Erchen decoction and its active flavonoids hesperidin and quercetin alleviate high-fat diet-induced neuroinflammation by targeting HK2-mediated microglial glycolysis.

ETHNOPHARMACOLOGICAL RELEVANCE: Erchen decoction (ECD), a classic Traditional Chinese Medicine formula recorded in the Taiping Huimin Heji Ju Fang, is historically recognized as the fundamental prescription for drying dampness and resolving phlegm. While ECD is widely used in modern clinical practice for metabolic disorders, the pharmacological mechanisms linking its traditional indications to the regulation of obesity-associated neuroinflammation remain elusive. AIM OF THE STUDY: This study aimed to systematically characterize the bioactive phytochemicals of ECD and elucidate its neuroprotective mechanism against high-fat diet (HFD)-induced neuroinflammation, with a specific focus on reprogramming microglial immunometabolism via the hexokinase 2 (HK2) checkpoint. MATERIALS AND METHODS: The phytochemical profile of ECD was qualitatively and quantitatively characterized using UPLC-MS. Male C57BL/6J mice were fed an HFD to establish the model, followed by ECD administration. Neuroinflammation, depression-like behaviors, and brain metabolic profiles were assessed. Potential targets were screened using network pharmacology and validated via public single-cell RNA sequencing (scRNA-seq) datasets. The underlying mechanism was further verified using molecular docking, molecular dynamics (MD) simulations, enzymatic activity assays, and in vitro in a palmitic acid-stimulated microglial cell model. RESULTS: UPLC-MS profiling coupled with pharmacokinetic screening prioritized hesperidin and quercetin as the major bioactive components. ECD administration significantly reduced body weight, ameliorated depression-like behaviors, and suppressed microglial activation. Brain metabolomics revealed that ECD restored cerebral energy homeostasis. Mechanistically, scRNA-seq analysis identified HK2 as a core microglial target. Notably, enzymatic assays and MD simulations confirmed that hesperidin and quercetin directly bind to and inhibit HK2, thereby blocking the HK2/HIF-1α axis and suppressing the microglial Warburg effect, mimicking the specific inhibitor 2-DG. CONCLUSIONS: ECD mitigates HFD-induced neuroinflammation by reprogramming microglial immunometabolism. This mechanism is driven by the direct inhibition of HK2-mediated glycolysis by its bioactive components, hesperidin and quercetin. These findings provide a modern scientific interpretation for the traditional use of ECD in resolving phlegm, attributing it to the restoration of cerebral metabolic homeostasis.