Xiaoxia Gao

Metabolomics is widely applied to dissect metabolic pathways and their correlations with biological phenotypes. Unlike genomics and proteomics, metabolites exhibit substantial heterogeneity in chemical structure, physicochemical properties, and biological origin. Accordingly, pathway enrichment and annotation relying merely on alterations in metabolite abundance are prone to incomplete coverage, ionization bias, and ambiguous annotation, which inevitably impair the accuracy of pathway interpretation. Metabolic flux analysis (MFA) coupled with stable isotope-resolved metabolomics (SIRM) offers a powerful quantitative framework for tracing in vivo carbon flow and estimating reaction fluxes across key metabolic nodes. Glucose metabolism lies at the core of systemic energy homeostasis; however, most current investigations are confined to cell lines or in vitro systems, and a simple, easy-to-implement computational pipeline for in vivo glucose flux analysis in animal models is still lacking. Herein, we established an in vivo 13C-labeling-based MFA workflow to trace and resolve the systemic metabolic fate of glucose in rats. The pipeline covers tracer administration, sample preparation, LC-MS detection, isotopologue data acquisition and correction, construction of a glucose-metabolism-related metabolite database, MFA model establishment, and metabolic flux quantification. By infusing rats with [U–13C6]-glucose and [U–13C3]-sodium L-lactate, we precisely characterized the in vivo metabolic fates of circulating glucose and lactate and quantified their respective contributions to glycolytic flux and tricarboxylic acid (TCA) cycle flux. We further applied this workflow to profile energy metabolic reprogramming in depression. The results revealed a systemic shift toward aerobic glycolysis in rats exposed to chronic unpredictable mild stress (CUMS). Overall, the expanded application of this MFA strategy can provide mechanistic and quantitative insights into the regulation of metabolic pathways.

Forsythia suspensa leaves black tea (FSLBT) is a fermented herbal tea traditionally consumed in Northern China, yet its bioactive constituents and antioxidant basis remain insufficiently understood. In this study, a phytochemical investigation of FSLBT led to the isolation and structural identification of nine compounds, including five lignans and four pentacyclic triterpenic acids, whose structures were elucidated by ¹H-NMR, ¹³C-NMR, and HRESIMS spectral analysis. Notably, epipinoresinol and pinoresinol monomethyl ether were isolated from Forsythia suspensa leaves (FSL) for the first time. Among the isolated lignans, phillygenin, epipinoresinol, pinoresinol monomethyl ether, and pinoresinol were further evaluated for antioxidant activity using DPPH•, ABTS•+, and FRAP assays. The four lignans exhibited concentration-dependent antioxidant activities, with IC₅₀ (half maximal inhibitory concentration) values ranging from 20.32 to 46.40 μg/mL for DPPH• scavenging and 37.29 to 72.71 μg/mL for ABTS•+ scavenging, while FRAP EC₅₀ (half maximal effective concentration) values ranged from 1.53 to 1.90 mg/mL. Quantitative HPLC analysis showed that the contents of phillygenin, epipinoresinol, pinoresinol monomethyl ether, and pinoresinol in FSLBT were 3.48 ± 1.12 wt%, 0.39 ± 0.21 wt%, 0.26 ± 0.20 wt%, and 0.18 ± 0.07 wt%, respectively. These results indicate that FSLBT is enriched in lignan aglycones, particularly phillygenin, and that these major lignans possess measurable chemical antioxidant activities, providing a phytochemical basis for further investigation of the functional properties of this fermented herbal tea.

Background: Mild cognitive impairment (MCI) is an intermediate condition between normal aging and dementia. Drug intervention is an important way to prevent MCI from developing into dementia. GuiLingJi (GLJ) is a traditional Chinese medicine formulae and it has the effect of enhancing memory. In view of the absence of special effective drugs for MCI, GLJ warrants investigation as a potential therapeutic agent. Methods: This study uses a rat model of MCI, induced by D-galactose injections and a semi-high-fat diet, to explore the therapeutic efficacy of GLJ in MCI and elucidate the potential underlying pharmacological mechanisms by behavioral experiments and biochemical indexes, combined with serum and hippocampal metabolomics. Results: GLJ treatment mitigated D-galactose combined with semi-high-fat diet induced impairments, including abnormal blood lipids, oxidative stress, inflammation, cholinergic dysfunction, apoptosis, and reduced brain-derived neurotrophic factors, along with hippocampal damage. LC-MS metabolomics indicated that these effects involved unsaturated fatty acid and amino acid metabolism. By normalizing linoleic acid and α-linolenic acid levels and activating GPR120, GLJ inhibited the NF-κB/TNF-α pathway. Conclusion: These findings demonstrate that GLJ alleviates MCI symptoms, at least in part, by modulating fatty acid metabolism and suppressing neuroinflammation via the GPR120/NF-κB pathway. This study supports GLJ as a promising proprietary TCM formulation for MCI treatment.

Background: This study aims to evaluate the efficacy of Guiling Prescription (GP)—a medicinal food homologous formula—in hyperuricemic rats, its effects on uric acid excretion and renal function, and to clarify the metabolic mechanisms involved in GP's alleviation of hyperuricemia. Methods: Sprague-Dawley (SD) rats of hyperuricemia was established using potassium oxonate (200 mg/kg, PO) and adenine (100 mg/kg) to assess the therapeutic effects of Guiling Prescription (GP). We measured body weight, serum levels of uric acid and creatinine, as well as xanthine oxidase (XOD) and adenosine deaminase (ADA) activity, alongside histopathological parameters. Serum concentrations of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and alanine aminotransferase (ALT), and aspartate aminotransferase (AST) were determined using ELISA kits. The expression of renal uric acid transporters was evaluated through Western blotting. Network pharmacology was utilized to predict the key drug-disease targets, and a non-targeted metabolomic assay was applied to identify the key metabolites and metabolic pathways, and validated these targets through molecular docking and western blot analyses. Results: GP showed an improvement effect on hyperuricemia model rats, with decreased levels of serum uric acid (UA), serum urea nitrogen, and creatinine, and serum ALT, AST. Furthermore, H&E staining results showed to improve renal injury in the hyperuricemic rat, and serum interleukin-6 and tumor necrosis factor-αwere improve the body's inflammatory response after administration of GP. In addition, GP could regulate multiple serum metabolic pathways such as arachidonic acid metabolism, pyrimidine metabolism, purine metabolism, citric acid cycle. On one side, GP decreased the synthesis of uric acid by inhibiting hepatic xanthine oxidase activities and adenosine deaminase activity. On the other side, GP increased the excretion of uric acid with the upregulation of UA excretion genes ABCG2, OAT1, and OAT3 and downregulation of UA resorption genes URAT1 and GLUT9. Conclusion: GP orchestrates uric acid metabolism through multi-target and multi-pathway regulation, highlighting its potential not only as a novel therapeutic strategy but also as a promising dietary supplement for the management of hyperuricemia.

Depression is a complex mental disorder. Studies have shown that purine metabolism disorders in depression and regulation of purine metabolites and related purinergic receptors may be an effective way to alleviate depression. Chaigui granules (CG) are a Chinese medicine prescription with antidepressant effects. Its antidepressant effect has been shown to be related to the improvement of purine metabolism disorders in depression. In this study, exogenous purine metabolite adenosine supplementation and adenosine A1 receptor antagonist (DPCPX) were employed to investigate the potential of Chaigui granules to exert an antidepressant effect by examining the behavioral indices of CUMS rats. The aim of this study was to determine whether the antidepressant effect of Chaigui granules is mediated by A1R receptors using DPCPX, an A1R receptor antagonist. Nontargeted metabolomic analysis was employed to compare and analyze the alterations in the metabolic profile of plasma and peripheral blood mononuclear cells (PBMCs) in each experimental group. Subsequently, combining the results from the metabolomics profile, targeted metabolomics was employed to identify key metabolites for purine metabolism. The objective was to investigate the effects of Chaigui granules, exogenous adenosine supplementation, and DPCPX on purine metabolism in depressed rats. Finally, the relevant signal pathways were validated by molecular biological means. The results of the depression-like behavior indicate that the antidepressant efficacy of Chaigui granules was associated with the modulation of adenosine and adenosine A1 receptor. Metabolomic analysis demonstrated that the Chaigui granule and adenosine exerted a pronounced regulatory effect on purine metabolism, and the regulatory effect on peripheral blood mononuclear cells (PBMCs) was markedly superior to that observed in plasma. In addition, targeted quantitative analysis showed that all eight purine metabolites were reversed after the administration of Chaigui granules and adenosine. Concurrently, the administration of an adenosine A1 receptor antagonist may serve to mitigate the regulatory impact of Chaigui granules on purine metabolites. Finally, the molecular biological results indicate that the antidepressant effect of Chaigui granules may be mediated by the A1R receptor, and it can play an antidepressant role by regulating the CAMP-PKA-CREB-BDNF pathway.