Case report
Suicidal death after injection of a castor bean extract (Ricinus communis L.)

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Abstract

The castor bean plant (Ricinus communis L.) or wonder tree is cultivated in many countries as an ornamental annual plant in gardens. The highest concentration of the lectin ricin is present in the seeds and pods. Ricin is considered as one of the most toxic natural poisons. Ricinine is a piperidine alkaloidal toxin present in castor bean and is described as a biomarker for the exposure to ricin. A case report is presented of a 49-year-old man who committed suicide by intravenous and subcutaneous injection of a castor bean extract. He was brought to the emergency department 24 h after injecting himself. On admission, the patient was conscious and he presented with a history of nausea, vomiting, diarrhoea, dyspnoea, vertigo and muscular pain. Despite symptomatic and supportive intensive care, the man died 9 h after admission due to multiorgan failure.

A body external examination was performed. Blood, urine, vitreous humour and the castor bean extract were submitted to the laboratory for toxicological analysis. The identification of ricinine in the extract was performed by solid phase extraction in combination with full-scan gas chromatography/mass spectrometry, high-performance liquid chromatography with photodiode array detection and liquid chromatography/mass spectrometry operated in the full-scan mode, respectively. An extraction procedure with Oasis HLB solid phase extraction cartridges was applied. Chromatography was achieved using a Symmetry® C18 column using a gradient mode with 0.15% formic acid and 0.15% formic acid in acetonitrile as mobile phase.

Exposure to the castor bean extract was confirmed by identification of the biomarker ricinine in blood, urine and vitreous humour using solid phase extraction and liquid chromatography tandem mass spectrometry with electro spray source in positive ionization mode. Multiple reaction monitoring was used for specific detection. To the authors’ knowledge, it is the first time that ricinine has been identified in vitreous humour in a case of castor bean poisoning. Based on the clinical symptoms and the results of the toxicological analysis, we concluded that death was caused by intoxication with plant toxins originated from R. communis L.

Introduction

The castor bean plant (Ricinus communis L.) or wonder tree belongs to the family of Euphorbiaceae and is cultivated in many countries, including Belgium, as an ornamental annual plant in gardens. The plant is native to tropical Africa. The plant is a shrub, 1–4 m high, branched with green or reddish leaves. It has clusters of seed pods covered with fleshly spines. The pods contain three seeds per capsule. The seeds have a smooth and glossy coat and are usually mottled with black, brown, grey and white spots (Fig. 1). All parts of the plant are poisonous [1], [2], [3]. The highest concentration of the lectin ricin is present in the seeds and pods. Ricin is considered as one of the most toxic natural poisons. It is a glycoprotein composed of two polypeptide chains, the A-chain (30 kDa) and B-chain (32 kDa), linked with a disulfide bond and with a molecular weight of about 63,000. Ricin inhibits protein synthesis by inactivating the ribosomes [1], [2], [3], [4]. Reported ricin content in the castor bean varies between 1% and 5%. Castor oil is industrially produced from castor beans and is used in lubricating oils, paints, varnishes and is orally administrated as a purgative in medicine. After isolation of the oil, ricin remains in the bean pulp but is inactivated if done under heated conditions. The castor oil is not considered to contain ricin [3], [5]. The monographs of castor oil in the European Pharmacopoeia do not contain a test for the detection of the plant toxins [5]. Since it is available as a by-product of castor oil production, is present in large quantities in nature, and is cheap and easy to extract, ricin is a potential biological warfare agent [1], [3]. Exposure can occur by ingestion, injection or inhalation. The toxicity of ricin varies with route of administration. The most potent routes of introducing ricin are inhalation and injection. When ingested, the castor bean is non-toxic as long as the hard, water-impermeable seed coat remains intact. The toxicity depends on the level of mastication or maceration of the seeds [1], [3]. Initial clinical findings of ricin poisoning by injection can include non-specific signs and symptoms such as generalized weakness and myalgias. After 24–36 h the clinical symptoms progress with possible vomiting, fever, dehydration, hypotension, and/or multiorgan failure and death [3]. At present, no antidote or effective therapy is available for the treatment of ricin intoxication. Only symptomatic and supportive measures can be taken [1], [3].

Ricinine (1,2-dihydro-4-methoxy-1-methyl-2-oxo-3-pyridinecarbonitrile) (Fig. 2) is a piperidine alkaloid toxin with low molecular weight (164.2) and a molecular formula of C8H8N2O2[6]. Ricinine contributes to the toxicity of castor bean and is present in small amounts in the castor bean and leaves. Reported clinical manifestations of ricinine ingestion are nausea, vomiting, hemorrhagic gastroenteritis, hepatic and renal damage, convulsions, coma, hypotension, respiratory depression and death [7], [8]. No reports of intoxication cases by ricinine only were found in literature. Ricinine is co-extracted with ricin and is described as a biomarker for ricin exposure [2], [9], [10], [11]. Analytical methods based on paper chromatography and UV detection, electron impact mass spectrometry and liquid chromatography-(photodiode array detection)–mass spectrometry were described for the determination of ricinine in plant material [2], [11], [12], [13]. Case reports of intoxications by injection of a castor bean extract are rare [8], [14], [15], [16], [17], [18]. The most cited case is the assassination in 1978 of the exiled Bulgarian journalist Georgi Markov who was most likely injected with ricin present in a platinum pellet injected into him when he was prodded with an umbrella [2], [9], [11]. A solid phase extraction and liquid chromatography–mass spectrometry method for the quantification of ricinine in urine was published by Johnson et al. and was applied in a forensic case of a man who committed suicide by ricin injection [9].

A case report is presented of a 49-year-old man who committed suicide by intravenous and subcutaneous injection of a castor bean extract. Ricinine was identified in the extract using full-scan gas chromatography/mass spectrometry (GC/MS), high-performance liquid chromatography with photodiode array detection (HPLC/DAD) and liquid chromatography/mass spectrometry (LC–MS) operated in the full-scan mode, respectively. Solid phase extraction (SPE) and liquid chromatography–tandem mass spectrometry with electro spray source in positive ionization mode (LC–MS/MS) were applied for the determination of ricinine in blood, urine and vitreous humour.

Section snippets

Case history

A 49-year-old man (83 kg, 175 cm tall) was brought to the emergency department 24 h after injecting himself intravenously and subcutaneously with approximately 10 mL of a ‘self-made’ acetone extract of castor beans. He presented with a history of nausea, vomiting, diarrhoea, dyspnoea, vertigo and muscular pain. On admission, the patient was conscious with a Glasgow Coma Score 14. He stated that he intended to commit suicide by ricin poisoning.

Clinical findings were consistent with hypovolemic shock

Systematic toxicological analysis

A comprehensive systematic toxicological analysis (STA) was performed on the post-mortem samples to investigate for illegal drugs, medical drugs, alcohol and volatile substances. Screening for the presence of drugs of abuse in urine and medication in serum was carried out using fluorescence polarization immunoassay on the Abbott AXSYM™ analyzer. Enzyme linked immunosorbent assay was used to screen for LSD in urine and opiates in serum. Presumptive colour tests on urine were used to detect

Results

The STA revealed the presence of laudanosine (atracurium metabolite), lidocaine, clonazepam, 7-aminoclonazepam, acetaminophen and metoclopramide in the blood. Acetone was determined in blood (30 mg/L), vitreous humour (34 mg/L) and urine (23 mg/L) by gas chromatography with flame ionization detector.

The morphological features of the peeled seeds and colour of the coat present in the bottle were consistent with seeds of R. communis L. Ricinine was identified in the sediment by comparison of

Discussion

In the presented case, the successive clinical symptoms were consistent with the typical clinical manifestations described in literature in cases of castor bean poisoning by injection [3], [14]. On admission, the laboratory tests showed dehydration and metabolic acidosis. The patient deteriorated with haemolysis, liver failure, renal dysfunction and respiratory system failure. No antidote for castor bean poisoning is available. Despite symptomatic and supportive intensive care the patient died

Conclusions

Identification of ricinine in SPE extracts of castor beans can be performed by full-scan GC/MS, HPLC/DAD and full-scan LC/MS, respectively. The novel HPLC/DAD assay has proven to be applicable for the identification of ricinine in seeds of R. communis L. The exposure to the castor bean extract was confirmed through the detection of the biomarker ricinine in blood, urine and vitreous humour. To the authors’ knowledge, it is the first time that ricinine is reported in vitreous humour in a case of

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