Metabolomic study of biochemical changes in the plasma and urine of primary dysmenorrhea patients using UPLC-MS coupled with a pattern recognition approach.

Primary dysmenorrhea (PD) is characterized by painful menstrual cramps without any organic pathology and has a prevalence of up to 90% in adolescents. Recent advances in its etiology and pathogenesis are providing more speculative hypotheses focused on integral systems. Using a targeted tandem mass spectrometry (MS/MS)-based metabolomic platform, we explored the changes of metabolic profiling in plasma/urine simultaneously between PD patients and healthy controls before and after a 3-month herbal medicine (namely Shaofu Zhuyu formula concentrated-granule, SFZYFG) therapy. To detect and identify potential biomarkers associated with PD and SFZYFG treatment, we also performed a combined UPLC-QTOF-MS/MS-based metabolomic profiling of the plasma/urine samples, indicating a further deviation of the patients' global metabolic profile from that of controls. The total thirty-five metabolites (nineteen in plasma and sixteen in urine), up-regulated or down-regulated (p < 0.05 or 0.01), were identified and contributed to PD progress. These promising identified biomarkers underpinning the metabolic pathway including sphingolipid metabolism, steroid hormone biosynthesis, and glycerophospholipid metabolism are disturbed in PD patients, which were identified by using pathway analysis with MetPA. Twenty-four altered metabolites and fourteen biochemical indicators were restored back to the control-like level after the treatment of SFZYFG and could be potential biomarkers for monitoring therapeutic efficacy. These findings may be promising to yield a valuable insight into the pathophysiology of PD and to advance the approaches of treatment, diagnosis, and prevention of PD and related syndromes.