An effective treatment for a deadly scorpion sting may have been hiding in pharmacies all along, a new study suggests. Two commonly used anti-inflammatory medications were able to rescue mice in the lab from a fatal blow of scorpion venom, raising the possibility that these widely available drugs could offer a cheap and simple way to save hundreds of lives each year. The work has been published in Nature Communications.
Step on a Brazilian yellow scorpion, and you might regret it. The most dangerous scorpion in Brazil, and perhaps South America, a sting from Tityus serrulatus delivers a venom that certainly packs a punch. While some may get off lightly with pain around the area of assault, the venom can also trigger a reaction that spreads to the heart, lungs, and nervous system, culminating in death from respiratory failure.
A shot of antivenom might save an unfortunate victim, but it doesn’t always work and can also make matters worse by leading to a life-threatening allergic reaction called anaphylaxis. While it may sound like the days are numbered either way, scientists may have just discovered a safer approach to tackle the sting.
After treating cells in a dish with the venom, the researchers began to piece together its mechanism of action, discovering that it leads to the activation of a large complex of proteins called the inflammasome. While important in our defense against foreign invaders, if the response they generate goes out of control it can cause more harm than good, prompting immune cells and inflammatory molecules to flood to areas of the body and interfere with organ function.
In the case of T. serrulatus, subsequent studies on mice injected with varying doses of the venom found that inflammasome activation triggered a cascade of events that ultimately led to severe lung inflammation, causing mice to die from suffocating fluid build-up in the lungs. However, when the team used mice that were lacking certain components of the inflammasome, or couldn’t produce a pro-inflammatory molecule called prostaglandin E2, all of them were able to survive a lethal dose of the venom.
But perhaps most importantly, when the team administered two commonly used nonsteroidal anti-inflammatory drugs – celecoxib and indomethacin – both of which work to relieve pain by blocking the production of inflammatory prostaglandins, they were once again able to prevent venom-induced mortality in mice.
Since there are already lots of approved nonsteroidal drugs available, the researchers think that if the findings can be confirmed in humans, they may have discovered an effective and low-cost strategy to treat envenomation, and maybe not only for this particular scorpion.
"It is possible that in [the] case of other species, the mechanism of inflammation is similar," study author Lúcia Faccioli from the University of São Paulo told IFLScience. "The venoms from different scorpions have variation of the content of toxins. So, the mechanisms of cell activation may be similar or different."
Only further investigation will tell, but hopefully this study at least opens up new doors for research.
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