Neuro- and Cardiovascular Activities of Montivipera bornmuelleri Snake Venom

Simple Summary

Snake venoms are rich in molecules acting on different biological systems, and they are responsible for the complications following snake bite envenoming. These bioactive molecules are of interest in pharmaceutical industries as templates for drug design. Different biological activities of Montivipera bornmuelleri snake venom have been already studied; however, the venom’s activity on the nervous system has not yet been studied, and its effect on the cardiovascular system needs further investigation. Herein, we show that this venom induces toxicity on the nervous system and disrupts the cardiovascular system, highlighting a broad spectrum of biological activities.

Abstract

The complications following snake bite envenoming are due to the venom’s biological activities, which can act on different systems of the prey. These activities arise from the fact that snake venoms are rich in bioactive molecules, which are also of interest for designing drugs. The venom of Montivipera bornmuelleri, known as the Lebanon viper, has been shown to exert antibacterial, anticancer, and immunomodulatory effects. However, the venom’s activity on the nervous system has not yet been studied, and its effect on the cardiovascular system needs further investigation. Because zebrafish is a convenient model to study tissue alterations induced by toxic agents, we challenged it with the venom of Montivipera bornmuelleri. We show that this venom leads to developmental toxicity but not teratogenicity in zebrafish embryos. The venom also induces neurotoxic effects and disrupts the zebrafish cardiovascular system, leading to heartbeat rate reduction and hemorrhage. Our findings demonstrate the potential neurotoxicity and cardiotoxicity of M. bornmuelleri’s venom, suggesting a multitarget strategy during envenomation.

Apis mellifera syriaca Venom: Evaluation of Its Anticoagulant Effect, Proteolytic Activity, and Cytotoxicity along with Its Two Main Compounds-MEL and PLA2-On HeLa Cancer Cells

Bee venom (BV) is one of the most remarkable natural products that has been a subject of studies since ancient times. Recent studies have shown that Apis mellifera syriaca venom possesses antibacterial as well as cytotoxic effects on cancer cell lines. The venom contains a variety of bioactive molecules-mainly melittin (MEL) and phospholipase A2 (PLA2), as well as other compounds that are not well characterized. In this work, we continue the biological characterization of A. mellifera syriaca venom by testing its anticoagulant effect on human plasma using the prothrombin time (PT) test, as well as assessing its proteolytic activity. In addition, the cytotoxicity of the crude venom-and of its two main components, MEL and PLA2-was tested on HeLa cancer cell lines for the first time. The results obtained showed the capacity of A. mellifera syriaca venom to increase clotting time, thereby proving its anticoagulant effect. Moreover, the venom did not demonstrate a significant proteolytic activity unless administrated at concentrations ≥ 5 mg/mL. Finally, we showed that crude A. mellifera syriaca venom, along with MEL, exhibit a strong in vitro cytotoxic effect on HeLa cancer cell lines, even at low concentrations. In summary, our findings could serve as a basis for the development of new natural-based drug candidates in the therapeutic field.

Montivipera bornmuelleri Venom: Inhibitory Effect on Staphylococcus epidermidis and Escherichia coli F1F0-ATPases and Cytotoxicity on HCT116 Cancer Cell Lines

In this work, we pursued the biological characterization of the venom of Montivipera bornmuelleri, a viper from the Lebanese mountains. In relation to its antibacterial potential, the inhibitory effect of this venom on the F1F0-ATPase enzymes of Gram-positive Staphylocoocus epidermidis and Gram-negative Escherichia coli bacteria was examined. In order to determine the degree of cytotoxicity of the venom on the HCT116 human colon cancer cell lines, the biological MTT proliferation and cell viability test were implemented. After validation of the enzymatic F1F0-ATPase model by the spectrophotometric method, using quercetin as the reference ligand, results revealed that M. bornmuelleri venom is able to inhibit the activity of the enzyme of these two bacteria with a concentration of the order of 100–150 µg/mL. In addition, a venom concentration of 10 µg/mL was sufficient to kill the totality of HCT116 cell lines cultivated in vitro. These data show that M. bornmuelleri venom is a mixture of diverse molecules presenting activities of interest, and is a potential source to explore in order to discover new drug candidates.

First Characterization of The Venom from Apis mellifera syriaca, A Honeybee from The Middle East Region

Bee venom is a mixture of several components with proven therapeutic benefits, among which are anti-inflammatory, analgesic, and various cardiovascular conditions. In this work, we analyzed for the first time the proteomic content and biological properties of the crude venom from Apis mellifera syriaca, a honeybee from the Middle East region. Using high-performance liquid chromatography-tandem mass spectrometry, we evidence the venom contains phospholipase A2, hyaluronidase, mast cell-degranulating peptide, adolapin, apamin, and melittin. The latter was purified by solid phase extraction method (SPE) and tested in parallel with crude venom for biological activities. Precisely, crude venom-but not melittin-exhibited antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa strains. Alongside, hemolytic activity was observed in human blood subjected to the venom at high doses. A. mellifera syriaca venom displayed antioxidant activities, and not surprisingly, PLA2 catalytic activity. Eventually, the venom proved to exert antiproliferative effects against MCF-7 and 3T3 cancer cells lines. This first report of a new bee venom opens new avenues for therapeutic uses of bee venoms.

Vipers of the Middle East: A Rich Source of Bioactive Molecules

Snake venom serves as a tool of defense against threat and helps in prey digestion. It consists of a mixture of enzymes, such as phospholipase A2, metalloproteases, and l-amino acid oxidase, and toxins, including neurotoxins and cytotoxins. Beside their toxicity, venom components possess many pharmacological effects and have been used to design drugs and as biomarkers of diseases. Viperidae is one family of venomous snakes that is found nearly worldwide. However, three main vipers exist in the Middle Eastern region: Montivipera bornmuelleri, Macrovipera lebetina, and Vipera (Daboia) palaestinae. The venoms of these vipers have been the subject of many studies and are considered as a promising source of bioactive molecules. In this review, we present an overview of these three vipers, with a special focus on their venom composition as well as their biological activities, and we discuss further frameworks for the exploration of each venom.

Venom proteomics and antivenom neutralization for the Chinese eastern Russell's viper, Daboia siamensis from Guangxi and Taiwan

The eastern Russell's viper (Daboia siamensis) causes primarily hemotoxic envenomation. Applying shotgun proteomic approach, the present study unveiled the protein complexity and geographical variation of eastern D. siamensis venoms originated from Guangxi and Taiwan. The snake venoms from the two geographical locales shared comparable expression of major proteins notwithstanding variability in their toxin proteoforms. More than 90% of total venom proteins belong to the toxin families of Kunitz-type serine protease inhibitor, phospholipase A2, C-type lectin/lectin-like protein, serine protease and metalloproteinase. Daboia siamensis Monovalent Antivenom produced in Taiwan (DsMAV-Taiwan) was immunoreactive toward the Guangxi D. siamensis venom, and effectively neutralized the venom lethality at a potency of 1.41 mg venom per ml antivenom. This was corroborated by the antivenom effective neutralization against the venom procoagulant (ED = 0.044 ± 0.002 µl, 2.03 ± 0.12 mg/ml) and hemorrhagic (ED50 = 0.871 ± 0.159 µl, 7.85 ± 3.70 mg/ml) effects. The hetero-specific Chinese pit viper antivenoms i.e. Deinagkistrodon acutus Monovalent Antivenom and Gloydius brevicaudus Monovalent Antivenom showed negligible immunoreactivity and poor neutralization against the Guangxi D. siamensis venom. The findings suggest the need for improving treatment of D. siamensis envenomation in the region through the production and the use of appropriate antivenom.

Isolation of Bioactive Compounds from Calicotome villosa Stems

A phenylethanoid, two steroids, a flavone glucoside and a chalcone have been isolated for the first time from the stems of Calicotome villosa together with a previously isolated flavone glucoside. Their structures were determined by spectroscopic analyses (NMR, HRMS) as basalethanoïd B (1), β-sitosterol and stigmasterol (2), chrysine-7-O-β-d-glucopyranoside (3), chrysine 7-((6′′-O-acetyl)-O-β-d-glucopyranoside) (4) and calythropsin (5). The crude extracts and the isolated compounds (except 4), were evaluated for their antioxidant, antimicrobial (against two Gram-positive bacterial strains: Staphylococcus aureus, Bacillus cereus, four Gram-negative bacterial strains: Staphylococcus epidermidis, Klebsiella pneumonia, Acinetobacter baumanii, and three yeasts: Candida albicans, Candida tropicalis, and Candida glabrata), hemolytic, antidiabetic, anti-inflammatory and cytotoxic activity. The crude extracts showed good ability to scavenge the free radical DPPH. Methanol stem extract followed by the dichloromethane stem extract showed moderate antimicrobial potency; furthermore, at 1 mg/mL the methanol extract showed an inhibition of C. albicans growth comparable to nystatin. Dichloromethane, methanol, and aqueous extracts inhibited 98%, 90%, and 80% of HeLa cell proliferation at 2 mg/mL respectively. Weak hypoglycemic and hemolytic effects were exhibited by the crude extracts. Among all the tested compounds, compound 3 showed remarkable hypoglycemic potential (93% at 0.1 mg/mL) followed by compound 5 (90% at 0.3 mg/mL). Compound 5 was the most effective in the DPPH^. scavenging assay (100% at 0.1 mg/mL) and cytotoxic assay on HeLa cells (99% and 90% after 24 and 48 h of treatment at 0.1 mg/mL, respectively). No anti-inflammatory effects were displayed by any of the crude extracts or the isolated compounds at any of the tested concentrations.

Functional venomics of the Sri Lankan Russell's viper (Daboia russelii) and its toxinological correlations

The venom proteome (venomics) of the Sri Lankan Daboia russelii was elucidated using 1D SDS PAGE nano-ESI-LCMS/MS shotgun proteomics. A total of 41 different venom proteins belonging to 11 different protein families were identified. The four main protein families are phospholipase A2 (PLA2, 35.0%), snaclec (SCL, 22.4%, mainly platelet aggregation inhibitors), snake venom serine proteinase (SVSP, 16.0%, mainly Factor V activating enzyme) and snake venom metalloproteinase (SVMP, 6.9%, mainly heavy chain of Factor X activating enzyme). Other protein families that account for more than 1% of the venom protein include l-amino acid oxidase (LAAO, 5.2%), Kunitz-type serine proteinase inhibitor (KSPI, 4.6%), venom nerve growth factor (VNGF. 3.5%), 5'-nucleotidase (5'NUC, 3.0%), cysteine-rich secretory protein (CRISP, 2.0%) and phosphodiesterase (PDE, 1.3%). The venom proteome is consistent with the enzymatic and toxic activities of the venom, and it correlates with the clinical manifestations of Sri Lankan D. russelii envenomation which include hemorrhage, coagulopathy, renal failure, neuro-myotoxicity and intravascular hemolysis. The venom exhibited remarkable presypnatic neurotoxicity presumably due to the action of basic PLA2 in high abundance (35.0%). Besides, SCLs, Factor X activating enzymes (SVMPs), SVSPs, and LAAOs are potential hemotoxins (50.5%), contributing to coagulopathy and hemorrhagic syndrome in Sri Lankan D. russelii envenomation.

SIGNIFICANCE

The study demonstrated the proteomic profile of the Sri Lankan Russell's viper venom, unraveling its complex composition of toxins and correlations with major toxic activities. The types, numbers, and relative abundances of toxins were reported. The venom content was dominated by the neurotoxic basic phospholipases A2 (>30% of total protein abundance) and several hemotoxic or coagulopathic protein families (approximately 50% in total). The proteome correlates with the functional and toxinological characterizations of the venom, and reflects the pathophysiological effects of envenomation by the Sri Lankan Russell's viper. The venom proteomics may serve to propel the understanding on pathogenesis and treatment strategy for envenomation by this viper in Sri Lanka. The enriched database contributed by the proteomic findings will be useful for comparing venom variations among Russell's vipers from different geographical areas.

Contribution to the food products' analysis: A research and evaluation on the hemolytic effect of some pesticides used in Lebanon

Pesticides are a real concern for the society as their use has become critical, leading sometimes to their accumulation as residues in fruits and vegetables. After examining the pesticides sold in Northern Lebanon, this study is focused on the analysis and identification of pesticides residues in fruits and vegetables that are harvested in this region and treated with the locally sold pesticides. Results show: first, (i) a use of Zineb by the name of another pesticide Micronized Sulfur to avoid prosecution; (ii) a significant presence of Metalaxyl in lemons and oranges; (iii) a significant presence of Trifluralin in strawberries; and (iv) a significant presence of Zineb in lemons and tomatoes. Second, with the use of hemolytic tests on human blood results show: (i) a critical concentration and a significant hemolytic effect of some pesticides used in Lebanon; and (ii) an absence of hemolytic effect in the collected fractions of the different analyzed fruit extracts containing pesticides. Finally, this work is the first step for pesticides' analysis in vegetables and fruits in Lebanon, initiating a wider analytical study in order to control and examine the use of pesticides which, according to our results, could have an adverse effect on human health over a long term.