Identification and Quantification of Thujone in a Case of Poisoning Due to Repeated Ingestion of an Infusion of Artemisia Vulgaris L.

Plants of the Artemisia genus are used worldwide as ingredients of botanical preparations. This paper describes the case of a 49-year-old man admitted to the emergency room at a Zurich hospital in a manic state after the ingestion of 1 L of an infusion of Artemisia vulgaris. Two monoterpenic ketones, α- and ß-thujone, are present in various concentrations in Artemisia spp., but adverse effects have previously been associated only with essential oil from Artemisia absinthium and attributed to the inhibition of gamma-aminobutyric acid receptors, with consequent excitation and convulsions. The aim of this work was to examine and quantify the possible presence of thujone in the patient's serum and urine. A High Performance Liquid Chromatography (HPLC) method with isocratic separation and fluorescence detection (FLD) was set up and validated. Serum thujone concentrations were found to be 27.7 ± 3.48 µg/mL at day 0 and 24.1 ± 0.15 µg/mL on day 1. Results were confirmed by a gas chromatography with flame ionization detection (FID). Poisoning due to thujone was thus confirmed, suggesting four possible scenarios: (1) an unusually high concentration of thujone in the A. vulgaris ingested; (2) chronic exposure as the cause of the poisoning; (3) low metabolic efficiency of the patient; (4) contamination or adulteration of the plant material with other Artemisia spp., for example, A. absinthium. PRACTICAL APPLICATION: These results could aid research in the field of adverse effects of botanicals, lead to better understanding and management of similar cases of poisoning, and promote more informed use of natural products.