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, ß 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 ß-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.