This article is part of the series Special Collection on Animal Toxins: Exploring novel bioactive compounds from toads, snakes and scorpions.
Review
Department of Physics and
Chemistry, School of Pharmaceutical Sciences of Ribeirão Preto,
University of São Paulo (USP), Avenida do Café, s/n, Ribeirão Preto
14.040-903, SP, Brazil
Journal of Venomous Animals and Toxins including Tropical Diseases 2015, 21:24
doi:10.1186/s40409-015-0028-5
The electronic version of this article is the complete one and can be found online at: http://www.jvat.org/content/21/1/24
The electronic version of this article is the complete one and can be found online at: http://www.jvat.org/content/21/1/24
| Received: | 5 December 2014 |
| Accepted: | 21 July 2015 |
| Published: | 13 August 2015 |
© 2015 Cordeiro et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
Abstract
Arachnida is the largest class among the arthropods, constituting over 60,000 described
species (spiders, mites, ticks, scorpions, palpigrades, pseudoscorpions, solpugids
and harvestmen). Many accidents are caused by arachnids, especially spiders and scorpions,
while some diseases can be transmitted by mites and ticks. These animals are widely
dispersed in urban centers due to the large availability of shelter and food, increasing
the incidence of accidents. Several protein and non-protein compounds present in the
venom and saliva of these animals are responsible for symptoms observed in envenoming,
exhibiting neurotoxic, dermonecrotic and hemorrhagic activities. The phylogenomic
analysis from the complementary DNA of single-copy nuclear protein-coding genes shows
that these animals share some common protein families known as neurotoxins, defensins,
hyaluronidase, antimicrobial peptides, phospholipases and proteinases. This indicates
that the venoms from these animals may present components with functional and structural
similarities. Therefore, we described in this review the main components present in
spider and scorpion venom as well as in tick saliva, since they have similar components.
These three arachnids are responsible for many accidents of medical relevance in Brazil.
Additionally, this study shows potential biotechnological applications of some components
with important biological activities, which may motivate the conducting of further
research studies on their action mechanisms.
Keywords:
Arachnid toxins; Scorpion venom; Spider venom; Tick salivaBackground
Envenomings are considered a neglected disease by the World Health Organization [1] and constitute a public health problem, especially in tropical countries. The animals
responsible for such accidents possess an apparatus associated with a venom gland
that is able to produce a mixture rich in toxic and nontoxic components [2]. Among the most studied arthropod venoms are those from scorpions, spiders and ticks,
belonging to the phylum Arthropoda, class Arachnida, which correspond to the purpose
of this review. They are widely dispersed in urban centers due to the large availability
of shelter and food, which facilitates their reproduction and consequently increases
the number of accidents [3], [4]. Therefore, this review will focus on the main Brazilian venomous animals of the
Arachnida class belonging to Scorpionida, Araneae, Ixodidae orders as well as on the
aspects related to envenoming caused by these animals and their venom/saliva composition,
highlighting the components of scientific and medical interest.
The phylogenomic analysis of the nuclear protein-coding sequences from arthropod species
suggests a common origin in the venom systems of scorpions, spiders and ticks [5], [6]. Specifically, catabolite activator protein (CAP), defensins, hyaluronidase, Kunitz-like
peptides (serine proteinase inhibitor), neurotoxins, lectins and phospholipase are
examples of compounds shared by these animals (Fig. 1). Some compounds such as alanine-valine-isoleucine-threonine protein (AVIT protein)
and sphingomyelinase have been identified in spiders and ticks. Cystatins, lipocalins
and peptidase S1 are found only in ticks [5].
Fig. 1. Venn diagram highlighting the protein families presented in tick saliva and scorpion/spider
venoms. Catabolite activator protein (CAP), defensins, hyaluronidase, Kunitz-like
peptides (serine proteinase inhibitor), neurotoxins, lectins and phospholipase are
some of the compounds shared among these arthropods
In this context, the study of the structural similarity among these compounds/toxins
identified in the venom/saliva of these animals may contribute to a better understanding
of the action mechanism involved in envenoming besides providing information about
molecules with great biotechnological potential.