scholarly journals Action of Varespladib (LY-315920), a Phospholipase A2 Inhibitor, on the Enzymatic, Coagulant and Haemorrhagic Activities of Lachesis muta rhombeata (South-American Bushmaster) Venom

2022 ◽  
Vol 12 ◽  
Author(s):  
Pamella G. Gutierres ◽  
Diego R. Pereira ◽  
Nataly L. Vieira ◽  
Lilian F. Arantes ◽  
Nelson J. Silva ◽  
...  
Keyword(s):  
Protective Action ◽  
Enzymatic Activities ◽  
South American ◽  
Snake Venoms ◽  
Enzymatic Assays ◽  
Hemorrhagic Activity ◽  
Lachesis Muta ◽  
Imagej Software ◽  
Lachesis Muta Rhombeata

Varespladib (VPL) was primarily developed to treat inflammatory disturbances associated with high levels of serum phospholipase A2 (PLA2). VPL has also demonstrated to be a potential antivenom support agent to prevent PLA2-dependent effects produced by snake venoms. In this study, we examined the action of VPL on the coagulant, haemorrhagic and enzymatic activities of Lachesis muta rhombeata (South-American bushmaster) venom. Conventional colorimetric enzymatic assays were performed for PLA2, caseinolytic and esterasic activities; in vitro coagulant activities for prothrombin time (PT) and activated partial thromboplastin time (aPTT) were performed in rat citrated plasma through a quick timer coagulometer, whereas the dimensions of haemorrhagic haloes obtained after i.d. injections of venom in Wistar rats were determined using ImageJ software. Venom (1 mg/ml) exhibited accentuated enzymatic activities for proteases and PLA2in vitro, with VPL abolishing the PLA2 activity from 0.01 mM; VPL did not affect caseinolytic and esterasic activities at any tested concentrations (0.001–1 mM). In rat citrated plasma in vitro, VPL (1 mM) alone efficiently prevented the venom (1 mg/ml)-induced procoagulant disorder associated to extrinsic (PT) pathway, whereas its association with a commercial antivenom successfully prevented changes in both intrinsic (aPTT) and extrinsic (PT) pathways; commercial antivenom by itself failed to avoid the procoagulant disorders by this venom. Venom (0.5 mg/kg)-induced hemorrhagic activity was slightly reduced by VPL (1 mM) alone or combined with antivenom (antivenom:venom ratio 1:3 ‘v/w’) in rats, with antivenom alone producing no protective action on this parameter. In conclusion, VPL does not inhibit other major enzymatic groups of L. m. rhombeata venom, with its high PLA2 antagonize activity efficaciously preventing the venom-induced coagulation disturbances.

Protective action of N-acetyl-L-cysteine associated with a polyvalent antivenom on the envenomation induced by Lachesis muta muta (South American bushmaster) in rats

Toxicon ◽  
2021 ◽  
Vol 198 ◽  
pp. 36-47
Author(s):  
Aline G. Leão-Torres ◽  
Carina V. Pires ◽  
Amanda C. Ribelato ◽  
Maria C. Zerbinatti ◽  
Cecília L. Santarém ◽  
...  
Keyword(s):  
Protective Action ◽  
South American ◽  
Lachesis Muta

An alternative method to access in vitro the hemorrhagic activity of snake venoms

Toxicon ◽  
2008 ◽  
Vol 51 (4) ◽  
pp. 479-487 ◽  
Author(s):  
A. Rafael ◽  
I. Tanjoni ◽  
I. Fernandes ◽  
A.M. Moura-da-Silva ◽  
M.F.D. Furtado
Keyword(s):  
Snake Venoms ◽  
Alternative Method ◽  
Hemorrhagic Activity

Analysis of phospholipase A2, l-amino acid oxidase, and proteinase enzymatic activities of the Lachesis muta rhombeata venom

2012 ◽  
Vol 26 (8) ◽  
pp. 308-314 ◽  
Author(s):  
Lucas Benício Campos ◽  
Manuela Berto Pucca ◽  
Eduardo Crosara Roncolato ◽  
Joaquim Coutinho Netto ◽  
José Elpidio Barbosa
Keyword(s):  
Amino Acid ◽  
Phospholipase A2 ◽  
Enzymatic Activities ◽  
Acid Oxidase ◽  
Amino Acid Oxidase ◽  
Lachesis Muta ◽  
Lachesis Muta Rhombeata

scholarly journals LmrBPP9: A synthetic bradykinin-potentiating peptide from Lachesis muta rhombeata venom that inhibits the angiotensin-converting enzyme activity in vitro and reduces the blood pressure of hypertensive rats

Peptides ◽  
2018 ◽  
Vol 102 ◽  
pp. 1-7 ◽  
Author(s):  
Ernesto Lopes Pinheiro-Júnior ◽  
Johara Boldrini-França ◽  
Luciana Mattoso Pires de Campos Araújo ◽  
Norival Alves Santos-Filho ◽  
Lusiane Maria Bendhack ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Enzyme Activity ◽  
Angiotensin Converting Enzyme ◽  
Converting Enzyme ◽  
Hypertensive Rats ◽  
Angiotensin Converting Enzyme Activity ◽  
Lachesis Muta ◽  
Lachesis Muta Rhombeata

scholarly journals Antivenom Effects of 1,2,3-Triazoles againstBothrops jararacaandLachesis mutaSnakes

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Thaisa F. S. Domingos ◽  
Laura de A. Moura ◽  
Carla Carvalho ◽  
Vinícius R. Campos ◽  
Alessandro K. Jordão ◽  
...  
Keyword(s):  
Biological Effects ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Snake Venoms ◽  
Concentration Dependent Manner ◽  
Biological Assays ◽  
Snake Bites ◽  
Lachesis Muta

Snake venoms are complex mixtures of proteins of both enzymes and nonenzymes, which are responsible for producing several biological effects. Human envenomation by snake bites particularly those of the viperid family induces a complex pathophysiological picture characterized by spectacular changes in hemostasis and frequently hemorrhage is also seen. The present work reports the ability of six of a series of 1,2,3-triazole derivatives to inhibit some pharmacological effects caused by the venoms ofBothrops jararacaandLachesis muta.In vitroassays showed that these compounds were impaired in a concentration-dependent manner, the fibrinogen or plasma clotting, hemolysis, and proteolysis produced by both venoms. Moreover, these compounds inhibited biological effectsin vivoas well. Mice treated with these compounds were fully protected from hemorrhagic lesions caused by such venoms. But, only theB. jararacaedema-inducing activity was neutralized by the triazoles. So the inhibitory effect of triazoles derivatives against somein vitroandin vivobiological assays of snake venoms points to promising aspects that may indicate them as molecular models to improve the production of effective antivenom or to complement antivenom neutralization, especially the local pathological effects, which are partially neutralized by antivenoms.

scholarly journals Do Antibiotics Potentiate Proteases in Hemotoxic Snake Venoms?

Toxins ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 240
Author(s):  
Christoffer V. Sørensen ◽  
Cecilie Knudsen ◽  
Ulrich auf dem Keller ◽  
Konstantinos Kalogeropoulos ◽  
Cristina Gutiérrez-Jiménez ◽  
...  
Keyword(s):  
Snake Venom ◽  
Bacterial Infections ◽  
Enzymatic Activities ◽  
In Vitro Assays ◽  
Clinical Implications ◽  
Snake Venoms ◽  
Venom Toxins

Antibiotics are often administered with antivenom following snakebite envenomings in order to avoid secondary bacterial infections. However, to this date, no studies have evaluated whether antibiotics may have undesirable potentiating effects on snake venom. Herein, we demonstrate that four commonly used antibiotics affect the enzymatic activities of proteolytic snake venom toxins in two different in vitro assays. Similar findings in vivo could have clinical implications for snakebite management and require further examination.

scholarly journals Inhibitory Effect of PlantManilkara subsericeaagainst Biological Activities ofLachesis mutaSnake Venom

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Eduardo Coriolano De Oliveira ◽  
Caio Pinho Fernandes ◽  
Eladio Flores Sanchez ◽  
Leandro Rocha ◽  
André Lopes Fuly
Keyword(s):  
Ethyl Acetate ◽  
Snake Venom ◽  
Biological Activities ◽  
Inhibitory Effect ◽  
Snake Venoms ◽  
Brazilian Flora ◽  
Inhibitory Potential ◽  
Lachesis Muta

Snake venom is composed of a mixture of substances that caused in victims a variety of pathophysiological effects. Besides antivenom, literature has described plants able to inhibit injuries and lethal activities induced by snake venoms. This work describes the inhibitory potential of ethanol, hexane, ethyl acetate, or dichloromethane extracts and fractions from stem and leaves ofManilkara subsericeaagainstin vivo(hemorrhagic and edema) andin vitro(clotting, hemolysis, and proteolysis) activities caused byLachesis mutavenom. All the tested activities were totally or at least partially reduced byM. subsericea. However, whenL. mutavenom was injected into mice 15 min first or after the materials, hemorrhage and edema were not inhibited. Thus,M. subsericeacould be used as antivenom in snakebites ofL. muta. And, this work also highlights Brazilian flora as a rich source of molecules with antivenom properties.

scholarly journals Critical enzymes for biosynthesis of cucurbitacin derivatives in watermelon and their biological significance

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Young-Cheon Kim ◽  
Daeun Choi ◽  
Ahra Cha ◽  
Yeong-Geun Lee ◽  
Nam-In Baek ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Candidate Genes ◽  
Citrullus Lanatus ◽  
Biological Significance ◽  
Enzymatic Activities ◽  
Economic Potential ◽  
Enzymatic Assays

AbstractVarious cucurbitacins have been isolated, and their structures have been elucidated. Owing to their economic potential and importance as active pharmacological compounds, their cytotoxicity in various cancer cells has been assessed. Here, we mined several candidate genes with potential involvement in cucurbitacin biosynthesis in watermelon (Citrullus lanatus) and performed in vitro enzymatic assays and instrumental analyses using various substrates to identify cucurbitacin functions and products. Enzymatic activities of two acetyltransferases (ACTs) and one UDP-glucosyltransferase (UGT) against cucurbitacins were confirmed, resulting in the synthesis of novel cucurbitacins in vivo and/or in vitro to our knowledge. As ACTs and UGT are involved in the dynamic conversion of cucurbitacins by catalyzing acetylation and glucosylation at moieties in the cucurbitacins skeleton, these findings improve our knowledge on how these genes contribute to the diversity of cucurbitacins.

Toxicity of South American snake venoms measured by an in vitro cell culture assay

Toxicon ◽  
2002 ◽  
Vol 40 (3) ◽  
pp. 321-325 ◽  
Author(s):  
J.C.R Oliveira ◽  
H Montes de Oca ◽  
M.M Duarte ◽  
C.R Diniz ◽  
C.L Fortes-Dias
Keyword(s):  
Cell Culture ◽  
South American ◽  
Snake Venoms ◽  
In Vitro Cell Culture ◽  
Cell Culture Assay

Action of Lysolecithin on Blood Platelets

1963 ◽  
Vol 09 (03) ◽  
pp. 512-524 ◽  
Author(s):  
Chava Kirschmann ◽  
Sara Aloof ◽  
Andre de Vries
Keyword(s):  
Blood Platelets ◽  
Protective Action ◽  
Platelet Surface ◽  
Washed Platelet ◽  
Sufficient Concentration ◽  
Saline Medium

SummaryLysolecithin is adsorbed to washed blood platelets and, at sufficient concentration, lyses them, inhibits their clot-retracting activity and promotes their thromboplastin-generating activity. Lysolecithin adsorption to the platelet was studied by using P32-labelled lysolecithin obtained from the liver of rats injected with labelled orthophosphate. The amount of lysolecithin adsorbed to the surface of the washed platelet in saline medium is dependent on the concentration of lysolecithin in solution and reaches saturation — 5 × 10-8 jig per platelet — at a concentration of 9—10 µg per ml. Platelet lysis in saline medium begins at a lysolecithin concentration higher than 18 jig per ml. Plasma and albumin prevent adsorption of lysolecithin to the platelet and protect the platelet from damage by lysolecithin. Albumin is able to remove previously adsorbed lysolecithin from the platelet surface. The protective action of plasma explains the lack of platelet damage in blood, the plasma lecithin of which has been converted to lysolecithin by the action of Vipera palestinae venom phosphatidase, in vitro and in vivo.

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