Ellagitannins from Terminalia calamansanai induced apoptosis in HL-60 cells

Terminalia calamansanai (Blanco) Rolf. (Combretaceae) is used medicinally as lithontriptic in Philippines. The 70% acetone extracts of T. calamansanai leaves inhibited the viability of human promyelocytic leukemia HL-60 cells. 1-alpha-O-Galloylpunicalagin, punicalagin, 2-O-galloylpunicalin, sanguiin H-4, and methyl gallate were the main components isolated from T. calamansanoi with the IC50 values of 65.2, 74.8, 42.2, 38.0 and >100 mu M, respectively, for HL-60 cells. Apoptosis of HL-60 cells treated with 1-alpha-O-galloylpunicalagin, punicalagin, 2-O-galloylpunicalin, and sanguiin H-4 was noted by the appearance of a sub-G(1) peak in flow cytometric analysis and DNA fragmentation by gel electrophoresis. 2-0-Galloylpunicalin and sanguiin H-4 induced a decrease of the human poly(ADP-ribose)polymerase (PARP) cleavage-related procaspase-3 and elevated activity of caspase-3 in HL-60 cells, but not normal human peripheral blood mononuclear cells (PBMCs), suggesting that both compounds may be new candidates for drug development in the prevention and treatment of cancer. (C) 2009 Elsevier Ltd. All rights reserved.