**1. Introduction**

The last two decades have witnessed a growing interest in the discovery of new chemical and pharmacological substances of animal origin. Pharmacological tests of toxins obtained from animal venoms revealed its effects on central nervous system, mainly acting on ion channels in heart, intestine, in vascular permeability, etc. Potential applications of these sub‐ stances have been proposed ranging from human disease treatment to plague control of ag‐ ricultural interest. In this scenario, the peptidomic analysis has played an increasingly important role.

Venomous organisms are widespread throughout the animal kingdom, comprising more than 100,000 species distributed in all major phyla. Virtually all ecosystems on Earth have venomous or poisonous organisms. Venoms represent an adaptive trait, and an example of convergent evolution. They are truly mortal cocktails, comprising unique mixtures of pepti‐ des and proteins naturally tailored by natural selection to operate in defense or attack sys‐ tems, for the prey or the victim. Venoms represent an enormous reservoir of bioactive compounds able to cure diseases that do not respond to conventional therapies. Darwinian evolution of animal venoms has accumulated in nature a wide variety of biological fluids which resulted in a true combinatorial libraries of hundreds of thousands of molecules po‐ tentially active and pharmacologically useful.

Venom is a general term which refers to a variety of toxins used by certain animals that inoculate its victims through a bite, a sting or other sharp body feature. Venoms of verte‐ brates and invertebrates contain a molecular diversity of proteins and peptides, and other classes of substances, which together form an arsenal of highly effective agents, paralyz‐ ing and lethal, mainly used for predation and defense. We must distinguish venom from poison, which is ingested or inhaled by the victim, being absorbed by its digestive system or respiratory system. Animal venoms, in contrast, are administered directly into the lym‐

© 2013 Cunha; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2013 Cunha; licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

phatic system, where it acts faster. Only those organisms possessing injection devices (stingers, fangs, spines, hypostomes, spurs or harpoons) which allow the active use of venom for predation can be correctly characterized as venomous. Many other animals se‐ crete lethal substances (insects, centipedes, frogs, fish, etc.), but, as these substances are used primarily for defense purposes, these animals are termed poisonous and cannot be accurately characterized as venomous.

the victim through tubular or channeled fangs. Snakes use their venom mainly for hunt‐ ing, although they can also use it for defense. A snakebite can cause a variety of symp‐ toms including pain, swelling, tissue damage, decreased blood pressure, seizures, bleeding, respiratory paralysis, kidney failure and coma, and may, in severe cases, cause the patient death. These symptoms will vary depending on snake specie. Snakebite is an important medical emergency in many parts of the world, particularly in tropical and sub‐ tropical regions. According to World Health Organization (WHO), the incidence of snake‐ bite reaches 5 million per year, causing 2.5 million envenomations and 125,000 deaths [22]. About 80% of envenomation deaths worldwide are caused by snakebite, followed by scor‐ pion bite, which causes 15% [23]. Most affected are healthy people, such as children and agricultural populations, usually in poor resources areas, away from health centers in lowincome countries in Africa, Asia and Latin America. As a result, WHO declared snakebite

Peptidomic Analysis of Animal Venoms http://dx.doi.org/10.5772/53773 5

In addition to snakes, there are other venomous reptiles, such as the beaded lizard (*Heloder‐ ma horridum*), the Gila monster (*Heloderma suspectum*) and other species of lizards [9]. The composition of the Komodo dragon (*Varanus komodoensis*) venom is as complex as snake venoms [24]. Because of recent studies of venom glands in squamata and analysis of nuclear protein-coding genes, a new hypothetical clade, Toxicofera, is being proposed [25]. This clade would include all poisonous Squamata: suborders Serpentes (snakes) and Iguania (iguanas, agamid lizards, chameleons, etc.) and the infraorder Anguimorpha, represented by the families Varanidae (monitor lizards), Anguidae (alligator lizards, glass lizards, etc.)

Venoms can also be found in some fish, such as cartilaginous (rays, sharks and chimae‐ ras) and teleostean, including monognathus eel-like fishes, catfishes, rockfishes, waspfish‐ es, scorpionfishes, lionfishes, goatfishes, rabbitfishes, spiderfishes, surgeonfishes, gurnards, scats, stargazers, weever, swarmfish, etc. [9, 19]. Another venomous fish, the doctor fish, also know as "reddish log sucker", is used by some spas to feed the affected and dead areas of the skin of psoriasis patients, leaving the healthy skin to grow. There are venomous mammals, including solenodons, shrews, slow loris and the male platypus [21]. There are few poisonous amphibian species [20]. Some salamanders can expel venom through a rib of a sharp edge. There are even reports of venomous dinosaurs [26]. *Sinorni‐ thosaurus*, a genus of Dromaeosauridae dinosaur with feathers, may have had a venomous bite. But this theory is still controversial. The coelophysoid dinosaur *Dilophosaurus* is com‐ monly portrayed in popular culture as being poisonous, but this superstition is not con‐

Until recently, the work in toxinology involved prospecting highly toxic or lethal toxins in animal venoms that could explain the symptoms observed clinically. Typically, such an ap‐ proach involved the isolation and structural characterization of the molecule which causes an specific adverse effect observed when a person is envenomed. However, small molecules with micro-effects that were not easily observed were neglected or poorly studied. This sit‐ uation changed in recent years with the improvement in sensitivity, resolution and accuracy of mass spectrometry and other techniques used in proteomic toxinology. With the advent

as a health crisis and a neglected tropical disease.

and Helodermatidae (Gila monster and beaded lizard).

sidered likely by the scientific community.

Venomous and poisonous invertebrates include cnidarians [1, 2] (sea anemones, jellyfish and corals), some families of mollusks [3] (mainly Conidae) and arthropods [4] (scorpions, pseudoscorpions, spiders, centipedes, ticks and hymenoptera insects, like bees, ants and wasps). Arthropods inject their venom through fangs (spiders and centipedes) or stingers (scorpions and pungent insects). The sting, in some insects, such as bees and wasps, is a modified egg-laying device, called ovipositor. Some caterpillars have venom defense glands associated to specialized bristles in the body known as urticating hairs, which can be lethal to humans (such as the moth *Lonomia*) [5]. Bees use an acidic poison (apitoxin), which causes pain in those bitten, to defend their hives and food stocks [6]. Wasps, on the other hand, use its venom to only paralyze the prey [7]. In this way, the pray can be stored alive in food chambers for the young. The ant *Polyrhachis dives* produces a poison that is applied topically on the victim for pathogen sterilization [8]. There are many other venomous and poisonous invertebrates, including jellyfish [9], bugs [10] and snails [11-13]. The sea wasp (*Chironex fleckeri*), also called box jellyfish, has about 500,000 cnidocytes in each tentacle, containing nematocysts, a harpoon-shaped mechanism that injects an extremely potent venom into the victim, which causes severe physical and psychological symptoms known as Irukandji syn‐ drome. In many cases, this inoculation leads to death of the victim, that is why sea wasp is popularly known as "the world's most venomous creature" [14].

Loxoscelism is a condition produced by the bite of spiders from the genus *Loxosceles*, and is the only proven cause of necrosis in humans of arachnological origin [15]. *Loxosceles* spi‐ ders can be found worldwide. However, their distribution is heavily concentrated at the Western Hemisphere, particularly at the Americas, with more evidence in the tropics. In urban areas of South America, the presence of this type of spider is so evident that loxo‐ scelism is considered a public health problem. Although *Loxosceles* bite is usually mild, it may ulcerate or cause more serious dermonecrotic injurie and even systemic reactions. This injurie is mainly due to the presence of the enzyme sphingomyelinase D in spider venom. Because the great number of diseases which mimic the loxoscelism symptoms, it is frequently misdiagnosed by physicians [16]. Although there is no known fully effective therapy for loxoscelism, research about potential antivenoms and vaccines has been ex‐ haustive, presently also using the peptidomic approach [17], and many palliative thera‐ pies are reported in literature [15, 18].

Among vertebrates, only few reptiles (snakes and lizards) have developed the machinery for venom production [9], although some fish [9, 19], amphibians [20] and mammals (pla‐ typus for example) [21] have venom glands. The best known venomous reptiles are the snakes, which normally inject venom into their prey through hollow fangs. The snake venom is produced by mandibular glands located below the eyes and is inoculated into the victim through tubular or channeled fangs. Snakes use their venom mainly for hunt‐ ing, although they can also use it for defense. A snakebite can cause a variety of symp‐ toms including pain, swelling, tissue damage, decreased blood pressure, seizures, bleeding, respiratory paralysis, kidney failure and coma, and may, in severe cases, cause the patient death. These symptoms will vary depending on snake specie. Snakebite is an important medical emergency in many parts of the world, particularly in tropical and sub‐ tropical regions. According to World Health Organization (WHO), the incidence of snake‐ bite reaches 5 million per year, causing 2.5 million envenomations and 125,000 deaths [22]. About 80% of envenomation deaths worldwide are caused by snakebite, followed by scor‐ pion bite, which causes 15% [23]. Most affected are healthy people, such as children and agricultural populations, usually in poor resources areas, away from health centers in lowincome countries in Africa, Asia and Latin America. As a result, WHO declared snakebite as a health crisis and a neglected tropical disease.

phatic system, where it acts faster. Only those organisms possessing injection devices (stingers, fangs, spines, hypostomes, spurs or harpoons) which allow the active use of venom for predation can be correctly characterized as venomous. Many other animals se‐ crete lethal substances (insects, centipedes, frogs, fish, etc.), but, as these substances are used primarily for defense purposes, these animals are termed poisonous and cannot be

An Integrated View of the Molecular Recognition and Toxinology - From Analytical Procedures to Biomedical

Venomous and poisonous invertebrates include cnidarians [1, 2] (sea anemones, jellyfish and corals), some families of mollusks [3] (mainly Conidae) and arthropods [4] (scorpions, pseudoscorpions, spiders, centipedes, ticks and hymenoptera insects, like bees, ants and wasps). Arthropods inject their venom through fangs (spiders and centipedes) or stingers (scorpions and pungent insects). The sting, in some insects, such as bees and wasps, is a modified egg-laying device, called ovipositor. Some caterpillars have venom defense glands associated to specialized bristles in the body known as urticating hairs, which can be lethal to humans (such as the moth *Lonomia*) [5]. Bees use an acidic poison (apitoxin), which causes pain in those bitten, to defend their hives and food stocks [6]. Wasps, on the other hand, use its venom to only paralyze the prey [7]. In this way, the pray can be stored alive in food chambers for the young. The ant *Polyrhachis dives* produces a poison that is applied topically on the victim for pathogen sterilization [8]. There are many other venomous and poisonous invertebrates, including jellyfish [9], bugs [10] and snails [11-13]. The sea wasp (*Chironex fleckeri*), also called box jellyfish, has about 500,000 cnidocytes in each tentacle, containing nematocysts, a harpoon-shaped mechanism that injects an extremely potent venom into the victim, which causes severe physical and psychological symptoms known as Irukandji syn‐ drome. In many cases, this inoculation leads to death of the victim, that is why sea wasp is

Loxoscelism is a condition produced by the bite of spiders from the genus *Loxosceles*, and is the only proven cause of necrosis in humans of arachnological origin [15]. *Loxosceles* spi‐ ders can be found worldwide. However, their distribution is heavily concentrated at the Western Hemisphere, particularly at the Americas, with more evidence in the tropics. In urban areas of South America, the presence of this type of spider is so evident that loxo‐ scelism is considered a public health problem. Although *Loxosceles* bite is usually mild, it may ulcerate or cause more serious dermonecrotic injurie and even systemic reactions. This injurie is mainly due to the presence of the enzyme sphingomyelinase D in spider venom. Because the great number of diseases which mimic the loxoscelism symptoms, it is frequently misdiagnosed by physicians [16]. Although there is no known fully effective therapy for loxoscelism, research about potential antivenoms and vaccines has been ex‐ haustive, presently also using the peptidomic approach [17], and many palliative thera‐

Among vertebrates, only few reptiles (snakes and lizards) have developed the machinery for venom production [9], although some fish [9, 19], amphibians [20] and mammals (pla‐ typus for example) [21] have venom glands. The best known venomous reptiles are the snakes, which normally inject venom into their prey through hollow fangs. The snake venom is produced by mandibular glands located below the eyes and is inoculated into

accurately characterized as venomous.

Applications

4

pies are reported in literature [15, 18].

popularly known as "the world's most venomous creature" [14].

In addition to snakes, there are other venomous reptiles, such as the beaded lizard (*Heloder‐ ma horridum*), the Gila monster (*Heloderma suspectum*) and other species of lizards [9]. The composition of the Komodo dragon (*Varanus komodoensis*) venom is as complex as snake venoms [24]. Because of recent studies of venom glands in squamata and analysis of nuclear protein-coding genes, a new hypothetical clade, Toxicofera, is being proposed [25]. This clade would include all poisonous Squamata: suborders Serpentes (snakes) and Iguania (iguanas, agamid lizards, chameleons, etc.) and the infraorder Anguimorpha, represented by the families Varanidae (monitor lizards), Anguidae (alligator lizards, glass lizards, etc.) and Helodermatidae (Gila monster and beaded lizard).

Venoms can also be found in some fish, such as cartilaginous (rays, sharks and chimae‐ ras) and teleostean, including monognathus eel-like fishes, catfishes, rockfishes, waspfish‐ es, scorpionfishes, lionfishes, goatfishes, rabbitfishes, spiderfishes, surgeonfishes, gurnards, scats, stargazers, weever, swarmfish, etc. [9, 19]. Another venomous fish, the doctor fish, also know as "reddish log sucker", is used by some spas to feed the affected and dead areas of the skin of psoriasis patients, leaving the healthy skin to grow. There are venomous mammals, including solenodons, shrews, slow loris and the male platypus [21]. There are few poisonous amphibian species [20]. Some salamanders can expel venom through a rib of a sharp edge. There are even reports of venomous dinosaurs [26]. *Sinorni‐ thosaurus*, a genus of Dromaeosauridae dinosaur with feathers, may have had a venomous bite. But this theory is still controversial. The coelophysoid dinosaur *Dilophosaurus* is com‐ monly portrayed in popular culture as being poisonous, but this superstition is not con‐ sidered likely by the scientific community.

Until recently, the work in toxinology involved prospecting highly toxic or lethal toxins in animal venoms that could explain the symptoms observed clinically. Typically, such an ap‐ proach involved the isolation and structural characterization of the molecule which causes an specific adverse effect observed when a person is envenomed. However, small molecules with micro-effects that were not easily observed were neglected or poorly studied. This sit‐ uation changed in recent years with the improvement in sensitivity, resolution and accuracy of mass spectrometry and other techniques used in proteomic toxinology. With the advent

of these new technologies, small peptides from animal venoms with unexplored biological activities started to be studied systematically, emerging, then, this new area of knowledge and scientific research called peptidomics. These molecules are potential candidates for new drugs or compounds with significant therapeutic actions.

successfully isolated from an animal venom [11]. This is a synthetic non-opioid peptide, non-NSAID, non-local anesthetic calcium channel blocker, isolated from the secretions of the cone snail *Conus magus*. Prialt® is used for the alleviation of chronic intractable pain and is administered directly into the spinal cord, due to deep side effects or lack of efficacy when it

Peptidomic Analysis of Animal Venoms http://dx.doi.org/10.5772/53773 7

The evolution of the venom secretion apparatus in animals is indeed an impressive biologi‐ cal achievement at the evolutionary point of view. Since venoms components result of bio‐ chemical and pharmacological refinement over a long period in evolutionary scale, they have been tuned for optimum activity by the natural evolution. Thus, nature has already prospected huge combinatorial libraries of potential therapeutic drugs. The biochemical evolution of proteins from salivary fluids or venom exocrine glands is remarkable, especial‐ ly when one considers the highly specialized functions of these proteins and its high specif‐

Several classes of organic molecules have been described in venoms, such as alkaloids and acylpolyamines. However, the main constituents are indeed polypeptides. Venoms of cone snail and arthropods, such as spiders, scorpions and insects, to a lesser extent, seem to be mainly peptidic, while snakes produce protein rich venoms. Snake venoms contain a variety of proteases, which hydrolyze peptide bonds of proteins, nucleases, which hydrolyze phos‐ phodiester bonds of DNA, and neurotoxins, which disable signaling in the nervous system. The brown spider venom contains a variety of toxins, the most important of which is the tis‐ sue destruction agent sphingomyelinase D, present in the venom of all species of *Loxosceles* in different concentrations [29]. Only another spider genus (*Sicarius*) and several pathogenic

Some venoms comprise several hundreds of components, which further expands its poten‐ tial as a source of new medicines. Many components of venoms affect the nervous system and modulate the generation and propagation of action potentials, acting on multiple molec‐ ular sites, which include central and peripheral neurons, axons, synapses and neuromuscu‐ lar junctions [30]. Many of these target receptors play important physiological roles or are associated with specific diseases. Therefore, the components of animal venoms are impor‐ tant biological tools for studying these receptors, and the discovery of molecules in venoms with selective activity for these receptors represents a very attractive approach to the search for new drugs. The venom components may therefore be probed for the development of new therapies for pain management [31], new anti-arrhythmic [32], anticonvulsant [33] or anxiolytic drugs [34], new antimicrobial agents [35-37] or pesticides [38, 39], etc. Even a sub‐ stance that causes priapism has been isolated from the venom of a Brazilian spider [40], be‐

Another reason to study the composition of animal venoms is trying to seek more effective prophylaxis for envenomings. Doctors treat victims of venomous sting with serum, which is produced by injecting into an animal, such as sheep, horse, goat or rabbit, a small amount of specific venom. The animal's immune system responds to the target dose, producing anti‐ bodies to active molecules of the venom. These antibodies can then be isolated from the ani‐ mal's blood and used in envenoming treatment in other animals, including humans.

is administered by the more common routes such as orally or intravenously.

icity with respect to the target molecule.

bacteria are known to produce this enzyme.

coming a potential drug candidate to attend erectile dysfunction.
