has had qite a "going over" by chemists and biologists for a good many decades now. Generally, the feeling is a positive one as to "whats happening" when Curcumin reacts with human metabolism; there is a general consencus that Curcumin is an antioxidant. There is of course, much more to the word "antioxidant". Those dirty, sneaky. pro-radical or "pre-radical" (if you prefer) molecules that can mess up a smoothly running biological system, until this battle waged in the cell says "uncle" and turns on the "apoptotic cycle" of the cell [always likes "apoptosis" instead of "death"] process.
Not only the oxygen atom can form bio-reactive destructive radicals, but nitrogen is a very common atom used by nature to form "radicals", those one-eyed, one handed valence varmints that are at the heart of many "diseases".
Of course Cucurmins can do a lot of cell interacting by just having a certain molecular "shape"; and this shape could be the lock to the "biological cascasde" messengers, for good or evil.
So, we now have evidence that the Cucurmin natural products may have important nitrogen based free radical inhibition. This is good work; it is a study that would recommend further investigation of "Curcurminoids" cs