Throughout history, humans have tried to treat erectile dysfunction in a number of weird and wacky ways. Ancient Egyptians, for example, believed that impotence was caused by an evil spell, and that a good way to get rid of the curse was to grind up baby crocodile hearts and rub them on the penis. In medieval times, witches, of course, were blamed, so men would track down the supposed perpetrator and force them, sometimes pretty violently, to restore their erections.
But thanks to modern medicine, we don’t need to sacrifice baby animals or torture women anymore, and there are some decent drugs on the market. Unfortunately, they’re not perfect, so scientists are still on the lookout for alternatives, and they may have discovered one from a rather unexpected source: spider venom. Although the promising molecule, which comes from an aggressive spider in Brazil, has yet to be tested on humans, new research at the Catholic University of Korea has demonstrated that it can successfully improve erectile function in rats, raising the possibility that it could help impotence in men. The study has been published in Urology.
Erectile dysfunction, or impotence, is the inability to get or maintain an erection. It’s actually extremely common, with half of all men between the ages of 40 and 70 estimated to have it to some degree. It’s known to have a range of causes, both physical and psychological, such as narrowing of the blood vessels going to the penis or anxiety and depression.
Because the condition can be caused by a number of things, treatment is geared towards tackling the source of the problem and therefore varies, but includes psychological treatments or medications like Viagra which work by increasing blood flow to the penis. Although such drugs have around an 8 in 10 chance of working, they can have unwanted side effects such as bloody urine or even blurred vision, so some scientists are looking to improve the treatments available to men. Now, a novel therapy could be in the pipeline, with the discovery of a protein present in highly toxic spider venom.
Scientists first discovered its therapeutic potential back in 2000 whilst conducting a study on the impact of wandering spider bites on individuals in Brazil. Among the range of symptoms reported, some men experienced priapism, or abnormally long erections. After later examining the venom in the lab, researchers eventually managed to isolate the compound responsible, a protein called PnTx2. Then, much like how we use bacteria to produce insulin, scientists generated the protein in cultured caterpillar cells in the lab using a modified virus, called baculovirus.
The team then tested out their supply of PnTx2-6 on rat models of erectile dysfunction, which had injuries to the nerves that facilitate erections. Not only did the spider venom significantly restore blood flow to the erectile tissue, but it also prevented muscle wastage. Taken together, the researchers conclude that PnTx2-6 helps improve erectile function in these rats, and may therefore present a promising treatment avenue for humans. Of course, it will be a while before we get to that stage, but it’s an interesting start nonetheless.