The remarkable biology of snakes, long associated with venom and danger, is now at the forefront of medical innovation, inspiring a new generation of drugs for conditions ranging from obesity and chronic pain to cancer. Researchers are investigating how these reptiles’ unique physiological adaptations can be translated into human therapies.
One area of intense focus is the Burmese python's ability to suppress appetite. Scientists have identified a chemical, para-tyramine-O-sulphate (pTOS), produced in the python's gut and liver after digestion. This compound travels to the brain, signaling fullness and suppressing the desire to eat. A study published in Nature Metabolism found that when obese mice were injected daily with pTOS for a month, they lost nearly a tenth of their bodyweight. Importantly, these mice did not exhibit the side effects, such as nausea, commonly associated with current weight-loss drugs like Wegovy and Ozempic. Research indicates that pTOS is a byproduct of gut bacteria breaking down food, and its absence in pythons treated with antibiotics suggests a crucial role for these microbes. While humans also have pTOS in their blood, levels are typically much lower, though some individuals show a significantly greater post-meal increase, hinting at a naturally stronger appetite-suppressing response.
This is not the first time reptiles have influenced obesity treatments. The widely used GLP-1 drugs, such as Wegovy and Ozempic, were inspired by exendin-4, a chemical discovered in the venom of the Gila monster lizard. These drugs mimic the action of a human hormone that regulates appetite and slows food transit, but often come with gastrointestinal side effects.
Beyond weight management, snake venom is a rich source for other medical breakthroughs. ACE inhibitors, commonly prescribed for high blood pressure, are based on the South American pit viper's venom, which causes a dramatic drop in blood pressure. The venom's chemicals were found to block the body's production of angiotensin-2, a hormone that constricts blood vessels, leading to the development of drugs that dilate them.
Tirofiban, an anti-clotting medication, is derived from the venom of the saw-scaled viper. This venom causes severe bleeding by preventing blood from clotting. Scientists isolated echistatin from the venom, a compound that inhibits human blood platelets from sticking together, making tirofiban effective in preventing clots in patients with heart conditions or undergoing surgery.
Emerging research also points to potential cancer therapies. An enzyme found in the venom of the horned desert viper has shown promise in preventing breast tumor cells from spreading by interfering with their ability to use proteins as an adhesive. Another enzyme from the same venom can inhibit tumor growth by preventing the formation of new blood vessels that feed the tumors.
Snake venom is also being explored for its potential to combat chronic pain and antibiotic-resistant bacteria. A nerve poison called crotoxin, isolated from South American rattlesnake venom, has been found to alleviate severe pain in cancer patients. Additionally, research in Malaysia suggests that snake venoms contain substances that can kill bacteria, including dangerous strains like MRSA, by disrupting their cell membranes and proteins. This antibacterial property stems from the snakes' own need to protect themselves from infections when feeding on prey.
Developing these therapies, however, presents challenges. While snake venom components can be highly effective at killing harmful cells, they can also be toxic to human cells. Scientists are employing artificial intelligence to analyze venoms for medically beneficial compounds while mitigating risks. For instance, a project at King's College London is using AI to scan venoms for potential therapeutic substances.
In the realm of anti-venom treatments, a man in the United States who has repeatedly injected himself with snake venom to build immunity has provided a unique resource for researchers. Antibodies from his blood have shown protective effects against multiple snake venoms in mice. This human-derived antibody approach could potentially reduce the severe allergic reactions sometimes seen with current anti-venoms, which are typically produced in horses and sheep.
Researchers are also working on universal anti-venom treatments. Scientists at the Liverpool School of Tropical Medicine are developing oral treatments that target common features across different venoms, aiming to create a single drug effective against a range of snakebites. These promising candidates, repurposed from existing safe drugs, are moving toward human trials.