The Brazilian Wandering Spider

Genus Phoneutria
Phoneutria negriventer
Spiders belonging to the genus Phoneutria are common to the biodiversity of Brazil. Their venoms contain a wide variety of proteins and peptides including neurotoxins, which act on ion channels and chemical receptors of the neuro-muscular systems in mammals and insects. Their venoms have been described as particularly useful for future development and discovery of biologically active molecules that have potential applications in medicine and agriculture.
The two most toxic peptides are found in the venom of P. nigriventer. These peptides are referred to as Tx2-6 and Tx2-5, both of which cause death within 2-5 minutes in mice injected with this spider venom (RICHARDSON et al., 2006).

The Brazilian Wandering Spider
Phoneutria negriventer
The Brazilian wandering Spider, also known as the Banana spider is considered to be very dangerous and deadly. One bite from this particular spider can be fatal. The toxin carried by this spider is a very potent neurotoxin called PhTx3. This neurotoxin is attributed to loss of muscle control and breathing problems. After exposure to the venom, people usually experience intense pain and inflammation around the injection site (RICHARDSON et al., 2006). As discussed in class, venom production is very costly and the Brazilian wandering spider often engages in dry bites as a warning to predators.
In 2007, an article appeared in online at that discussed a potential benefit for the use of Brazilian wandering spider venom. As described in the article a Brazilian spider delivers more than a painful bite because its venom is able to stimulate an hours-long erection. The erection is a side effect seen in men, that is a result of an increase in blood pressure due to exposure to their toxic venom.

Research conducted at John Hopkins University found that about 18 million men in the U.S. suffer from erectile dysfunction and that 1 in 3 men do not respond to Viagra or other ED medication (BRYNER, 2007). The active compound in the spider venom that stimulates erection was experimentally determined using male rats. This particular compound turned out to be a peptide named Tx2-6. The mechanism of action of the toxin Tx2-6 is different than traditional ED medications because it affects an earlier step in the erection process by increasing the amount of nitric oxide, a chemical that is released due to sensations of sexual arousal (BRYNER, 2007).
Scientists are currently working on creating a synthetic version of the toxin Tx2-6 found in the Brazilian Wandering Spider and finding ways to combine it with active components in common ED medication like Viagra to get a drug that would be more efficient in patients that don’t respond well to Viagra (BRYNER, 2007).

Bryner, J. (2007). Natural Viagra: Spider bite causes erection. Retrieved from:
Richardson, M., Pimenta, A.M.C., Bemquerer, M.P., Santoro, M.M., et al. 2006. Comparison of the partial proteomes of the venoms of Brazilian spiders of the genus Phoneutria. Comparative Biochemistry and Physiology Part C Vol:142 (1) 173-187.