Abstract: 3-Deoxyflavonoid compounds and methods for inhibiting T-cell activity and treating diseases and disorders (e.g., autoimmune disorders, inflammatory disorders, diabetes, ALS, MS, rheumatoid arthritis, etc.). In some cases the efficacy and/or duration of action of luteolin and/or other 3-dioxyflavinoid compounds may be increased by administering such compounds along with Rutin, a Rutin congener and/or a Rutin derivative. Also, in some cases, first pass metabolism of luteolin or other 3-deoxyflavinoids may be avoided by administering such compounds by parenteral routes (e.g., sublingual, buccal, intranasal, injection, etc.).