ARTICLE | doi:10.20944/preprints202310.0130.v1
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: acetylcholine; adrenoceptors; environment; habitat; Tokara Islands; serotonin; snake; vasoreactivity
Online: 3 October 2023 (09:14:37 CEST)
Vasoreactivity is relatively well documented in terrestrial snakes, but has previously been investigated in only one semi-arboreal snake species. Consequently, the extent to which vasoreactivity is common across snake taxa, or varies by habitat is unclear. The Tokara habu (Protobothrops tokarensis) is a semi-arboreal snake endemic to only two small adjacent Japanese islands, and hence a useful species for further investigation of vasoreactivity. We evaluated responses to known vasoactive substances in thoracic aortas isolated from Tokara habu. Under resting tension, noradrenaline and angiotensin II induced concentration-dependent contraction, but acetylcholine, serotonin (5-hydroxytriptamine; 5-HT), and isoproterenol induced relaxation followed by contraction. Histamine and rattlesnake bradykinin had no effect. Experiments with receptor-specific antagonists suggest that M1 and M3 receptors are involved in the acetylcholine-induced response, 5-HT1, 5-HT2 and 5-HT7 receptors in the serotonin-induced response, and β1 and β2 receptors in isoproterenol-induced relaxation. NO may be involved in acetylcholine-induced relaxation, but not the responses to serotonin or isoproterenol. In contrast to the uniform vasoreactivity observed in terrestrial snakes, the vasoreactivity of semi-arboreal snakes may be governed by diverse regulatory mechanisms.
ARTICLE | doi:10.20944/preprints201908.0123.v1
Subject: Biology And Life Sciences, Ecology, Evolution, Behavior And Systematics Keywords: snake demography; moonlight; rain; temperature; climate change in Osa
Online: 11 August 2019 (05:35:15 CEST)
Introduction: studies in the last two decades have found declining snake populations in both temperate and tropical sites, including informal reports from Drake Bay, Costa Rica. Objective: to investigate if reports of decreasing snake populations in Drake Bay had a real basis, and if environmental factors, particularly temperature, rain and light, have played a role in that decrease. Methods: we worked at Drake Bay from 2012 through 2017 and made over 4000 h of transect counts. Using head flashlights we surveyed a transect covered by lowland tropical rainforest at an altitude of 12–38 m above sea level, near the Agujas River, mostly at 1930–2200 hours. We counted all the snakes that we could see along the transect. Results: snake counts increase from August to September and then decline rapidly. The May snakes/rainfall peaks coincide, but the second snake peak occurs one month before the rain peak; we counted more snakes in dry nights, with the exception of Imantodes cenchoa which was equally common despite rain conditions. We saw less Leptodeira septentrionalis on bright nights, but all other species were unaffected. Along the six years, the number of species with each diet type remained relatively constant, but the number of individuals declined sharply for those that feed on amphibians and reptiles. We report Rhadinella godmani, a highland species, at 12–38 m of altitude. Conclusion: night field counts of snakes in Drake Bay, Costa Rica, show a strong decline from 2012 through 2017.
ARTICLE | doi:10.20944/preprints201708.0097.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: snake venom; Bothrops asper; acidic myotoxic phospholipase A2; myotoxicity; edema
Online: 28 August 2017 (06:27:59 CEST)
Myotoxic phospholipases A2 are responsible for many clinical signs in envenomation by Bothropssnakes. A new myotoxic acidic PLA2 Asp 49 was isolated from Colombian Bothrops asper venom. It was isolated by high efficiency liquid chromatography and named BaCol PLA2. It had a molecular weight of 14180.69 Da and an isoelectric point of 4.4. The complete sequenceobtained by cDNA cloning, with access number in the gene bank MF319968; this sequenceevidenced a mature product of 124 amino acids with Asp in 49 position. In vivoassaysin mice demonstrated profuse oedemaand myotoxicity evidenced by increase of creatinakinasa in plasma and severe and diffuse damage to the muscular fibers, further vacuolization and hyalinization necrosis of the sarcoplasm showed by histopathology with hematoxylin and eosin staining of gastrocnemius muscle. In vitro studies showed cell membrane damage without phosphatidylserine exposure, an early apoptosis hallmark. Further BaCol PLA2 evidenced high indirect hemolytic activityand moderate anticoagulant action. The toxin showed homology with others acidic PLA2 isolated from Bothrops venoms, including one isolated from B. asper of Costa Rica. Unlike this, BaCol PLA2 was myotoxic.
ARTICLE | doi:10.20944/preprints202311.0349.v1
Subject: Computer Science And Mathematics, Mathematics Keywords: Edge labeling; Irregularity strength; Irregular labelling; Total edge irregularity strength; Star snake graph.
Online: 6 November 2023 (11:13:09 CET)
In different fields in our life, like physics, coding theory and computer science, graph labeling dramas an vital role and appears in many applications. A labeling of a graph is a map which assign each element in with a positive integer number. An edge irregular total -labeling is a function such that where and are weights for any two distinct edges. In this case, has total edge irregularity strength (TEIS) if is minimum. In our paper, we defined a new type of graphs called a triple star snake graph and star snake graph . Also, we investigated TEIS for a triple star snake graph . After that, we generalized the results for star snake graph .
ARTICLE | doi:10.20944/preprints202005.0098.v1
Subject: Medicine And Pharmacology, Oncology And Oncogenics Keywords: breast cancer; snake venom; cytotoxin II; recombinant protein; apoptosis; cell cycle progression; cytotoxicity
Online: 6 May 2020 (15:12:05 CEST)
Breast cancer (BC) is among the leading causes of mortality from cancer in women. Many of the available anticancer drugs have various side effects. Therefore, researchers are seeking novel anticancer agents particularly from natural compounds and in this regard, snake venom is still one of the main sources of drug discovery. Previous studies showed potential anticancer effects of Cytotoxin II (CTII) from Naja naja oxiana against the different types of cancers. In this study, a pET-SUMO-CTII vector was transformed into SHuffle® T7 Express, an Escherichia coli strain, for recombinant protein expression (rCTII) and the cytotoxic effects of this protein was assessed in MCF-7 cells. The flow cytometry assay was applied to measure the apoptosis and cell cycle. Also, mRNA levels of the Bax, Bcl2, P53, caspase-3, caspase-8, caspase-9, caspase-10, matrix metalloproteinases (MMP)-3, and MMP-9 were analyzed by quantitative real-time PCR to determine the underlying cellular pathways affected by rCTII. The results of this study showed that treatment with 4 µg mL-1 of rCTII enhanced apoptosis through the intrinsic and extrinsic pathways. Also, the increase of the cells' proportion in the sub-G1 phase as well as a reduction in S phase was observed. In addition, the expression of MMP-3 and MMP-9 was decreased in the treated group in comparison to the control group that may contribute to the reduced migratory ability of tumor cells. These experimental results indicate that rCTII has anti-proliferative potential, and so this protein could be a potential drug for BC therapy in combination with other drugs.
ARTICLE | doi:10.20944/preprints202106.0050.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Montivipera bornmuelleri snake venom; F1F0-ATPase; Staphylococcus epidermidis; Escherichia coli; antibacterial activity; HCT116 cells; anticancer activity
Online: 2 June 2021 (07:21:59 CEST)
In this work, we pursued the biological characterization of the venom of Montivipera born-muelleri, a viper from the Lebanese mountains. In relativity to its antibacterial potential, the in-hibitory effect of this venom on the F1F0-ATPase enzymes of Gram-positive Staphylocoocus epider-midis and Gram-negative Escherichia coli bacteria was examined. In order to determine the de-gree 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, re-sults 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.
ARTICLE | doi:10.20944/preprints201807.0123.v1
Subject: Biology And Life Sciences, Virology Keywords: Snake venomics; Viperidae; Protobothrops flavoviridis; Habu pit viper; Bottom-Up; Top-Down; BPP; Tripeptide metalloprotease inhibitor; Cytotoxicity
Online: 6 July 2018 (16:34:48 CEST)
The Asian world is home to a multitude of venomous and dangerous snakes, which are attributed to various medical effects used in the preparation of traditional snake tinctures and alcoholics, like the Japanese snake wine, named Habushu. The aim of this work was to perform the first quantitative proteomic analysis of the Protobothrops flavoviridis pit viper venom. Accordingly, the venom was analyzed by complimentary bottom-up and top-down mass spectrometry techniques. The mass spectrometry-based snake venomics approach revealed that more than half of the venom is composed of different phospholipases A2 (PLA2). The combination with an intact mass profiling led to the identification of the three main Habu PLA2s. Furthermore, nearly one-third of the total venom consists of snake venom metalloproteinases and disintegrins, and several minor represented toxins families were detected: CTL, CRISP, svSP, LAAO, PDE and 5’-nucleotidase. Finally, the venom of P. flavoviridis contains certain bradykinin-potentiating peptides and related peptides, like the svMP inhibitors pEKW, pEQW, pEEW and pENW. In preliminary MTT cytotoxicity assays the highest cancerous-cytotoxicity of the crude venom was measured against human neuroblastoma SH-SY5Y cells and shows in some fractions disintegrin-like effects.