Antioxidative and Antitumor Effects of Isoflavones Isolated from the Leaves of Maackia fauriei .

The flowers of Maackia fauriei have traditionally been used to treat hypertension, apoplexy, hemostasis, vaginal bleeding, and dystocia; moreover, the bark of this plant has been used as a natural dye. In the present study, activity-guided isolation of the leaves of M. fauriei yielded five isoflavones [genistein (1), pratensein (2), genistin (3), 2'-hydroxygenistein-7-O-β-D-glucopyranoside (4), and 2,3-dehydrokievitone (5)]; three pterocarpans [medicarpin (6), maackiain (7), and 4-hydroxy maackiain (8)]; and one flavonol [isoquercitrin (9)]. To evaluate the anti-oxidative effects of these compounds, their 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging assays and nitrotetrazolium blue chloride (NBT) superoxide scavenging assays were measured. And the anti-tumor activity against human cancer cell lines in genital system, LNCaP, PC-3,HeLa and OVCAR-3 cells were evaluated by MTT method. Furthermore, the apoptosis of the PC-3 and HeLa cells were determined by by annexin V-FITC and PI their fluorescence was analyzed by flow cytometry. The flavonol (9, isoquercitrin) and pterocarpan (8, 4-hydroxymaackiain) showed strong anti-oxidative activities. Besides, the isoflavones (1-5) did not showed anti-oxidative activity and the isoflavones (1-5) and pterocarpans (6-8) generally showed the potent cytotoxic activity against all of four human genital cancer cells. Especially, 2,3-dehydrokievitone (5) which had a prenyl group at C-8 position of the A-ring exhibited strong cytotoxic activity and induced apoptosis efficiently in cancer cells.