I have used Curcumin before I knew I had Crohns, in small amounts, just as a cancer preventative, for joint pain, and other benefits.
Now I am using Tumeric in larger doses, which contains Curcumin, in addition to ginger in an attempt to prevent inflammation.
Unfortunately, I cannot tell you if it works or not since my symptoms are so slight. Until i get another colonoscopy I am flying blind. It did get rid of my joint pain which was not that bad to begin with.
Old Hat's link is a very good one for info on these supplements. Check out Google Scholar for actual studies done on any of these.
Coenzyme Q10 is often taken if you are using certain Statin drugs. Some of these drugs deplete this enzyme in your body which is important for proper heart function. Other than that I do not know much about it.
D Bergy