Mate (Ilex paraguariensis St. Hilaire) saponins induce caspase-3-dependent apoptosis in human colon cancer cells in vitro

Saponins are naturally occurring metabolites associated with several health benefits. The objective was to quantify and purify saponins from mate dry leaves, and to assess their anti inflammatory and apoptotic mechanisms in human colon cancer cells in vitro. Matesaponins were extracted with methanol from dry leaves, partially purified and quantified. Leaves contained 10–15 mg/g dry weight total saponins, predominantly matesaponins 1 and 2. HPLC and LC/ESI-MS-MS identified saponins in six preparative chromatographic fractions (A, B, C, D, E, and F). Major matesaponins were identified as 1 [M–H]− = 911 and 2 [M–H]− = 1057, with trace amounts of 3 [M–H]− = 1073, 4 [M–H]− = 1219, and 5 [M–H]− = 1383. Fractions D, E, and F significantly inhibited iNOS (IC35 = 36.3, 29.5, 43.7 μM), PGE2 (IC35 = 23.1, 22.3, 11.7 μM) and COX-2 (IC35 = 45.7, 32.4, 17.0 μM). Fraction F reduced nuclear translocation of nuclear factor-κB subunits p50 (49.8%) and p65 (49.0%) and induced apoptosis through suppression of Bcl-2 and increased Bax protein expressions and activated caspase-3 activity. Saponins in leaves of mate prevent inflammation and colon cancer in vitro.