Curcumin, the bright yellow active ingredient in turmeric which gives curry a yellow color, has been reported (Chem. Biol. 10, 2003 695) to irreversibly inhibit aminopeptidase N (APN), an enzyme that spurs tumor invasiveness and blood vessel growth (angiogenesis). APN, a newly identified player in angiogenesis, is a membrane-bound zinc-dependent metalloproteinase that breaks down proteins at the cell surface and helps a cancer cell invade the space of neighboring cells. In a recent large-scale investigation of over 3000 chemicals for their antiangiogeneic activity, scientists from South Korea found that curcumin was a potent direct and irreversible inhibitor of APN. Dr. Kleinman at NIH, who studies angiogenesis, claims that these findings from South Korea will open the possibility of more potent APN inhibitors based on the structure of curcumin.
Since the early 1990s, curcumin has been found to slow the growth of new cancers and arrest angiogenesis. Currently, this compound is in Phase I clinical trials for colon cancer. Earlier this year, a team of scientists from the US, Finland and Hong Kong found that curcumin prevents activation of a genetic factor leading to liver inflammation and necrosis, and might be useful in preventing alcoholic liver disease. Because curcumin can be given safely to humans – taken orally, as in milk or food – the results of these studies have potentially important therapeutic implications for individuals at risk for alcoholic liver disease or cancer.