Elucidating the anti-melanoma effect and mechanisms of Hispolon.

There is a rapid increase in the incidence of melanoma which has led to a global crisis. Thus, there is a great need for developing novel, safe and effective drugs for the treatment of melanoma. Hispolon is a small molecular weight polyphenol derived from Phellinus linteus, which has antioxidant, anti-inflammatory and anti-proliferative activities. Hispolon has been reported to induce apoptosis in gastric cancer, hepatocellular carcinoma, and myeloid leukemia. However, the anticancer effect in melanoma is not well elucidated. Thus, our present study was to investigate the anti-cancer effect of hispolon on melanoma cancer cells. B16BL6 cells were treated with different concentrations of hispolon for 24 h and the effect on oxidative stress, mitochondrial functions, apoptosis and cell proliferation were studied. Hispolon is a potent generator of reactive oxygen species, nitrite and lipid peroxide levels. Furthermore, it significantly inhibits the expression of Bcl-2 and promotes the expression of Bax, increases the activity of caspase 1 and 3, inhibits mitochondrial Complex I and IV activities. By the above mechanisms, hispolon dose-dependently exhibited the antimelanoma effect similar to the well established pharmacological agent, curcumin. Thus, hispolon can be a potent anti-melanoma drug in the future if the pharmacodynamic effects and the toxicological studies are appropriately carried out.