New insights on arthropod toxins that potentiate erectile function

• Published in: Toxicon (Oxford) 2013-07, Vol.69, p.152-159
• Main Authors: Nunes, Kenia P., Torres, Fernanda S., Borges, Marcia H., Matavel, Alessandra, Pimenta, Adriano M.C., De Lima, Maria E.
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Erectile dysfunction; Erectile Dysfunction - physiopathology; Erectile Dysfunction - therapy; Humans; Male; Molecular Sequence Data; Penile Erection - drug effects; Peptides - chemistry; Peptides - pharmacology; PnTx2-6; Priapism; Priapism - chemically induced; Priapism - pathology; Scorpion venom; Scorpion Venoms - chemistry; Scorpion Venoms - pharmacology; Scorpions; Spider venom; Spider Venoms - chemistry; Spider Venoms - pharmacology; Spiders; Ts3
• ISSN: 0041-0101; 1879-3150
• DOI: 10.1016/j.toxicon.2013.03.017

The use of natural substances for the treatment of diseases or injuries is an ancient practice of many cultures. According to folklore, natural aphrodisiacs may help to raise libido and increase desire. The supposed aphrodisiacs mainly include a plethora of preparations of plants, among other substances. However, the real boundary between myth and reality has not been established yet in most cases and such boundaries must be drawn by scientific methods. A growing interest of the scientific community has been focused on animal venoms, especially those from arthropods, i.e. spiders and scorpions, which cause priapism, a prolonged and painful erection. This review highlights the studies that have been performed with venoms and toxins from arthropods known to cause priapism, among other toxic symptoms, pointing out some pharmacological approaches for better understanding this effect. To date, the venom of some spiders, mainly Phoneutria nigriventer, and scorpions, such as the yellow South American scorpion Tityus serrulatus, among others, have been known to cause priapism. Since erectile dysfunction (ED) is a growing health problem in the world, more common in patients with vascular diseases as diabetes and hypertension, the use of animal venoms and toxins as pharmacological tools could not only shed light to the mechanisms involved in erectile function, but also represent a possible model for new drugs to treat ED. Unfortunately, attempts to correlate the structure of those priapism-related toxins were unfruitful. Such difficulties lie firstly on the poor data concerning purified priapism-related toxins, instead of whole venoms and/or semi-purified fractions, and secondly, on the scarce available primary sequences and structural data, mainly from spider toxins. It has been shown that all these toxins modify the sodium (Na+) channel activity, mostly slowing down its inactivation current. Improving the knowledge on the tertiary structure of these toxins could provide a key in the search of a new drug for ED treatment. •Some arthropod toxins of spider and scorpion venoms potentiate erectile function (EF).•Toxins act primarily, in Nav and erection seems to be mediated by nitric oxide.•PnTx2-6 was able to restore EF in diabetic, elderly and hypertensive animals.