title: Antioxidant activity of newly discovered lineage of marine actinobacteria.
abstract: OBJECTIVE
  To investigate the antioxidant activity of marine actinobacteria.
  
  
  METHODS
  The content of total phenolics, the level of antioxidant potential by DPPH radical scavenging activity, metal chelating activity, FRAP method, β carotene assay and NO scavenging activity in extract were determined.
  
  
  RESULTS
  In all the methods the extract exhibited good scavenging activity except NO scavenging activity. The IC(50) values of marine actinobacteria extract on DPPH radical were found to be 41.09 μg/mL. The zone of color retention was 12 mm in β-carotene bleaching assay. DNA protective efficiency of the extracts was also studied using UV-photolysed H(2)O(2)-driven oxidative damage to pBR322. HPLC analysis identified some of the major phenolic compounds in extracts, which might be responsible for the antioxidant potential and cyto-protection. It showed a 100% cytotoxic effect in brine shrimp lethality assay within 10 mins. The novel actinobacteria was identified as Streptomyces LK-3 (JF710608) through 16S rDNA Sequencing.
  
  
  CONCLUSIONS
  The results obtained suggest that the extracts bear anti-cancer metabolites and could be considered as a potential source for anti-cancer drug development.
authors.affiliation: Environmental Biotechnology Division, School of Bio Sciences and Technology, VIT University, Vellore, Tamil Nadu, India.
authors.forename: Loganathan
authors.initials: L
authors.lastname: Karthik
authors.forename: Gaurav
authors.initials: G
authors.lastname: Kumar
authors.forename: Kokati Venkata
authors.initials: KV
authors.lastname: Bhaskara Rao
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000302:isolation & purification; D000970:Antineoplastic Agents / Q000302:isolation & purification; D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification*; D001156:Artemia / Q000187:drug effects; D001713:Biphenyl Compounds / Q000737:chemistry; D002614:Chelating Agents / Q000737:chemistry / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid; D004249:DNA Damage / Q000187:drug effects; D007202:Indicators and Reagents / Q000737:chemistry; D008826:Microbial Sensitivity Tests; D009569:Nitric Oxide / Q000737:chemistry; D010084:Oxidation-Reduction / Q000187:drug effects; D010636:Phenols / Q000032:analysis*; D010851:Picrates / Q000737:chemistry; D013302:Streptomyces; D019207:beta Carotene / Q000737:chemistry
chemical_list: D000900:Anti-Bacterial Agents; D000970:Antineoplastic Agents; D000975:Antioxidants; D001713:Biphenyl Compounds; D002614:Chelating Agents; D007202:Indicators and Reagents; D010636:Phenols; D010851:Picrates; D019207:beta Carotene; D009569:Nitric Oxide; C004931:1,1-diphenyl-2-picrylhydrazyl