Reviewed: Belcaro G, Cesarone M, Dugall M, et al. Product-evaluation registry of Meriva^®, a curcumin-phosphatidylcholine complex, for the complementary management of osteoarthritis. Panminerva Med. 2010;52(2):1-8.

Turmeric (Curcuma longa, Zingiberaceae) rhizomes and tubers contain curcumin. This yellow pigment has been extensively researched to assess its efficacy in the treatment of chronic diseases, and especially inflammation, in over 2,500 preclinical investigations. There are several challenges with curcumin pharmacokinetics, including instability at physiological pH values, poor oral absorption, and quick elimination. However, some researchers believe, and some research demonstrates, that these challenges can be improved by complexing curcumin with phospholipids, specifically phosphatidylcholine (PC). The resulting non-covalent adducts are named Phytosomes^® (a group of patented phytomedicinal formulations made by Indena SpA of Milan, Italy). The authors state that this proprietary, patented combination improves curcumin’s utilization in the human body by a combination of higher hydrolytic stability and better intestinal absorption.

Osteoarthritis (OA) could potentially benefit from curcumin’s anti-inflammatory properties. Meriva_®SR_® Curcumin Phytosome formula, a curcumin and PC combination (1:2 ratio), was studied in a 3-month trial of 50 patients with X-ray diagnosed OA in one or both knees to assess the effects on their inflammation symptoms. The 50 patients were selected from the Vascular Screening Project at the University of Chieti in Italy, and sorted out into 2 groups. Patients from group A took only their prescribed medication, while those from group B took their prescribed medication along with 1.0 gram of Meriva capsules per day, corresponding to 200 mg of unformulated curcumin. (Meriva is produced by Indena SpA; this formulation is produced and marketed to healthcare professionals in the United States and North America by Thorne Research Inc., Dover, Idaho.)

The Western Ontario and McMaster Universities Arthritis Index (WOMAC) questionnaire was utilized to rate the patients’ OA symptoms. The questionnaire scores were evaluated at inclusion and at the conclusion of the 3-month study. A treadmill walking test at 3 km/h with a 10% inclination was also employed to assess mobility and walking distance before knee joint pain occurred, at inclusion and at 3 months. Edema was evaluated and found to exist in 88% of the 50 patients at inclusion. C-reactive protein (CRP) plasma levels were measured to evaluate the inflammation status of the patients. CRP levels were assessed with the use of laser nephelometry at inclusion, 8 weeks, and 3 months. A healthy level of CRP, a marker for inflammation, is lower than 10 mg/L.

The results showed a significant decrease of the WOMAC median score for pain, stiffness, and physical function in patients from the Meriva group, where this score changed from 83.4 at inclusion to 34.8 by the end of the 3-month trial. In the control group, this score only decreased from 80.6 to 78.8. Walking ability increased from 76 m to 332 m (>400% improvement) in the Meriva group versus a 30.8% improvement in the control group at 3 months. Edema in both groups was reduced. Group A (control) began the study with an edema score of 2.76 (standard deviation [SD] 0.4) and Group B's (Meriva) average score was 2.81 (SD 0.33). At 3 months, Group B had edema reduction with a mean decrease of 65% to 1.2 (SD 0.3). Group A completed the trial with a mean decrease of 5.0% and an edema score of 2.13 with P<0.05 between the groups.

A sub-population of 23 patients had elevated CRP levels, and was separated into 2 groups, Meriva (mean age 43.3; 8 females) and control (mean age 44.2; 6 females), to assess the effects of Meriva on CRP levels. Meriva patients experienced a significant decrease in CRP from 168 mg/L at inclusion to a final level of 13.1 mg/L at 3 months, with a significant improvement detected after 2 months. The control group began the trial at 175 mg/L, and at the end of the trial had decreased to only 112 mg/L. The Meriva patients had a significantly greater reduction in CRP levels, which were almost normalized, while in the control group the CRP level remained elevated by the end of the 3-month trial (P<0.05).

Several other measures were considered as secondary end-points, including emotional wellbeing, decrease in pharmaceutical medication consumption, and digestive disturbances. Emotional wellbeing improved significantly in the Meriva group (from 34.9 to 10.5 [P<0.05]), while it remained constant in the control group. The decrease in digestive problems was 38% in Meriva and 15% in the control group. Analgesic medication (non-steroidal anti-inflammatory drugs, NSAIDs) consumption decreased 63% in the Meriva group compared to 12% in the control group (P<0.05).

Previous research has indicated that this proprietary curcumin-phosphatidylcholine complex had a superior bioavailability to curcumin alone, with an over 20-fold improvement of plasma curcuminoid concentration.¹ The overall results from this new clinical study suggest that Meriva, when integrated with conventional medication, improves the general quality of life of OA patients, decreasing the painful symptoms associated with the disease, improving joint functionality, and reducing the consumption of NSAIDs.

Whether Meriva affects the levels of other inflammatory cytokines, e.g., TNF-alpha, was not investigated in this trial. Such information would have been constructive, as TNF-alpha blocker medications have been approved for this disease. Furthermore, a potential weakness of this study is the lack of a control group taking a non-formulated curcumin extract alone to compare with Meriva. Such direct comparison could help determine the possible superiority of Meriva over a more conventional curcumin extract. The dosage of curcumin in Meriva used in the study (200 mg) was significantly lower than those of unformulated curcumin preparations found clinically active in the treatment of inflammatory diseases (over 1 g).²