Celastrol was found to inhibit the increased epidermal thickness, reduce spleen and lymph node weights, attenuate inflammatory cell infiltration and mast cell degranulation and decrease thymic stromal lymphopoietin (TSLP) as well as various inflammatory factors (IL‐4, IL‐13, TNF‐α, IL‐5, IL‐31, IL‐33, IgE, TSLP, IL‐17, IL‐23, IL‐1β, CCL11 and CCL17) in AD mice. The gene discussed is IL33; the disease is Alzheimer disease.