The active ingredients of the three tea alcoholic extracts could modulate multiple signaling pathways through a variety of target proteins such as TNF-α, IL-17, FLG, Cytokeratin 17, IL-23, STAT3, FLG, IFN-γ, IL-22, etc., and thus attenuate or inhibit psoriasis. The gene discussed is IL17A; the disease is psoriasis.