Glycyrrhizin and glycyrrhetinic acid determination from formalin-fixed tissue.

Glycyrrhetinic acid (GA), the main metabolic product of glycyrrhizin (GLY), could be detected in formalin-fixed tissue from a man who died 6 hours after therapeutic administration of a GLY-containing agent. GA was extracted from homogenized formalin-fixed liver tissue and 3 ng GA/g could be detected by HPLC. The extraction from formalin-fixed liver tissue gave the same retention time peak as the GLY control. GA could also be detected by mass spectrometry in the blood sample. This confirms that the man had received a GLY-containing agent for therapeutic use prior to his death and that GA can be determined from formalin-fixed tissue.