In vitro metabolism of selected bioactive compounds of Eurycoma longifolia root extract to identify suitable markers in doping control. Issue 1 (9th August 2018)

• Record Type: Journal Article
• Authors: Bräuer, Pia; Anielski, Patricia; Schwaiger, Stefan; Stuppner, Hermann; Tran, Thi Van Anh; Vollmer, Günter; Zierau, Oliver; Thieme, Detlef; Keiler, Annekathrin Martina
• Is Part Of: Drug testing and analysis. Volume 11:Issue 1(2019)
• Page Start: 86
• Page End: 94
• Publication Date: 2018-08-09
• Subjects: biotransformation -- doping -- Eurycoma longifolia -- LC–MS/MS -- Tongkat Ali; Drugs -- Analysis -- Periodicals; Drug testing -- Periodicals; Chemistry, Forensic -- Periodicals; 615.1901
• DOI: 10.1002/dta.2449
• Languages: English
• ISSNs: 1942-7603

Abstract

Abstract: Eurycoma longifolia Jack (Tongkat Ali, Simaroubaceae) is a medicinal plant endemic to South‐East Asia. For centuries, different parts of the plant have been used as a natural remedy to treat fever, hypertension, or sexual insufficiency. Today, Eurycoma longifolia preparations are commercially available and advertised to enhance athletic performance and muscle strength. Several studies have demonstrated a testosterone‐boosting effect that might be caused by the release of free testosterone from the sex‐hormone‐binding globulin. To date, many phytochemical constituents of Eurycoma longifolia root extracts have been identified and physiological effects have been examined, while studies on their biotransformation and monitoring are still lacking. Within this study, eurycomalide C, eurycomalactone, 5, 6‐dehydro‐eurycomalactone, longilactone, 14, 15β‐dihydroklaieanone, 11‐dehydroklaieanone, 9‐hydroxycanthin‐6‐one, and 9‐methoxycanthin‐6‐one isolated from E. longifolia root were incubated with liver microsomes. Respective metabolites were analyzed by liquid chromatography–tandem (high‐resolution) mass spectrometry. The compounds were chosen based on their potential androgenic effects (estimated by in vitro assays), their concentrations in plant extracts, and presumptive metabolic pathways. Hydroxylated phase I metabolites were only observed for 5, 6‐dehydro‐eurycomalactone, 11‐dehydroklaieanone, 9‐hydroxycanthin‐6‐one, and 9‐methoxycanthin‐6‐one. Moreover, an O‐demethylated metabolite of 9‐methoxycanthin‐6‐one was found. Besides, the glucuronide of 9‐hydroxycanthin‐6‐one was detected after in vitro glucuronidation using liver microsomes. The in vitro generated metabolites were comparable to that detected in urine and serum after a single ingestion of either 9‐methoxycanthin‐6‐one or an Eurycoma longifolia root extract. Hence, 9‐methoxycanthin‐6‐one, its glucuronide, and the glucuronide of its O‐demethylated biotransformation product are proposed to be the most suitable targets for detection of 9‐methoxycanthin‐6‐one or Tongkat Ali application in urine and serum. Abstract : Tongkat Ali is used as dietary supplement with anabolic effects among bodybuilders. In vitro and in vivo metabolism of Tongkat Ali compounds are described. LC‐MS/MS analysis of parent compounds and metabolites identified target analytes suitable for doping routine analysis.