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Kakumanu R, Kemp-Harper BK, Silva A, Kuruppu S, Isbister GK, Hodgson WC. An in vivo examination of the differences between rapid cardiovascular collapse and prolonged hypotension induced by snake venom. Sci Rep 2019; 9:20231. [PMID: 31882843 PMCID: PMC6934742 DOI: 10.1038/s41598-019-56643-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 12/16/2019] [Indexed: 11/10/2022] Open
Abstract
We investigated the cardiovascular effects of venoms from seven medically important species of snakes: Australian Eastern Brown snake (Pseudonaja textilis), Sri Lankan Russell’s viper (Daboia russelii), Javanese Russell’s viper (D. siamensis), Gaboon viper (Bitis gabonica), Uracoan rattlesnake (Crotalus vegrandis), Carpet viper (Echis ocellatus) and Puff adder (Bitis arietans), and identified two distinct patterns of effects: i.e. rapid cardiovascular collapse and prolonged hypotension. P. textilis (5 µg/kg, i.v.) and E. ocellatus (50 µg/kg, i.v.) venoms induced rapid (i.e. within 2 min) cardiovascular collapse in anaesthetised rats. P. textilis (20 mg/kg, i.m.) caused collapse within 10 min. D. russelii (100 µg/kg, i.v.) and D. siamensis (100 µg/kg, i.v.) venoms caused ‘prolonged hypotension’, characterised by a persistent decrease in blood pressure with recovery. D. russelii venom (50 mg/kg and 100 mg/kg, i.m.) also caused prolonged hypotension. A priming dose of P. textilis venom (2 µg/kg, i.v.) prevented collapse by E. ocellatus venom (50 µg/kg, i.v.), but had no significant effect on subsequent addition of D. russelii venom (1 mg/kg, i.v). Two priming doses (1 µg/kg, i.v.) of E. ocellatus venom prevented collapse by E. ocellatus venom (50 µg/kg, i.v.). B. gabonica, C. vegrandis and B. arietans (all at 200 µg/kg, i.v.) induced mild transient hypotension. Artificial respiration prevented D. russelii venom induced prolonged hypotension but not rapid cardiovascular collapse from E. ocellatus venom. D. russelii venom (0.001–1 μg/ml) caused concentration-dependent relaxation (EC50 = 82.2 ± 15.3 ng/ml, Rmax = 91 ± 1%) in pre-contracted mesenteric arteries. In contrast, E. ocellatus venom (1 µg/ml) only produced a maximum relaxant effect of 27 ± 14%, suggesting that rapid cardiovascular collapse is unlikely to be due to peripheral vasodilation. The prevention of rapid cardiovascular collapse, by ‘priming’ doses of venom, supports a role for depletable endogenous mediators in this phenomenon.
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Affiliation(s)
- Rahini Kakumanu
- Monash Venom Group, Department of Pharmacology, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, 3168, Australia
| | - Barbara K Kemp-Harper
- Monash Venom Group, Department of Pharmacology, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, 3168, Australia
| | - Anjana Silva
- Monash Venom Group, Department of Pharmacology, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, 3168, Australia.,Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Saliyapura, 50008, Sri Lanka
| | - Sanjaya Kuruppu
- Department of Biochemistry & Molecular Biology, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, 3168, Australia
| | - Geoffrey K Isbister
- Monash Venom Group, Department of Pharmacology, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, 3168, Australia.,Clinical Toxicology Research Group, University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Wayne C Hodgson
- Monash Venom Group, Department of Pharmacology, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, 3168, Australia.
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Kakumanu R, Kuruppu S, Rash LD, Isbister GK, Hodgson WC, Kemp-Harper BK. D. russelii Venom Mediates Vasodilatation of Resistance Like Arteries via Activation of K v and K Ca Channels. Toxins (Basel) 2019; 11:E197. [PMID: 30939844 PMCID: PMC6520720 DOI: 10.3390/toxins11040197] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 03/17/2019] [Accepted: 03/28/2019] [Indexed: 11/16/2022] Open
Abstract
Russell's viper (Daboia russelii) venom causes a range of clinical effects in humans. Hypotension is an uncommon but severe complication of Russell's viper envenoming. The mechanism(s) responsible for this effect are unclear. In this study, we examined the cardiovascular effects of Sri Lankan D. russelii venom in anaesthetised rats and in isolated mesenteric arteries. D. russelii venom (100 μg/kg, i.v.) caused a 45 ± 8% decrease in blood pressure within 10 min of administration in anaesthetised (100 μg/kg ketamine/xylazine 10:1 ratio, i.p.) rats. Venom (1 ng/mL⁻1 μg/mL) caused concentration-dependent relaxation (EC50 = 145.4 ± 63.6 ng/mL, Rmax = 92 ± 2%) in U46619 pre-contracted rat small mesenteric arteries mounted in a myograph. Vasorelaxant potency of venom was unchanged in the presence of the nitric oxide synthase inhibitor, L-NAME (100 µM), or removal of the endothelium. In the presence of high K⁺ (30 mM), the vasorelaxant response to venom was abolished. Similarly, blocking voltage-dependent (Kv: 4-aminopryidine; 1000 µM) and Ca2+-activated (KCa: tetraethylammonium (TEA; 1000 µM); SKCa: apamin (0.1 µM); IKCa: TRAM-34 (1 µM); BKCa; iberiotoxin (0.1 µM)) K⁺ channels markedly attenuated venom-induced relaxation. Responses were unchanged in the presence of the ATP-sensitive K⁺ channel blocker glibenclamide (10 µM), or H1 receptor antagonist, mepyramine (0.1 µM). Venom-induced vasorelaxtion was also markedly decreased in the presence of the transient receptor potential cation channel subfamily V member 4 (TRPV4) antagonist, RN-1734 (10 µM). In conclusion, D. russelii-venom-induced hypotension in rodents may be due to activation of Kv and KCa channels, leading to vasorelaxation predominantly via an endothelium-independent mechanism. Further investigation is required to identify the toxin(s) responsible for this effect.
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Affiliation(s)
- Rahini Kakumanu
- Department of Pharmacology, Biomedicine Discovery Institute, Faculty of Medicine, Nursing & Health Sciences, Monash University, Clayton VIC 3800, Australia.
| | - Sanjaya Kuruppu
- Department of Biochemistry & Molecular Biology, Biomedicine Discovery Institute, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton VIC 3800, Australia.
| | - Lachlan D Rash
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, St Lucia QLD 4072, Australia.
| | - Geoffrey K Isbister
- Clinical Toxicology Research Group, University of Newcastle, Callaghan NSW 2308, Australia.
| | - Wayne C Hodgson
- Department of Pharmacology, Biomedicine Discovery Institute, Faculty of Medicine, Nursing & Health Sciences, Monash University, Clayton VIC 3800, Australia.
| | - Barbara K Kemp-Harper
- Department of Pharmacology, Biomedicine Discovery Institute, Faculty of Medicine, Nursing & Health Sciences, Monash University, Clayton VIC 3800, Australia.
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Charoenpitakchai M, Wiwatwarayos K, Jaisupa N, Rusmili MRA, Mangmool S, Hodgson WC, Ruangpratheep C, Chanhome L, Chaisakul J. Non-neurotoxic activity of Malayan krait ( Bungarus candidus) venom from Thailand. J Venom Anim Toxins Incl Trop Dis 2018; 24:9. [PMID: 29556251 PMCID: PMC5845229 DOI: 10.1186/s40409-018-0146-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 03/02/2018] [Indexed: 12/11/2022] Open
Abstract
Background Envenoming by kraits (genus Bungarus) is a medically significant issue in South Asia and Southeast Asia. Malayan krait (Bungarus candidus) venom is known to contain highly potent neurotoxins. In recent years, there have been reports on the non-neurotoxic activities of krait venom that include myotoxicity and nephrotoxicity. However, research on such non-neurotoxicity activities of Malayan krait venom is extremely limited. Thus, the aim of the present study was to determine the myotoxic, cytotoxic and nephrotoxic activities of B. candidus venoms from northeastern (BC-NE) and southern (BC-S) Thailand in experimentally envenomed rats. Methods Rats were administered Malayan krait (BC-NE or BC-S) venom (50 μg/kg, i.m.) or 0.9% NaCl solution (50 μL, i.m.) into the right hind limb. The animals were sacrificed 3, 6 and 24 h after venom administration. The right gastrocnemius muscle and both kidneys were collected for histopathological analysis. Blood samples were also taken for determination of creatine kinase (CK) and lactate dehydrogenase (LDH) levels. The human embryonic kidney cell line (HEK-293) was used in a cell proliferation assay to determine cytotoxic activity. Results Administration of BC-NE or BC-S venom (50 μg/kg, i.m.) caused time-dependent myotoxicity, characterized by an elevation of CK and LDH levels. Histopathological examination of skeletal muscle displayed marked muscle necrosis and myofiber disintegration 24 h following venom administration. Both Malayan krait venoms also induced extensive renal tubular injury with glomerular and interstitial congestion in rats. BC-NE and BC-S venoms (100–0.2 μg/mL) caused concentration-dependent cytotoxicity on the HEK-293 cell line. However, BC-NE venom (IC50 = 8 ± 1 μg/mL; at 24 h incubation; n = 4) was found to be significantly more cytotoxic than BC-S venom (IC50 = 15 ± 2 μg/mL; at 24 h incubation; n = 4). In addition, the PLA2 activity of BC-NE venom was significantly higher than that of BC-S venom. Conclusions This study found that Malayan krait venoms from both populations possess myotoxic, cytotoxic and nephrotoxic activities. These findings may aid in clinical diagnosis and treatment of envenomed patients in the future.
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Affiliation(s)
| | - Kulachet Wiwatwarayos
- Department of Anatomical Pathology, Army Institute of Pathology, Royal Thai Army Medical Department, Bangkok, 10400 Thailand
| | - Nattapon Jaisupa
- 3Department of Pharmacology, Phramongkutklao College of Medicine, Bangkok, 10400 Thailand
| | - Muhamad Rusdi Ahmad Rusmili
- 4Kulliyyah of Pharmacy, International Islamic University Malaysia, Kuantan Campus, Bandar Indera Mahkota, 25200 Kuantan, Pahang Darul Makmur Malaysia
| | - Supachoke Mangmool
- 5Department of Pharmacology, Faculty of Pharmacy, Mahidol University, Bangkok, 10400 Thailand
| | - Wayne C Hodgson
- 6Monash Venom Group, Department of Pharmacology, Biomedical Discovery Institute, Monash University, Clayton, VIC 3800 Australia
| | - Chetana Ruangpratheep
- 1Department of Pathology, Phramongkutklao College of Medicine, Bangkok, 10400 Thailand
| | - Lawan Chanhome
- 7Queen Saovabha Memorial Institute, Thai Red Cross Society, Bangkok, 10330 Thailand
| | - Janeyuth Chaisakul
- 3Department of Pharmacology, Phramongkutklao College of Medicine, Bangkok, 10400 Thailand
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Silva A, Kuruppu S, Othman I, Goode RJA, Hodgson WC, Isbister GK. Neurotoxicity in Sri Lankan Russell's Viper (Daboia russelii) Envenoming is Primarily due to U1-viperitoxin-Dr1a, a Pre-Synaptic Neurotoxin. Neurotox Res 2017; 31:11-19. [PMID: 27401825 DOI: 10.1007/s12640-016-9650-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 06/29/2016] [Accepted: 07/01/2016] [Indexed: 10/21/2022]
Abstract
Russell's vipers are snakes of major medical importance in Asia. Russell's viper (Daboia russelii) envenoming in Sri Lanka and South India leads to a unique, mild neuromuscular paralysis, not seen in other parts of the world where the snake is found. This study aimed to identify and pharmacologically characterise the major neurotoxic components of Sri Lankan Russell's viper venom. Venom was fractionated using size exclusion chromatography and reverse-phase high-performance liquid chromatography (RP-HPLC). In vitro neurotoxicities of the venoms, fractions and isolated toxins were measured using chick biventer and rat hemidiaphragm preparations. A phospholipase A2 (PLA2) toxin, U1-viperitoxin-Dr1a (13.6 kDa), which constitutes 19.2 % of the crude venom, was isolated and purified using HPLC. U1-viperitoxin-Dr1a produced concentration-dependent in vitro neurotoxicity abolishing indirect twitches in the chick biventer nerve-muscle preparation, with a t 90 of 55 ± 7 min only at 1 μM. The toxin did not abolish responses to acetylcholine and carbachol indicating pre-synaptic neurotoxicity. Venom, in the absence of U1-viperitoxin-Dr1a, did not induce in vitro neurotoxicity. Indian polyvalent antivenom, at the recommended concentration, only partially prevented the neurotoxic effects of U1-viperitoxin-Dr1a. Liquid chromatography mass spectrometry analysis confirmed that U1-viperitoxin-Dr1a was the basic S-type PLA2 toxin previously identified from this venom (NCBI-GI: 298351762; SwissProt: P86368). The present study demonstrates that neurotoxicity following Sri Lankan Russell's viper envenoming is primarily due to the pre-synaptic neurotoxin U1-viperitoxin-Dr1a. Mild neurotoxicity observed in severely envenomed Sri Lankan Russell's viper bites is most likely due to the low potency of U1-viperitoxin-Dr1a, despite its high relative abundance in the venom.
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Affiliation(s)
- Anjana Silva
- Monash Venom Group, Department of Pharmacology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, 3800, Australia.
- Department of Parasitology, Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Saliyapura, 50008, Sri Lanka.
| | - Sanjaya Kuruppu
- Monash Venom Group, Department of Pharmacology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, 3800, Australia
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton Campus, Melbourne, VIC, 3800, Australia
| | - Iekhsan Othman
- Jeffrey Cheah School of Medicine, Monash University Malaysia, Jalan Lagoon Selatan, 47500, Bandar Sunway, Selangor Darul Ehsan, Malaysia
| | - Robert J A Goode
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton Campus, Melbourne, VIC, 3800, Australia
| | - Wayne C Hodgson
- Monash Venom Group, Department of Pharmacology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, 3800, Australia
| | - Geoffrey K Isbister
- Monash Venom Group, Department of Pharmacology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, 3800, Australia
- Clinical Toxicology Research Group, Faculty of Health and Medicine, University of Newcastle, Level 5, New Med Building, Calvary Mater Hospital, Edith Street, Waratah, NSW, 2298, Australia
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Silva A, Johnston C, Kuruppu S, Kneisz D, Maduwage K, Kleifeld O, Smith AI, Siribaddana S, Buckley NA, Hodgson WC, Isbister GK. Clinical and Pharmacological Investigation of Myotoxicity in Sri Lankan Russell's Viper (Daboia russelii) Envenoming. PLoS Negl Trop Dis 2016; 10:e0005172. [PMID: 27911900 PMCID: PMC5135039 DOI: 10.1371/journal.pntd.0005172] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 11/08/2016] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Sri Lankan Russell's viper (Daboia russelii) envenoming is reported to cause myotoxicity and neurotoxicity, which are different to the effects of envenoming by most other populations of Russell's vipers. This study aimed to investigate evidence of myotoxicity in Russell's viper envenoming, response to antivenom and the toxins responsible for myotoxicity. METHODOLOGY AND FINDINGS Clinical features of myotoxicity were assessed in authenticated Russell's viper bite patients admitted to a Sri Lankan teaching hospital. Toxins were isolated using high-performance liquid chromatography. In-vitro myotoxicity of the venom and toxins was investigated in chick biventer nerve-muscle preparations. Of 245 enrolled patients, 177 (72.2%) had local myalgia and 173 (70.6%) had local muscle tenderness. Generalized myalgia and muscle tenderness were present in 35 (14.2%) and 29 (11.8%) patients, respectively. Thirty-seven patients had high (>300 U/l) serum creatine kinase (CK) concentrations in samples 24h post-bite (median: 666 U/l; maximum: 1066 U/l). Peak venom and 24h CK concentrations were not associated (Spearman's correlation; p = 0.48). The 24h CK concentrations differed in patients without myotoxicity (median 58 U/l), compared to those with local (137 U/l) and generalised signs/symptoms of myotoxicity (107 U/l; p = 0.049). Venom caused concentration-dependent inhibition of direct twitches in the chick biventer cervicis nerve-muscle preparation, without completely abolishing direct twitches after 3 h even at 80 μg/ml. Indian polyvalent antivenom did not prevent in-vitro myotoxicity at recommended concentrations. Two phospholipase A2 toxins with molecular weights of 13kDa, U1-viperitoxin-Dr1a (19.2% of venom) and U1-viperitoxin-Dr1b (22.7% of venom), concentration dependently inhibited direct twitches in the chick biventer cervicis nerve-muscle preparation. At 3 μM, U1-viperitoxin-Dr1a abolished twitches, while U1-viperitoxin-Dr1b caused 70% inhibition of twitch force after 3h. Removal of both toxins from whole venom resulted in no in-vitro myotoxicity. CONCLUSION The study shows that myotoxicity in Sri Lankan Russell's viper envenoming is mild and non-life threatening, and due to two PLA2 toxins with weak myotoxic properties.
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Affiliation(s)
- Anjana Silva
- Monash Venom Group, Department of Pharmacology, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
- Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Saliyapura, Sri Lanka
- South Asian Clinical Toxicology Research Collaboration, University of Peradeniya, Peradeniya, Sri Lanka
| | - Christopher Johnston
- Clinical Toxicology Research Group, University of Newcastle, Newcastle, New South Wales, Australia
| | - Sanjaya Kuruppu
- Monash Venom Group, Department of Pharmacology, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Daniela Kneisz
- Monash Venom Group, Department of Pharmacology, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Kalana Maduwage
- South Asian Clinical Toxicology Research Collaboration, University of Peradeniya, Peradeniya, Sri Lanka
- Clinical Toxicology Research Group, University of Newcastle, Newcastle, New South Wales, Australia
- Department of Biochemistry, Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka
| | - Oded Kleifeld
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - A. Ian Smith
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Sisira Siribaddana
- Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Saliyapura, Sri Lanka
| | - Nicholas A. Buckley
- South Asian Clinical Toxicology Research Collaboration, University of Peradeniya, Peradeniya, Sri Lanka
- Clinical Pharmacology, University of Sydney, Sydney, Australia
| | - Wayne C. Hodgson
- Monash Venom Group, Department of Pharmacology, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Geoffrey K. Isbister
- Monash Venom Group, Department of Pharmacology, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
- South Asian Clinical Toxicology Research Collaboration, University of Peradeniya, Peradeniya, Sri Lanka
- Clinical Toxicology Research Group, University of Newcastle, Newcastle, New South Wales, Australia
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Silva A, Hodgson WC, Isbister GK. Cross-Neutralisation of In Vitro Neurotoxicity of Asian and Australian Snake Neurotoxins and Venoms by Different Antivenoms. Toxins (Basel) 2016; 8:toxins8100302. [PMID: 27763543 PMCID: PMC5086662 DOI: 10.3390/toxins8100302] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 09/22/2016] [Accepted: 10/01/2016] [Indexed: 01/30/2023] Open
Abstract
There is limited information on the cross-neutralisation of neurotoxic venoms with antivenoms. Cross-neutralisation of the in vitro neurotoxicity of four Asian and four Australian snake venoms, four post-synaptic neurotoxins (α-bungarotoxin, α-elapitoxin-Nk2a, α-elapitoxin-Ppr1 and α-scutoxin; 100 nM) and one pre-synaptic neurotoxin (taipoxin; 100 nM) was studied with five antivenoms: Thai cobra antivenom (TCAV), death adder antivenom (DAAV), Thai neuro polyvalent antivenom (TNPAV), Indian Polyvalent antivenom (IPAV) and Australian polyvalent antivenom (APAV). The chick biventer cervicis nerve-muscle preparation was used for this study. Antivenom was added to the organ bath 20 min prior to venom. Pre- and post-synaptic neurotoxicity of Bungarus caeruleus and Bungarus fasciatus venoms was neutralised by all antivenoms except TCAV, which did not neutralise pre-synaptic activity. Post-synaptic neurotoxicity of Ophiophagus hannah was neutralised by all antivenoms, and Naja kaouthia by all antivenoms except IPAV. Pre- and post-synaptic neurotoxicity of Notechis scutatus was neutralised by all antivenoms, except TCAV, which only partially neutralised pre-synaptic activity. Pre- and post-synaptic neurotoxicity of Oxyuranus scutellatus was neutralised by TNPAV and APAV, but TCAV and IPAV only neutralised post-synaptic neurotoxicity. Post-synaptic neurotoxicity of Acanthophis antarcticus was neutralised by all antivenoms except IPAV. Pseudonaja textillis post-synaptic neurotoxicity was only neutralised by APAV. The α-neurotoxins were neutralised by TNPAV and APAV, and taipoxin by all antivenoms except IPAV. Antivenoms raised against venoms with post-synaptic neurotoxic activity (TCAV) cross-neutralised the post-synaptic activity of multiple snake venoms. Antivenoms raised against pre- and post-synaptic neurotoxic venoms (TNPAV, IPAV, APAV) cross-neutralised both activities of Asian and Australian venoms. While acknowledging the limitations of adding antivenom prior to venom in an in vitro preparation, cross-neutralization of neurotoxicity means that antivenoms from one region may be effective in other regions which do not have effective antivenoms. TCAV only neutralized post-synaptic neurotoxicity and is potentially useful in distinguishing pre-synaptic and post-synaptic effects in the chick biventer cervicis preparation.
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Affiliation(s)
- Anjana Silva
- Monash Venom Group, Department of Pharmacology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia.
- Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Saliyapura 50008, Sri Lanka.
| | - Wayne C Hodgson
- Monash Venom Group, Department of Pharmacology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia.
| | - Geoffrey K Isbister
- Monash Venom Group, Department of Pharmacology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia.
- Clinical Toxicology Research Group, University of Newcastle, Newcastle, NSW 2298, Australia.
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Chaisakul J, Isbister GK, O'Leary MA, Parkington HC, Smith AI, Hodgson WC, Kuruppu S. Prothrombin activator-like toxin appears to mediate cardiovascular collapse following envenoming by Pseudonaja textilis. Toxicon 2015; 102:48-54. [PMID: 25959508 DOI: 10.1016/j.toxicon.2015.05.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Revised: 05/04/2015] [Accepted: 05/06/2015] [Indexed: 11/16/2022]
Abstract
Brown snake (Pseudonaja spp.)-induced early cardiovascular collapse is a life-threatening medical emergency in Australia. We have previously shown that this effect can be mimicked in animals and is mediated via the release of endogenous mediators. In the present study, we aimed to purify and characterize the component in Pseudonaja textilis venom which induces cardiovascular collapse following envenoming. The component (fraction 3) was isolated using a combination of techniques including hydroxyapatite and reverse phase chromatography. Fraction 3 (10 or 20 μg/kg, i.v.) produced a rapid decrease in mean arterial pressure (MAP) followed by cardiovascular collapse. Fraction 3-induced early collapse was abolished by prior administration of smaller priming doses of fraction 3 (i.e. 2 and 5 μg/kg, i.v.) or heparin (300 units/kg, i.v.). P. textilis whole venom (1 and 3 μg/ml), but not fraction 3 (1 or 3 μg/ml), induced endothelium-dependent relaxation in isolated rat mesenteric arteries. SDS-PAGE gel indicated the presence of 9-10 protein bands of fraction 3. Using proteomic based analysis some protein bands of fraction 3 were identified as subunits of venom prothrombin activator, pseutarin C of P. textilis venom. Our results conclude that prothrombin activator-like toxin is likely to be a contributor to the rapid collapse induced by P. textilis venom.
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Affiliation(s)
- Janeyuth Chaisakul
- Monash Venom Group, Department of Pharmacology, Monash University, VIC, 3800, Australia; Department of Pharmacology, Phramongkutklao College of Medicine, Bangkok, 10400, Thailand
| | - Geoffrey K Isbister
- Monash Venom Group, Department of Pharmacology, Monash University, VIC, 3800, Australia; Department of Clinical Pharmacology and Toxicology, Calvary Mater, NSW, 2298, Australia
| | - Margaret A O'Leary
- Department of Clinical Pharmacology and Toxicology, Calvary Mater, NSW, 2298, Australia
| | | | - A Ian Smith
- Department of Biochemistry and Molecular Biology, Monash University, VIC, 3800, Australia
| | - Wayne C Hodgson
- Monash Venom Group, Department of Pharmacology, Monash University, VIC, 3800, Australia
| | - Sanjaya Kuruppu
- Department of Biochemistry and Molecular Biology, Monash University, VIC, 3800, Australia.
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Rusmili MRA, Yee TT, Mustafa MR, Hodgson WC, Othman I. Isolation and characterization of a presynaptic neurotoxin, P-elapitoxin-Bf1a from Malaysian Bungarus fasciatus venom. Biochem Pharmacol 2014; 91:409-16. [PMID: 25064255 DOI: 10.1016/j.bcp.2014.07.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 06/26/2014] [Accepted: 07/01/2014] [Indexed: 11/27/2022]
Abstract
Presynaptic neurotoxins are one of the major components in Bungarus venom. Unlike other Bungarus species that have been studied, β-bungarotoxin has never been isolated from Bungarus fasciatus venom. It was hypothesized that the absence of β-bungarotoxin in this species was due to divergence during evolution prior to evolution of β-bungarotoxin. In this study, we have isolated a β-bungarotoxin isoform we named P-elapitoxin-Bf1a by using gel filtration, cation-exchange and reverse-phase chromatography from Malaysian B. fasciatus venom. The toxin consists of two heterogeneous subunits, subunit A and subunit B. LCMS/MS data showed that subunit A was homologous to acidic phospholipase A2 subunit A3 from Bungarus candidus and B. multicinctus venoms, whereas subunit B was homologous with subunit B1 from B. fasciatus venom that was previously detected by cDNA cloning. The toxin showed concentration- and time-dependent reduction of indirect-twitches without affecting contractile responses to ACh, CCh or KCl at the end of experiment in the chick biventer preparation. Toxin modification with 4-BPB inhibited the neurotoxic effect suggesting the importance of His-48. Tissue pre-incubation with monovalent B. fasciatus (BFAV) or neuro-polyvalent antivenom (NPV), at the recommended titer, was unable to inhibit the twitch reduction induced by the toxin. This study indicates that Malaysian B. fasciatus venom has a unique β-bungarotoxin isoform which was not neutralized by antivenoms. This suggests that there might be other presynaptic neurotoxins present in the venom and there is a variation in the enzymatic neurotoxin composition in venoms from different localities.
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Affiliation(s)
- Muhamad Rusdi Ahmad Rusmili
- Monash Venom Group, Faculty of Medicine, Nursing and Health Sciences, Monash University, Victoria, Australia; Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Malaysia; Department of Basic Medical Sciences, Kulliyyah of Pharmacy, International Islamic University Malaysia, Pahang, Malaysia
| | - Tee Ting Yee
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Malaysia
| | - Mohd Rais Mustafa
- Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Wayne C Hodgson
- Monash Venom Group, Faculty of Medicine, Nursing and Health Sciences, Monash University, Victoria, Australia
| | - Iekhsan Othman
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Malaysia.
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9
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Venom down under: dynamic evolution of Australian elapid snake toxins. Toxins (Basel) 2013; 5:2621-55. [PMID: 24351719 PMCID: PMC3873703 DOI: 10.3390/toxins5122621] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2013] [Revised: 12/13/2013] [Accepted: 12/16/2013] [Indexed: 12/30/2022] Open
Abstract
Despite the unparalleled diversity of venomous snakes in Australia, research has concentrated on a handful of medically significant species and even of these very few toxins have been fully sequenced. In this study, venom gland transcriptomes were sequenced from eleven species of small Australian elapid snakes, from eleven genera, spanning a broad phylogenetic range. The particularly large number of sequences obtained for three-finger toxin (3FTx) peptides allowed for robust reconstructions of their dynamic molecular evolutionary histories. We demonstrated that each species preferentially favoured different types of α-neurotoxic 3FTx, probably as a result of differing feeding ecologies. The three forms of α-neurotoxin [Type I (also known as (aka): short-chain), Type II (aka: long-chain) and Type III] not only adopted differential rates of evolution, but have also conserved a diversity of residues, presumably to potentiate prey-specific toxicity. Despite these differences, the different α-neurotoxin types were shown to accumulate mutations in similar regions of the protein, largely in the loops and structurally unimportant regions, highlighting the significant role of focal mutagenesis. We theorize that this phenomenon not only affects toxin potency or specificity, but also generates necessary variation for preventing/delaying prey animals from acquiring venom-resistance. This study also recovered the first full-length sequences for multimeric phospholipase A2 (PLA2) ‘taipoxin/paradoxin’ subunits from non-Oxyuranus species, confirming the early recruitment of this extremely potent neurotoxin complex to the venom arsenal of Australian elapid snakes. We also recovered the first natriuretic peptides from an elapid that lack the derived C-terminal tail and resemble the plesiotypic form (ancestral character state) found in viper venoms. This provides supporting evidence for a single early recruitment of natriuretic peptides into snake venoms. Novel forms of kunitz and waprin peptides were recovered, including dual domain kunitz-kunitz precursors and the first kunitz-waprin hybrid precursors from elapid snakes. The novel sequences recovered in this study reveal that the huge diversity of unstudied venomous Australian snakes are of considerable interest not only for the investigation of venom and whole organism evolution but also represent an untapped bioresource in the search for novel compounds for use in drug design and development.
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10
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Chaisakul J, Isbister GK, Tare M, Parkington HC, Hodgson WC. Hypotensive and vascular relaxant effects of phospholipase A2 toxins from Papuan taipan (Oxyuranus scutellatus) venom. Eur J Pharmacol 2013; 723:227-33. [PMID: 24296315 DOI: 10.1016/j.ejphar.2013.11.028] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 11/13/2013] [Accepted: 11/22/2013] [Indexed: 11/16/2022]
Abstract
Phospholipase A2 (PLA2) toxins are common and abundant components of Australasian elapid venoms. These toxins are associated with a range of activities including neurotoxicity, myotoxicity and coagulation disturbances. We have recently reported that sudden cardiovascular collapse induced by Papuan taipan (Oxyuranus scutellatus) venom involves a combination of the release of dilator autacoids and a direct effect on the smooth muscle. In this study, we aimed to isolate PLA2 components from Papuan taipan venom and investigate their contribution to the hypotensive action of this venom. O. scutellatus venom was fractionated using size-exclusion high performance liquid chromatography (HPLC), and fractions screened for activity in anaesthetized rats. Fraction three from O. scutellatus venom (i.e. OSC3, 14.2±1.0% of whole venom) produced a 64% decrease in mean arterial pressure. Reverse-phase HPLC indicated that OSC3 consisted of two major components (i.e. OSC3a and OSC3b). OSC3a and OSC3b produced a significant hypotensive response in anaesthetized rats which were attenuated by prior administration of indomethacin or the combination of mepyramine and heparin. N-terminal analysis indicated that OSC3a and b displayed sequence homology to PLA2 toxins isolated from coastal taipan (O. scutellatus scutellatus) venom. These findings indicate that PLA2 components may play an important role in the development of hypotension and vascular relaxation which may contribute to the effects observed after envenoming by these Australasian elapids.
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Affiliation(s)
- Janeyuth Chaisakul
- Monash Venom Group, Department of Pharmacology, Monash University, Victoria 3800, Australia; Department of Pharmacology, Phramongkutklao College of Medicine, Bangkok 10400, Thailand
| | - Geoffrey K Isbister
- Monash Venom Group, Department of Pharmacology, Monash University, Victoria 3800, Australia; School of Medicine and Public Health, University of Newcastle, New South Wales 2300, Australia
| | - Marianne Tare
- Department of Physiology, Monash University, Victoria 3800, Australia
| | | | - Wayne C Hodgson
- Monash Venom Group, Department of Pharmacology, Monash University, Victoria 3800, Australia.
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11
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Marcon F, Purtell L, Santos J, Hains PG, Escoubas P, Graudins A, Nicholson GM. Characterization of monomeric and multimeric snake neurotoxins and other bioactive proteins from the venom of the lethal Australian common copperhead (Austrelaps superbus). Biochem Pharmacol 2013; 85:1555-73. [PMID: 23500536 DOI: 10.1016/j.bcp.2013.02.034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 02/27/2013] [Accepted: 02/28/2013] [Indexed: 10/27/2022]
Abstract
Envenomation by Australian copperheads results mainly in muscle paralysis largely attributed to the presence of postsynaptic α-neurotoxins. However, poorly reversible neurotoxic effects suggest that these venoms may contain snake presynaptic phospholipase A2 neurotoxins (SPANs) that irreversibly inhibit neurotransmitter release. Using size-exclusion liquid chromatography, the present study isolated the first multimeric SPAN complex from the venom of the Australian common copperhead, Austrelaps superbus. The multimeric SPAN P-elapitoxin-As1a (P-EPTX-As1a) along with two novel monomeric SPANs and a new postsynaptic α-neurotoxin were then pharmacologically characterized using the chick biventer cervicis nerve-muscle preparation. All SPANs inhibited nerve-evoked twitch contractions at the neuromuscular junction without inhibiting contractile responses to cholinergic agonists or KCl. These actions are consistent with a prejunctional action to inhibit neurotransmitter release, without direct myotoxicity. Furthermore, the multimeric P-EPTX-As1a caused tetanic 'fade' in muscle tension under high frequency nerve stimulation, and produced a triphasic alteration to neurotransmitter release. These actions have been previously noted with other multimeric SPAN complexes such as taipoxin. Moreover, the neurotoxic α-subunit of P-EPTX-As1a shows high homology to taipoxin α-chain. Several other coagulopathic and myotoxic high mass proteins including a class PIII snake venom metalloproteinase, C-type lectin, l-amino acid oxidase, acetylcholinesterase and phospholipase B were also identified that may contribute to the overall toxicity of A. superbus venom. In conclusion, clinicians should be aware that early antivenom intervention might be necessary to prevent the onset of irreversible presynaptic neurotoxicity caused by multimeric and monomeric SPANs and that A. superbus venom is potentially capable of producing coagulopathic and myotoxic effects.
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Affiliation(s)
- Francesca Marcon
- Neurotoxin Research Group, School of Medical and Molecular Biosciences, University of Technology, Sydney, P.O. Box 123, Broadway, NSW 2007, Australia
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12
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Chaisakul J, Parkington HC, Isbister GK, Konstantakopoulos N, Hodgson WC. Differential myotoxic and cytotoxic activities of pre-synaptic neurotoxins from Papuan taipan (Oxyuranus scutellatus) and Irian Jayan death adder (Acanthophis rugosus) venoms. Basic Clin Pharmacol Toxicol 2013; 112:325-34. [PMID: 23311944 DOI: 10.1111/bcpt.12048] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Accepted: 12/23/2012] [Indexed: 11/28/2022]
Abstract
Pre-synaptic PLA(2) neurotoxins are important components of many Australasian elapid snake venoms. These toxins disrupt neurotransmitter release. Taipoxin, a pre-synaptic neurotoxin isolated from the venom of the coastal taipan (Oxyuranus scutellatus), causes necrosis and muscle degeneration. The present study examined the myotoxic and cytotoxic activities of venoms from the Papuan taipan (O. scutellatus) and Irian Jayan death adder (Acanthophis rugosus), and also tested their pre-synaptic neurotoxins: cannitoxin and P-EPTX-Ar1a. Based on size-exclusion chromatography analysis, cannitoxin represents 16% of O. scutellatus venom, while P-EPTX-Ar1a represents 6% of A. rugosus venom. In the chick biventer cervicis nerve-muscle preparation, A. rugosus venom displayed significantly higher myotoxic activity than O. scutellatus venom as indicated by inhibition of direct twitches, and an increase in baseline tension. Both cannitoxin and P-EPTX-Ar1a displayed marked myotoxic activity. A. rugosus venom (50-300 μg/ml) produced concentration-dependent inhibition of cell proliferation in a rat skeletal muscle cell line (L6), while 300 μg/ml of O. scutellatus venom was required to inhibit cell proliferation, following 24-hr incubation. P-EPTX-Ar1a had greater cytotoxicity than cannitoxin, inhibiting cell proliferation after 24-hr incubation in L6 cells. Lactate dehydrogenase levels were increased after 1-hr incubation with A. rugosus venom (100-250 μg/ml), O. scutellatus venom (200-250 μg/ml) and P-EPTX-Ar1a (1-2 μM), but not cannitoxin (1-2 μM), suggesting venoms/toxin generated cell necrosis. Thus, A. rugosus and O. scutellatus venoms possess different myotoxic and cytotoxic activities. The proportion of pre-synaptic neurotoxin in the venoms and PLA(2) activity of the whole venoms are unlikely to be responsible for these activities.
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Affiliation(s)
- Janeyuth Chaisakul
- Monash Venom Group, Department of Pharmacology, Monash University, Clayton, Vic, Australia
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13
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Barber CM, Isbister GK, Hodgson WC. Alpha neurotoxins. Toxicon 2013; 66:47-58. [PMID: 23416229 DOI: 10.1016/j.toxicon.2013.01.019] [Citation(s) in RCA: 116] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Accepted: 01/29/2013] [Indexed: 10/27/2022]
Abstract
α-Neurotoxins have been isolated from hydrophid, elapid and, more recently, colubrid snake venoms. Also referred to as postsynaptic neurotoxins or 'curare mimetic' neurotoxins, they play an important role in the capture and/or killing of prey by binding to the nicotinic acetylcholine receptor on the skeletal muscle disrupting neurotransmission. They are also thought to cause respiratory paralysis in envenomed humans. This review will discuss the historical background into the discovery, isolation, structure and mechanism of action of the α-neurotoxins, including targets and cellular outcomes, and then will examine the potential uses of α-neurotoxins as pharmacological tools and/or as drug leads.
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Affiliation(s)
- Carmel M Barber
- Monash Venom Group, Department of Pharmacology, Monash University, Clayton, Victoria 3800, Australia
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14
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Del Brutto OH. Neurological effects of venomous bites and stings: snakes, spiders, and scorpions. HANDBOOK OF CLINICAL NEUROLOGY 2013; 114:349-68. [PMID: 23829924 DOI: 10.1016/b978-0-444-53490-3.00028-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Snake and spider bites, as well as scorpion sting envenoming, are neglected diseases affecting millions of people all over the world. Neurological complications vary according to the offending animal, and are often directly related to toxic effects of the venom, affecting the central nervous system, the neuromuscular transmission, the cardiovascular system, or the coagulation cascade. Snake bite envenoming may result in stroke or muscle paralysis. Metalloproteinases and other substances (common in vipers and colubrids) have anticoagulant or procoagulant activity, and may induce ischemic or hemorrhagic strokes. The venom of elapids is rich in neurotoxins affecting the neuromuscular transmission at either presynaptic or postsynaptic levels. The clinical picture of scorpion sting envenoming is dominated by muscle weakness associated with arterial hypertension, cardiac arrythmias, myocarditis, or pulmonary edema. These manifestations occur as the result of release of catecholamines into the bloodstream or due to direct cardiac toxicity of the venom. Cerebrovascular complications have been reported after the sting of the Indian red scorpion. Intracranial hemorrhages occur in the setting of acute increases in arterial blood pressure related to sympathetic overstimulation, and cerebral infarctions are related to either cerebral hypoperfusion, consumption coagulopathy, vasculitis, or cardiogenic brain embolism. Three main syndromes result from spider bite envenoming: latrodectism, loxoscelism, and funnel-web spider envenoming. Latrodectism is related to neurotoxins present in the venom of widow spiders. Most cases present with headache, lethargy, irritability, myalgia, tremor, fasciculation, or ataxia. Loxoscelism is caused by envenoming by spiders of the family Sicariidae. It may present with a stroke due to a severe coagulopathy. The venom of funnel-web spiders also has neurotoxins that stimulate neurotransmitter release, resulting in sensory disturbances and muscle paralysis. Proper management of the envenomed patient, including prompt transport to the hospital, correction of the hemostatic disorder, ventilatory support, and administration of antivenom, significantly reduce the risk of neurological complications which, in turn, reduce the mortality and improve the functional outcome of survivors.
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Affiliation(s)
- Oscar H Del Brutto
- School of Medicine, Universidad Espiritu Santo, Guayaquil, Ecuador; Department of Neurological Sciences, Hospital Clinica Kennedy, Guayaquil, Ecuador.
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15
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Johnston CI, O'Leary MA, Brown SGA, Currie BJ, Halkidis L, Whitaker R, Close B, Isbister GK. Death adder envenoming causes neurotoxicity not reversed by antivenom--Australian Snakebite Project (ASP-16). PLoS Negl Trop Dis 2012; 6:e1841. [PMID: 23029595 PMCID: PMC3459885 DOI: 10.1371/journal.pntd.0001841] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Accepted: 08/16/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Death adders (Acanthophis spp) are found in Australia, Papua New Guinea and parts of eastern Indonesia. This study aimed to investigate the clinical syndrome of death adder envenoming and response to antivenom treatment. METHODOLOGY/PRINCIPAL FINDINGS Definite death adder bites were recruited from the Australian Snakebite Project (ASP) as defined by expert identification or detection of death adder venom in blood. Clinical effects and laboratory results were collected prospectively, including the time course of neurotoxicity and response to treatment. Enzyme immunoassay was used to measure venom concentrations. Twenty nine patients had definite death adder bites; median age 45 yr (5-74 yr); 25 were male. Envenoming occurred in 14 patients. Two further patients had allergic reactions without envenoming, both snake handlers with previous death adder bites. Of 14 envenomed patients, 12 developed neurotoxicity characterised by ptosis (12), diplopia (9), bulbar weakness (7), intercostal muscle weakness (2) and limb weakness (2). Intubation and mechanical ventilation were required for two patients for 17 and 83 hours. The median time to onset of neurotoxicity was 4 hours (0.5-15.5 hr). One patient bitten by a northern death adder developed myotoxicity and one patient only developed systemic symptoms without neurotoxicity. No patient developed venom induced consumption coagulopathy. Antivenom was administered to 13 patients, all receiving one vial initially. The median time for resolution of neurotoxicity post-antivenom was 21 hours (5-168). The median peak venom concentration in 13 envenomed patients with blood samples was 22 ng/mL (4.4-245 ng/mL). In eight patients where post-antivenom bloods were available, no venom was detected after one vial of antivenom. CONCLUSIONS/SIGNIFICANCE Death adder envenoming is characterised by neurotoxicity, which is mild in most cases. One vial of death adder antivenom was sufficient to bind all circulating venom. The persistent neurological effects despite antivenom, suggests that neurotoxicity is not reversed by antivenom.
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Affiliation(s)
- Christopher I. Johnston
- School of Medicine Sydney, University of Notre Dame Australia, Darlinghurst, New South Wales, Australia
- NSW Poisons Information Centre, Sydney Children's Hospital Network, Sydney, New South Wales, Australia
| | - Margaret A. O'Leary
- Department of Clinical Toxicology and Pharmacology, Calvary Mater Newcastle and the Discipline of Clinical Pharmacology, University of Newcastle, Newcastle, New South Wales, Australia
| | - Simon G. A. Brown
- Centre for Clinical Research in Emergency Medicine, Western Australian Institute for Medical Research, Royal Perth Hospital and University of Western Australia, Perth, Western Australia, Australia
| | - Bart J. Currie
- Menzies School of Health Research and Northern Territory Clinical School, Royal Darwin Hospital, Darwin, Northern Territory, Australia
| | - Lambros Halkidis
- Emergency Department, Cairns Base Hospital, Cairns, Queensland, Australia
| | - Richard Whitaker
- Emergency Department, Cairns Base Hospital, Cairns, Queensland, Australia
| | - Benjamin Close
- Emergency Department, The Townsville Hospital, Townsville, Queensland, Australia
| | - Geoffrey K. Isbister
- NSW Poisons Information Centre, Sydney Children's Hospital Network, Sydney, New South Wales, Australia
- Department of Clinical Toxicology and Pharmacology, Calvary Mater Newcastle and the Discipline of Clinical Pharmacology, University of Newcastle, Newcastle, New South Wales, Australia
- * E-mail:
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16
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Abstract
Snake bite envenoming is a neglected tropical disease affecting millions of people living in the developing world. According to the offending snake species, the clinical picture may be dominated by swelling and soft tissue necrosis in the bitten limb, or by systemic or neurological manifestations. Serious neurological complications, including stroke and muscle paralysis, are related to the toxic effects of the venom, which contains a complex mixture of toxins affecting the coagulation cascade, the neuromuscular transmission, or both. Metalloproteinases, serine proteases, and C-type lentins (common in viper and colubrid venoms) have anticoagulant or procoagulant activity and may be either agonists or antagonists of platelet aggregation; as a result, ischemic or hemorrhagic strokes may occur. In contrast, the venom of elapids is rich in phospholipase A(2) and three-finger proteins, which are potent neurotoxins affecting the neuromuscular transmission at either presynaptic or post-synaptic levels. Presynaptic-acting neurotoxins (called β-neurotoxins) inhibit the release of acetylcholine, while post-synaptic-acting neurotoxins (called α-neurotoxins) cause a reversible blockage of acetylcholine receptors. Proper management of the envenomed patient, including prompt transport to the hospital, correction of the hemostatic disorder, ventilatory support, and administration of antivenom, significantly reduces the risk of neurological complications which, in turn, reduce the mortality and improve the functional outcome of survivors.
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Affiliation(s)
- O H Del Brutto
- Department of Neurological Sciences, Hospital - Clínica Kennedy, Guayaquil, Ecuador.
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17
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Marcon F, Nicholson GM. Identification of presynaptic neurotoxin complexes in the venoms of three Australian copperheads (Austrelaps spp.) and the efficacy of tiger snake antivenom to prevent or reverse neurotoxicity. Toxicon 2011; 58:439-52. [DOI: 10.1016/j.toxicon.2011.08.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Revised: 08/02/2011] [Accepted: 08/03/2011] [Indexed: 11/25/2022]
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