Contrasting aspects of snake venom toxins: deadly to humans and useful for the development of diagnostic tests
Alessio Cortelazzo
Clinical Trial Manager | Director Diagnostic | Associate Professor in Clinical Biochemistry and Clinical Molecular Biology
Cortelazzo Alessio
The first studies on snake venom date back to 1700 and were made by the Italian scientist Felice Fontana (1720-1805), who first discovered the coagulant effects of snake venom. He noted that following an injection of viper venom in the rabbit jugular vein, the blood of animal clot quickly and it followed the death. Nowadays, the snake bite poisoning is a medical and social problem of considerable importance, showing from 94.000 to 125.000 deaths per year [1].
Up to now the potential of snake venom has not yet been fully explored, it is also incomplete understanding of the proteome and its components devoid of enzymatic activity [2]. Snake venoms, in particular those of Viperidae and Elapidae, contain hundreds of important molecules, pharmacologically active, with low molecular weight, including histamine, polyamide, alkaloids, small peptides and other allergens. Snake venom is a complex mixture consisting mainly of proteins and peptides (representing about 60-80% of dry weight), belonging to several major families including enzymes (serine proteases, Zn2+-metalloproteases, L-amino oxidase, PLA2), and proteins without enzymatic activity (disintegrins, lectin-type C, natriuretic peptides, ohanin, miotoxins, secretory proteins rich in cysteines, nerves and vascular endothelium growth factors), although, it should be noted that different poisons show a distinct profile distribution of these proteins [3]. Proteases affect platelet aggregation, blood coagulation, fibrinolysis, the complement system, blood pressure and nervous system. Mainly, the proteases involved in hemostasis are divided in metalloproteases and serine proteases. Both can serve as tools for studying the molecular details of the activation of specific factors involved in coagulation, the fibrinolytic process and treatment of various pathological conditions of hemostasis and thrombotic [4].
In addition to proteolytic enzymes, snake venom is rich in phosphatase, phosphodiesterase, acetylcholinesterase and oxidase, which are enzymes able to degrade nucleic acids and 5’ -nucleotidases [5]. Many snake venoms contain secretory PLA2, involved in digestion of prey, in the toxicity and danger of poisoning. The venom PLA2, are capable of inducing a wide variety of pathological effects, including neurotoxicity, myotoxicity, cardiotoxicity, cytotoxicity and necrosis [6]. In most cases, poisoning requires medical emergency and treatment of victims with antivenom that are often effective but, in some cases, needs to be supplemented with support for respiratory or renal failure. Animal-derived antivenoms have been used to treat snake envenomation for more than 100 years. Major technological advantages in the past 30 years have produced antivenoms that are highly purified and chemically modified to reduce the risk of acute hypersensitivity reactions.
In many cases the problem is addressed with the use of therapies with traditional medicinal plants. Previous articles have reported that plants belonging to the Asteraceae, Flucourticaceae, Boraginaceae, Apocymacaea, Fabaceae and Musaceae families are able to counteract the lethal effect of snake venom. The components that can minimize or totally inhibit the effect of snake venom are steroids such as cholesterol, diterpenes, triterpenes and phenolic compounds [7]. Among the plants with medicinal antivenom properties we studied Mucuna pruriens (Fabaceae ), which is used in traditional Nigerian medicine. Our previous work demonstrated that the aqueous extract of Mucuna pruriens seeds is able to protect mice from the effects of Echis carinatus venom [8]. The research on snake venom can lead to give structure to folk medicine and also to enrich with new and important information the medical Biochemistry, Proteomics and in particular the Venomics. The search for possible solutions to the toxic effects of snake venom is a field of study and research is still evolving. It may be concluded that information is now available to establish that snake venom toxin may serve as a starting material for drug design to combat several pathophysiological problems.
References
5. Russel F. E., Dart R. C. Toxic effect of animal toxin. Toxic agents. 1984; 22: 753-765.
8. Guerranti R., Ogueli I. G., Bertocci E., Muzzi C., Aguiyi J. C., Cianti R., Armini A., Bini L., Leoncini R., Marinello E., Pagani R. Proteomic analysis of the pathophysiological process involved in the antisnake venom effect of Mucuna pruriens extract. Proteomics. 2008 Jan;8 (2): 402-412.