Soyasaponin Bb is a triterpenoid saponin that has been found in soy and has enzyme inhibitory, antimetastatic, anti-inflammatory, and neuroprotective biological activities. It selectively inhibits human recombinant and porcine kidney renin (IC50s = 30 and 30 μg/ml, respectively) over bovine trypsin, human urinary kallikrein, and rabbit angiotensin converting enzyme (ACE) when used at a concentration of 100 μg/ml. Soyasaponin Bb inhibits the mouse brain sialyltransferase ST3GAL1 (Ki = 2.1 μM) and decreases levels of α2,3-linked sialic acid on the cell surface and decreases migration of B16/F10 mouse melanoma cells in vitro when used at a concentration of 75 μM. It also dose-dependently increases viability and mRNA expression of heme oxygenase-1 (HO-1) in BRL 3A immortalized rat hepatocytes subjected to alcohol-induced oxidative stress. Soyasaponin Bb (10 mg/kg per day) increases the latency to enter the dark chamber in a passive avoidance test and the percentage of spontaneous alterations in the Y-maze test in a rat model of learning and memory impairment induced by ibotenic acid .
