Eugenol with antioxidant activity inhibits MMP-9 related to metastasis in human fibrosarcoma cells

The oxidative damage of lipid, protein and DNA is known to be involved in chronic inflammation as well as metastasis. It has been highlighted for searching natural compounds without toxicity to prevent development of these diseases. Thus, it was investigated whether eugenol can inhibit matrix metalloproteinase (MMP) expression and activity as well as antioxidant effect. Eugenol was contained as a major ingredient in herbs such as clove and Magnoliae Flos. The direct scavenging effects of eugenol on DPPH radical, hydrogen peroxide, reducing power, lipid peroxidation and genomic DNA damage related to oxidative stress were evaluated in cell free system. It was observed that eugenol specifically exhibited higher inhibitory effect on hydrogen peroxide than other reactive oxygen species, and also blocked DNA oxidation and lipid peroxidation induced by hydroxyl radical. In addition, the inhibitory effects of eugenol on the activity and expression of MMP-9 activity related to metastasis were determined using gelatin zymography and western-blot. The data showed that it inhibited MMP-9 activities in PMA-stimulated HT1080 cells. Furthermore, it was found that eugenol exerts inhibitory effects on MMP-9 via inactivation of ERK. Therefore, these results suggest that eugenol could be available as an excellent agent for prevention of metastasis related to oxidative stress.