Inhibitory effects on nuclear factor κB of the Vietnamese freshwater cyanobacteria

Several Vietnamese freshwater cyanobacteria were collected and evaluated for their effects on the transcriptional nuclear factor κB (NF-κB) which are involving in the cancer and inflammatory diseases. Five extraction conditions were tested and a solution of 2% acetic acid in methanol provided highest yield of extract from bacterial biomass. The Microcystis aeruginosa TC-1 and TC-3 strains showed strong NF-κB inhibitory activity with IC50 values of 6.1 and 5.3 μg/ml, respectively. Moreover, all tested cyanobacteria exhibited cytotoxicity on human cervical cancer HeLa cells in a dose-dependent manner. Ergosterol (1) isolated from M. aeruginosa TC-3 strains strongly inhibited NF-κB activation with IC50 values of 0.91 μg/ml.