Comparative venomic profiles of three spiders of the genus Phoneutria

Spider venoms induce different physio-pharmacological effects by binding with high affinity on molecular targets, therefore being of biotechnological interest. Some of these toxins, acting on different types of ion channels, have been identified in the venom of spiders of the genus Phoneutria, mainly from P. nigriventer. In spite of the pharmaceutical potential demonstrated by P. nigriventer toxins, there is limited information on molecules from venoms of the same genus, as their toxins remain poorly characterized. Understanding this diversity and clarifying the differences in the mechanisms of action of spider toxins is of great importance for establishing their true biotechnological potential. This prompted us to compare three different venoms of the Phoneutria genus: P. nigriventer (Pn-V), P. eickstedtae (Pe-V) and P. pertyi (Pp-V). Methods: Biochemical and functional comparison of the venoms were carried out by SDS-PAGE, HPLC, mass spectrometry, enzymatic activities and electrophysiological assays (whole-cell patch clamp). Results: The employed approach revealed that all three venoms had an overall similarity in their components, with only minor differences. The presence of a high number of similar proteins was evident, particularly toxins in the mass range of ~6.0 kDa. Hyaluronidase and proteolytic activities were detected in all venoms, in addition to isoforms of the toxins Tx1 and Tx2-6. All Tx1 isoforms blocked Nav1.6 ion currents, with slight differences. Conclusion: Our findings showed that Pn-V, Pe-V and Pp-V are highly similar concerning protein composition and enzymatic activities, containing isoforms of the same toxins sharing high sequence homology, with minor modifications. However, these structural and functional variations are very important for venom diversity. In addition, our findings will contribute to the comprehension of the molecular diversity of the venoms of the other species from Phoneutria genus, exposing their biotechnological potential as a source for searching for new active molecules.(AU)

Samsum ant venom modulates the immune response and redox status at the acute toxic dose in vivo

Background:Ant venoms express surface molecules that participate in antigen presentation involving pro- and anti-inflammatory cytokines. This work aims to investigate the expression of MHC-II, CD80 and CD86 on the polymorphonuclear cells (PMNs) in rats injected with samsum ant venom (SAV).Methods:Rats were divided into three groups - control, SAV-treated (intraperitoneal route, 600 μg/kg), and SAV-treated (subcutaneous route, 600 μg/kg). After five doses, animals were euthanized and samples collected for analysis.Results:The subcutaneous SAV-trated rats presented decreased levels of glutathione with increased cholesterol and triglyceride levels. Intraperitoneal SAV-treated animals displayed significantly reduced concentrations of both IFN-γ and IL-17 in comparison with the control group. However, intraperitoneal and subcutaneous SAV-treated rats were able to upregulate the expressions of MHC-II, CD80 and CD86 on PMNs in comparison with the control respectively. The histological examination showed severe lymphocyte depletion in the splenic white pulp of the intraperitoneal SAV-injected rats.Conclusion:Stimulation of PMNs by SAV leads to upregulation of MHC-II, CD 80, and CD 86, which plays critical roles in antigen presentation and consequently proliferation of T-cells. Subcutaneous route was more efficient than intraperitoneal by elevating MHC-II, CD80 and CD86 expression, disturbing oxidative stability and increasing lipogram concentration.

The history of venomous spider identification, venom extraction methods and antivenom production: a long journey at the Butantan Institute, São Paulo, Brazil

The article provides a historical report on venomous spider identification, venom obtainment methods and serum production at the Butantan Institute, São Paulo, Brazil. It is based on literature and personnal experience during the last 50 years. This result is the discovery that the real species causing potential severe human accidents were the spiders of the genus Loxosceles and Phoneutria.

Morphological characterization of the venom apparatus in the wolf spider Lycosa singoriensis (Laxmann, 1770)

The wolf spider Lycosa singoriensis (Laxmann, 1770) (Lycosidae: Araneae) is distributed throughout central and eastern Europe, including Russia, Kazakhistan and Turkey. This study describes the venom apparatus morphology of L. singoriensis through scanning electron microscopy (SEM). Its structure follows the general architecture observed in other spiders. Generally, a venom apparatus is composed by a pair of venom glands and chelicerae. L. singoriensis chelicerae are robust and consist of a stout basis and a movable apical segment (fang). The fang rests in a groove on the basal segment that is covered by different types of hair. L. singoriensis venom glands present equal size and measure about 4 mm in length. Each gland is enclosed by irregular muscular layers.(AU)

Production of TNF-alfa by primary cultures of human keratinocytes challenged with Loxosceles gaucho venom

Culturas primarias de queratinocitos humanos foram incubadas com veneno de aranha Loxosceles gaucho, que possui atividades esfingomielinase D, responsavel por lesao dermo-necrotica nos acidentes humanos. As celulas das culturas primarias foram agredidas com o veneno em doses crescentes de 10 ng/mL a 2 ug/mL. No sobrenadante das culturas...

Algunas características de los venenos y secreciones digestivas de Aphonopelma seemanni y Sphaerobothria hoffmanni (Araneae: Theraphosidae) de Costa Rica / Characteristics of the venoms and digestive secretions of Aphonopelma seemanni and Sphaerobothria hoffmanni (Araneae: Theraphosidae) of Costa Rica

A comparison of some components of the venoms of two Costa Rican tarantulas, Aphonopelma seeamanni (Cambridge) and Sphaerobothria hoffmanni (Karsch) by polyacrylamide gel electrophoresis shows patterns similar to those of Dugesiella hentzi (Girard), a North American tarantula. The digestive secretions have proteins that do not enter the 15% gels; thus no bands are obsorved. The method used by the tarantulas to consume their prey involves the action of both the venom and the digestive secretions. The percent protein, pH, proteolytic activity and hemolytic activity of venom and digestive secretions of both species were determined, and a high proteolytic activity for digestive secretions was found.