This study demonstrates the immunosuppressive property of hispidulin in ACD via reduction of infiltrated immune cells at the inflammation site, downregulation of IFN-γ gene expression, and suppression of Th1 skewing reaction (i.e., IFN-γ production of CD4+ T cells), all of which result in decreased edema, spongiosis and ear swelling. Here, CD4 is linked to granular corneal dystrophy type II.