An anticancer effect of a new saponin component from Gymnocladus chinensis Baillon through inactivation of nuclear factor-κB

Gymnocladus chinensis Baillon is widely distributed in China, and its fruits have been used in the treatment of rheumatism, furunculosis, soreness and swelling in traditional Chinese medicine for a long time. Few biological components were, however, isolated. In this study, a new triterpenoid saponin (GC-1) was extracted from the fruit of Gymnocladus chinensis Baillon and its biological actions were investigated. The results showed that GC-1 inhibited growth of a panel of human cancer cell lines in vitro by 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl tetrazolium bromide and sulforhodamine B assays. Furthermore, GC-1 was demonstrated to induce apoptosis in HL-60 cells in a dose-dependent manner. By using a reporter gene assay, nuclear factor-KB activity induced by tumor necrosis factor-α was decreased gradually by addition of increasing concentration of GC-1 (1-40 μmol/l). In parallel, the blockage of nuclear factor-KB translocation from cytoplasm to nucleus was determined by Western blotting. This is the first study investigating the link of antiproliferative action of the compound with the inhibition of nuclear factor-KB activation. The mechanism of the actions of GC-1 might be due to the interruption of nuclear factor-KB translocation in the signaling pathway, which contributes to the chemotherapy potential.