Regular ArticleThe effect of different snake venoms and anti-venoms on thrombin clotting time in human plasma
Introduction
Snake venoms can be deadly and the only specific treatment is available through the use of anti-venoms. Therefore, understanding of the specificity of particular anti-venoms against particular snake venoms is crucial.
Previous studies have investigated the feeding behaviour, reportable events of envenomation, haematological effects, including the purification and characterization of haemorrhagic fraction of members of the crotalid snake species including Crotalus unicolor, Crotalus atrox, Crotalus adamanteus[1], [2], [3], [4]. Further investigations on the venoms of the crotalus species, including Crotalus adamanteus and Crotalus atrox, were performed, focusing on the haemorrhagic dose required to determine the LD50 using mice rodents. Anti-venoms including Anticoral were used to reverse the haemorrhagic effects of the venoms from the Crotalus species of snakes [5].
In addition, the Cortaid and Viperid species was investigated on their pro-coagulant properties, including a comparison study of the biochemical and physicochemical properties and interference in platelet functions [6] and a study on the effects of snake venoms on hemostasis [7]. The effect of snake venom pro-coagulants on snake plasma was also characterized in 2002 [8].
The effectiveness of Antivipmyn anti-venom was previously characterized in 2008 against African vipers and elapids [9] and its efficacy against two anti-venoms from North American snakes was investigated in a study in 2003 [10]. The Antivipmyn anti-venom was not previously tested against any of the venoms used in this study and has to date not been directly tested in human plasma.
A study performed in 2001 focused on Phospholipase A2 enzymes in snake venoms. Phospholipase A2 (PLA2), are enzymes which target specific tissues and organs and thereby exert their pharmacology activity according to their catalytic activity, was investigated in this study too. PLA2 enzymes are able to degrade coagulant phospholipids and therefore having an anti-coagulant activity [11].
The difference in efficiency between monovalent (Anticrotalico, Antivipmy, Antibotropico) and polyvalent (Antifidico, SAIMR) anti-venoms for treating envenomation by Crotalid (Crotalus unicolor, Crotalus adamanteus, Crotalus vegrandis) and Viperid (Calloselasma rhodostoma, Agkistrodon, Bothriechis schlegelii and Trimeresurus spp) snake venoms has not been investigated to date. This study aimed to determine the differences in the interaction of these venoms and anti-venoms by evaluating their effect on the thrombin clotting time in human plasma.
Section snippets
Venoms:
The following groups of Crotalid and Viperid snake venoms were used in the present study. The venoms which belong to the Crotalid snake family include Crotalus unicolor (Aruba island rattlesnake); Crotalus adamanteus (Eastern diamondback rattlesnake); Crotalus vegrandis (Uracoan rattlesnake). The venoms which belong to the Viperid snake family include the following venoms: Trimeresurus spp (Green pitviper); Calloselasma rhodostoma (Malayan pitviper), Bothriechis schlegeli (Eyelash viper) and
Results
In this study, five anti-venoms were used to determine their specificity and effectiveness in neutralizing the pro-coagulant effect of seven different snake-venoms in human plasma. All venoms differ in their pro-coagulant effects and the different anti-venoms therefore vary in their efficiency in neutralizing the venoms. All results were compared with a reference value, which was determined for every venom tested. Therefore venom was added to plasma until a clot was formed.
Table 1 demonstrates
Discussion
This study investigated the assumption monovalent anti-venoms are specific and effective for the venom, for which they were originally prepared. On the other hand, polyvalent anti-venoms should be effective at neutralizing the effects of every venom species they were made for, not only one species but for the family/genus, therefore, not being as specific in effect as monovalent anti-venoms.
This study demonstrates that Anticrotalico anti-venom was most effective at neutralizing the coagulant
Conflict of interest
The authors declare that there are no conflicts of interest.
Acknowledgements
The authors acknowledge Dr. Ken D. Winkel, as the head of the Australian Venom Research Unit for supplying the anti-venoms and Venom Supplies and Monash University for supplying the venoms used in this study.
References (19)
- et al.
Purification and characterisation of a haemorrhagic fraction from the venom of the Uracoan rattlesnake Crotalus vegrandis
Biochem Biophys Acta-Protein Struct Molec Enzym
(2001) Preclinical assessment of the ability of polyvalent (Crotalinae) and anticoral (Elapidae) antivenoms produced in Costa Rica to neutralize the venoms of North American snakes
Toxicon
(2003)Effect of snake venom procoagulants on snake plasma: implications for the coagulation cascade of snakes
Toxicon
(2002)- et al.
The efficacy of two antivenoms against the venom of North American snakes
Toxicon
(2003) Effects of chemical modifications of crotoxin B, the phospholipase A2 subunit of crotoxin from Crotalus durissus terrificus snake venom, on its enzymatic and pharmacological activities
Int J Biochem Cell Biol
(2001)- et al.
Field observations on feeding behavior in an aruba island rattlesnakes (crotalus-durissus-unicolor)
Bull Psychon Soc
(1990) - et al.
Eastern diamondback rattlesnake (Crotalus adamanteus) envenomation of dogs: 31 cases (1982-2002)
J Am Hosp Assoc
(2005) - et al.
Snake venomics and antivenomics of the arboreal neotropical pitvipers Bothriechis lateralis and Bothriechis schlegelii
J Proteom Res
(2008) Comparison of some biochemical and physicochemical properties and interference in platelet functions
Comp Biochem Physiol C- Toxicol Pharm
(1998)