Comparative evaluation of the pain-relieving properties of a lecithinized formulation of curcumin (Meriva®), nimesulide, and acetaminophen

In addition to its anti-inflammatory activity, Meriva®, a proprietary lecithin formulation of curcumin, has been anecdotally reported to decrease acute pain in patients with various chronic diseases. Given that curcumin can desensitize transient receptor potential A1, a nociceptor seemingly also mediating the analgesic effect of acetaminophen, as well as inhibiting and downregulating the expression of cyclo-oxygenase 2, the selective target of nimesulide, a nonsteroidal anti-inflammatory agent, we carried out a pilot comparative study of the acute pain-relieving properties of these three agents. At a dose of 2 g (corresponding to 400 mg of curcumin), Meriva showed clear analgesic activity, comparable with that of a standard dose (1 g) of acetaminophen, but lower than that of a therapeutic (100 mg) dose of nimesulide. The analgesic activity of lower (1.5 g) doses of Meriva was less satisfactory, and the onset of activity was longer than that of nimesulide for both doses. On the other hand, gastric tolerability was significantly better than that of nimesulide and comparable with that of acetaminophen. Taken together, our results show that the preclinical analgesic properties of curcumin have clinical relevance, at least at a dose of 2 g as the Meriva formulation. While this dose is significantly higher than that used to relieve chronic inflammatory conditions (1-1.2 g/day), its pain-relieving activity could benefit from the general downregulation of the inflammatory response induced by curcumin, considering that the transient receptor potential channel-mediated mechanisms of analgesia are magnified by attenuation of inflammation. In patients on treatment with Meriva, this would also translate into better control of acute pain, providing a rationale for the analgesic properties associated with this curcumin formulation.