Macrovipera Lebetina Obtusa Venom Research Articles

Histopathological changes of mice tissues in course of the envenomation by the Macrovipera lebetina obtusa venom and the neutralizing effect of the ovine-derived experimental antivenom

Viper bites pose a significant public health issue in Armenia, even within urban areas, often resulting in clotting disorders, hypofibrinogenemia, and tissue necrosis in humans. This study investigates histopathological changes in various tissues during mice envenomation by West-Asian blunt-nosed viper (Macrovipera lebetina obtusa) venom, as well as the recovery process aided by experimental antivenom derived from sheep. The high venom dose caused substantial damage to the heart, lungs, liver, and kidneys in mice, indicating systemic harm. While antivenom administration can prevent mortality in mice envenomation, it may not fully mitigate histological damage in affected organs. Additionally, the study highlights the importance of timing antivenom administration, as the severity of tissue alterations can vary depending on the duration of envenomation. These findings shed light on antivenom's effects on viper envenomation and stress the need for further research to optimize its timing and dosage for minimizing histological damage and enhancing clinical outcomes.

Changes in attachment and metabolic activity of rat neonatal cardiomyocytes and nonmyocytes caused by Macrovipera lebetina obtusa venom

The Caucasian viper Macrovipera lebetina obtusa (MLO) is one of the most prevalent and venomous snakes in the Caucasus and the surrounding regions, yet the effects of MLO venom on cardiac function remain largely unknown. We examined the influence of MLO venom (crude and with inhibited metalloproteinases and phospholipase A2) on attachment and metabolic activity of rat neonatal cardiomyocytes (CM) and nonmyocytes (nCM), assessed at 1 and 24 h. After exposing both CM and nCM to varying concentrations of MLO venom, we observed immediate cytotoxic effects at a concentration of 100 μg/ml, causing detachment from the culture substrate. At lower MLO venom concentrations both cell types detached in a dose-dependent manner. Inhibition of MLO venom metalloproteinases significantly improved CM and nCM attachment after 1-hour exposure. At 24-hour exposure to metalloproteinases inhibited venom statistically significant enhancement was observed only in nCM attachment. However, metabolic activity of CM and nCM did not decrease upon exposure to the lower dose of the venom. Moreover, we demonstrated that metalloproteinases and phospholipases A2 are not the components of the MLO venom that change metabolic activity of both CM and nCM. These results provide a valuable platform to study the impact of MLO venom on prey cardiac function. They also call for further exploration of individual venom components for pharmaceutical purposes.

The Transition of Pain into Anesthesia—The Effect of Various Doses of Macrovipera lebetina obtusa Venom

The Transition of Pain into Anesthesia—The Effect of Various Doses of Macrovipera lebetina obtusa Venom

Antioxidant, cytotoxic and anti-inflammatory properties of Anthemis tricolor Boiss. through a series of cellular assays and inhibition of Turkish Macrovipera lebetina obtusa venom induced inflammation in rat

Antioxidant, cytotoxic and anti-inflammatory properties of Anthemis tricolor Boiss. through a series of cellular assays and inhibition of Turkish Macrovipera lebetina obtusa venom induced inflammation in rat

Hemorrhagic changes and microglia activation induced by Macrovipera lebetina obtusa venom with the inhibited enzymatic activity in rat brain.

The metalloproteinases and phospholipase A2 are the main enzymes in the venom of Macrovipera lebetina obtusa that play a decisive role in the destructive and toxic effects on the organism of the prey. Metalloproteinases cause hemorrhagic damage, destroy the basement membrane of the blood vessel and disrupt the connections between endothelial cells. Phospholipase A2 causes hemolysis of erythrocytes, destroy the cell membranes, and inhibits the adhesion of platelets and so on. The state of the capillaries of the rat brain and microglia under the action of the venom with separately inhibited enzymes was investigated and compared to the action of the crude venom. Also, the toxicity LD50 of the venom of Macrovipera lebetina obtusa with the inhibited enzymatic activity was determined. The histochemical study showed that the inhibition of phospholipase A2 enzymatic activity did not significantly change the vasodestructive effect of the venoms. In case of action of a venom with inhibited enzymatic activity of metalloproteinases, low activity of microglia and less damaged capillaries were observed. The toxicity of the venom with inhibited phospholipase A2 and with inhibited metalloproteinases was respectively 1.8 and 3.7 times weaker than that of the crude venom. We can claim that both the toxicity of the venom of Macrovipera lebetina obtusa, the damaged brain vessels and the increased activity of CNS microglia are determined mainly by the action of metalloproteinases.

The Synergy of Membranotropic Effect of the Two Pla2 Fractions of Macrovipera lebetina obtusa Venom on the Model Membranes.

It is known that snake venoms are a complex of enzymes and proteins and the interaction of different venom components with the membranes could be significantly enhanced in course of their action in an orchestra. The aim of the proposed investigation is to obtain detailed information about the mechanism and topology of two snake venom PLA2 isoforms from the Macrovipera lebetina obtusa venom in the membrane-binding process. We investigated the impact of the interaction on the properties of the model membrane (namely, GUVs and erythrocytes ghost) for each of these isoforms, as well as their synergetic action if they act simultaneously. The 6-lauroyl-2-dimethylaminonaphthalene and 6-propionyl-2-dimethylaminonaphthalene fluorescence probes were used to allow us to determine the membrane polarity more accurately via a generalized polarization function. Our results show that two types of PLA2 bring viscosity reduction in GUVs membrane and the effect became more potent when these PLA2 acts together. Intriguingly, we have not observed any significant difference in the case of the erythrocytes ghost membrane.

Effects of MLO crude venom, PLA2 and metalloproteinases enzymes on cardiac cells

Macrovipera lebetina obtusa (MLO) snakes presented by several sub-species, which are characterized by a very specific combination of components. Along with common enzymes characteristic of Vipera species, MLO venom contains unique components specific for “obtusa” sub-species, such as disintegrin obtustatin. MLO venom contents metalloproteinases, phospholipase A2, serine proteases, L-alfa amino acid oxidase, few kinds of disintegrins and some other active agents. The cluster of MLO venom components, such as metalloproteinases, obtustatin, C-type lectins and few others are known as cell adhesion inhibition molecules, which are breaking up integrins and cadherins or bind to them. Therefore, the adhesion affecting properties of MLO venom and its action on cell binding in tissue culture is of great interest. We studied effect of venom of MLO living in Armenia on adhesion and metabolic activity of myocardial cells [cardiomyocytes (CM) and cardiac fibroblasts (CF)] and identification of major effector components of MLO venom. Attachment properties of both CM and CF were affected by MLO venom in a dose-dependent manner. Time exposure also has an effect on CMs and CFs attachment to the substrate and to cell-to-cell contact. Longer exposures times result in higher detachment even at the same MLO venom concentrations. Interestingly, both cell types demonstrated increase in metabolic activity upon exposure to non-lethal doses of crude venom. Analysis of individual components of MLO venom resulted improved adhesion of both CM and CF upon inhibition of metalloproteinases by EDTA-Na2 chelating agent or complete block of PLA2 enzyme by bromophenacyl bromide. These results indicate that the aggressive detaching effect of MLO venom is delivered not by an individual component of the venom, but rather is a combinatorial effect of several active ingredients.

Toxicity and microglia activity in murine induced by Macrovipera lebetina obtusa venom with inhibited enzymatic activity

Toxicity and microglia activity in murine induced by Macrovipera lebetina obtusa venom with inhibited enzymatic activity

Action of Macrovipera lebetina obtusa venom in hippocampal neurons in the Alzheimer's disease rat model

Action of Macrovipera lebetina obtusa venom in hippocampal neurons in the Alzheimer's disease rat model

Changes in microglia activity of rat brain induced by Macrovipera lebetina obtusa venom

Changes in microglia activity of rat brain induced by Macrovipera lebetina obtusa venom

Anti-tumor effect investigation of obtustatin and crude Macrovipera lebetina obtusa venom in S-180 sarcoma bearing mice

Over the last few decades, research on snake venom toxins has provided not only new tools to decipher molecular details of various physiological processes, but also inspiration to design and develop a number of therapeutic agents. Isolated from the venom of Macrovipera lebetina obutusa (MLO), obtustatin represents the shortest known snake venom monomeric disintegrin specific inhibitor of α1β1 integrin. This low molecular weight peptide revealed a potent therapeutic effect on melanoma progression. Its oncostatic effect was related to the inhibition of angiogenesis. The aim of the proposed investigation was to study the influence of obtustatin and crude MLO venom on the S-180 sarcoma growth in vitro and in vivo. A S-180 sarcoma bearing mouse model, histological examination, DNA retardation assay were utilized to investigate the anti-tumor effects of MLO and obtustatin. In addition, some biochemical tests (chemiluminescence-ChL, TBA-test) were applied to elucidate the influence of obtustatin and crude MLO venom on the S-180 sarcoma. The size of tumor was significantly inhibited by MLO venom and obtustatin with the inhibitory rate of 50% and 33% at the doses of 10µg/mouse and 1mg/kg/day respectively. Both ChL and MDA decrease in the two treated groups. Both obtustatin and MLO venom have an anticancer activity and might be candidates for the treatment of malignant sarcoma. All our results have shown that both obtustatin and MLO venom have an anticancer activity and might be candidates for the treatment of malignant sarcoma.

Screening of cytotoxic and antimicrobial activity potential of Anatolian Macrovipera lebetina obtusa (Ophidia: Viperidae) crude venom

The effects of snake venoms have been well known since ancient times. They contain a variety of biologically active proteins which have therapeutic potential. This study investigated the cytotoxic and antimicrobial activities of Anatolian Macrovipera lebetina obtusa venom against various cancer cells, Gram-negative and Gram-positive bacteria, and a fungal species. A549, HeLa, CaCo-2, U-87 MG and MCF-7 cancer cell lines and a normal cell line (Vero) were screened by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. The antimicrobial activity was evaluated by determining the minimum inhibitory concentration (MIC) using the broth dilution method. The species included were Escherichia coli ATCC 25922, E. coli 0157:H7, Enterococcus faecalis, Enterococcus faecium DSM 13590, Staphylococcus aureus ATCC 25923, Staphylococcus epidermidis ATCC 12228, Salmonella typhimurium CCM 5445, Proteus vulgaris ATCC 6957, Bacillus cereus ATCC 7064 and Candida albicans ATCC 10239. Half-maximal inhibitory concentration (IC50) values of M. l. obtusa venom on cultured cells varied from 1.18 ± 0.11 to 12.80 ± 0.22 µg/ml, with the most potent activities against Vero, U-87 MG, MCF-7 and CaCo-2 cells. Venom showed moderate antifungal activity against C. albicans, with an MIC of 62.50 µg/ml. In short, the venom of Anatolian M. l. obtusa showed promising results as a potential source of alternative therapeutics, cytotoxic and antifungal agent prototypes.

(274) Phospholipase A2 of Macrovipera lebetina obtusa venom as a main target to relief pain after snake bites

Snake venoms are complex mixture of proteins and peptides, which comprise about 90-95 % of venom dry weight and other minor components (e.g. ions, carbohydrates, amines etc.). The majority of damages on victims’ organism are caused by viper venoms’ metalloproteinases, serine proteases and phospholipase A2 (svPLA2). Besides heavy damages, snake bites may also cause strong pain sensations. Particularly, pain syndrome is characteristic for the bites of Levantine viper. The main aim of this study was to reveal the mechanism of Macrovipera lebetina obtusa (MLO) venom’s nociceptive action.

Paraspecificity of Vipera a. ammodytes-specific antivenom towards Montivipera raddei and Macrovipera lebetina obtusa venoms

Antivenom raised against the venom of nose-horned viper, Vipera ammodytes (V. a.) ammodytes (European viper venom antiserum, Zagreb antivenom), contains neutralising equine F(ab′)2 fragments that are clinically successful against homologous venom, but also against the venoms of several others medically important European snakes due to its paraspecific action. In this work we demonstrated that Zagreb antivenom is preclinically effective in neutralising lethal toxicity and hemorrhagicity of venoms of Armenian mountain snakes – Montivipera raddei and Macrovipera lebetina obtusa as well. In order to better understand the biochemical basis of the observed paraspecificity, the ability of anti-V. a. ammodytes serum to recognise and neutralise proteinases of the two venoms was also investigated. Anti-V. a. ammodytes serum showed surprisingly low capacity to inhibit metalloproteinases of both venoms included in the study, probably due to weak immunorecognition of their P-I representatives. Also, it completely failed to abolish enzymatic action of serine proteinases from Macrovipera lebetina obtusa venom. Relevance of such finding is yet to be established.

Morphological Changes of Proteolipid Giant Unilamellar Vesicles Affected by Macrovipera lebetina obtusa Venom Visualized with Fluorescence Microscope

As a rule, zootoxins are complex and biologically active, and therefore the greater part of zootoxins is subjected to biotransformation and interacts with biological membranes. In this case, the interaction of different venom components with the membranes is not always the same. The present study shows how the giant unilamellar vesicles (GUV) from bovine brain proteolipids interact with Macrovipera lebetina obtusa venom. GUV (mean diameter 30 μm) were formed by the electroformation method. We used 8-anilino-1-naphthalenesulfonic acid and pyrene as fluorescence probes, which allowed us to quantify the fluidity changes in the membrane by measuring the fluorescence intensity.

Behavior of Proteolipid GUVs formed in Macrovipera Lebetina Obtusa Venom Solution

Introduction: Macrovipera lebetina obtusa belongs to sister clade of the Middle East complex within the monophyletic Eurasian Vipera genus. This snake is responsible for a number of bites in western Asia every year, and should be considered as dangerous. Proteolipids are a type of lipoproteins in which lipid material forms more than half of the molecule solubilized in organic solvents (chloroform/methanol/water mixtures) and have the solubility characteristics of lipids. GUVs are ideal for studying protein/lipid and lipid/lipid interactions due to their size (similar to that of cells) and to their ease of observation by optical microscopy.Method: Proteolipid fraction was separated from the bovine brain by the Folch method. Proteolipid GUVs (mean diameter 30 μm) are formed with the electroformation method as developed by Angelova and Dimitrov. GUVs have a minimum curvature and mimic cell membranes in this respect. We formed proteolipid GUVs in the solution of Macrovipera lebetina obtusa (MLO) venom (final concentration 3∗10−5M). Images were collected on an epi-fluorescent microscope FM320-5M (AmScope, USA). The GUVs were visualized with ANS fluorescent probe.Results: While GUVs filled with proteins are more stable and there are little increases in size, the GUVs filled with fewer proteins are deformed, not stable. They diminish during 25 seconds, and eventually pull in and dissolve (instead of the usual vesicles formed from phospholipids). The same effect is seen, when MLO was added after GUVs formation.