Scorpion Venom: Detriments and Benefits

Abstract

Scorpion venom may cause severe medical complications and untimely death if injected into the human body. Neurotoxins are the main components of scorpion venom that are known to be responsible for the pathological manifestations of envenoming. Besides neurotoxins, a wide range of other bioactive molecules can be found in scorpion venoms. Advances in separation, characterization, and biotechnological approaches have enabled not only the development of more effective treatments against scorpion envenomings, but have also led to the discovery of several scorpion venom peptides with interesting therapeutic properties. Thus, scorpion venom may not only be a medical threat to human health, but could prove to be a valuable source of bioactive molecules that may serve as leads for the development of new therapies against current and emerging diseases. This review presents both the detrimental and beneficial properties of scorpion venom toxins and discusses the newest advances within the development of novel therapies against scorpion envenoming and the therapeutic perspectives for scorpion toxins in drug discovery.

Keywords: analgesics; antivenom; bradykinin potentiating peptide; calcins; fungicide; parasiticide; potassium channel toxins; scorpion venom; scorpionism.

Figure 1

Ribbon diagrams of the 3D structure of selected scorpion venom peptides containing the cysteine-stabilized (CS) α/β motif. (A) AaHII from Androctonus australis is a classical α-NaTx. (B) Cn2 from Centruroides noxius venom is a classical β-NaTx. (C) Cn12, also from C. noxius venom, shows structural resemblance to β-NaTxs, but exhibits an α-NaTx function. (D) Agitoxin 1 from Leiurus hebraeus (previously L. quinquestriatus hebraeus) is an α-KTx toxin. The Protein Database accession numbers are 1PTX for AhHII; 1CN2 for Cn2, 1PE4 for Cn12, and 1AGT for agitoxin 1. KTx: potassium channel toxins, NaTx: sodium channel toxins.

Figure 2

Clinical manifestations and symptoms of mild, moderate, and severe scorpion envenomings. Typical symptoms of mild stings last for minutes to hours and include great local pain, a reddened and swollen site of sting (erythema and edema), numbness, sweating, body tremors, and agitation. More intense stings from scorpions with venom containing cytolytic toxins may result in blood blisters, hemorrhages, and necrosis of the surrounding tissue. In moderate envenoming cases, the body additionally reacts with fever, abdominal and joint pain, hyperglycemia, abnormally rapid breathing, increased heart rate, and nausea with vomiting. These symptoms can reside for days and are mostly caused by neurotoxins: Na⁺, K⁺, and Ca²⁺ ion channel modulators. Neurotoxins can also cause severe envenomings, which can lead to cardiovascular, neurological, pulmonary, and/or gastrointestinal complications, such as pulmonary edema, myocardial failure, arrhythmia, congestive heart failure, extreme muscular convulsion, hypertensive encephalopathy, acute peptic ulcers, pancreatitis and lethal multiple organ failure, mental confusion, and coma. After several days, most victims of lethal scorpion stings die from cardiac or respiratory failure.

Figure 3

Scorpion envenoming treatments. Conventional pharmaceuticals are used for mild envenomings, while antivenom therapy is applied in moderate and severe cases. Recombinant antivenoms are suggested to have higher therapeutic value over the conventional antivenoms and may become the future mainstay of treatment.

Figure 4

The potential therapeutic applications of scorpion venom compounds discussed in this article.