Fuente de la imagen, Universal Images Group vía Getty Images
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- Autor, Redacción
- Título del autor, BBC News Mundo
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Tiempo de lectura: 5 min
A rare and highly potent toxin found in the skin of poison dart frogs was used to poison Russian opposition leader Alexei Navalny, according to a joint accusation made Saturday by the United Kingdom and several European allies.
The governments of the United Kingdom, Sweden, France, Germany and the Netherlands jointly stated that Russia is responsible for Navalny’s death on February 16, 2024, in a Siberian prison.
“We are confident that Alexei Navalny was poisoned with a lethal toxin,” they affirmed after analyzing samples taken from his body.
“These analyses have conclusively confirmed the presence of epibatidine,” the statement continued.
Epibatidine is a toxin exclusively found in a species of amphibian known as the Ecuadorian poison dart frog, native to certain areas of Ecuador and Colombia.
According to the European countries’ statement, the animal is not naturally found in Russia.
“Epibatidine is a natural neurotoxin isolated from the skin of the poison dart frog” and “is 200 times more potent than morphine,” explained toxicology expert Jill Johnson to the BBC Russian Service.
“This potent chemical compound acts on nicotinic receptors in the central nervous system (brain and spinal cord) and the peripheral nervous system,” she continued.
Johnson indicated that due to the fact that epibatidine overstimulates these nerve receptors, it can cause muscle spasms, paralysis, convulsions, slow heart rate, respiratory failure, and death.
“Breathing stops and anyone poisoned dies of asphyxiation,” said Professor Emeritus of Environmental Toxicology at the University of Leeds, Alastair Hay, to the British news agency Press Association.
“Epibatidine is extremely rare. This proves found only in one species of wild frog, in a specific geographical region and in minimal quantities. Frogs produce it by absorbing alkaloids from their diet and accumulating it in their skin. If the frog’s diet changes, its reserves of epibatidine are depleted,” Johnson explained.
Fuente de la imagen, Universal Images Group vía Getty Images
Animals from different habitats have presented different levels of the toxin, while those raised in captivity show none.
For the toxicologist, “finding a wild frog in the right place, eating exactly the food needed to produce the right alkaloids, is almost impossible.”
Among those that secrete this toxin in their skin are the brightly colored Ecuadorian tricolor frog and Anthony’s poison frog.
Epibatidine has been investigated as a pain reliever and for the relief of painful inflammatory lung conditions, such as asthma and pulmonary fibrosis.
However, it is not used clinically due to its toxicity.
Hay affirmed that the presence of the toxin in a person’s blood “suggests deliberate administration.”
“The toxicity of epibatidine can even be increased by the co-administration of certain other drugs, and these combinations have been investigated,” Hay added.
An Incredibly Rare Method of Poisoning
Epibatidine can be detected using a combination of gas chromatography and mass spectrometry.
Gas chromatography helps to separate the compounds of interest, while mass spectrometry breaks down the chemical substances into specific fragments to create a unique fingerprint of the substance, which can then be identified.
“Here’s an incredibly rare method of human poisoning. The only cases of epibatidine poisoning I am aware of were laboratory cases and were not fatal,” Johnson noted.
The Russian government, which has repeatedly denied any responsibility for Navalny’s death, dismissed the latest accusations as “a Western propaganda hoax,” according to the state-run Russian news agency TASS.
The Russian embassy in London stated: “One has to wonder what kind of person would believe this nonsense about a frog.”
Fuente de la imagen, AFP vía Getty Images
In the joint statement, the European countries said that “given the toxicity of epibatidine and the reported symptoms, poisoning was highly likely the cause of his death.”
“Navalny died while in prison, meaning Russia had the means, motive, and opportunity to administer this poison to him,” they added.
Navalny, an anti-corruption activist and Russia’s most prominent opposition leader, died suddenly in prison at the age of 47. The accusation adds another layer to a case that has drawn international condemnation.
In 2020, he was poisoned with the Novichok nerve agent. He received treatment in Germany and was arrested upon his return to Russia.
Prior to Saturday’s announcement, Navalny’s wife, Yulia, had repeatedly argued that her husband was killed by poisoning while serving a sentence in an Arctic penal colony in 2024.
In September of last year, Yulia Navalnaya claimed that analysis of samples smuggled from her husband showed he had been “murdered.”
Navalny had been in prison for three years on what his supporters say were politically motivated charges, and was recently transferred to the Arctic penal colony.
Russian accounts state the 47-year-old took a brief walk in his Siberian penal colony, felt unwell, then collapsed and never regained consciousness.
Navalny’s family later confirmed the political activist died that same day.
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