title: A potential human hepatocellular carcinoma inhibitor from Bauhinia purpurea L. seeds: from purification to mechanism exploration.
abstract: A 20-kDa Kunitz-type trypsin-chymotrypsin inhibitor, Bauhinia purpurea trypsin inhibitor (BPLTI), has been isolated from the seeds of B. purpurea L. by using liquid chromatography procedures that involved ion exchange chromatography on Sp-Sepharose and Mono S and gel filtration on Superdex 75. BPLTI demonstrated protease inhibitory activities of 7226 BAEE units/mg and 65 BTEE units/mg toward trypsin and α-chymotrypsin, respectively. BPLTI was relatively thermal (0-60°C) and pH (3-10) stable and its activity could be decreased by dithiothreitol treatment. BPLTI exhibited a wide spectrum of anti-proliferative and pro-apoptotic activities especially on human hepatocellular carcinoma Hep G2 cells. However, it was devoid of a significant antiproliferative effect on immortal human hepatic WRL 68 cells. We show here that BPLTI stimulates apoptosis in Hep G2 cells, including (1) evoking DNA damage including the production of chromatin condensation and apoptotic bodies; (2) induction of cell apoptosis/necrosis; (3) mitochondrial membrane depolarization; and (4) increasing the production of cytokines. Taken together, our findings show for the first time that purified protease inhibitor from B. purpurea L. seeds is a promising candidate for the treatment of human hepatocellular carcinoma.
authors.affiliation: School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Choh Ming Li Basic Medicinal Sciences Building, Shatin, Hong Kong. fangfei1030@yahoo.com.cn
authors.forename: Evandro Fei
authors.initials: EF
authors.lastname: Fang
authors.forename: Clara Shui Fern
authors.initials: CS
authors.lastname: Bah
authors.forename: Jack Ho
authors.initials: JH
authors.lastname: Wong
authors.forename: Wen Liang
authors.initials: WL
authors.lastname: Pan
authors.forename: Yau Sang
authors.initials: YS
authors.lastname: Chan
authors.forename: Xiu Juan
authors.initials: XJ
authors.lastname: Ye
authors.forename: Tzi Bun
authors.initials: TB
authors.lastname: Ng
mesh_terms: D000970:Antineoplastic Agents / Q000302:isolation & purification / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D036481:Bauhinia / Q000737:chemistry*; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy*; D056945:Hep G2 Cells; D006801:Humans; D008113:Liver Neoplasms / Q000188:drug therapy*; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology*; D012639:Seeds / Q000737:chemistry; D014361:Trypsin Inhibitors / Q000302:isolation & purification / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D010936:Plant Extracts; D014361:Trypsin Inhibitors