Last week Sherlock sent me a German study that confirms what I read in other studies that I posted about more than a year ago (on May 10 2007, to be precise). The German study was published in the “Journal of Cancer Research and Clinical Oncology” last month (see abstract: http://tinyurl.com/6xnp7y ). It opens with the hypothesis that curcumin lessens osteoclast differentiation and function. If true, that would be a good good good (!) thing.
Well, I am happy to report that this hypothesis was indeed confirmed by test results, which showed that Curcumin inhibits RANKL-induced osteoclast differentiation and resorptional activity in a dose-dependent manner. Then, in the “Discussion” part, we read that Bone is a dynamic organ which is continuously remodelled by resorption of primary bone and build-up of new bone, a process that requires coordinated cross-talk between osteoclasts and osteoblasts. Okay, I will attempt to put this into simpler (?) words.
Osteoclasts are a type of bone cell that break down bone in a process known as bone resorption, while their counterpart, called osteoblasts, rebuild it. This is a perfectly normal state of affairs in healthy folks. In abnormal cases such as cancer and inflammatory diseases, though, an unbalance occurs: osteoclast activity increases…and the number of osteoblasts decreases. In other words, there are not enough osteoblasts to rebuild the bone that is being destroyed by the pesky little osteoclasts. One of the consequences is that bone calcium gets “chipped off” and released into the bloodstream. We know what that means!
Ah, a quick reminder about RANKL, too. The acronym stands for “Receptor Activator for Nuclear Factor-kappaB Ligand.” It’s a protein that activates osteoclasts and is thus important in bone metabolism. Under normal circumstances, this is not a problem. But in the case of myeloma, for instance, a vicious cycle forms. Myeloma cells overstimulate RANKL, which in turn overstimulates the formation of osteoclasts, and we know what happens at that point: bone lesions. RANKL is thus a therapeutic target, and that is why, in my opinion, the recent confirmation that curcumin inhibits this mischievous protein is an excellent bit of news!
The German researchers also treated osteoclasts with curcumin, stimulated them with RANKL and observed a reduction of NF-kB binding activity. Even if we don’t understand this bit, or understand it only in part, the point is that this is all very good news, which can be summarized as follows: