The Russian millionaire Alexander Perepilichny, who died suddenly outside his UK home in November 2012, is reported to have had in his body a substance that could only have come from species of gelsemium in the family of Loganiaceae, which also includes strychnos nux vomica, the source of strychnine.
Gelsemium species, which include G. elegans, G. sempervirens and G. rankinii, also variously known as trumpet flower, jessamine, yellow or false jasmine, woodbine, or heartbreak grass, contain over 100 alkaloids, including beta-carbolines, spiroindolones, iridoids, monoterpenoids, and triterpenoids. They include the unhelpfully named gelsemine, gelseminine, gelsenicine, gelsemiol and gelsemoxonine. Gelsemine is an antagonist at nicotinic acetylcholine receptors and may block glycine receptors in the spinal cord; it may also be a GABA receptor antagonist. Gelsemium alkaloids may produce antinociception by activating the spinal α3 glycine/allopregnanolone pathway. Some are inhibitors of acetylcholinesterase and butyrylcholinesterase.
In Chinese traditional medicine G. elegans has been used to treat migraine, neuralgia, sciatica, cancers, and various types of sores. Mrs M Grieve, in A Modern Herbal (1931), described Gelsemium nitidum (i.e. sempervirens) as an antispasmodic, sedative, febrifuge, and diaphoretic, and wrote that it had been used in the treatment of disorders such as asthma and whooping cough, spasmodic croup, and other conditions associated with localized muscular spasm; for neuralgic pains, especially those involving the facial nerves, particularly when arising from decaying teeth; for dysmenorrhea, hysteria, chorea, epilepsy, and urinary retention; acute rheumatism and pleurisy, pneumonia, and bronchitis. However, there is no evidence of benefit in any of these conditions.
Gelsemium plants are poisonous, as is honey made from the nectar. They have been used to commit suicide and murder. Accidental poisoning can occur when they are mistaken for other plants, such as Mussaenda pubescens, Tadehagi triquetrum, and Ficus simplicissima.
In one case, a 3-year-old girl ate the yellow flowers of Carolina jessamine and developed a wide-based gait, bilateral ptosis, and an inability to raise her chin off her chest. Her blood pressure fell, she became semicomatose, and had muscle weakness with brisk deep tendon reflexes and flexor plantar responses; there were no sensory deficits. She recovered after gastric lavage with charcoal, which she later vomited, and supportive measures.
The toxic effects of increasing doses of gelsemium were well described by Arthur Conan Doyle, writing in 1879 to the British Medical Journal (1879; 2: 483) from his home, Clifton House, in Aston Road, Birmingham:
SIR,-Some years ago, a persistent neuralgia led me to use the tincture of gelseminum to a considerable extent. I several times overstepped the maximum doses of the text-books without suffering any ill effects. Having recently had an opportunity of experimenting with a quantity of the fresh tincture, I determined to ascertain how far one might go in taking the drug, and what the primary symptoms of an overdose might be. I took each dose about the same hour on successive days, and avoided tobacco or any other agent which might influence the physiological action of the drug. Here are the results as jotted down at the time of the experiment. On Monday and Tuesday, forty and sixty minims produced no effect whatever. On Wednesday, ninety minins were taken at 10.30. At 10.50, on rising from my chair, I became seized with an extreme giddiness and weakness of the limbs, which, however, quickly passed off. There was no nausea or other effect. The pulse was weak but normal. On Thursday, I took 120 minims. The giddiness of yesterday came on in a much milder form. On going out about one o’clock, however, I noticed for the first time that I had a difficulty in accommodating the eye for distant objects. It needed a distinct voluntary effort, and indeed a facial contortion to do it. On Friday, 150 minims were taken. As I increased the dose, I found that the more marked physiological symptoms disappeared. To-day, the giddiness was almost gone, but I suffered from a severe frontal headache, with diarrhoea and general lassitude. On Saturday and Sunday, I took three drachms and 200 minims. The diarrhoea was so persistent and prostrating, that I must stop at 200 minims. I felt great depression and a severe frontal headache. The pulse was still normal, but weak.
From these experiments I would draw the following conclusions.
- In spite of a case described some time ago in which 75 minims proved fatal, a healthy adult may take as much as 60 minims with perfect immunity.
- In doses of from 90 to 120 minims, the drug acts apparently as a motor paralyser to a certain extent, causing languor, giddiness, and a partial paralysis of the ciliary muscle.
- After that point, it causes headache, with diarrhoea and extreme lassitude.
- The system may learn to tolerate gelseminum, as it may opium, if it be gradually inured to it. I feel convinced that I could have taken as much as half an ounce of the tincture, had it not been for the extreme diarrhoea it brought on.Believe me, yours sincerely, A. C. D.
The case of the Russian millionaire is reminiscent of the case of a Chinese millionaire, Long Liyuan, who was poisoned by G. elegans in Guangdong in 2011 after eating a meal of stewed cat with sliced ginger and aromatic spices. A local official, Huang Guang, reportedly later confessed to the crime.
Gelsemium species are not indigenous to the UK.