Spider venom peptides Ht1a and Gg1a are toxic to honeybee parasite Varroa destructor by topical application

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  Spider venom peptides Ht1a and Gg1a are toxic to honeybee parasite Varroa destructor by topical application Abstract Global food supply strongly depends on honeybee pollination services, which are threatened by insecticides and pests such as parasitic Varroa destructor mites. Chemical varroacides/acaricides are hampered by resistance development, necessitating the development of sustainable and environmentally friendly alternatives, with arthropod venom peptides being considered promising sources of acaricidal toxins. With only a few acaricidal venom peptides being reported, we performed a systematic topical screening of 50 arthropod venoms against V. destructor , with 78% of the venoms causing 100% mortality after 24 h. Deconvolution of the venoms from the Tasmanian cave spider Hickmania troglodytes and the Giant Japanese funnel-web spider Gigathele gigas led to identification of the varroacidal peptides Ht1a and Gg1a. Topical application of Ht1a and Gg1a reduced varroa mite ...

Inhibitory effects of 6-O-palmitoyl-l-ascorbic acid (ASC16) on the enzymatic activity of Bothrops alternatus venom

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By Cláudio Timm - https://www.flickr.com/photos/cdtimm/4267955250/, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=13205355

Inhibitory effects of 6-O-palmitoyl-l-ascorbic acid (ASC16) on the enzymatic activity of Bothrops alternatus venom

Abstract

In the anti-venom production process, it is essential to use whole venom during immunization to generate specific antibodies capable of neutralizing all venom components. However, efforts are being made to improve the traditional immunization process by reducing the toxic effects of venom components on the immunized animals while ensuring an optimal immune response in accordance with good manufacturing practices. In this context, we aimed to evaluate the capacity of ASC16 to inhibit the enzymatic activity of the main components of B. alternatus venom. In vitro studies were conducted to evaluate the inhibitory effect of ASC16 on metalloproteinases (SVMP), serine proteinases (SVSP) and phospholipases A2 (PLA2) using specific substrates. In vivo assays measured edema-forming activity, and histological analysis with hematoxylin and eosin staining were performed. Additionally, hemorrhage inhibition was tested using a murine model. In silico studies were also carried out using bothropasin as a model. The results of enzyme inhibition showed that ASC16 significantly inhibited SVMP (49.31% ± 0.62), SVSP (63.11 ± 3.86%) and PLA2 activity (36.52% ± 0.09). ASC16 did not reduce edema but it significantly inhibited hemorrhage (66.32%). In silico analysis suggested that ASC16’s hydrophobic portion binds to critical residues involved in catalysis of the SVMP (Glu146 and His145), while the hydrophilic fraction also interacts with the protein (Pro109, Thr110, Gly112, and Tyr132). These findings position ASC16 as a promising candidate for use as an additive inhibitor in adjuvant formulations in antivenom immunization schemes for B. alternatus.

Maslovski, F., Pereañez, J.A., Hernández, D. et al. Inhibitory effects of 6-O-palmitoyl-l-ascorbic acid (ASC16) on the enzymatic activity of Bothrops alternatus venom. Arch Toxicol (2025). https://doi.org/10.1007/s00204-025-04188-9