The team discovered the venom of all three snakes contains a compound that “supercharges” their venom, making it more painful when put to use.
“The venom contained cytotoxins, which are found quite widely in the venom of many different snakes, but it also contained an enzyme toxin, phospholipase-A2,” Professor Vetter said.
“That component alone doesn’t actually do anything to your pain sensors, but combined with the cytotoxins it caused a much greater pain response than the cytotoxin alone.”
The UQ researchers were focused on what insights the analysis of the venom could offer in their search for more effective painkillers.
Professor Vetter said being able to discover exactly how a compound causes pain can show how to achieve the opposite and prevent pain.
“When we understand how something causes pain you can work backwards and discover mechanisms for blocking pain, that’s our long-term goal,” she said.
Spitting cobras can spray venom up to 2.5 metres with remarkable accuracy, and it can cause permanent blindness if it gets into a person’s eyes and is not treated.
The fact that the behaviour and the same venom components evolved separately in three different snake species suggests it was an effective defensive measure, the researchers said.
Lead author Professor Nick Casewell from the Liverpool School of Tropical Medicine said this research has given them more indication that the snakes may have developed the behaviour to deal with larger animals, possibly even humans specifically.
“It is intriguing to think that our ancestors may have influenced the origin of this defensive chemical weapon in snakes,” he said.
