The effects of Polygonum capitatum in treating atopic dermatitis via modulation of the th2 cytokine pathway

Background This study combined network pharmacology with experimental validation to assess the therapeutic potential of Polygonum capitatum against atopic dermatitis (AD), elucidating its multi-target mechanisms and antibacterial/antipyretic properties in AD-related complications. Methods Potential targets and pathways were predicted using network pharmacology. HPLC was employed to quantify gallic acid, protocatechuic acid, rutin, quercitrin, and quercetin. Antimicrobial activity was evaluated via agar diffusion assays against Escherichia coli and Staphylococcus aureus . Anti-inflammatory activity was assessed by measuring ROS and NO levels in lipopolysaccharide-induced zebrafish. Models of AD were analyzed through SCORAD scoring, histopathological examination, and quantification of cytokines including LTB4 and Th1/Th2 markers. Thermoregulatory responses and serum inflammatory markers were examined using yeast-induced fever models. Finally, molecular docking was performed to validate interactions between the core components and their potential targets. Results Network analysis revealed 88 common targets and identified TNF, JAK2, and PTGS2 as core targets, enriched in immune-inflammatory pathways. Significant levels of the five compounds were detected, with flavonoid content being ethanol-dependent. The 95% ethanol extract inhibited bacterial growth and ameliorated AD-like pathology, including immune dysregulation. Both extracts reduced ROS/NO and fever responses, attenuating pro-inflammatory cytokines. Molecular docking confirmed stable binding between quercetin/rutin and core targets. Conclusion P. capitatum exerts multimodal anti-AD effects through multi-component, multi-target mechanisms involving antimicrobial, immunomodulatory, and antipyretic activities, attributable to its phenolic and flavonoid constituents.