Opioid drugs will soon no longer be the only ones to treat pain. The venom of a sea cone should give rise to a new class of painkillers.
Its elegant shape, original pattern and colors catch the eye. Behind its appearance of harmless shell, the marine cone is nevertheless a fierce predator. With the help of a powerful venom, it paralyzes its prey. This same venom could prove beneficial to humans. One of its compounds contains an equally strong pain reliever. It opens up an alternative route to opioid drugs, say American researchers in PNAS, the journal of the American Academy of Sciences.
Effective 72 hours
This predator of the Caribbean Sea has revealed its secrets, under the eye and the microscope of scientists at the University of Utah (United States). “We looked at venoms to understand the different mechanisms of the nervous system,” explains Baldomera Olivera, co-author of the study. One compound in particular caught the team’s attention: Rg1A, which acts on nicotinic receptors in the brain. By this mechanism, it blocks the pain.
The interest of this painkiller is twofold. The body eliminates it in four hours. But the benefits are extended beyond this period. “We found that the compound still works 72 hours after injection; it continues to avoid pain, ”explains J. Michael McIntosh, also the signatory of the work.
Thanks to a precise analysis of the rodents used for the tests, the researchers suggest that a restorative effect occurs on certain elements of the nervous system. The action therefore occurs upstream of the painful sensation. A feat that no drug currently available can achieve. However, “once chronic pain develops, it is difficult to treat it,” says J. Michael McIntosh.
The end of overdoses?
Beyond chronic pain, such a class of drugs could end the opioid crisis. These powerful painkillers are currently the last solution for many people with pain. But they are also highly addictive. Every day, 91 Americans die from overdoses.
If hope is allowed, it will still be necessary to find an application in humans. The Utah team has already done this, and produced 20 synthetic analogues. One of them, Rg1A4, is effective in rodents. Several animals have received chemotherapy which makes them hypersensitive to cold and to touch. The treated animals did not suffer from this severe side effect. The next step is therefore clear: preclinical trials will be launched to study the safety and efficacy of this new drug candidate. The marine cone has to worry about.
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