Polybia occidentalis and Polybia fastidiosa venom: a cytogenotoxic approach of effects on human and vegetal cells.

The venoms of wasps are a complex mixture of biologically active compounds, such as low molecular mass compounds, peptides, and proteins. The aim of the study was to evaluate the action of wasp venoms, Polybia occidentalis and Polybia fastidiosa, on the DNA of human leukocytes and on the cell cycle and genetic material of the plant model Lactuca sativa L. (lettuce). The cultured leukocytes were treated with the venoms and then evaluated by the comet assay. On another assay, seeds were exposed to a venom solution; the emitted roots were collected and the occurrence of cell cycle alterations (CCAs) and DNA fragmentation were evaluated by agarose gel electrophoresis and TUNEL assay. The results demonstrated that the venom of both wasps induces several CCAs and reduces the mitotic index (MI) on treated cells. They induced damage on human leukocytes DNA. High frequencies of fragments were observed in cells exposed to P. occidentalis venom, while those exposed to P. fastidiosa showed a high frequency of non-oriented chromosome. Both venoms induced the occurrence of various condensed nuclei (CN). This alteration is an excellent cytological mark to cell death (CD). Additionally, CD was evidenced by positive signals in TUNEL assay, by DNA fragmentation in agarose gel electrophoresis with vegetal cells, and by DNA fragmentation of the human leukocytes evaluated. Furthermore, human leukocytes exposed to the venom of P. fastidiosa had high rate of damage. The data demonstrate that both vegetal and human cells are adequate to evaluate the genotoxicity induced by venoms.

Prospection of Enzyme Modulators in Aqueous and Ethanolic Extracts of Lippia sidoides Leaves: Genotoxicity, Digestion, Inflammation, and Hemostasis.

The aqueous and ethanolic extracts of Lippia sidoides Cham. were chemically characterized and tested for their action on enzymes involved in processes such as inflammation, blood coagulation, and digestion. Both extracts potentiated the activity of phospholipases A2 present in the venom of Bothrops atrox in 12 % and completely inhibited the hemolysis induced by B. jararacussu and B. moojeni venoms in the proportions between 1 : 0.5 and 1 : 5 (venom/extracts (w/w)). They inhibited the thrombolysis induced by B. moojeni (10 to 25 %), potentiated the thrombolysis induced by the Lachesis muta muta venom (30 to 80 %), prolonged the coagulation time induced by B. moojeni and L. muta muta venoms, and presented antigenotoxic action. Both extracts reduced the activity of α-glycosidases, the aqueous extract inhibited lipases, and the ethanolic extract inhibited α-amylases. The results demonstrate the modulatory action of the extracts on proteases, phospholipases, and digestive enzymes. In addition, the rich phenolic composition of these extracts highlights their potential for nutraceutical use.