Abstract: 【Abstract】 Objective To explore the potential targets and pathways for Poria cocos in the treatment of atopic dermatitis （AD） through network pharmacology, and to experimentally validate its intervention mechanism using pachymic acid as a representative component in human keratinocyte HaCaT cell experiments, thereby providing a theoretical basis for the therapeutic application of natural medicines against AD?related inflammatory responses. Methods Network pharmacology analysis was performed to predict the potential targets of Poria cocos, and to screen overlapping targets associated with AD. A protein-protein interaction network was constructed, followed by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes （KEGG） enrichment analyses. Molecular docking was performed to assess the binding affinity between the active components of Poria cocos and key targets. An in vitro AD model was established by stimulating HaCaT cells with tumor necrosis factor （TNF）-α and interferon （IFN）-γ （model group）; model cells were then treated with 2, 4, or 8 μmol/L pachymic acid （2, 4, 8 μmol/L pachymic acid + model groups）; a blank group （normally cultured HaCaT cells） and a dimethyl sulfoxide group （HaCaT cells treated with 1‰ dimethyl sulfoxide） served as controls. To verify the regulatory role of hypoxia‐inducible factor‐1α （HIF1A） in AD, validation experiments were conducted by treating the model cells with 5 μmol/L 2- methoxyestradiol （2-ME ［a HIF1A inhibitor］, 2-ME group）; the blank group, dimethyl sulfoxide group, and model group were treated as described above. Enzyme-linked immunosorbent assay was conducted to detect the levels of interleukin （IL）-1β, IL-6, and IL-8; Western blot analysis was performed to determine the protein expression of HIF1A, key glycolytic enzymes （lactate dehydrogenase A ［LDHA］, phosphofructokinase 1 ［PFK1］, hexokinase 2 ［HK2］）, and the barrier protein loricrin （LOR）; flow cytometry was used to assess the effect of pachymic acid on cell apoptosis; additionally, lactate dehydrogenase （LDH） activity, L-lactate, and pyruvate levels were measured. Results Network pharmacology analysis identified 247 overlapping targets between Poria cocos and AD, mainly involving inflammatory response, infection-related and cellular stress response pathways. Among these, the HIF-1, TNF, and IL-17 signaling pathways were prominently enriched in KEGG analysis. Molecular docking confirmed good binding affinity between pachymic acid and HIF1A as well as LDHA （binding energies < ?5.0 kcal/mol）. In HaCaT cell experiments, compared with the blank group, the model group exhibited significantly higher levels of IL-1β, IL-6, and IL-8, a higher apoptosis rate （all P < 0.001）, lower LOR expression （P < 0.001）, higher LDH activity, L-lactate level, and L-lactate/pyruvate ratio （all P < 0.001）, and stronger expression of glycolysis-related proteins HIF1A, LDHA, HK2, and PFK1 （all P < 0.05）; compared with the model group, the model cells treated with 2, 4, and 8 μmol/L pachymic acid all showed significantly reduced levels of IL-1β, IL-6, and IL-8 （all P < 0.001）, increased LOR expression （all P < 0.05）, decreased apoptosis rates, LDH activity, L-lactate levels, and L-lactate/pyruvate ratios （all P < 0.05）, and downregulated protein expression of HIF1A, LDHA, HK2, and PFK1 （all P < 0.05）. The 5 μmol/L 2-ME + model group showed trends similar to the pachymic acid-treated groups. Conclusion Pachymic acid, as a key active component of Poria cocos, may ameliorate inflammatory injury and glycolytic dysregulation in AD cell models by inhibiting HIF1A. Poria cocos may regulate AD?related inflammation through multiple targets and pathways, offering a new direction for natural medicine-based treatment of AD.

Key words: Dermatitis, atopic, Poria, Pachymic acid, Network pharmacology, HaCaT cells, HIF1A/LDHA pathway, Glycolysis