In vivo: 3.5% DSS-induced experimental colitis mice were treated with BTW (Pulsatilla chinensis (Bunge) Regel, Phellodendron chinense C. K. Schneid, Coptis chinensis Franch and Fraxinus chinensis Roxb), kynurenine or DOPA decarboxylase (DDC) inhibitor (carbidopa). The gene discussed is DDC; the disease is colitis.