Snake Venom and Antivenom Pharmacology

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  SNAKE VENOM & ANTIVENOM Chemistry, Composition, Mechanisms and Pharmacology Abstract This integrated teaching session for Phase III MBBS students focused on the pharmacology and toxicology of snake venom and the principles of antivenom therapy. The lecture covered the chemistry, composition, mechanisms of action, and pharmacological effects of snake venoms and antivenoms. Rational use of antivenoms, indications, administration protocols, adverse reactions, and supportive management strategies were discussed. The session also highlighted the translational importance of venom-derived compounds in modern drug development. Recent advances in antivenom research, including recombinant human monoclonal antibodies, toxin-specific inhibitors, synthetic antibody technologies, and next-generation broad-spectrum antivenoms, were reviewed. Current discoveries and emerging approaches aimed at improving efficacy, safety, affordability, and accessibility of antivenom therapy were also explor...

LaIT6: A Novel Insect-Selective K+-Channel Toxin from Liocheles australasiae Scorpion Venom

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LaIT6: A Novel Insect-Selective K+-Channel Toxin from Liocheles australasiae Scorpion Venom

Abstract

Scorpion venom contains various insecticidal peptides. Previously, through transcriptome analysis of the venom gland of Liocheles australasiae, we identified precursor sequences of several peptides that share sequences similar to those acting on K+ channels. In this study, we chemically synthesized five of the peptides which were found in the venom and evaluated their insecticidal activity against crickets. This revealed that one of the peptides, named LaIT6, exhibited significant insecticidal activity without mammalian toxicity. To identify amino acid residues important for the insecticidal activity of LaIT6, nine analogs were synthesized mainly by substituting acidic, basic, and aromatic residues with alanine. This revealed that two basic residues and an aromatic residue in the C-terminal region are important for the activity. This characteristic of structure-activity relationships, known as a functional dyad, is commonly observed in peptides that act on K+ channels, suggesting that the action target of LaIT6 is K+ channels. As expected, LaIT6 showed significant inhibitory activity against insect K+ channels. Since no activity against human K+ channels was observed, we concluded that the selectivity of LaIT6 is determined by differences in the action on K+ channels between insects and mammals.

Kumagai K, Kishimoto T, Carleer K, Butatsu N, Teramoto T, Mitani N, Tytgat J, Nakagawa Y, Miyashita M. LaIT6: A Novel Insect-Selective K+-Channel Toxin from Liocheles australasiae Scorpion Venom. Molecules. 2025; 30(16):3346. https://doi.org/10.3390/molecules30163346