Lizard spit cuts cravings
Plants get all the publicity when it comes to being a source of inspiration for amazing medicines. In truth though, animals contribute their own portion to the medical wisdom of humanity. The saliva of the Gila Monster for instance, has yielded a drug that we use to treat type 2 diabetes and now new research suggests that drug can also reduce food cravings.
The Gila monster is one of only a handful of venomous lizards in the world. Its venom is a fairly mild neurotoxin and though a Gila bite is extremely painful, none has resulted in a reported human death. Unlike snakes, which inject venom, Gilas latch onto victims and chew to allow neurotoxins to move through grooves in their teeth and into the open wound.
Gila Monsters are lethargic creatures that feed primarily on eggs raided from nests and newborn mammals. They may spend more than 95 per cent of their lives in underground burrows, emerging only to feed and occasionally to bask in the desert sun. They can store fat in their oversized tails and are able to go months between meals. It is their unique metabolism that has given rise to a hormonal profile that has proved beneficial for humans.
Exenatide is a synthetic form of a hormone called exendin-4 that occurs naturally in the saliva of the Gila monster. The lizard hormone is about 50 per ent identical to a similar hormone in the human digestive tract, called glucagon-like peptide-1 analog, or GLP-1, that increases the production of insulin when blood sugar levels are high. Insulin helps move sugar from the blood into other body tissues where it is used for energy. The lizard hormone remains effective much longer than the human hormone, and thus its synthetic form helps diabetics keep their blood sugar levels from getting too high. Exenatide also slows the emptying of the stomach and causes a decrease in appetite.
New research however, has found an unexpected effect of the lizard-inspired substance.
A rat based study has found that Exenatide reduces cravings for food by impacting the parts of the brain that are involved in addiction, reward, and motivation. The researchers say that decisions to eat are often governed by reward and that food cravings are behind the failure of most people to stick to a diet. They hope that Exenatide might be able to help people take control of their weight, eat healthily, and that it might even be useful for compulsive eating disorders.
As a sobering note, Gila Monsters are on the endangered species list because of human encroachment on their habitat. The drug Exenatide is a synthetic form of a naturally occurring hormone in Gila monster’s, so Gila Monster’s are not harmed or even needed for its production. Yet Without them we would never have known that something like Exenatide could be made. If that does not teach a bit of humility and respect, then what will? Human beings are a part of the entire natural organism. The loss of any part diminishes the whole. Maybe self-interest will remind us that as each species is lost so dies the potential for learning the gifts that they have to share.
