Plasma metabolomics indicates potential biomarkers and metabolic pathways of melasma

Introduction: Melasma is a common and chronic pigmentary disorder that has negatively impacted patients’ quality of life. The pathogenesis of melasma is complicated. Metabolomics may contribute to understanding the pathogenesis and identifying intervention strategies for melasma. Objectives: To analyze changes in plasma metabolites of female melasma patients and search for disease markers and potential therapeutic targets. Methods: Plasma samples from 20 female patients with melasma and 21 age-matched healthy female controls were collected for untargeted metabolomics. Ultra-high performance liquid chromatography-mass spectrometry (UPLC-MS) was used to analyze the plasma metabolites. Significantly differential metabolites in patients with melasma were identified by metabolic pathways and receiver operating characteristic curves, and correlation analysis was conducted with modified Melasma Area and Severity Index (mMASI) and oxidative stress level. Results: Compared with healthy subjects, melasma patients showed significant changes in 125 plasma metabolites, including amino acids, lipids, and carbohydrate-related metabolites. KEGG pathway analysis indicated that tryptophan metabolism and biosynthesis of phenylalanine, tyrosine, and tryptophan pathways may be the main pathways related to melasma pathogenesis. Some metabolites can be considered as biomarkers significantly associated with melasma by ROC analysis and correlation analysis. Conclusions: This study identified significant changes in plasma metabolites in melasma patients using UPLC-MS-based metabolomics, which may provide new insights into the pathogenesis of melasma and explore new therapeutic methods.