Ovophis tonkinensis envenoming presenting with severe isolated thrombocytopenia and local necrosis: A case report

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  Image Credit: iNaturalist (c) randall_f –  some rights reserved (CC BY-NC) Ovophis tonkinensis envenoming presenting with severe isolated thrombocytopenia and local necrosis: A case report Abstract Pit viper envenoming commonly causes venom-induced consumption coagulopathy with hypofibrinogenaemia. However, isolated thrombocytopenia without fibrinogen depletion is less recognised and may alter transfusion strategy. We report a confirmed  Ovophis tonkinensis  bite from northern Vietnam presenting with severe isolated thrombocytopenia and local necrosis. The case highlights the importance of serial platelet monitoring, awareness of fibrinogen availability and appropriate timing of antivenom and platelet support in resource-limited tropical settings. Duc ND, Hong Anh LN, Hong Khanh LN, Bach ND. Ovophis tonkinensis envenoming presenting with severe isolated thrombocytopenia and local necrosis: A case report. Tropical Doctor . 2026;0(0). doi: 10.1177/00494755261435153

Purification and Characterization of Two Neurotoxins BmKNT1 and BmKNT2 from the Scorpion Buthus martensii Karsch venom

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Purification and Characterization of Two Neurotoxins BmKNT1 and BmKNT2 from the Scorpion Buthus martensii Karsch venom

Abstract

Scorpion venom is a heterogeneous mixture of proteins and peptides, many of which have multiple bioactivities, including antitumor activity, modulation of ion channels, analgesia, and anti-inflammatory effects. This study, two peptides named BmKNT1 and BmKNT2 were isolated and purified from the Buthus martensii Karsch (BmK) venom by gel filtration chromatography (GFC), ion-exchange chromatography (IEC) and Reverse phase high-performance liquid chromatography (RP-HPLC), respectively. The primary structure of BmKNT1 (69 amino acid residues, theoretical pI/Mw: 7.66/7660.5 Da) and BmKNT2 (64 amino acid residues, theoretical pI/Mw: 6.05/7270.33) were determined by a combination of Edman degradation and MALDI-TOF-MS/MS sequencing analysis. It showed a high similarity to that of other scorpion neurotoxins. The Effects of both neurotoxins on Na+-channel, K+-channel and Ca2+-channel in rat dorsal root ganglion (DRG) were determined at 100 μg/ml. The results showed BmKNT2 had inhibitory activity on K+-channels expressed on DRG cells, which is a typical characteristic of voltage-gated potassium channel pore area inhibitors. On the contrary, BmKNT1 has activation activity on the K+-channel in rat DRG, and both toxins have inhibitory activity on Ca2+-channels in rat DRG.
Ali, Y., Fazliddinov, S., Hu, A., Dongmulati, N., He, H., Yang, Z., Gao, Y., Wali, A., Aisa, H. A., Mirzaakhmedov, S., Asrorov, A., & Yili, A. (2026). Purification and Characterization of Two Neurotoxins BmKNT1 and BmKNT2 from the Scorpion Buthus martensii Karsch venom. Toxicon, 109014. https://doi.org/10.1016/j.toxicon.2026.109014