Nitric oxide synthesis inhibition and cytotoxicity of Korean horse mussel Modiolus modiolus extracts on cancer cells in culture.

The Korean horse mussel extract was purified and fractionated by a bioassay-guided purification step. The final fraction contained seven steroid and one polycyclic aromatic compounds, in which cholest-7-en-3-ol, (3β,5α)- (58.7 %) was a main component followed by ergosta-7,22dien-3-ol (3β,5α,22E) (13.0 %). This extract exhibited strong anti-inflammatory activity determined solely through the nitric oxide inhibition assay in a dose-dependant manner with the IC50 value of 9.6 µg/mL and no cytotoxic effect on the macrophages. Moreover, it also exhibited strong cytotoxicity with the IC50 values of 21.4, 36.4, and 37.1 µg/mL against AGS, DLD-1, and HeLa cells, respectively. These results indicated that the horse mussel extract might be a functional ingredient in the prevention of inflammation and human cancers.