title: Purification, partial characterization and antitumor effect of an exopolysaccharide from Rhizopus nigricans.
abstract: In this study, a homogeneous exopolysaccharide (EPS1-1) was purified from the fermentation broth of Rhizopus nigricans. EPS1-1 was composed of glucose, mannose, galactose and fructose in the molar ratio of 5.89:3.64:3.20:1.00 with weight average molecular weight of 9.7×10(3)g/mol. EPS1-1 could significantly inhibit proliferation of human colorectal carcinoma HCT-116 cells in vitro. EPS1-1 also induced S phase cell cycle arrest and increased sub-G0/G1 population, a hallmark of apoptosis. The results of morphological characterization and flow cytometry showed that EPS1-1 induced apoptotic cell death in HCT-116 cells. EPS1-1 caused dissipation of mitochondrial membrane potential, accumulation of reactive oxygen species, up-regulation of Bax and p53 mRNA expression and down-regulation of Bcl-2 mRNA expression, which suggested that mitochondrial pathway was involved in the EPS1-1-induced apoptosis. These findings bring new insights into the potential use of EPS1-1 as antitumor drug against human colorectal carcinoma.
authors.affiliation: School of Life Science and National Glycoengineering Research Center, Shandong University, Jinan 250100, China; Institute of Cardiovascular Disease, General Hospital of Jinan Military Region, Jinan 250022, China.
authors.forename: Wenqian
authors.initials: W
authors.lastname: Yu
authors.affiliation: School of Life Science and National Glycoengineering Research Center, Shandong University, Jinan 250100, China.
authors.forename: Guochuang
authors.initials: G
authors.lastname: Chen
authors.affiliation: School of Life Science and National Glycoengineering Research Center, Shandong University, Jinan 250100, China. Electronic address: zhangpy888@126.com.
authors.forename: Pengying
authors.initials: P
authors.lastname: Zhang
authors.affiliation: School of Life Science and National Glycoengineering Research Center, Shandong University, Jinan 250100, China. Electronic address: ksc313@126.com.
authors.forename: Kaoshan
authors.initials: K
authors.lastname: Chen
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D059447:Cell Cycle Checkpoints / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D062610:Fungal Polysaccharides / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D045325:HCT116 Cells; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008970:Molecular Weight; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics; D017382:Reactive Oxygen Species / Q000378:metabolism; D012233:Rhizopus / Q000737:chemistry*; D016159:Tumor Suppressor Protein p53 / Q000235:genetics; D051028:bcl-2-Associated X Protein / Q000235:genetics
chemical_list: D000970:Antineoplastic Agents; D062610:Fungal Polysaccharides; D019253:Proto-Oncogene Proteins c-bcl-2; D017382:Reactive Oxygen Species; D016159:Tumor Suppressor Protein p53; D051028:bcl-2-Associated X Protein
keywords: Apoptosis; Exopolysaccharide; Human colorectal cancer cell; Rhizopus nigricans; S phase cell cycle arrest