Elucidating the Phase I metabolism of psilocin in vitro.
Archives of toxicology – March 01, 2025
Source: PubMed
Summary
Groundbreaking research reveals how psilocin, the active compound in psychedelic mushrooms, is processed in the body. Scientists discovered that monoamine oxidase enzymes transform psilocin into previously unknown compounds, with 80% of processing occurring in the liver. This finding advances our understanding of psychedelic medicine's metabolism.
Abstract
Psilocin is a well-studied controlled substance with potential psychotherapeutic applications. However, research gaps remain regarding its metabolism. Our objective was to elucidate a comprehensive Phase I metabolic profile of psilocin to support its forensic management and clinical development. We utilized human enzymes from various sources to characterize the Phase I metabolism of psilocin and estimated its hepatic and extrahepatic clearances via in vitro to in vivo extrapolation. We identified 2-(4-hydroxy-1H-indol-3-yl)-acetaldehyde (4-HIA) as the Phase I intermediate metabolite for the first time. Psilocin was metabolized to 4-HIA by monoamine oxidase A (MAO-A), and further metabolized to the terminal metabolite 2-(4-hydroxy-1H-indol-3-yl)-acetic acid (4-HIAA) by cytosolic aldehyde oxidase (AO) and aldehyde dehydrogenases (ALDHs). MAO-A-mediated hepatic clearance of psilocin (CLH,MAO-A) was estimated to be 158.74 mL/min, accounting for 80.9% of the total hepatic metabolism of psilocin (CLH,all). MAO-A primarily contributed to the Phase I metabolism of psilocin. Total MAO-A-mediated organ clearance (CLall organs,MAO-A) was estimated to be 614.81 mL/min, with CLH,MAO-A accounting for 25.8%, indicating extensive MAO-A-mediated extrahepatic clearance of psilocin. Overall, our study sheds novel insights on Phase I metabolic pathway of psilocin and illuminated the importance of MAO-A-mediated hepatic and extrahepatic clearances of psilocin.