scholarly journals Rapid Purification of a New P-I Class Metalloproteinase fromBothrops moojeniVenom with Antiplatelet Activity

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Mayara R. de Queiroz ◽  
Carla C. Neves Mamede ◽  
Kelly C. Fonseca ◽  
Nadia C. G. de Morais ◽  
Bruna B. de Sousa ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Snake Venom ◽  
Biological Activities ◽  
Dependent Manner ◽  
Inhibitory Effects ◽  
Concentration Dependent Manner ◽  
Morphological Alterations ◽  
Sds Page ◽  
Fibrinogenolytic Activity ◽  
Rapid Purification

The present study aimed to evaluate the proteolytic and biological activities of a new metalloproteinase fromB. moojenivenom. The purification of BmooMPα-II was carried out through two chromatographic steps (ion-exchange and affinity). BmooMPα-II is a monomeric protein with an apparent molecular mass of 22.5 kDa on SDS-PAGE 14% under nonreducing conditions. The N-terminal sequence (FSPRYIELVVVADHGMFTKYKSNLN) revealed homology with other snake venom metalloproteinases, mainly among P-I class. BmooMPα-II cleaves Aα-chain of fibrinogen followed by Bβ-chain, and does not show any effect on theγ-chain. Its optimum temperature and pH for the fibrinogenolytic activity were 30–50°C and pH 8, respectively. The inhibitory effects of EDTA and 1,10-phenantroline on the fibrinogenolytic activity suggest that BmooMPα-II is a metalloproteinase. This proteinase was devoid of haemorrhagic, coagulant, or anticoagulant activities. BmooMPα-II caused morphological alterations in liver, lung, kidney, and muscle of Swiss mice. The enzymatically active protein yet inhibited collagen, ADP, and ristocetin-induced platelet aggregation in a concentration-dependent manner. Our results suggest that BmooMPα-II contributes to the toxic effect of the envenomation and that more investigations to elucidate the mechanisms of inhibition of platelet aggregation may contribute to the studies of snake venom on thrombotic disorders.

Trimucytin: A Collagen-Like Aggregating Inducer Isolated from Trimeresurus mucrosquamatus Snake Venom

1993 ◽  
Vol 69 (03) ◽  
pp. 286-292 ◽  
Author(s):  
Che-Ming Teng ◽  
Feng-Nien Ko ◽  
Inn-Ho Tsai ◽  
Man-Ling Hung ◽  
Tur-Fu Huang
Keyword(s):  
Platelet Aggregation ◽  
Snake Venom ◽  
Inositol Phosphate ◽  
Shape Change ◽  
Platelet Activating Factor ◽  
Atp Release ◽  
Platelet Membrane ◽  
Thromboxane B2 ◽  
Dependent Manner ◽  
Concentration Dependent Manner

SummaryTrimucytin is a potent platelet aggregation inducer isolated from Trimeresurus mucrosquamatus snake venom. Similar to collagen, trimucytin has a run of (Gly-Pro-X) repeats at the N-terminal amino acids sequence. It induced platelet aggregation, ATP release and thromboxane formation in rabbit platelets in a concentration-dependent manner. The aggregation was not due to released ADP since it was not suppressed by creatine phosphate/creatine phosphokinase. It was not either due to thromboxane A2 formation because indomethacin and BW755C did not have any effect on the aggregation even thromboxane B2 formation was completely abolished by indomethacin. Platelet-activating factor (PAF) was not involved in the aggregation since a PAF antagonist, kadsurenone, did not affect. However, RGD-containing peptide triflavin inhibited the aggregation, but not the release of ATP, of platelets induced by trimucytin. Indomethacin, mepacrine, prostaglandin E1 and tetracaine inhibited the thromboxane B2 formation of platelets caused by collagen and trimucytin. Forskolin and sodium nitroprusside inhibited both platelet aggregation and ATP release, but not the shape change induced by trimucytin. In quin-2 loaded platelets, the rise of intracellular calcium concentration caused by trimucytin was decreased by 12-O-tetradecanoyl phorbol-13 acetate, imipramine, TMB-8 and indomethacin. In the absence of extracellular calcium, both collagen and trimucytin caused no thromboxane B2 formation, but still induced ATP release which was completely blocked by R 59022. Inositol phosphate formation in platelets was markedly enhanced by trimucytin and collagen. MAB1988, an antibody against platelet membrane glycoprotein Ia, inhibited trimucytinand collagen-induced platelet aggregation and ATP release. However, trimucytin did not replace the binding of 125I-labeled MAB1988 to platelets. Platelets pre-exposed to trimucytin were resistant to the second challenge with trimucytin itself or collagen. It is concluded that trimucytin may activate collagen receptors on platelet membrane, and cause aggregation and release mainly through phospholipase C-phosphoinositide pathway.

Inhibitory Effects of Resveratrol on Platelet Activation Induced by Thromboxane A2Receptor Agonist in Human Platelets

2011 ◽  
Vol 39 (01) ◽  
pp. 145-159 ◽  
Author(s):  
Yumin Yang ◽  
Xiaoling Wang ◽  
Li Zhang ◽  
Huiping An ◽  
Zhigao Zao
Keyword(s):  
Protein Kinase C ◽  
Platelet Aggregation ◽  
Protein Kinase ◽  
Red Wine ◽  
Human Platelets ◽  
Dependent Manner ◽  
Inhibitory Effects ◽  
Signal Transduction System ◽  
Concentration Dependent Manner ◽  
Kinase C

Resveratrol (RSVL), a polyphenolic compound found in red wine is believed to be a contributor in decreasing the incidence of coronary heart disease. Although its primary target is unknown, it blocks platelet aggregation by an ill-defined mechanism. Protein kinase C (PKC), which would redistribute from the cytosol to the platelet membrane upon platelet stimulation, plays a key role in the signal transduction system of platelets in human. In this study, we investigated the effect of RSVL and a PKC inhibitor (DL-erythro-1,3-Dihydroxy-2-aminooctadecane, PKCI) on platelet aggregation induced by a thromboxane A2receptor agonist (U46619, 9,11-Dideoxy-11α, 9α-epoxymethanoprostaglandin F2α) using a platelet aggregometer. We also studied the platelet membranebound fibrinogen (PFig) content and the activity of protein kinase C (PKC) in platelets from healthy volunteers using flow cytometry, and a phosphorimaging system, respectively. Our results showed that RSVL blocked platelet aggregation and PFig content induced by U46619 in a concentration-dependent manner. PKCI and RSVL had an additive effect in inhibiting platelet aggregation and PFig content. Furthermore, RSVL (final concentration 50 μM) remarkably depressed the activity of PKC in the membrane of platelets and the percentage of membrane PKC activity in total PKC activity. Taken together, these results suggested that RSVL suppressed U46619-induced platelet aggregation and PFig content partially through the inhibition of the activity of PKC in platelets.

Effect of Aspirin Infusions on Platelet Function in Humans

1990 ◽  
Vol 79 (1) ◽  
pp. 37-42 ◽  
Author(s):  
K. M. Wilson ◽  
D. M. Siebert ◽  
E. M. Duncan ◽  
A. A. Somogyi ◽  
J. V. Lloyd ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Blood Coagulation ◽  
Platelet Function ◽  
Whole Blood ◽  
Dependent Manner ◽  
Inhibitory Effects ◽  
Concentration Dependent Manner ◽  
Infusion Period

1. The inhibitory effects of aspirin on platelet function in vitro have been shown to be both time (over 3 h) and concentration (1–10 μmol/l) dependent. 2. To determine if these effects occurred in vivo, four volunteers received intravenous infusions on four occasions, to give constant plasma aspirin concentrations of 0, 1, 2 and 4 μmol/l over 3 h. Infusions were performed at intervals of at least 2 weeks. 3. Before and during the infusions, blood was taken for assay of aspirin concentrations, and measurements of platelet aggregation in response to collagen, adenosine 5′-pyrophosphate and arachidonate. Thromboxane generation after stimulated platelet aggregation and whole-blood coagulation was also measured. 4. At each aspirin concentration, both platelet aggregation and thromboxane generation in response to collagen and arachidonate were inhibited progressively over the 3 h infusion period. Greatest inhibition was seen during the 4 μmol/l infusion, which produced maximal or near-maximal inhibition by the third hour. 5. Thromboxane generated during whole-blood coagulation was similarly inhibited in both a time- and concentration-dependent manner throughout all aspirin infusions. 6. The progressive nature of the inhibition of platelet function with these low aspirin concentrations may be due to either slow aspirin transport across the platelet membrane or delayed interaction with cyclo-oxygenase.

scholarly journals Bioactivity-Guided Extract Optimization of Osmanthus fragrans var. aurantiacus Leaves and Anti-Inflammatory Activities of Phillyrin

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1545
Author(s):  
Hwa-Young Song ◽  
Da-Eun Jeong ◽  
Mina Lee
Keyword(s):  
Biological Activities ◽  
Radical Scavenging ◽  
No Production ◽  
Dependent Manner ◽  
Optimal Method ◽  
Concentration Dependent Manner ◽  
Osmanthus Fragrans ◽  
Tnf Α ◽  
Anti Inflammatory ◽  
Extracellular Regulated Kinase

The aim of this study was to identify the optimal extraction conditions for leaves of Osmanthus fragrans var. aurantiacus. Inhibitory effects of various extracts on NO production were compared. Antioxidant evaluations for total phenol and flavonoid contents were carried out using various extracts of O. fragrans var. aurantiacus leaves obtained under optimal extraction conditions that showed the greatest effect on NO production. The optimal method for extracting O. fragrans var. aurantiacus leaves resulted in an extract named OP OFLE. OP OFLE showed DPPH and ABTS radical scavenging activities in a concentration-dependent manner. Phillyrin (PH) was isolated as a major compound from OP OFLE by HPLC/DAD analysis. OP OFLE and PH reduced inducible nitric oxide (iNOS) and cyclooxygenase (COX)-2 protein expression and downregulated proinflammatory cytokines such as interleukin (IL)-1β, IL-6, IL-8, and tumor necrosis factor (TNF)-α in LPS-stimulated RAW 264.7 and HT-29 cells. To determine the signal pathway involved in the inhibition of NO production, a Western blot analysis was performed. Results showed that OP OFLE decreased phosphorylation of extracellular regulated kinase (pERK) 1/2 and the expression of nuclear factor-kappa B (NF-κB). Our results suggest that extracts of O. fragrans var. aurantiacus leaves and its major components have biological activities such as antioxidative and anti-inflammatory properties.

scholarly journals Biosynthesis of silver nanoparticles using Haloferax sp. NRS1: image analysis, characterization, in vitro thrombolysis and cytotoxicity

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hend M. Tag ◽  
Amna A. Saddiq ◽  
Monagi Alkinani ◽  
Nashwa Hagagy
Keyword(s):  
Silver Nanoparticles ◽  
Image Analysis ◽  
Biological Activities ◽  
Positive Control ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Vis Spectroscopy ◽  
Negative Surface ◽  
Biosynthesized Agnps

AbstractHaloferax sp strain NRS1 (MT967913) was isolated from a solar saltern on the southern coast of the Red Sea, Jeddah, Saudi Arabia. The present study was designed for estimate the potential capacity of the Haloferax sp strain NRS1 to synthesize (silver nanoparticles) AgNPs. Biological activities such as thrombolysis and cytotoxicity of biosynthesized AgNPs were evaluated. The characterization of silver nanoparticles biosynthesized by Haloferax sp (Hfx-AgNPs) was analyzed using UV–vis spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). The dark brown color of the Hfx-AgNPs colloidal showed maximum absorbance at 458 nm. TEM image analysis revealed that the shape of the Hfx-AgNPs was spherical and a size range was 5.77- 73.14 nm. The XRD spectra showed a crystallographic plane of silver nanoparticles, with a crystalline size of 29.28 nm. The prominent FTIR peaks obtained at 3281, 1644 and 1250 cm− 1 identified the Functional groups involved in the reduction of silver ion reduction to AgNPs. Zeta potential results revealed a negative surface charge and stability of Hfx-AgNPs. Colloidal solution of Hfx-AgNPs with concentrations ranging from 3.125 to 100 μg/mL was used to determine its hemolytic activity. Less than 12.5 μg/mL of tested agent showed no hemolysis with high significant decrease compared with positive control, which confirms that Hfx-AgNPs are considered non-hemolytic (non-toxic) agents according to the ISO/TR 7405-1984(f) protocol. Thrombolysis activity of Hfx-AgNPs was observed in a concentration-dependent manner. Further, Hfx-AgNPs may be considered a promising lead compound for the pharmacological industry.

scholarly journals Antithrombotic Effect of the Ethanol Extract of Angelica gigas Nakai (AGE 232)

Life ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 939
Author(s):  
Pia Loreto Werlinger Bravo ◽  
Hui Jin ◽  
Hyunwoo Park ◽  
Min Sang Kim ◽  
Hirofumi Matsui ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Thrombus Formation ◽  
Umbilical Vein ◽  
Ethanol Extract ◽  
Developed Countries ◽  
Severe Bleeding ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Angelica Gigas ◽  
Angelica Gigas Nakai

Cardiovascular diseases, such as stroke, are the most common causes of death in developed countries. Ischemic stroke accounts for 85% of the total cases and is caused by abnormal thrombus formation in the vessels, causing deficient blood and oxygen supply to the brain. Prophylactic treatments include the prevention of thrombus formation, of which the most used is acetylsalicylic acid (ASA); however, it is associated with a high incidence of side effects. Angelica gigas Nakai (AG) is a natural herb used to improve blood circulation via anti-platelet aggregation, one of the key processes involved in thrombus formation. We examined the antithrombotic effects of AGE 232, the ethanol extract of A. gigas Nakai. AGE 232 showed a significant reduction in death or paralysis in mice caused by collagen/epinephrine-induced thromboembolism in a dose-dependent manner and inhibition of collagen-induced human platelet aggregation in a concentration-dependent manner. Additionally, AGE 232-treated mice did not show severe bleeding in the gut compared to ASA-treated mice. AGE 232 resulted in a decrease in the number of neutrophils attached to the human umbilical vein endothelial cells (HUVECs) and lower inhibition of COX-1 in response to bleeding and damage to blood vessels, a major side effect of ASA. Therefore, AGE 232 can prevent thrombus formation and stroke.

scholarly journals Antioxidant and Anti-Inflammatory Activities of Safflower (Carthamus tinctorius L.) Honey Extract

Foods ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1039
Author(s):  
Li-Ping Sun ◽  
Feng-Feng Shi ◽  
Wen-Wen Zhang ◽  
Zhi-Hao Zhang ◽  
Kai Wang
Keyword(s):  
Chemical Composition ◽  
Biological Activities ◽  
Carthamus Tinctorius ◽  
Raw 264.7 Cells ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Unique Type ◽  
Antioxidant Genes ◽  
Anti Inflammatory

Safflower honey is a unique type of monofloral honey collected from the nectar of Carthamus tinctorius L. in the Apis mellifera colonies of northwestern China. Scant information is available regarding its chemical composition and biological activities. Here, for the first time, we investigated this honey’s chemical composition and evaluated its in vitro antioxidant and anti-inflammatory activities. Basic physicochemical parameters of the safflower honey samples in comparison to established quality standards suggested that safflower honeys presented a good level of quality. The in vitro antioxidant tests showed that extract from Carthamus tinctorius L. honey (ECH) effectively scavenged DPPH and ABTS+ free radicals. In lipopolysaccharides (LPS) activated murine macrophages inflammatory model, ECH treatment to the cells inhibited the release of nitric oxide and down-regulated the expressions of inflammatory-relating genes (iNOS, IL-1β, TNF-α and MCP-1). The expressions of the antioxidant genes TXNRD, HO-1, and NQO-1, were significantly boosted in a concentration-dependent manner. ECH decreased the phosphorylation of IκBα and inhibited the nuclear entry of the NF-κB-p65 protein, in LPS-stimulated Raw 264.7 cells, accompany with the increased expressions of Nrf-2 and HO-1, suggesting that ECH achieved the anti-inflammatory effects by inhibiting NF-κB signal transduction and boosting the antioxidant system via activating Nrf-2/HO-1 signaling. These results, taken together, indicated that safflower honey has great potential into developing as a high-quality agriproduct.

scholarly journals Rapid Purification and Procoagulant and Platelet Aggregating Activities of Rhombeobin: A Thrombin-Like/Gyroxin-Like Enzyme fromLachesis muta rhombeataSnake Venom

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Frank Denis Torres-Huaco ◽  
Cláudio C. Werneck ◽  
Cristina Pontes Vicente ◽  
Talita Vassequi-Silva ◽  
Ana Cláudia Coelho Nery-Diez ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Proteinase Inhibitors ◽  
Ex Vivo ◽  
Serine Proteinase ◽  
Dependent Manner ◽  
Amidolytic Activity ◽  
Venom Component ◽  
Purification Method ◽  
Rapid Purification

We report a rapid purification method using one-step chromatography of SVSP Rhombeobin (LMR-47) fromLachesis muta rhombeatavenom and its procoagulant activities and effects on platelet aggregation. The venom was fractionated by a single chromatographic step in RP-HPLC on a C8 Discovery BIO Wide Pore, showing high degree of molecular homogeneity with molecular mass of 47035.49 Da. Rhombeobin showed amidolytic activity upon BAρNA, with a broad optimum pH (7–10) and was stable in solution up to 60°C. The amidolytic activity was inhibited by serine proteinase inhibitors and reducing agents, but not chelating agents. Rhombeobin showed high coagulant activity on mice plasma and bovine fibrinogen. The deduced amino acid sequence of Rhombeobin showed homology with other SVSPs, especially with LM-TL (L. m. muta) and Gyroxin (C. d. terrificus). Rhombeobin acts,in vitro, as a strong procoagulant enzyme on mice citrated plasma, shortening the APTT and PT tests in adose-dependent manner. The protein showed, “ex vivo”, a strong defibrinogenating effect with 1 µg/animal. Lower doses activated the intrinsic and extrinsic coagulation pathways and impaired the platelet aggregation induced by ADP. Thus, this is the first report of a venom component that produces a venom-induced consumptive coagulopathy (VICC).

scholarly journals A potent antiplatelet peptide, triflavin, from Trimeresurus flavoviridis snake venom

1991 ◽  
Vol 277 (2) ◽  
pp. 351-357 ◽  
Author(s):  
T F Huang ◽  
J R Sheu ◽  
C M Teng
Keyword(s):  
Platelet Aggregation ◽  
Snake Venom ◽  
Ionic Exchange ◽  
Dependent Manner ◽  
Single Chain ◽  
Platelet Suspension ◽  
Trimeresurus Flavoviridis ◽  
Platelet Membranes ◽  
Fibrinogen Binding ◽  
Induced Aggregation

The interaction of fibrinogen with its receptors on platelet surfaces leads to platelet aggregation. A snake-venom peptide, trigramin, has previously been demonstrated to inhibit platelet aggregation by acting as a fibrinogen-receptor antagonist. By means of gel filtration, ionic-exchange chromatography and reverse-phase h.p.l.c., a potent platelet-aggregation inhibitor, triflavin, has now been purified from the venom of Trimeresurus flavoviridis. The purified triflavin is a single-chain polypeptide, consisting of about 71 amino acid residues with a molecular mass of 7600 Da, and its N-terminal sequence is Gly-Glu-Glu-Cys-Asp. Triflavin dose-dependently inhibited human platelet aggregation stimulated by ADP, adrenaline, collagen, thrombin or prostaglandin endoperoxide analogue U46619 in preparations of platelet-rich plasma, platelet suspension and whole blood. Its IC50 ranged from 38 to 84 nM, depending on the aggregation inducer used and the platelet preparation. However, triflavin apparently did not affect the platelet shape change and ATP-release reactions caused by these agonists. Triflavin inhibited fibrinogen-induced aggregation of human elastase-treated platelets in a dose-dependent manner, indicating that it directly interferes with the binding of fibrinogen to its receptors on platelet membranes exposed by elastase treatment. Additionally, triflavin dose-dependently blocked 125I-labelled fibrinogen binding to ADP-activated platelets. In conclusion, triflavin inhibits platelet aggregation through the blockade of fibrinogen binding to fibrinogen receptors on platelet membranes.

scholarly journals Twenty Traditional Algerian Plants Used in Diabetes Therapy as Strong Inhibitors of α-Amylase Activity

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Ihcen Khacheba ◽  
Amar Djeridane ◽  
Mohamed Yousfi
Keyword(s):  
Amylase Activity ◽  
Aluminium Chloride ◽  
Total Phenolic ◽  
Dependent Manner ◽  
Inhibitory Effects ◽  
Concentration Dependent Manner ◽  
Diabetes Therapy ◽  
Methanolic Extracts ◽  
Phenolic Extract ◽  
Gallic Acid Equivalent

In the present work, we have studied the inhibitory effects of aqueous and alcoholic extracts of six Algerian medicinal plants known by their therapeutic virtues against diabetes. The total phenolic compounds content, assayed using Folin-Ciocalteu’s reagent, of the samples ranged from 0.183 mg/g to 43.088 mg/g and from 1.197 mg/g to 7.445 mg/g, expressed as gallic acid equivalent (GAE), for the, respectively, whereas the total flavonoids concentrations, detected using 2% of the aluminium chloride, ranged from 0.41 mg/g to 11.613 mg/g and from 0.0097 mg/g to 1.591 mg/g, expressed as rutin equivalents (RE), for the aqueous and methanolic extracts, respectively. The major plants were found to inhibit enzymatic activities of Aspergillus oryzae-amylase in a concentration dependent manner. The values of the inhibition constants (Ki) have been determined according to the Dixon and Lineweaver-Burk methods. The results showed that the Ki values were less than 55 ppm for the all extracts. A strong inhibition was found in the phenolic extract of Salvia officinalis with a Ki of 8 ppm.

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