Daboia

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Anna-bella Failloux - One of the best experts on this subject based on the ideXlab platform.

Choo Hock Tan - One of the best experts on this subject based on the ideXlab platform.

  • thai russell s viper monospecific antivenom is immunoreactive and effective in neutralizing the venom of Daboia siamensis from java indonesia
    Toxicon, 2019
    Co-Authors: Thava Malar Changra Lingam, Kae Yi Tan, Choo Hock Tan
    Abstract:

    Abstract Daboia siamensis monovalent antivenom (DSMAV, Thailand) exhibited comparable immunoreactivity toward the venoms of eastern Russell's vipers from Thailand and Indonesia. It also effectively neutralized the procoagulant and lethal effects of both venoms, showing high potency. The Indonesian heterologous trivalent antivenom SABU (Serum Anti Bisa Ular), however, has very weak immunoreactivity and it failed to neutralize the Russell's viper venoms. DSMAV appears to be the appropriate choice of antivenom to treat Russell's viper envenoming.

  • venom proteomics and antivenom neutralization for the chinese eastern russell s viper Daboia siamensis from guangxi and taiwan
    Scientific Reports, 2018
    Co-Authors: Kae Yi Tan, Nget Hong Tan, Choo Hock Tan
    Abstract:

    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.

  • Venom proteomics and antivenom neutralization for the Chinese eastern Russell’s viper, Daboia siamensis from Guangxi and Taiwan
    Scientific Reports, 2018
    Co-Authors: Kae Yi Tan, Nget Hong Tan, Choo Hock Tan
    Abstract:

    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 A_2, 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 (ED_50 = 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.

Da Warrell - One of the best experts on this subject based on the ideXlab platform.

  • Development of an ELISA assay to determine neutralising capacity of horse serum following immunisation with Daboia siamensis venom in Myanmar
    'Elsevier BV', 2018
    Co-Authors: Em Khaing, Da Warrell, Pr Hurtado, Hurtado E, Zaw A, White J, Alfred S, Ca Peh
    Abstract:

    Snakebite envenoming is a serious problem in Myanmar. The great majority of snakebite in this country is due to Russell's Viper (Daboia siamensis). For many years, the Burma Pharmaceutical Industry has produced a monovalent antivenom to Russell's Viper in horses. At present, the only way of determining the level of antibody against D. siamensis venom in hyperimmune horse serum is to perform venom neutralisation tests in mice. In this study, we describe the development of an in vitro ELISA assay to estimate neutralising capacity of horse serum. We found a strong correlation between the ELISA assay and the venom neutralisation test in mice (r = 0.982). The assay is robust and has sufficient sensitivity (92%) and specificity (96%) to replace the venom neutralisation test in mice during the immunisation phase in horses

  • (Daboia RUSSELII RUSSELII): A PRELIMINARY DOSE-FINDING AND PHARMACOKINETIC STUDY
    2015
    Co-Authors: A. M. Richards, R. D. G. Theakston, Da Warrell
    Abstract:

    Abstract. Russell’s viper is the most important cause of life-threatening snake bite and acute renal failure in Sri Lanka. Only equine polyspecific antivenoms imported from India are available. They have not proved effective clinically or in clearing venom antigenemia and they frequently cause reactions. In an attempt to reduce mortality and morbidity, a new monospecific ovine Fab fragment antivenom (PolongaTaby; Therapeutic Antibodies, Inc., London, United Kingdom) was raised against Sri Lankan Russell’s viper venom. In a preliminary dose-finding study in 35 patients, an initial dose of 3–4 g restored blood coagulability permanently and stopped systemic bleeding, even in severely envenomed patients. Venom antigenemia disappeared within 1 hr of antivenom treatment but recurred, probably as a result of continued absorption of venom from the site of the bite, after the rapid clearance of therapeutic antibody. Twelve patients (34%) experienced early reactions that were usually mild and always responded to epi-nephrine. In Sri Lanka, Russell’s viper (Daboia russelii russelii, Sin-hala thith polonga) is responsible for most cases of severe and fatal envenoming.1 It contributes to an overall incidence of bites exceeding 400 per 100,000 population per year and to a total snake bite mortality of more than 5 per 100,00

  • Syndromic approach to treatment of snake bite in Sri Lanka based on results of a prospective national hospital-based survey of patients envenomed by identified snakes.
    'American Society of Tropical Medicine and Hygiene', 2009
    Co-Authors: Ca Ariaratnam, Mh Sheriff, Arambepola C, Rd Theakston, Da Warrell
    Abstract:

    Of 860 snakes brought to 10 hospitals in Sri Lanka with the patients they had bitten, 762 (89%) were venomous. Russell's vipers (Daboia russelii) and hump-nosed pit vipers (Hypnale hypnale) were the most numerous and H. hypnale was the most widely distributed. Fifty-one (6%) were misidentified by hospital staff, causing inappropriate antivenom treatment of 13 patients. Distinctive clinical syndromes were identified to aid species diagnosis in most cases of snake bite in Sri Lanka where the biting species is unknown. Diagnostic sensitivities and specificities of these syndromes for envenoming were 78% and 96% by Naja naja, 66% and 100% by Bungarus caeruleus, 14% and 100% by Daboia russelii, and 10% and 97% by Hypnale hypnale, respectively. Although only polyspecific antivenoms are used in Sri Lanka, species diagnosis remains important to anticipate life-threatening complications such as local necrosis, hemorrhage and renal and respiratory failure and to identify likely victims of envenoming by H. hypnale who will not benefit from existing antivenoms. The technique of hospital-based collection, labeling and preservation of dead snakes brought by bitten patients is recommended for rapid assessment of a country's medically-important herpetofauna

  • Venom phospholipases of Russell's vipers from Myanmar and eastern India--cloning, characterization and phylogeographic analysis.
    2007
    Co-Authors: Ih Tsai, Hy Tsai, Ym Wang, Da Warrell
    Abstract:

    Venoms of Russell's vipers (genus Daboia) are known for their deadly coagulopathic and other effects. We herein studied various isoforms of venom phospholipases A(2) (PLAs) from two Daboia species at their geographic boundary. From Myanmar Daboia siamensis venom (designated as DsM), four PLAs (designated DsM-aI, aI', aII' and bI') were purified, and the cDNAs encoding two acidic (DsM-aI and aII) and two basic PLAs (DsM-bI and S1) were also cloned from its venom-glands. DsM-S1 is identical to the major venom PLA of southern India Daboia russelii, but the protein is absent from the venom. Additionally, four PLAs (designated DrK-aI, aII, bI and bII) were cloned from cDNA obtained from venom glands of a Kolkata D. russelii, and the PLAs were purified from the pooled venom (designated as DrK). The acidic DrK-aI is the most neurotoxic and lethal among these PLAs; DsM-aI which differs from DrK-aI by only the Phe2 substitution shows greatly reduced enzymatic activity and lethality. Both acidic PLAs do not form dimeric complex with basic PLAs in the same venoms. DsM-bI' is neurotoxic and lethal but its orthologous DrK-bI (97% identical to DsM-bI') is a much weaker toxin. Given the fact that most of the orthologous PLAs of DrK and DsM share 97-100% sequence identity, Daboia vipers of Myanmar and Kolkata must be closely related. Molecular phylogenetic analyses on 30 venom PLAs of Eurasian vipers' revealed co-evolution of five subtypes of venom PLAs in both Daboia and Vipera genera. Our results shed light on the intra- and inter-species variations and structure-function relationships of viperid venom PLAs

  • Synopsis of recent developments in venomous snake systematics, No. 2.
    'Elsevier BV', 1998
    Co-Authors: Wüster W, Golay P, Da Warrell
    Abstract:

    Developments in our understanding of the systematics of venomous snakes since the beginning of 1996 are discussed and reviewed with special emphasis on their relevance and implications for toxinologists and clinicians. Groups of snakes affected by recent developments include the genera Elapomorphus, Rhabdophis, Vermicella, Atheris, Daboia, Agkistrodon/Gloydius, Bothrops/Bothriopsis and Trimeresurus. Other important publications on venomous snakes are noted

Ashis K Mukherjee - One of the best experts on this subject based on the ideXlab platform.

  • structural and functional characterization of complex formation between two kunitz type serine protease inhibitors from russell s viper venom
    Biochimie, 2016
    Co-Authors: Ashis K Mukherjee, Sumita Dutta, Bhargab Kalita, Deepak Kumar Jha, Pritam Deb, Stephen P Mackessy
    Abstract:

    Snake venom Kunitz-type serine protease inhibitors (KSPIs) exhibit various biological functions including anticoagulant activity. This study elucidates the occurrence and subunit stoichiometry of a putative complex formed between two KSPIs (Rusvikunin and Rusvikunin-II) purified from the native Rusvikunin complex of Pakistan Russell's Viper (Daboia russelii russelii) venom (RVV). The protein components of the Rusvikunin complex were identified by LC-MS/MS analysis. The non-covalent interaction between two major components of the complex (Rusvikunin and Rusvikunin-II) at 1:2 stoichiometric ratio to form a stable complex was demonstrated by biophysical techniques such as spectrofluorometric, classical gel-filtration, equilibrium gel-filtration, circular dichroism (CD), dynamic light scattering (DLS), RP-HPLC and SDS-PAGE analyses. CD measurement showed that interaction between Rusvikunin and Rusvikunin-II did not change their overall secondary structure; however, the protein complex exhibited enhanced hydrodynamic diameter and anticoagulant activity as compared to the individual components of the complex. This study may lay the foundation for understanding the basis of protein complexes in snake venoms and their role in pathophysiology of snakebite.

  • characterization of a kunitz type protease inhibitor peptide rusvikunin purified from Daboia russelii russelii venom
    International Journal of Biological Macromolecules, 2014
    Co-Authors: Ashis K Mukherjee, Stephen P Mackessy, Sumita Dutta
    Abstract:

    The snake venom may be considered as a potent source of untapped therapeutic proteins and peptides. The peptide mass fingerprinting and N-terminal sequence alignment of a 6.9kDa peptide named Rusvikunin from Daboia russelii russelii venom show the presence of putative conserved domains of the KU superfamily. Further, BLAST analysis of two of the de novo peptide sequences of Rusvikunin demonstrates significant sequence homology with serine proteases reported in the NCBI database. Rusvikunin possesses conserved cysteine residues and Arg15 at the P1 position. It inhibits amidolytic activity of trypsin (IC50=50nmol/l), plasmin (IC50=1.1μmol/l), and fibrinogen clotting as well as plasma clotting activity of thrombin (IC50=1.3μmol/l); however, it does not inhibit the amidolytic activity of chymotrypsin, thrombin, factor Xa, and tissue plasminogen activator. Rusvikunin is a glycoprotein, demonstrates dose-dependent BAEE-esterase activity. It does not show lethality in mice or in vitro cytotoxicity against mammalian cells but shows in vivo anticoagulant activity 6h after i.p. injection in the mouse model. The commercial polyvalent and monovalent antivenom failed to inhibit the functional properties of Rusvikunin. The possible biomedical applications of Rusvikunin in the treatment and/or prevention of cardiovascular disorders such as thrombosis and trypsin-induced inflammation are suggested.

  • biochemical and pharmacological properties of a new thrombin like serine protease russelobin from the venom of russell s viper Daboia russelii russelii and assessment of its therapeutic potential
    Biochimica et Biophysica Acta, 2013
    Co-Authors: Ashis K Mukherjee, Stephen P Mackessy
    Abstract:

    Abstract Background Snake venoms are rich sources of bioactive molecules, and several venom-derived proteins have entered clinical trials for use in ischemic disorders; however, late-stage failure of a recent drug candidate due to low in vivo efficacy demonstrated the need for new sources of fibrinogenolytic drug candidates. Methods A 51.3 kDa thrombin-like serine protease (Russelobin) purified from the venom of Russell's Viper (Daboia russelii russelii) was subjected to extensive biochemical characterization, including N-terminal sequencing, substrate specificity, kinetic and inhibitor assays, glycosylation analysis and stability assays. Toxicity and pathology analyses were conducted in NSA mice. Results Russelobin has extensive N-terminus identity with a beta-fibrinogenase-like serine proteinase precursor from Daboia russelii siamensis venom, a mass of 51.3 kDa and contains extensive N-linked oligosaccharides. Serine protease inhibitors and heparin significantly decreased activity, with much lower inhibition by DTT, antithrombin-III and α2-macroglobulin. Russelobin preferentially released FPA and slowly released FPB from human fibrinogen, forming a labile fibrin clot readily hydrolyzed by plasmin. The partially deglycosylated enzyme showed significantly lower activity toward fibrinogen and less resistance against neutralization by plasma α2MG and antithrombin-III. Russelobin was non-cytotoxic, non-lethal and produced no histopathologies in mice, and it demonstrated in vivo dose-dependent defibrinogenating activity. Conclusions Russelobin is an A/B fibrinogenase with high specificity toward fibrinogen, both in vitro and in vivo. Extensive glycosylation appears to protect the molecule against endogenous protease inhibitors, prolonging its in vivo efficacy. General significance Due to its low toxicity, stability and activity as a defibrinogenating agent, Russelobin shows high potential for cardiovascular drug development.

  • isolation of a snake venom phospholipase a2 pla2 inhibitor aiplai from leaves of azadirachta indica neem mechanism of pla2 inhibition by aiplai in vitro condition
    Toxicon, 2008
    Co-Authors: Ashis K Mukherjee, Robin Doley, Debashree Saikia
    Abstract:

    A compound (AIPLAI (Azadirachta indica PLA2 inhibitor)) purified from the methanolic leaf extract of A. indica (Neem) inhibits the cobra and Russell's viper venoms (RVVs) phospholipase A2 enzymes in a dose-dependent manner. Inhibition of catalytic and tested pharmacological properties of cobra venom (Naja naja and Naja kaouthia) PLA2 enzymes by AIPLAI is significantly higher (P<0.05) compared to the inhibition of PLA2 enzymes of crude RVV (Daboia russelli) when tested under the same condition. Kinetic study reveals that in in vitro condition, AIPLAI inhibits the purified N. kaouthia PLA2 enzymes in a non-competitive manner. The AIPLAI is quite stable at room temperature. The present study shows that AIPLAI holds good promise for the development of novel anti-snake venom drug in future.

  • characterization of a novel pro coagulant metalloprotease rvbcmp possessing α fibrinogenase and tissue haemorrhagic activity from venom of Daboia russelli russelli russell s viper evidence of distinct coagulant and haemorrhagic sites in rvbcmp
    Toxicon, 2008
    Co-Authors: Ashis K Mukherjee
    Abstract:

    Abstract A novel, basic pro-coagulation metalloprotease (Russell's viper basic coagulant metalloprotease, RVBCMP) with an approximate molecular weight of 15 kDa was purified from the venom of Daboia russelli russelli (Russell's viper) from eastern India. RVBCMP exerted dose-dependent coagulation of platelet-poor human plasma; however, RVBCMP possessed less coagulant activity as compared with the coagulant activity of crude Russell's viper venom (RVV). RVBCMP did not show oedema induction, direct haemolysis of washed erythrocytes, hydrolysis of human plasma albumin or globulin, and thrombin-like activity, but exhibited caseinolytic, α -fibrinogenolytic, and liver tissue haemorrhagic activities. Inhibition of coagulant and protease activities of RVBCMP by EDTA suggested a metalloprotease nature of this protein. RVBCMP showed antigenicity as was evident from the immunoblotting experiment. None of the tested plant extracts, except Leucus lavandulaefolia , inhibited the coagulant or haemorrhagic activity of RVBCMP. Interestingly, aqueous extracts of the tested plants as well as the commercial polyvalent antivenom raised against crude RVV differentially inhibited the coagulant and tissue haemorrhagic activity of RVBCMP. The current investigation provides a fairly good indication that RVBCMP possesses a distinct, perhaps overlapping, site for coagulant and tissue haemorrhagic activity.

Thomas Garrigues - One of the best experts on this subject based on the ideXlab platform.

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