Scorpion Venom Research Around the World: Chinese Scorpion Mesobuthus martensii Karsch

Abstract

Scorpions, or “Quanxie” as named in traditional Chinese medical prescriptions, have long been exploited as remedy for expelling or relieving many disorders and syndromes, such as chronic pain, convulsions, cardiovascular diseases, or even tumors. In Chinese traditional medicine, the active part of scorpions is considered to be the tip of the tail containing a great reservoir of active components. However, it was not until recent decades that the pharmacological mechanisms of the venom and toxins of Chinese scorpion have been systematically studied. These toxins are known to be toxic polypeptides that specifically target membrane ion channels, through either enhancing the channel activity or suppressing the peak currents of channels, hereby drastically affecting the excitability of local neuronal circuits. Recent mapping of receptor sites of these toxins located on ion channels validates themselves as potential tools for probing and modulating the channel subtypes or gating properties involved in physiological/pathological conditions. While this chapter briefly covers the current knowledge regarding the traditional use of scorpions in traditional Chinese medicine, its main subject is the “state-of-the-art” view of physiological and pharmacological actions of neurotoxins found in the Chinese scorpion Mesobuthus martensii Karsch associated with ion channels, including nociceptive/antinociceptive effects, epileptic/antiepileptic functions, cardiovascular modulation, and antitumor effects. Meanwhile, the toxin-driven intracellular events parallel to behavioral phenotypes and the underlying linkage between structure and function of ion channels elucidated by molecular interactions with toxins will also be discussed.