vascular barrier disruption, cell adhesion molecule (CAM) expression, and neutrophil adhesion/transendothelial migration toward human endothelial cells. DAB also suppressed TGFBIp-induced hyperpermeability and leukocyte migration in vivo. These results suggest that DAB exerts anti-inflammatory effects by inhibiting hyperpermeability, CAM expression, and leukocyte adhesion and migration, indicating its utility for treating vascular inflammatory diseases.

Antithrombotic properties of JJ1, a potent and novel thrombin inhibitor

The development of new anticoagulants is an important goal for the improvement of thrombosis treatment. Recent studies have suggested the importance of thrombin inhibitors in the modulation of thromboembolic disorders. The aim of this study was to discover a new small-molecule thrombin inhibitor. In this study, the compound JJ1, which has a novel scaffold, was selected by structure-based docking simulation to determine its potential inhibitory activity against thrombin. JJ1 was shown to inhibit the catalytic activity of human α-thrombin with a K _i of 0.019 μM by direct binding to the active site and with at least 10,000-fold selectivity relative to that reported for the inhibition of other biologically important serine proteases. JJ1 prolonged clotting times (activated partial thromboplastin time and prothrombin time) and inhibited the activity and production of thrombin. Furthermore, it inhibited thrombin-catalyzed fibrin polymerization and platelet aggregation. Similar to its in vitro antithrombotic activities, JJ1 showed enhanced antithrombotic effects in an in vivo pulmonary embolism and arterial thrombosis model. It also exhibited anticoagulant effects in mice. Collectively, these results demonstrated that JJ1 was a potent, direct, and selective thrombin inhibitor that may be useful in the management of various thrombotic disorders.

Zingerone Suppresses the Shedding of Endothelial Protein C Receptor

Zingerone (ZGR), a phenolic alkanone found in Zingiber officinale, has been reported to have various pharmacological activities including anti-inflammatory and anti-apoptotic activities. The endothelial cell protein C receptor (EPCR) plays an important role in the cytoprotective pathway and activation of protein C EPCR can be shed from the cell surface, which is mediated by tumor necrosis factor-α converting enzyme (TACE). However, little is known about the effects of ZGR on EPCR shedding. We investigated this by monitoring the effects of ZGR on phorbol-12-myristate 13-acetate (PMA)-, tumor necrosis factor (TNF)-a, and interleukin (IL)-1p-induced EPCR shedding in human umbilical vein endothelial cells (HUVECs), and cecal ligation and puncture (CLP)-mediated EPCR shedding in mice, as well as by analyzing the underlying mechanisms. Here, ZGR triggered potent inhibition of PMA-, TNF-α-, IL-1β-and CLP-induced EPCR shedding through the inhibition of phosphorylation of mitogen-activated protein kinases (MAPKs) such as p38, janus kinase (JNK), and extracellular signal-regulated kinase (ERK) 1/2. ZGR also inhibited PMA-induced TACE expression and activity in HUVECs, suggesting that p38, ERK1/2, and JNK could be molecular targets of ZGR. These results demonstrate the potential of ZGR as an agent against PMA- and CLP-mediated EPCR shedding.

Sulforaphane Reduces HMGB1-Mediated Septic Responses and Improves Survival Rate in Septic Mice

Sulforaphane (SFN), a natural isothiocyanate present in cruciferous vegetables such as broccoli and cabbage, is effective in preventing carcinogenesis, diabetes, and inflammatory responses. Inhibition of high mobility group box 1 (HMGB1) and restoration of endothelial integrity is emerging as an attractive therapeutic strategy in the management of severe sepsis or septic shock. In this study, we examined the effects of SFN on HMGB1-mediated septic responses and survival rate in a mouse sepsis model. The anti-inflammatory activities of SFN were monitored based on its effects on lipopolysaccharide (LPS)- or cecal ligation and puncture (CLP)-mediated release of HMGB1. The antiseptic activities of SFN were determined by measuring permeability, leukocyte adhesion and migration, and the activation of pro-inflammatory proteins in HMGB1-activated human umbilical vein endothelial cells (HUVECs) and mice. SFN inhibited the release of HMGB1 and downregulated HMGB1-dependent inflammatory responses in human endothelial cells. SFN also inhibited HMGB1-mediated hyperpermeability and leukocyte migration in mice. In addition, treatment with SFN reduced CLP-induced release of HMGB1 and sepsis-related mortality and pulmonary injury in vivo. Our results indicate that SFN is a possible therapeutic agent that can be used to treat various severe vascular inflammatory diseases via the inhibition of the HMGB1 signaling pathway.

Anti-factor Xa activities of zingerone with anti-platelet aggregation activity

Zingerone (ZGR), a phenolic alkanone found in Zingiber officinale, has been reported to have various pharmacological activities such as anti-inflammatory, anti-apoptotic, and protecting myocardial infarction and irritable bowel disorder. The aim was to identify the unreported bioactive anti-factor Xa (FXa) and anti-platelet activities of ZGR. ZGR was evaluated for their anti-FXa and anti-platelet aggregation properties by monitoring clotting time, platelet aggregation, FXa activity and production, and thrombus formation. ZGR reduced activated partial thromboplastin time and it inhibited the catalytic activity of FXa toward its substrate S-2222 in a noncompetitive inhibition model and inhibited platelet aggregation induced by adenosine diphosphate (ADP) and U46619 (not thrombin). However, ZGR did not prolong bleeding time in mice, as shown by tail clipping. ZGR also inhibited ADP- and U46619- induced phosphorylation of myristolated alanine-rich C-kinase substrate (MARCKS) and the expressions of P-selectin and PAC-1 in platelets. In an animal model of arterial and pulmonary thrombosis, ZGR showed enhanced antithrombotic effects. ZGR also elicited anticoagulant effects in mice. Our results reveal that ZGR is an antithrombotic compound with both FXa inhibitory and anti-platelet aggregation activities. Collectively, these results show that ZGR could serve as candidates and provide scaffolds for the development of new anti-FXa and anti-platelet drugs.

Cudratricusxanthone A attenuates renal injury in septic mice

As a natural compound extracted from the roots of Cudrania tricuspidata Bureau, Cudratricusxanthone A (CTXA) is known to possess hepatoprotective, anti-inflammatory, and anti-proliferative activities. This study was aimed to clarify the role of CTXA in modulating renal functional damage in a mouse model of sepsis and to elucidate its underlying mechanisms. We examined the renal protective effects of CTXA on cecal ligation and puncture (CLP)-induced renal damage by assessment of serum creatinine, blood urea nitrogen (BUN), lipid peroxidation, total glutathione, glutathione peroxidase activity, catalase activity, and superoxide dismutase activity. Post-treatment with CTXA resulted in a significant reduction in the deleterious renal functions by CLP, such as elevated BUN, creatinine, and urine protein. Induction of nitric oxide synthase and excessive production of nitric acid by CLP surgery were significantly reduced by post-treatment with CTXA via inhibiting nuclear factor-κB activation. Furthermore, the plasma levels of interleukin-6 and tumor necrosis factor-α were suppressed by CTXA post-treatment. Concurrently, CTXA treatment potently suppressed the CLP-induced septic lethality, rise of lipid peroxidation and markedly enhanced the antioxidant defense system by restoring the levels of superoxide dismutase, glutathione peroxidase, and catalase in kidney. The present results suggested that CTXA could protect against sepsis-triggered renal injury in mice.

Zingerone reduces HMGB1-mediated septic responses and improves survival in septic mice

High mobility group box 1 (HMGB1) is considered a late mediator of sepsis and the inhibition of HMGB1-mediated severe inflammatory responses and restoration of endothelial integrity have emerged as attractive therapeutic strategies for the management of sepsis. Zingerone (ZGR), a phenolic alkanone isolated from ginger, has been reported to possess various pharmacological activities. We examined the effects of ZGR on HMGB1-mediated septic responses and survival rate in a mouse model of sepsis. ZGR was administered after HMGB1 challenge. The antiseptic activity of ZGR was determined from the measurements of permeability, leukocyte adhesion and migration, activation of pro-inflammatory proteins, and the production of tissue injury markers in HMGB1-activated HUVECs and mice. ZGR significantly reduced HMGB1 release in LPS-activated HUVECs via the SIRT1-mediated deacetylation of HMGB1. And, ZGR suppressed the production of TNF-α and IL-6 and the activation of NF-κB and ERK 1/2 by HMGB1. ZGR also inhibited HMGB1-mediated hyperpermeability and leukocyte migration in mice. In addition, treatment with ZGR reduced the CLP-induced release of HMGB1, sepsis-related mortality, and tissue injury in vivo. Our results indicated that ZGR might be useful in the treatment of sepsis by targeting HMGB1.

Inhibitory Effect of Zingerone on Secretory Group IIA Phospholipase A2

The expression of secretory group IIA phospholipase A2 (sPLA2-IIA) has been shown to be elevated in various inflammatory diseases, and lipopolysaccharide (LPS) up-regulates the expression of sPLA2-IIA in human umbilical vein endothelial cells (HUVECs). Zingerone (ZGR), a phenolic alkanone isolated from ginger, has been reported to have various pharmacological activities. Here, we examined the effects of ZRG on the expression and activity of sPLA2-IIA in LPS-activated HUVECs and in mouse models of endotoxemia and sepsis. Treatment of cells or mice with ZRG inhibited LPS-induced expression and activity of sPLA2-IIA. In addition, ZRG suppressed LPS-mediated activation of cytosolic phospholipase A2 (cPLA2) and extracellular signal-regulated kinase (ERK) 1/2. These results suggest that ZRG inhibits LPS-mediated activation of sPLA2-IIA expression by suppressing cPLA2 and ERK 1/2.

Anti-inflammatory effects of pelargonidin on TGFBIp-induced responses

Transforming growth factor β induced protein (TGFBIp) is an extracellular matrix protein expressed in several cell types in response to TGF-β. TGFBIp is released by human umbilical vein endothelial cells (HUVECs) and functions as a mediator of experimental sepsis. Pelargonidin (PEL) is a well-known red pigment found in plants, and has been reported as having important biological activities that are potentially beneficial for human health. This study was undertaken to investigate whether PEL can modulate TGFBIp-mediated inflammatory responses in HUVECs and in mice. The anti-inflammatory activities of PEL were determined by measuring permeability, leukocyte adhesion and migration, and activation of proinflammatory proteins in TGFBIp-activated HUVECs and mice. In addition, the beneficial effects of PEL on survival rate in a mouse sepsis model were tested. We found that PEL inhibited TGFBIp-induced barrier disruption, expression of cell adhesion molecules and adhesion/transendothelial migration of neutrophils to human endothelial cells. PEL also suppressed TGFBIp-induced hyperpermeability and leukocyte migration in vivo. These results suggest that PEL possesses anti-inflammatory properties that result in inhibition of hyperpermeability, expression of cell adhesion molecules, and adhesion and migration of leukocytes, thereby endorsing its usefulness as a therapy for vascular inflammatory diseases.

Suppressive effects of pelargonidin on PolyPhosphate-mediated vascular inflammatory responses

Previous reports suggest that human endothelial cells-derived PolyPhosphate (PolyP) is one of the pro-inflammatory mediators. As a well-known red pigment and found in plants, Pelargonidin (PEL) has been known to have several biological activates which are beneficial for human health. This study was undertaken to investigate whether PEL can modulate PolyP-mediated inflammatory responses in human umbilical vein endothelial cells (HUVECs) and in mice. The anti-inflammatory activities of PEL were determined by measuring permeability, leukocytes adhesion and migration, and activation of pro-inflammatory proteins in PolyP-activated HUVECs and mice. In addition, the beneficial effects of PEL on survival rate in PolyP-injected mice. We found that PEL inhibits PolyP-mediated barrier disruption, the expressions of cell adhesion molecules, and leukocyte to HUVEC adhesion/migration. Interestingly, PolyP-induced NF-κB activation and the productions of TNF-α and IL-6 were inhibited by PEL in HUVECs. These anti-inflammatory functions of PEL were confirmed in PolyP injected mice. These results suggest that PEL have therapeutic potential for various systemic inflammatory diseases.

Inhibitory Effect of Three Diketopiperazines from Marine-derived Bacteria on Secretory Group IIA Phospholipase A2

Diketopiperazines, natural products found in bacteria, fungi, marine sponges, gorgonian and red algae, are cyclic dipeptides possessing relatively simple and rigid structures with chiral nature and various side chains. The compounds in this structure class have been known to possess diverse bioactivities including antibiotic activity, anti-cancer activity, neuroprotective activity, and anti-inflammatory activity. The expression of secretory group IIA phospholipase A2 (sPLA2-IIA) is enhanced by development of inflammatory disorders. Aim of this study is to determine the effects of diketopiperazines on the secretion and activity of sPLA2-IIA by lipopolysaccharide (LPS) in human umbilical vein endothelial cells (HUVECs). To do this, sPLA2-IIA expression was induced in the LPS-stimulated HUVECs and mice to evaluate the effect of diketopiperazines. Results showed that diketopiperazines remarkably suppressed the LPS-mediated protein expression and activity of sPLA2-IIA via inhibition of phosphorylation of cytosolic phospholipase A2 (cPLA2) and extracellular signal-regulated kinase (ERK) 1/2. These results demonstrated that diketopiperazines might play an important role in the modulation of sPLA2-IIA expression and activity in response to the inflammatory diseases.

Suppressive effects of methylthiouracil on polyphosphate-mediated vascular inflammatory responses

Drug repositioning is used to discover drug candidates to treat human diseases, through the application of drugs or compounds that are approved for the treatment of other diseases. This method can significantly reduce the time required and cost of discovering new drug candidates for human diseases. Previous studies have reported pro‐inflammatory responses of endothelial cells to the release of polyphosphate (PolyP). In this study, we examined the anti‐inflammatory responses and mechanisms of methylthiouracil (MTU), which is an antithyroid drug, and its effects on PolyP‐induced septic activities in human umbilical vein endothelial cells (HUVECs) and mice. The survival rates, septic biomarker levels, behaviour of human neutrophils and vascular permeability were determined in PolyP‐activated HUVECs and mice. MTU suppressed the PolyP‐mediated vascular barrier permeability, up‐regulation of inflammatory biomarkers, adhesion/migration of leucocytes, and activation and/or production of nuclear factor‐κB, tumour necrosis factor‐α and interleukin‐6. Furthermore, MTU demonstrated protective effects on PolyP‐mediated lethal death and the levels of the related septic biomarkers. Therefore, these results indicated the therapeutic potential of MTU on various systemic inflammatory diseases, such as sepsis or septic shock.

Inhibitory effects of three diketopiperazines from marine-derived bacteria on endothelial protein C receptor shedding in human endothelial cells and mice

Diketopiperazine is a natural products found from bacteria, fungi, marine sponges, gorgonian and red algae. They are cyclic dipeptides possessing relatively simple and rigid structures with chiral nature and various side chains. The compounds in this structure class have been known to possess diverse bioactivities including antibiotic activity, anti-cancer activity, neuroprotective activity, and anti-inflammatory activity. The endothelial cell protein C receptor (EPCR) plays an important role in the cytoprotective pathway and in the activation of protein C. Endothelial cell protein C receptor (EPCR) can be shed from the cell surface, which is mediated by tumor necrosis factor-α converting enzyme (TACE). However, little is known about the effects of diketopiperazine on EPCR shedding. We investigated this issue by monitoring the effects of diketopiperazine on phorbol-12-myristate 13-acetate (PMA)-, tumor necrosis factor (TNF)-α, and interleukin (IL)-1β-induced EPCR shedding in human umbilical vein endothelial cells (HUVECs), and cecal ligation and puncture (CLP)-mediated EPCR shedding in mice and underlying mechanism. Here, three (1-3) of diketopiperazines were isolated from two strains of marine-derived bacteria and 1-3 induced potent inhibition of PMA-, TNF-α-, IL-1β (in HUVECs), and CLP-induced EPCR shedding (in mice) via inhibition of phosphorylation of mitogen-activated protein kinases (MAPKs) such as p38, janus kinase (JNK), and extracellular signal-regulated kinase (ERK) 1/2. 1-3 also inhibited the expression and activity of PMA-induced TACE in HUVECs suggesting that p38, ERK1/2, and JNK could be molecular targets of 1-3. These results demonstrate the potential of 1-3 as an anti-EPCR shedding reagent against PMA-mediated and CLP-mediated EPCR shedding.