Interactions of PLA2-s from Vipera lebetina, Vipera berus berus and Naja naja oxiana venom with platelets, bacterial and cancer cells

Bee venom as a promising therapeutic strategy in central nervous system diseases

Central nervous system (CNS) disorders are one of the leading health problems today, accounting for a large proportion of global morbidity and mortality. Most these disorders are characterized by high levels of oxidative stress and intense inflammatory responses in degenerated neuronal tissues. While extensive research has been conducted on CNS diseases, but few breakthroughs have been made in treatment methods. To date, there are no disease-modifying drugs available for CNS treatment, underscoring the urgent need for finding effective medications. Bee venom (BV), which is produced by honeybee workers' stingers, has been a subject of interest and study across various cultures. Over the past few decades, extensive research has focused on BV and its therapeutic potentials. BV consists a variety of substances, mainly proteins and peptides like melittin and phospholipase A2 (PLA2). Research has proven that BV is effective in various medical conditions, including pain, arthritis and inflammation and CNS disorders such as Multiple sclerosis, Alzheimer's disease and Parkinson's disease. This review provides a comprehensive overview of the existing knowledge concerning the therapeutic effects of BV and its primary compounds on various CNS diseases. Additionally, we aim to shed light on the potential cellular and molecular mechanisms underlying these effects.

Emerging anticancer potential and mechanisms of snake venom toxins: A review

Animal-derived venom, like snake venom, has been proven to be valuable natural resources for the drug development. Previously, snake venom was mainly investigated in its pharmacological activities in regulating coagulation, vasodilation, and cardiovascular function, and several marketed cardiovascular drugs were successfully developed from snake venom. In recent years, snake venom fractions have been demonstrated with anticancer properties of inducing apoptotic and autophagic cell death, restraining proliferation, suppressing angiogenesis, inhibiting cell adhesion and migration, improving immunity, and so on. A number of active anticancer enzymes and peptides have been identified from snake venom toxins, such as L-amino acid oxidases (LAAOs), phospholipase A2 (PLA2), metalloproteinases (MPs), three-finger toxins (3FTxs), serine proteinases (SPs), disintegrins, C-type lectin-like proteins (CTLPs), cell-penetrating peptides, cysteine-rich secretory proteins (CRISPs). In this review, we focus on summarizing these snake venom-derived anticancer components on their anticancer activities and underlying mechanisms. We will also discuss their potential to be developed as anticancer drugs in the future.

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.

Functional Characterization and Anti-Tumor Effect of a Novel Group II Secreted Phospholipase A2 from Snake Venom of Saudi Cerastes cerates gasperetti

Secreted phospholipases A2 are snake-venom proteins with many biological activities, notably anti-tumor activity. Phospholipases from the same snake type but different geographical locations have shown similar biochemical and biological activities with minor differences in protein sequences. Thus, the discovery of a new phospholipase A2 with unique characteristics identified in a previously studied venom could suggest the origins of these differences. Here, a new Group II secreted phospholipase A2 (Cc-PLA2-II) from the snake venom of Saudi Cerastes cerastes gasperetti was isolated and characterized. The purified enzyme had a molecular weight of 13.945 kDa and showed high specific activity on emulsified phosphatidylcholine of 1560 U/mg at pH 9.5 and 50 °C with strict calcium dependence. Interestingly, stability in extreme pH and high temperatures was observed after enzyme incubation at several pH levels and temperatures. Moreover, a significant dose-dependent cytotoxic anti-tumor effect against six human cancer cell lines was observed with concentrations of Cc-PLA2 ranging from 2.5 to 8 µM. No cytotoxic effect on normal human umbilical-vein endothelial cells was noted. These results suggest that Cc-PLA2-II potentially has angiogenic activity of besides cytotoxicity as part of its anti-tumor mechanism. This study justifies the inclusion of this enzyme in many applications for anticancer drug development.

Can Bee Venom Be Used as Anticancer Agent in Modern Medicine?

Honey bee venom in its composition contains many biologically active peptides and enzymes that are effective in the fight against diseases of various etiologies. The history of the use of bee venom for medicinal purposes dates back thousands of years. There are many reports in the literature on the pharmacological properties of bee venom and/or its main components, e.g., anti-arthritic, anti-inflammatory, anti-microbial or neuroprotective properties. In addition, both crude venom and melittin exhibit cytotoxic activity against a wide range of tumor cells, with significant anti-metastatic activity in pre-clinical studies. Due to the constantly increasing incidence of cancer, the development of new therapeutic strategies in oncology is a particular challenge for modern medicine. A review paper discusses the various properties of bee venom with an emphasis on its anticancer properties. For this purpose, the PubMed database was searched, and publications related to "bee", "venom", "cancer" from the last 10 years were selected.

Cytotoxic effect of crotoxin on cancer cells and its antitumoral effects correlated to tumor microenvironment: A review

Cancer is the second leading cause of death worldwide, and despite the effort of standard treatments, the search for new tools against this disease is necessary. Importantly, it is known that the tumor microenvironment plays a crucial role in tumor initiation, progression, and response to therapies. Therefore, studies of potential drugs that act on these components are as critical as studies regarding antiproliferative substances. Through the years, studies of several natural products, including animal toxins, have been conducted to guide the development of medical compounds. In this review, we present the remarkable antitumor activities of crotoxin, a toxin from the rattlesnake Crotalus durissus terrificus, highlighting its effects on cancer cells and in the modulation of relevant elements in the tumor microenvironment as well as the clinical trials conducted with this compound. In summary, crotoxin acts through several mechanisms of action, such as activation of apoptosis, induction of cell cycle arrest, inhibition of metastasis, and decrease of tumor growth, in different tumor types. Crotoxin also modulates tumor-associated fibroblasts, endothelial cells, and immune cells, which contribute to its antitumoral effects. In addition, preliminary clinical studies confirm the promising results of crotoxin and support its potential future use as an anticancer drug.

Snake venom, a potential treatment for melanoma. A systematic review

Despite advances in treating patients with melanoma, there are still many treatment challenges to overcome. Studies with snake venom-derived proteins/peptides describe their binding potential, and inhibition of some proliferative mechanisms in melanoma. The combined use of these compounds with current therapies could be the strategic gap that will help us discover more effective treatments for melanoma. The present study aimed to carry out a systematic review identifying snake venom proteins and peptides described in the literature with antitumor, antimetastatic, or antiangiogenic effects on melanoma and determine the mechanisms of action that lead to these anti-tumor effects. Snake venoms contain proteins and peptides which are antiaggregant, antimetastatic, and antiangiogenic. The in vivo results are encouraging, considering the reduction of metastases and tumor size after treatment. In addition to these results, it was reported that these venom compounds could act in combination with chemotherapeutics (Acurhagin-C; Macrovipecetin), sensitizing and preparing tumor cells for treatment. There is a consensus that snake venom is a promising strategy for the improvement of antimelanoma therapies, but it has been little explored in the current context, combined with inhibitors, immunotherapy or tumor microenvironment, for example. We suggest Lebein as a candidate for combination therapy with BRAF inhibitors.

Cytogenetic Analysis of the Bimodal Karyotype of the Common European Adder, Vipera berus (Viperidae)

Vipera berus is the species with the largest range of snakes on Earth and one of the largest among reptiles in general. It is also the only snake species found in the Arctic Circle. Vipera berus is the most involved species of the genus Vipera in the process of interspecific hybridization in nature. The taxonomy of the genus Vipera is based on molecular markers and morphology and requires clarification using SC-karyotyping. This work is a detailed comparative study of the somatic and meiotic karyotypes of V. berus, with special attention to DNA and protein markers associated with synaptonemal complexes. The karyotype of V. berus is a remarkable example of a bimodal karyotype containing both 16 large macrochromosomes and 20 microchromosomes. We traced the stages of the asynchronous assembly of both types of bivalents. The number of crossing-over sites per pachytene nucleus, the localization of the nucleolar organizer, and the unique heterochromatin block on the autosomal bivalent 6-an important marker-were determined. Our results show that the average number of crossing-over sites per pachytene nucleus is 49.5, and the number of MLH1 sites per bivalent 1 reached 11, which is comparable to several species of agamas.

Biochemistry and toxicology of proteins and peptides purified from the venom of Vipera berus berus

The isolation and characterization of individual snake venom components is important for a deeper understanding of the pathophysiology of envenomation and for improving the therapeutic procedures of patients. It also opens possibilities for the discovery of novel toxins that might be useful as tools for understanding cellular and molecular processes. The variable venom composition, toxicological and immunological properties of the common vipers (Vipera berus berus) have been reviewed. The combination of venom gland transcriptomics, bottom-up and top-down proteomics enabled comparison of common viper venom proteomes from multiple individuals. V. b. berus venom contains proteins and peptides belonging to 10–15 toxin families: snake venom metalloproteinase, phospholipases A₂ (PLA₂), snake venom serine proteinase, aspartic protease, L-amino acid oxidase (LAAO), hyaluronidase, 5′-nucleotidase, glutaminyl-peptide cyclotransferase, disintegrin, C-type lectin (snaclec), nerve growth factor, Kunitz type serine protease inhibitor, snake venom vascular endothelial growth factor, cysteine-rich secretory protein, bradykinin potentiating peptide, natriuretic peptides. PLA₂ and LAAO from V. b. berus venom produce more pronounced cytotoxic effects in cancer cells than normal cells, via induction of apoptosis, cell cycle arrest and suppression of proliferation. Proteomic data of V. b. berus venoms from different parts of Russia and Slovakian Republic have been compared with analogous data for Vipera nikolskii venom. Proteomic studies demonstrated quantitative differences in the composition of V. b. berus venom from different geographical regions. Differences in the venom composition of V. berus were mainly driven by the age, sex, habitat and diet of the snakes. The venom variability of V. berus results in a loss of antivenom efficacy against snakebites. The effectiveness of antibodies is discussed. This review presents an overview with a special focus on different toxins that have been isolated and characterized from the venoms of V. b. berus. Their main biochemical properties and toxic actions are described.

•

Vipera berus berus venom composition is variable among different populations.

•

Venom contains about 15 protein/peptide families.

•

It disturbs blood coagulation inducing pro- or anticoagulant effects.

•

Venom contains different types of blood factor X activators.

•

PLA₂ and L-amino acid oxidase produce cytotoxic effects in cancer cells.

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.

Phospholipase A2 superfamily in cancer

Phospholipase A2 enzymes (PLA₂s) comprise a superfamily that is generally divided into six subfamilies known as cytosolic PLA₂s (cPLA₂s), calcium-independent PLA₂s (iPLA₂s), secreted PLA₂s (sPLA₂s), lysosomal PLA₂s, platelet-activating factor (PAF) acetylhydrolases, and adipose specific PLA₂s. Each subfamily consists of several isozymes that possess PLA₂ activity. The first three PLA₂ subfamilies play important roles in inflammation-related diseases and cancer. In this review, the roles of well-studied enzymes sPLA₂-IIA, cPLA₂α and iPLA₂β in carcinogenesis and cancer development were discussed. sPLA₂-IIA seems to play conflicting roles and can act as a tumor suppressor or a tumor promoter according to the cancer type, but cPLA₂α and iPLA₂β play protumorigenic role in most cancers. The mechanisms of PLA₂-mediated signal transduction and crosstalk between cancer cells and endothelial cells in the tumor microenvironment are described. Moreover, the mechanisms by which PLA₂s mediate lipid reprogramming and glycerophospholipid remodeling in cancer cells are illustrated. PLA₂s as the upstream regulators of the arachidonic acid cascade are generally high expressed and activated in various cancers. Therefore, they can be considered as potential pharmacological targets and biomarkers in cancer. The detailed information summarized in this review may aid in understanding the roles of PLA₂s in cancer, and provide new clues for the development of novel agents and strategies for tumor prevention and treatment.

Comparison of Methods for Measuring Protein Concentration in Venom Samples

Snake venom is an extremely interesting natural mixture of proteins and peptides, characterized by both high diversity and high pharmacological potential. Much attention has been paid to the study of venom composition of different species and also detailed analysis of the properties of individual components. Since proteins and peptides are the active ingredients in venom, rapidly developing proteomic techniques are used to analyze them. During such analyses, one of the routine operations is to measure the protein concentration in the sample. The aim of this study was to compare five methods used to measure protein content in venoms of two snake species: the Viperids representative, Agkistrodon contortrix, and the Elapids representative, Naja ashei. The study showed that for A. contortrix venom, the concentration of venom protein measured by four methods is very similar and only the NanoDrop method clearly stands out from the rest. However, in the case of N. ashei venom, each technique yields significantly different results. We hope that this report will help to draw attention to the problem of measuring protein concentration, especially in such a complex mixture as animal venoms.

Bee Venom: Overview of Main Compounds and Bioactivities for Therapeutic Interests

Apitherapy is an alternate therapy that relies on the usage of honeybee products, most importantly bee venom for the treatment of many human diseases. The venom can be introduced into the human body by manual injection or by direct bee stings. Bee venom contains several active molecules such as peptides and enzymes that have advantageous potential in treating inflammation and central nervous system diseases, such as Parkinson's disease, Alzheimer's disease, and amyotrophic lateral sclerosis. Moreover, bee venom has shown promising benefits against different types of cancer as well as anti-viral activity, even against the challenging human immunodeficiency virus (HIV). Many studies described biological activities of bee venom components and launched preclinical trials to improve the potential use of apitoxin and its constituents as the next generation of drugs. The aim of this review is to summarize the main compounds of bee venom, their primary biological properties, mechanisms of action, and their therapeutic values in alternative therapy strategies.

Inhibition of PLA2G4A Reduces the Expression of Lung Cancer-Related Cytokines

Phospholipase A2-IVA (PLA2G4A) is the most abundant subtype of cytoplasmic phospholipase A2 (cPLA2) and is an important enzyme in tumor development. Our study aimed to explore the role of PLA2G4A in the regulation of lung cancer. The contents of cell-related cytokines (microsomal prostaglandin E synthase-1 [mPGES], PGE2, and prostacyclin [PGI2]) in A549 cells were analyzed by ELISA kits. Cell counting kit-8 (CCK8) was used to detect the effects of inhibitor of cPLA2 (arachidonyl trifluoromethyl ketone [AACOCF3]) on the proliferation of A549 cells. The migration and invasion of A549 cells were tested by cell scratch wound healing assay and transwell assay, respectively. Real-time quantitative PCR and Western blotting were used to detect the effect of inhibitor AACOCF3 on the expression of related mRNA and protein in A549 cells. ELISA result showed that the levels of mPGES, PGE2, and PGI2 in control group were significantly higher than those in the AACOCF3 group. Cell inhibition rate in the control group was significantly lower than that in the AACOCF3 group. The percentage of wound healing in the control group was significantly higher than that in the AACOCF3 group. Meanwhile, the relative invasive number of cells in the control group was significantly higher than those in the AACOCF3 group. The expression levels of related mRNA of PLA2G4A and cyclooxygenase-2 (COX-2) and the expression levels of mPGES, COX-1, and COX-2 protein in the control group were significantly higher than those in the AACOCF3 group. Our research showed that PLA2G4A was involved in migration and invasion of lung cancer cells.

Nanobodies as novel therapeutic agents in envenomation

BACKGROUND

An effective therapy against envenoming should be a priority in view of the high number scorpion stings and snakebites. Serum therapy is still widely applied to treat the envenomation victims; however this approach suffers from several shortcomings. The employment of monoclonal antibodies might be an outcome as these molecules are at the core of a variety of applications from protein structure determination to cancer treatment. The progress of activities in the twilight zone between genetic and antibody engineering have led to the development of a unique class of antibody fragments. These molecules possess several benefits and lack many possible disadvantages over classical antibodies. Within recombinant antibody formats, nanobodies or single domain antigen binding fragments derived from heavy chain only antibodies in camelids occupy a privileged position.

SCOPE OF REVIEW

In this paper we will briefly review the common methods of envenomation treatment and focus on details of various in vivo research activities that investigate the performance of recombinant, monoclonal nanobodies in venom neutralization.

MAJOR CONCLUSIONS

Nanobodies bind to their cognate target with high specificity and affinity, they can be produced in large quantities from microbial expression systems and are very robust even when challenged with harsh environmental conditions. Upon administering, they rapidly distribute throughout the body and seem to be well tolerated in humans posing low immunogenicity.

GENERAL SIGNIFICANCE

Scorpion and snake envenomation is a major issue in developing countries and nanobodies as a venom-neutralizing agent can be considered as a valuable and promising candidate in envenomation therapy.

Antimicrobial activity of apitoxin, melittin and phospholipase A₂ of honey bee (Apis mellifera) venom against oral pathogens

In this work, we used the Minimum Inhibitory Concentration (MIC) technique to evaluate the antibacterial potential of the apitoxin produced by Apis mellifera bees against the causative agents of tooth decay. Apitoxin was assayed in natura and in the commercially available form. The antibacterial actions of the main components of this apitoxin, phospholipase A2, and melittin were also assessed, alone and in combination. The following bacteria were tested: Streptococcus salivarius, S. sobrinus, S. mutans, S. mitis, S. sanguinis, Lactobacillus casei, and Enterococcus faecalis. The MIC results obtained for the commercially available apitoxin and for the apitoxin in natura were close and lay between 20 and 40 µg / mL, which indicated good antibacterial activity. Melittin was the most active component in apitoxin; it displayed very promising MIC values, from 4 to 40 µg / mL. Phospholipase A2 presented MIC values higher than 400 µg / mL. Association of mellitin with phospholipase A2 yielded MIC values ranging between 6 and 80 µg / mL. Considering that tooth decay affects people's health, apitoxin and its component melittin have potential application against oral pathogens.

Screening of cytotoxic, anti-angiogenic, anti-tumorogenic and antimicrobial activities of Anatolian Vipera ammodytes (Nose-horned viper) venom

Objective:

In the present study, we aimed to screen the cytotoxic, antimicrobial, anti-angiogenic and anti-tumorogenic activities of Anatolian

Material and methods:

The cytotoxicity was screened against PC3, HeLa, CaCo-2, U-87MG, MCF-7 and Vero cells by using MTT assay. The antimicrobial activity on

Results:

The IC

Conclusion:

The results of the present study contributed to the knowledge of the biological activities of Anatolian

Novel phospholipase A2 inhibitors from python serum are potent peptide antibiotics

Antimicrobial peptides (AMPs) play a vital role in defense against resistant bacteria. In this study, eight different AMPs synthesized from Python reticulatus serum protein were tested for bactericidal activity against various Gram-positive and Gram-negative bacteria (Staphylococcus aureus, Burkholderia pseudomallei (KHW and TES strains), and Proteus vulgaris) using a disc-diffusion method (20 μg/disc). Among the tested peptides, phospholipase A2 inhibitory peptide (PIP)-18[59-76], β-Asp65-PIP[59-67], D-Ala66-PNT.II, and D60,65E-PIP[59-67] displayed the most potent bactericidal activity against all tested pathogens in a dose-dependent manner (100-6.8 μg/ml), with a remarkable activity noted against S. aureus at 6.8 μg/ml dose within 6 h of incubation. Determination of minimum inhibitory concentrations (MICs) by a micro-broth dilution method at 100-3.125 μg/ml revealed that PIP-18[59-76], β-Asp65-PIP[59-67] and D-Ala66-PNT.II peptides exerted a potent inhibitory effect against S. aureus and B. pseudomallei (KHW) (MICs 3.125 μg/ml), while a much less inhibitory potency (MICs 12.5 μg/ml) was noted for β-Asp65-PIP[59-67] and D-Ala66-PNT.II peptides against B. pseudomallei (TES). Higher doses of peptides had no effect on the other two strains (i.e., Klebsiella pneumoniae and Streptococcus pneumoniae). Overall, PIP-18[59-76] possessed higher antimicrobial activity than that of chloramphenicol (CHL), ceftazidime (CF) and streptomycin (ST) (30 μg/disc). When the two most active peptides, PIP-18[59-76] and β-Asp65-PIP[59-67], were applied topically at a 150 mg/kg dose for testing wound healing activity in a mouse model of S. aureus infection, the former accelerates faster wound healing than the latter peptide at 14 days post-treatment. The western blot data suggest that the topical application of peptides (PIP-18[59-67] and β-Asp65-PIP[59-67]) modulates NF-kB mediated wound repair in mice with relatively little haemolytic (100-1.56 μg/ml) and cytotoxic (1000-3.125 μg/ml) effects evident on human cells in vitro.

Interactions of pharmacologically active snake venom sPLA2 with different cell lines

Secreted Phospholipases A₂ (sPLA₂s) represent a large family of structurally related enzymes, which target different tissues and organs and induce numerous pharmacological effects based on their catalytic specificity – hydrolysis of the sn-2 ester bond of glycerophospholipids. The neurotoxin vipoxin, isolated from the venom of Vipera ammodytes meriodionalis, is a heterodimeric postsynaptic ionic complex composed of two protein subunits – a basic and toxic His48 sPLA₂ enzyme and an acidic, enzymatically inactive and non-toxic component. In this paper, for the first time, we demonstrate that vipoxin sPLA₂ enzyme affects cell integrity and viability of four cell types and causes different cell responses. The most dramatic local tissue effects were observed with RPE-1 (retinal pigment epithelial) cells followed by A549 (adenocarcinomic human alveolar epithelial) cells and MDCK (Madin-Darby Canine Kidney epithelial) cells. Products of the enzymatic reaction, lysophospholipids and unsaturated free fatty acids, act as lipid mediators that can induce membrane damaging or can stimulate cell proliferation. Our preliminary results on the cytotoxic effect of vipoxin sPLA₂ on A549 cells are promising in searching of its eventual anticancer potential.