A potent toxin, reportedly 100 times more powerful than morphine, has been linked to the death of Russian opposition leader Alexei Navalny. This substance, known as epibatidine, is an extremely toxic compound with effects similar to nicotine.
Epibatidine is not a substance found in Australia or commonly encountered in everyday life. Its origin lies with a specific genus of poison dart frogs, Epipedobates, which are exclusively found in the northern regions of South America. Prominent examples of these amphibians include the vividly coloured Anthony’s poison arrow frog and the Phantasmal poison frog. These species possess the remarkable ability to secrete epibatidine onto their skin.
Scientists theorise that these frogs acquire the toxin through their diet in their natural habitat. This is supported by the observation that captive-bred frogs typically lack the substance, and the concentration of epibatidine in wild populations can vary significantly depending on their specific environment.
Investigating Epibatidine’s Potential
Despite its extreme toxicity, epibatidine has been the subject of scientific investigation for its potential medicinal properties. Researchers have explored its use as a powerful painkiller, and for its efficacy in treating severe inflammatory lung conditions such as asthma and pulmonary fibrosis.
However, its clinical application has been severely hampered by its potency and inherent toxicity. As Professor Alastair Hay, Emeritus Professor of Environmental Toxicology at the University of Leeds, explained, epibatidine exerts its effects by inhibiting nerve action.
- Mechanism of Action:
- Epibatidine acts by blocking nicotinic receptors within both the central and peripheral nervous systems.
The consequences of this receptor blockade are severe:
- Physiological Impact:
- Muscle paralysis.
- Paralysis of the respiratory system.
Professor Hay elaborated on the dire outcome of such paralysis: “So, breathing is blocked, and any person poisoned dies from suffocation.”
Deliberate Administration and International Law
The presence of epibatidine in a person’s blood, particularly in circumstances like those surrounding Alexei Navalny’s death, “suggests deliberate administration,” according to Professor Hay. He further noted that the toxic effects of epibatidine can be dangerously amplified by the co-administration of certain other drugs, a combination that has been a subject of research.
The use of epibatidine as a poison would represent a significant breach of international agreements:
- Violated Treaties:
- The 1972 Biological and Toxin Weapons Convention (BTWC).
- The 1993 Chemical Weapons Convention (CWC).
Professor Hay pointed out the historical context, stating, “The Soviet Union was a co-sponsor of the BTWC. Russia is a signatory of both the BTWC and CWC.” Therefore, he concluded, “If Russia used Epibatidine to poison Mr Navalny it has violated two treaties it has sworn to uphold.”
Detecting Epibatidine
The detection of epibatidine in biological samples is a sophisticated process, typically involving a combination of advanced analytical techniques:
- Gas Chromatography (GC): This method is used to separate complex mixtures of compounds into their individual components. In the context of epibatidine detection, GC helps isolate the toxin from other substances present in a sample.
- Mass Spectrometry (MS): Once separated by GC, the compounds are then analysed by MS. This technique works by breaking down chemicals into characteristic fragments, generating a unique “fingerprint” for each substance. This precise fingerprint allows for the definitive identification of epibatidine.
The combination of GC-MS provides a highly sensitive and specific method for confirming the presence of this dangerous toxin.
