Soyasaponin Ab has anti-inflammatory effects, it can inhibit colon shortening, myeloperoxidase activity, the expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS), and activation of the transcription factor nuclear factor-κB (NF-κB); soyasaponin Ab (1, 2, 5, and 10 μM) can inhibit the production of NO (IC50 = 1.6 ± 0.1 uM) and prosta.