Efficacy and serum metabolomic analysis of Jiu Wei Qingzhi Formula in treating non-alcoholic fatty liver disease: study protocol for a parallel-armed, randomized controlled trial

The incidence of non-alcoholic fatty liver disease (NAFLD) is on the rise, leading to severe liver conditions. Jiu Wei Qingzhi Formula (JWQZG), a traditional Chinese medicine, has shown promise in improving liver enzymes and blood lipids, though its mechanisms are not well-understood. This study aimed to evaluate the efficacy and safety of JWQZG in the treatment of NAFLD, with a particular focus on serum alanine aminotransferase (ALT) as the primary outcome, and to explore lipid metabolic changes using untargeted lipidomics. Ninety participants were recruited and randomly assigned to a treatment group (JWQZG + conventional treatment) or a control group (placebo + conventional treatment) in a 2:1 ratio. Both groups received lifestyle interventions for the first 4 weeks. The primary endpoint was the change in serum ALT levels from baseline to the end of treatment. Secondary outcomes included changes in AST, fasting glucose, lipid parameters, MRI-proton density fat fraction (MRI-PDFF), and body mass index (BMI). Serum samples were collected pre- and post-treatment for lipidomic profiling via untargeted liquid chromatography–mass spectrometry (LC–MS). Seventy-one patients completed the study (26 control, 45 treatment). Compared to baseline, the JWQZG group exhibited significant reductions in ALT, AST, glucose, total cholesterol, MRI-PDFF, and BMI (all P < 0.05), while triglyceride levels remained unchanged (P > 0.05). Between-group analysis showed that ALT levels decreased significantly more in the JWQZG group than in the control group (P = 0.028). Lipidomics analysis identified 837 lipid species, with increased phosphatidylcholines in both groups and decreased sphingomyelins uniquely in the JWQZG group. KEGG analysis indicated enrichment in glycerophospholipid metabolism for both treatments, and sphingolipid metabolism only in the JWQZG group. We employed ROC analysis to evaluate the therapeutic effects of JWQZG and identified three potential biomarkers: PC (18:2/19:2COOH), SM (d20:1/24:4), and TG (18:0COOH/8:0/8:0), which may serve as indicators for JWQZG treatment of NAFLD. JWQZG effectively and safely reduced ALT and blood lipid levels in NAFLD patients, with lipidomics suggesting beneficial effects on phospholipid metabolism and unique inhibition of sphingolipid metabolism, highlighting potential biomarkers for NAFLD diagnosis. Further research is encouraged to explore JWQZG’s mechanisms.