Deadly spider found in UK shopping could provide alternative to Viagra
October has been dubbed ‘spider season’ in the Northern hemisphere according to UK newspaper the Guardian, which says a recent surge in numbers of the eight legged critters is due to increased use of central heating in the autumn months that has "horny" males running around believing it is Spring.
One spider, which made the UK broadsheet and tabloid press yesterday after being discovered in the shopping of a South London family, may be ‘hornier’ than others, as the Brazilian Wandering Spider – one of the most dangerous spiders in the world – contains a potent neurotoxin known as PhTx3 that can cause priapism in humans, leading to erections that last many hours.
Scientists have been studying the spider’s venom in the treatment of erectile dysfunction (ED). A study published in the Journal of Sexual Medicine in August 2012 found an extract from the venom, PnTx2-6 toxin, improves penile relaxation in aged rats and could be developed as a natural alternative to Pfizer’s Viagra or Eli Lilly’s Cialis.
Natural toxins
Toxins from the plant and animal kingdom are a complex mix of hundreds of peptides with some venoms being used directly to make anti-venoms to spider, snake and scorpion bites, while others – if the peptides can be identified and separated - can potentially treat a variety of diseases.
Bristol-Myers Squibb’s hypertension drug Capoten (Captopril), for example, was developed from a peptide in the venom of a lancehead viper (Bothrops jararaca), while Merck & Co.’s angina drug Integrilin (eptifibatide) is a cyclic heptapeptide derived from a protein found in the venom of the southeastern pygmy rattlesnake (Sistrurus miliarius barbouri).
So far the Brazilian Wandering Spider research carried out by US and Brazilian scientists has not been taken up by a pharma company, but last month clinical stage biopharmaceutical firm Akashi Therapeutics acquired the global rights to GsMTx-4, another spider-based peptide developed by Tonus Therapeutics.
GsMTx-4 was discovered and extracted from the venom of the Chilean Rose Tarantula (Grammostola spatulata) by researchers at the State University of New York at Buffalo, and has been shown to positively affect cellular calcium homeostasis in preclinical Duchenne muscular dystrophy model studies. The candidate has been granted orphan drug status by the US Food and Drug Administration (FDA).