A refined Indigo Naturalis extract or Indigo-producing plant extract containing at least 65% (w/w) an indirubin derivative based on total weight of active ingredients is described. Also described are a pharmaceutical composition containing the refined extract, and the use of the pharmaceutical composition for treating or alleviating a disease or condition.La présente invention concerne une composition pharmaceutique, ainsi que l'utilisation de la composition dans des applications médicales.