Envenomization with Snake Versus Scorpion Venom: Postmortem Repercussions on the Successional Dynamics of Carcass-Attracted Flies in a Forensic Context

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  Envenomization with Snake Versus Scorpion Venom: Postmortem Repercussions on the Successional Dynamics of Carcass-Attracted Flies in a Forensic Context Abstract Background: Animal venoms may alter postmortem carcass conditions and thereby influence carrion-associated insects. However, it remains unclear whether lethal envenomization affects adult Diptera as a broad assemblage-level response or as taxon-specific changes during decomposition. Methods: Fifteen rabbits were assigned to control, snake-envenomized, or scorpion-envenomized treatments (with five carcasses each). Carcasses were exposed under semi-natural conditions, until complete dryness, over 11 days postmortem. Adult flies were collected daily for analyzing abundance at total, family, and selected species levels, using negative GLMM, with carcass identity as a random effect and postmortem day as a nonlinear predictor. Results: A total of 5497 adult flies representing 13 species in seven families was recorded. Total fly...

Brown spider venom phospholipase D as a tool to modulate melanoma cell biology

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Brown spider venom phospholipase D as a tool to modulate melanoma cell biology

Abstract

Phospholipases D (PLDs) from Loxosceles venoms are enzymes that cleave phospholipids triggering biological effects, as uncontrolled inflammatory response. We treated melanoma cell lines B16-F1 and B16-F10 with recombinant PLD from the venom of the spider Loxosceles intermedia. Toxin binding to cell surface and modulating events were evaluated by specific antibodies, or a chimera PLD-GFP and confocal fluorescence microscopy, flow cytometry, inverted microscopy, and scanning electron microscopy. Cytotoxicity was performed using MTT, Trypan Blue, and CellTiterGlo; and intracellular calcium measured using Fluo-4, spectrofluorimetry, fluorescence confocal microscopy, and flow cytometry. Phosphatidylserine externalization was evaluated using annexin V and flow cytometry. Cellular behaviors as cell growth and proliferation (MTT and Cyquant), colony formation (Clonogenic assay and Soft Agar Assay), migration (Scratch assay), and the expression of related migration and proliferation gene transcripts were studied through Systems Biology and real-timePCR). The PLD binding on the cell surface and the production of ectosomes, followed by nanoclusters, is in a concentration- and time-dependent manner. The treatments did not cause cytotoxicity, but increased intracellular calcium, phosphatidylserine externalization, cell growth, proliferation, colony formation, and migration. The toxin triggers cellular activation, with formation of ectosomes, protrusion-derived ectosomes, tunneling nanotubes, and increased expression of genes related to proliferation and migration. These events are more pronounced in the more aggressive lineage B16-F10. These findings highlight the potential of exploring these toxins as biotools in studies of tumor cell biology.
De Souza Mello, E., Graeff, Z. S., Donatti, L., E.Vargas, J., Senff-Ribeiro, A., Arni, R. K., Gremski, L. H., & Veiga, S. S. (2026). Brown spider venom phospholipase D as a tool to modulate melanoma cell biology. International Journal of Biological Macromolecules, 152230. https://doi.org/10.1016/j.ijbiomac.2026.152230