Antioxidant activity and free radical scavenging activities of Streptomyces sp. strain MJM 10778

ABSTRACT

OBJECTIVE@#To investigate the antioxidant activity of soil-borne actinobacteria.@*METHODS@#The total phenolic contents, the level of antioxidant potential by DPPH radical scavenging activity, NO scavenging activity, and ABTS radical scavenging activity in ethyl acetate extract were determined.@*RESULTS@#The 16S rDNA sequencing analysis revealed that Streptomyces sp. strain MJM 10778, which was isolated from Hambak Mountain, Korea, has 99.9% similarity to Streptomyces misionensis (S. misionensis) NBRC 13063. The physiological and the morphological test revealed that the strain MJM 10778 has different characteristics from the strain NBRC 13063. The entire antioxidant assay with the ethyl acetate extract displayed good radical scavenging activity. The IC50 values of the strain MJM 10778 extract on DPPH, NO, and ABTS radicals were identified to be 92.8 μg/mL, 0.02 μg/mL, and 134.9 μg/mL, respectively. The ethyl acetate extract of the strain MJM 10778 showed an 81.50% of cell viability at 100 μg/mL in Raw264.7 cell viability assay.@*CONCLUSIONS@#The results obtained suggest that the ethyl acetate extract of Streptomyces sp. strain MJM 10778 could be considered as a potential source of drug for the diseases that is caused by free radicals with its anti-oxidant activities and low cytotoxicity.