Hidden crustacean toxins offer hope for neurological treatment

Scientists are analyzing toxins produced by a previously little-known species of crustacean living in underwater caves on the Yucatan Peninsula. They discovered that the toxins may be key in treating neurological diseases. The discovery was reported in the journal BMC Biology.

The journal BMC Biology reports that toxins produced by the crustacean Xibalbanus tulumensis, which lives in the water-flooded caves of the Yucatan Peninsula, may be used to treat neurological diseases.

The venom many animals produce, consisting of toxins, is typically used for self-defence or hunting. These toxins affect various physiological processes and can be particularly interesting from a pharmacological perspective.

Until now, the most understood venoms were those of certain groups of animals, such as snakes, spiders, or scorpions. However, much less is known about toxins found in marine animals, creating significant opportunities for discoveries.

Just a few years ago, venomous crustaceans belonging to the group Remipedia living in water-flooded caves were discovered.

Dr. Björn von Reumont was the first to describe Remipedia's ability to produce venom in 2014. He is currently continuing studies on this phenomenon with an interdisciplinary team of researchers from Goethe University in Frankfurt. The team collaborates with the Fraunhofer Institute for Translational Medicine (ITMP) and research centres in Leuven, Cologne, Berlin, and Munich.

As a result of the research, scientists characterized a group of toxins produced by the Remipede Xibalbanus tulumensis, which resembles a centipede. The name of this crustacean comes from "Xibalba," referring to the mythical underworld of the dead, whose entrances are said to be located in cave systems on the Mexican Yucatan Peninsula.

The aforementioned animal injects venom into its prey through a specialized venom gland. The toxin's composition is exceptionally diverse, and the latest studies have revealed the presence of a new type of peptide, named by scientists as xibalbin.

Some of the xibalbins contain unique structural elements similar to those known from other venomous animals, including spiders. These peptides possess a knot-like structure, making them resistant to enzymes, high temperatures, and extreme pH values.

Such knot-like structures often operate as neurotoxins, interacting with ion channels and paralyzing the victim. Research has shown that numerous xibalbins, particularly Xib1, Xib2, and Xib13, can block potassium channels in mammalian cells.

This inhibition is greatly important when it comes to developing drugs ... neurological diseases, including epilepsy, explained Dr. Björn von Reumont.

Moreover, Xib1 and Xib13 can also block voltage-gated sodium channels, similar to those found in nerve or heart muscle cells.

Research also revealed that in higher mammalian sensory neurons, these peptides can activate two key proteins — PKA-II and ERK1/2 kinases. These processes suggest that peptides play a role in the pain sensitization mechanism, which opens new perspectives in treating pain conditions.

Finding suitable candidates, comprehensively characterizing their effects, and thus laying the foundations for safe and effective drugs is currently only possible in a large interdisciplinary team, as von Reumont indicates in the research.

Researchers face many challenges. Their work is hampered by the fact that the habitat of the Remipedes is seriously threatened by the construction of the Tren Maya intercity railway, which cuts through the Yucatan Peninsula.

— Cenotes (natural limestone wells filled with water) are an extremely sensitive ecosystem, emphasized von Reumont, who, as an experienced cave diver, personally collected Remipedes during an expedition to the Yucatan. — Our research underscores the importance of biodiversity protection for its ecological significance and potential substances that may be crucial to us humans, he noted.