Antioxidant activity of newly discovered lineage of marine actinobacteria

ObjectiveTo investigate the antioxidant activity of marine actinobacteria.MethodsThe 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.ResultsIn all the methods the extract exhibited good scavenging activity except NO scavenging activity. The IC₅₀ 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 H₂O₂-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.ConclusionsThe results obtained suggest that the extracts bear anti-cancer metabolites and could be considered as a potential source for anti-cancer drug development.