Abstract
Anticancer activity of 9,10-anthraquinone isolated from soil-derived (Doddabetta forest, Nilgiris, Tamil Nadu, India) filamentous bacterium Streptomyces sp. isolate ERINLG-26 was tested to explore the molecular mechanisms of action. The culture liquid ethyl acetate extract showed high cytotoxic activity against tested colorectal adenocarcinoma cell line COLO320. The ethyl acetate extract was fractionated by column chromatography over silica gel and preparative HPLC. The isolated compound, 9,10-anthraquinone, showed prominent cytotoxic activity in vitro against colorectal adenocarcinoma cell line COLO320. It showed 79.7% cytotoxicity at concentration of compound 300 mu g/mL with IC50 value of 75 mu g/mL. Treatment of the COLO320 cancer cells with isolated 9,10-anthraquinone significantly reduced cell proliferation and increased formation of fragmented DNA and apoptotic bodies. The expression of p53 and caspase-3 was up-regulated by 9,10-anthraquinone in colorectal adenocarcinoma cell line COLO320.