Toxin found in sea slugs proves to be toxic to cancer cell lines

Posted Jan 22, 2016 by Karen Graham
Sea slugs are small and colorful sea creatures, well-known for containing deadly chemicals that they use on their enemies. Scientists know they slurp up toxins from what they are eating, but a new study found out that sea slugs are selective.
This is a photograph of the sea slug species in the UQ-led study  Chromodoris magnifica.
This is a photograph of the sea slug species in the UQ-led study, Chromodoris magnifica.
Eva McClure
Sea slugs are marine gastropod mollusks, resembling our terrestrial slugs, and most often, the term sea slug applies to the nudibranchs.
These "butterflies of the ocean" are known to slurp up deadly chemicals, stockpiling them for use on an enemy if bothered in any way. However, in a new study published on Thursday, researchers found the sea slugs were selective in which toxin they stored up.
In the University of Queensland-led study, it was discovered that a toxic compound called Latrunculin A was the chemical of choice to be stored. Toxicity tests using a very small amount of the toxin proved to be lethal to brine shrimp.
Latrunculins are a family of natural products and toxins produced by certain sponges. A study published in 2009 in the journal Anticancer Research, demonstrated the anticancer effect of latrunculin A in a dose-dependent manner on mice.
Dr. Karen Cheney of UQ's School of Biological Sciences said the study examined five closely-related nudibranchs (sea slugs) collected from the Great Barrier Reef and South East Queensland, Australia, according to Eureka Alert.
Dr. Cheney said, "Further tests conducted at the Institute for Molecular Bioscience demonstrated that this compound (latrunculin A) was more toxic to cancer cell lines than other compounds found in sea slugs."
The research team's investigation led them to find out if the brightness or intensity of the sea slug's coloration had anything to do with how toxic the chemical was they harbored.
"We are investigating whether the most brightly coloured sea slugs are the most toxic, and also whether cryptic sea slugs that blend in with their environment also contain strong toxic defences," she added.
Co-author Professor Mary Garson of UQ's School of Chemistry and Molecular Biosciences has been studying chemicals stored by marine animals for the past 20 years. "One interesting study aspect is the potency of the compound which five different sea slug species chose to store," Professor Garson said.
This study, "Choose Your Weaponry: Selective Storage of a Single Toxic Compound, Latrunculin A, by Closely Related Nudibranch Molluscs," was published in the journal PLOS One on January 20, 2016.