Cytotoxic, genotoxic/antigenotoxic and mutagenic/antimutagenic effects of the venom of the wasp Polybia paulista

Hymenoptera venoms are constituted by a complex mixture of chemically or pharmacologically bioactive agents, such as phospholipases, hyaluronidases and mastoparans. Venoms can also contain substances that are able to inhibit and/or diminish the genotoxic or mutagenic action of other compounds that are capable of promoting damages in the genetic material. Thus, the present study aimed to assess the effect of the venom of Polybia paulista, a neotropical wasp, by assays with HepG2 cells maintained in culture. The cytotoxic potential of the wasp venom, assessed by the methyl thiazolyl tetrazolium assay (MTT assay), was tested for the concentrations of 10μg/mL, 5μg/mL and 1μg/mL. As these concentrations were not cytotoxic, they were used to evaluate the genotoxic (comet assay) and mutagenic potential (micronucleus test) of the venom. In this study, it was verified that these concentrations induced damages in the DNA of the exposed cells, and it was necessary to test lower concentrations until it was found those that were not considered genotoxic and mutagenic. The concentrations of 1ng/mL, 100pg/mL and 10pg/mL, which did not induce genotoxicity and mutagenicity, were used in four different treatments (post-treatment, pre-treatment, simultaneous treatment with and without incubation), in order to evaluate if these concentrations were able to inhibit or decrease the genotoxic and mutagenic action of methyl methanesulfonate (MMS). None of the concentrations was able to inhibit and/or decrease the MMS activity. The genotoxic and mutagenic activity of the venom of P. paulista could be caused by the action of phospholipase, mastoparan and hyaluronidase, which are able to disrupt the cell membrane and thereby interact with the genetic material of the cells or even facilitate the entrance of other compounds of the venom that can act on the DNA. Another possible explanation for the genotoxicity and mutagenicity of the venom can be the presence of substances able to trigger inflammatory process and, consequently, generate oxygen reactive species that can interact with the DNA of the exposed cells. © 2013 Elsevier Ltd.

Structure-function relationships of the peptide Paulistine: A novel toxin from the venom of the social wasp Polybia paulista

Background: The peptide Paulistine was isolated from the venom of wasp Polybia paulista. This peptide exists under a natural equilibrium between the forms: oxidised - with an intra-molecular disulphide bridge; and reduced - in which the thiol groups of the cysteine residues do not form the disulphide bridge. The biological activities of both forms of the peptide are unknown up to now. Methods: Both forms of Paulistine were synthesised and the thiol groups of the reduced form were protected with the acetamidemethyl group [Acm-Paulistine] to prevent re-oxidation. The structure/activity relationships of the two forms were investigated, taking into account the importance of the disulphide bridge. Results: Paulistine has a more compact structure, while Acm-Paulistine has a more expanded conformation. Bioassays reported that Paulistine caused hyperalgesia by interacting with the receptors of lipid mediators involved in the cyclooxygenase type II pathway, while Acm-Paullistine also caused hyperalgesia, but mediated by receptors involved in the participation of prostanoids in the cyclooxygenase type II pathway. Conclusion: The acetamidemethylation of the thiol groups of cysteine residues caused small structural changes, which in turn may have affected some physicochemical properties of the Paulistine. Thus, the dissociation of the hyperalgesy from the edematogenic effect when the actions of Paulistine and Acm-Paulistine are compared to each other may be resulting from the influence of the introduction of Acm-group in the structure of Paulistine. General significance: The peptides Paulistine and Acm-Paulistine may be used as interesting tools to investigate the mechanisms of pain and inflammation in future studies. © 2013 Elsevier B.V.

A gramaticalização de então no português paulista: um estudo pancrônico

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

As vogais médias pretônicas dos verbos na fala culta do interior paulista

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A haplologia na variedade paulista

Pós-graduação em Estudos Linguísticos - IBILCE

As vogais pretônicas na fala culta do Noroeste Paulista

Pós-graduação em Estudos Linguísticos - IBILCE

Vale de ferro: estudo histórico e estético das estações ferroviárias do Vale do Paraíba Paulista

Pós-graduação em Artes - IA

Estudo estrutural por RMN do peptídeo policatiônico polybine I de veneno da vespa social Polybia paulista

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Diversidade de vespas sociais (Hymenoptera: Vespidae; Polistinae) em fragmentos de Floresta Estacional Semidecidual no noroeste paulista

Pós-graduação em Biologia Animal - IBILCE

Uso de hábitat, micro-hábitat e coexistência com predadores em taxocenoses de girinos de anuros no noroeste paulista

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Comunidade de aves em um remanescente florestal no Noroeste paulista: estrutura trófica, dinâmica e efeitos da sazonalidade

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Diversidade de morcegos (Chiroptera; Mammalia) em três áreas do noroeste paulista, com ênfase nas relações tróficas em Phyllostomidae

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Diversidade e estrutura de taxocenoses de anfíbios anuros em uma paisagem fragmentada no centro-oeste paulista

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influência da heterogeneidade ambiental na diversidade, uso de hábitat e biocústica de anuros de área aberta no noroeste paulista

Pós-graduação em Biologia Animal - IBILCE

Caracterização molecular e expressão heteróloga do alérgeno fosfolipase A1 do veneno de Polybia paulista (Hymenoptera; Vespidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)