ABSTRACT
There are several scorpion species of medical relevance around the world. Some of them are well characterized by their toxins and clinical outcomes. Brazilian Amazon has a great amount of these arthropods that have an impact in the scorpionism events specifically in this region of Brazil. Recently, several studies pointed out the immune system activation during scorpion envenouming as an important facet of scorpionism, inducing a sepsis-like state that culminates in clinical severity and death. In this work, we characterized the macrophage response of three species of clinical relevance in Brazilian Amazon: Tityus silvestris, T. metuendus and T. obscurus and one specie with no toxic effects to humans, Brotheas amazonicus. All the four species analyzed were able to induce pro- and anti-inflammatory cytokine production in a J774.1 murine macrophage model. This activation was dependent on TLR2/TLR4/MyD88 activation and abolished by TLRs antagonists. These results suggest that the venoms of the four species analyzed were able to induce macrophage response in agreement to the well-established immune activation by T. serrulatus venom. Our findings provide new insights into the clinical repercussions of scorpionism of uncharacterized species and point to new biotechnological applications of these venoms and possible supportive therapies in scorpionism.
Subject(s)
Scorpion Stings , Scorpion Venoms , Humans , Mice , Animals , Brazil , Scorpion Venoms/toxicity , Scorpions , MacrophagesABSTRACT
Scorpionism is a relevant medical condition in Brazil. It is responsible for most accidents involving venomous animals in the country, which leads to severe symptoms that can evolve to death. In recent years, an increase of almost 50% in the incidence of scorpionism has been observed in the Northern Region, where the highest severity of envenoming has been notified since the beginning of the 21st century. This review aims to provide an in-depth assessment of public data and reports on symptoms and epidemiology of envenoming, ecological aspects of scorpions, and characterization of venoms and toxins to access the gaps that need to be filled in the knowledge of the scorpion species of medical importance from the Brazilian Amazon. A systematic search using the string words "Amazon" and "scorpion" was performed on 11 databases. No restriction on date, language or status of the publication was applied. Reports not related to the Brazilian Amazon were excluded. Therefore, 88 studies remained. It is shown that populations of scorpions of medical importance, even of the same species, may present significant toxic variations peculiar to some regions in the Brazilian Amazon, and commercial scorpion antivenoms were not able to shorten the intensity and duration of neurological manifestations in patients stung by T. silvestris, T. apiacas or T. obscurus. It is also highlighted that the toxins responsible for triggering these alterations have not been elucidated yet and this is a fruitful field for the development of more efficient antivenoms. Furthermore, the geographic distribution of scorpions of the genus Tityus in the Brazilian Amazon was revised and updated. The cumulative and detailed information provided in this review may help physicians and scientists interested in scorpionism in the Brazilian Amazon.
ABSTRACT
Scorpionism is a relevant medical condition in Brazil. It is responsible for most accidents involving venomous animals in the country, which leads to severe symptoms that can evolve to death. In recent years, an increase of almost 50% in the incidence of scorpionism has been observed in the Northern Region, where the highest severity of envenoming has been notified since the beginning of the 21st century. This review aims to provide an in-depth assessment of public data and reports on symptoms and epidemiology of envenoming, ecological aspects of scorpions, and characterization of venoms and toxins to access the gaps that need to be filled in the knowledge of the scorpion species of medical importance from the Brazilian Amazon. A systematic search using the string words "Amazon" and "scorpion" was performed on 11 databases. No restriction on date, language or status of the publication was applied. Reports not related to the Brazilian Amazon were excluded. Therefore, 88 studies remained. It is shown that populations of scorpions of medical importance, even of the same species, may present significant toxic variations peculiar to some regions in the Brazilian Amazon, and commercial scorpion antivenoms were not able to shorten the intensity and duration of neurological manifestations in patients stung by T. silvestris, T. apiacas or T. obscurus. It is also highlighted that the toxins responsible for triggering these alterations have not been elucidated yet and this is a fruitful field for the development of more efficient antivenoms. Furthermore, the geographic distribution of scorpions of the genus Tityus in the Brazilian Amazon was revised and updated. The cumulative and detailed information provided in this review may help physicians and scientists interested in scorpionism in the Brazilian Amazon.(AU)
