New research into the venom of stonefish, arguably the world's most venomous fish, has discovered novel molecules that may lead to improvements in treatment of stings and help develop drug treatments.
Lead author Dr Silvia Luiza Saggiomo was at James Cook University's Australian Institute of Tropical Health and Medicine (AITHM) while conducting this research, which examined the venoms of estuarine and reef stonefish, both of which are common along Queensland shorelines.
Dr Saggiomo, who is currently with the Queensland Institute of Medical Research Berghofer, said the study focused on medically relevant small molecules, and discovered and identified the presence of three neurotransmitters new to stonefish venom.
"Through different techniques we discovered gamma-aminobutyric acid (GABA), choline and 0-acetylcholine, and provided the first report of GABA identified in a fish venom," she said.
"Usually, people relate GABA to blocking or inhibiting signals in the central nervous system. Some people take GABA tablets to help them sleep or relieve anxiety symptoms, for instance, so seeing it in stonefish venom was quite interesting.
"GABA plays roles in modulating cardiovascular function, having a range of effects including increased heart rate and lowered blood pressure.
"GABA has been found in spider venoms and more recently in a wasp and a snake species but never fish, so given these small molecules are present in a wide range of species which occupy a diverse range of habitats, we speculate they may play important roles in envenomation effects."
The estuarine and reef stonefish used in the experiments were housed at JCU's aquarium in Cairns and venom collected from their dorsal spines, with at least a four-week interval between milking events, based on venom regeneration times.
Stonefish stings are regular occurrences in Australia and abroad. Dr Saggiomo said while stonefish antivenoms are currently quite effective, these discoveries could assist with treatments and lead to other medical advances.
"Antivenom for stonefish is incredibly good, compared to jellyfish antivenom for example, and we are very fortunate to have it produced here in Australia with support from JCU," she said.
"What the characterisation of the specific composition of each of these fish species' venom provides us with is a better understanding of envenomation mechanisms, which are needed for the development of targeted treatments against venom effects.
"It may also aid in the exploration and development of venom-derived compounds in drug discovery."
Dr Saggiomo said this could translate to improved and more effective treatment of sting victims, or even provide opportunities for novel drug discovery.
"The more we understand what's in the venom, the easier it is to see what could potentially be included in a drug down the track," she said.
"As technologies and methodologies continue to improve, so does the ability to tease apart the intricate composition of complex venom mixtures.
"It is essential to continue investigating stonefish venoms to improve treatment and to explore their potential as drug leads or as physiological tools."
