Astilbin ameliorates propranolol-induced psoriasis-like lesions through restoring Th17/Treg immune homeostasis in lymph nodes

Psoriasis is a challenging immune-mediated dermatological disorder with an urgent need for effective clinical therapeutics, while astilbin has shown considerable efficacy in suppressing psoriasis progression, its underlying mechanisms are not fully clarified. This study aimed to systematically investigate the anti-psoriatic effects of astilbin and to elucidate its potential mechanisms of action. A psoriasis-like mouse model was established via cold water swimming, dietary restriction, and topical application of 5% propranolol emulsion, followed by daily treatment with low- (25.6 mg/kg), middle- (51.2 mg/kg), or high-dose (76.8 mg/kg) astilbin for 6 consecutive days, with evaluations including PASI scoring, histopathological examination, Baker scoring, inflammatory cytokine detection, and flow cytometric analysis of lymphocyte populations in lymph nodes and spleen. Middle and high doses of astilbin significantly reduced skin lesions and erythema, with PASI scores decreasing by 23.6%, and 44.9% respectively, Baker scores significantly reduced by 23.1% and 24.1% in the middle- and high-dose groups, and astilbin also significantly suppressed skin IL-17A, IL-6, and IFN-γ levels; moreover, middle and high doses substantially downregulated Th1, Th17, and Treg cell populations in lymph nodes and effectively restored Th17/Treg balance. Astilbin effectively ameliorates psoriatic skin lesions through immunomodulatory mechanisms involving the correction of lymph node Th17/Treg imbalance, highlighting its potential as a therapeutic agent for psoriasis.