Smoking of Gentiana lutea leaves: Validation of its traditional use

The roots and rhizomes of Gentiana lutea L. are officially listed in the European Pharmacopeia and numerous national pharmacopeias and are used mainly to treat gastrointestinal disorders. In contrast, the leaves are traditionally smoked for the treatment of angina pectoris, but scientific support and justification for its traditional use are missing. Therefore, the chemical composition and gentian leaves before and after smoking were investigated in this study. A standardized smoking machine was used to generate cigarette smoke and the chemical constituents were analyzed by high-performance liquid chromatography (HPLC). The analysis showed that a significant proportion (68.77 %) of the xanthone isogentisin was transferred intact from the leaves to the smoke stream, making it the only compound detected in the smoke condensate. Thermogravimetric analysis revealed that isogentisin underwent thermal decomposition within the temperature range of 250-448 °C. These findings provide scientific evidence supporting the medicinal potential of gentian leaves, with isogentisin identified as the active constituent. Furthermore, the thermal stability profile of isogentisin offers valuable insights into its behavior during combustion.