title: Antioxidant and DNA Damage Protecting Activity of Exopolysaccharides from the Endophytic Bacterium Bacillus cereus SZ1.
abstract: An endophytic bacterium was isolated from the Chinese medicinal plant Artemisia annua L. The phylogenetic and physiological characterization indicated that the isolate, strain SZ-1, was Bacillus cereus. The endophyte could produce an exopolysaccharide (EPS) at 46 mg/L. The 1,1-diphenyl-2-picrylhydracyl (DPPH) radical scavenging activity of the EPS reached more than 50% at 3-5 mg/mL. The EPS was also effective in scavenging superoxide radical in a concentration dependent fashion with an EC50 value of 2.6 mg/mL. The corresponding EC50 for scavenging hydroxyl radical was 3.1 mg/mL. Moreover, phenanthroline-copper complex-mediated chemiluminescent emission of DNA damage was both inhibited and delayed by EPS. The EPS at 0.7-1.7 mg/mL also protected supercoiled DNA strands in plasmid pBR322 against scission induced by Fenton-mediated hydroxyl radical. The preincubation of PC12 cells with the EPS prior to H₂O₂ exposure increased the cell survival and glutathione (GSH) level and catalase (CAT) activities, and decreased the level of malondialdehyde (MDA) and lactate dehydrogenase (LDH) activity in a dose-dependent manner, suggesting a pronounced protective effect against H₂O₂-induced cytotoxicity. Our study indicated that the EPS could be useful for preventing oxidative DNA damage and cellular oxidation in pharmaceutical and food industries.
authors: Department of Horticulture, School of Architecture, Soochow University, Suzhou 215123, China. lpzheng@suda.edu.cn.
authors: Li Ping
authors: LP
authors: Zheng
authors: College of Pharmaceutical Sciences, Soochow University, Suzhou 215123, China. zouting0723@163.com.
authors: Tin
authors: T
authors: Zou
authors: College of Pharmaceutical Sciences, Soochow University, Suzhou 215123, China. mdsdyx@126.com.
authors: Yan Jun
authors: YJ
authors: Ma
authors: College of Pharmaceutical Sciences, Soochow University, Suzhou 215123, China. jwwang@suda.edu.cn.
authors: Jian Wen
authors: JW
authors: Wang
authors: School of Biology &amp; Basic Medical Sciences, Soochow University, Suzhou 215123, China. bcjwwang@gmail.com.
authors: Yu Qing
authors: YQ
authors: Zhang
mesh_terms: D000818:Animals; D001409:Bacillus cereus / Q000737:chemistry* / Q000235:genetics; D001713:Biphenyl Compounds / Q000737:chemistry; D004249:DNA Damage; D004353:Drug Evaluation, Preclinical; D060026:Endophytes / Q000737:chemistry / Q000235:genetics; D016166:Free Radical Scavengers / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D006861:Hydrogen Peroxide / Q000494:pharmacology; D058889:Molecular Typing; D016877:Oxidants / Q000494:pharmacology; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D016716:PC12 Cells; D010802:Phylogeny; D010851:Picrates / Q000737:chemistry; D010957:Plasmids / Q000737:chemistry / Q000235:genetics; D011135:Polysaccharides, Bacterial / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D051381:Rats; D013481:Superoxides / Q000737:chemistry
chemical_list: D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D016877:Oxidants; D010851:Picrates; D011135:Polysaccharides, Bacterial; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D013481:Superoxides; D006861:Hydrogen Peroxide; C004931:1,1-diphenyl-2-picrylhydrazyl
keywords: Artemisia annua L.; Bacillus cereus; exopolysaccharide; oxidative damage; radical scavenging activity