Mortality induced by scorpion venom may be prevented through administration of widely-available anti-inflammatory drugs, finds a study in mice published in Nature Communications this week.
Each year thousands of people die from injection of venom by Tityus serrulatus, the Brazilian yellow scorpion. The only currently available treatment is an antiserum, which offers only partial protection and can cause anaphylaxis - a dangerous, sometimes fatal, allergic reaction. The molecular mechanisms underlying T. serrulatus venom activity have remained unclear until now.
Lucia Helena Faccioli and colleagues study groups of 4-6 mice across a number of experiments and find that injecting various doses of scorpion venom in the mice induces a potent inflammatory response in the lungs, leading to lung swelling, which results in death due to loss of respiration. They show that the mice that survived a lethal dose of the venom lacked specific genetic components of the inflammasome - a multi-protein complex that initiates inflammation - or specific enzymes producing a signalling molecule (prostaglandin E2) which increases inflammation and leads to lung pathology. In addition, mice that did not lack these components could be rescued from venom-induced death by administration of indomethacin, a commonly used anti-inflammatory drug that blocks synthesis of prostaglandins (a group of molecules that lead to increased inflammation).
These results suggest that commonly used, non-steroidal anti-inflammatory drugs - such as indomethacin and celecoxib - may be repurposed as a treatment following scorpion bites. However, these findings will first need to be confirmed in human studies. The study also identifies a molecular mechanism through which scorpion venom causes fatal pathology in the lungs of mice, which may help design further treatments.