Efficacy and safety of curcumin and its combination with boswellic acid in osteoarthritis: a comparative, randomized, double-blind, placebo-controlled study

Abstract

Background: The aim of this clinical trial was to assess the efficacy and safety of curcuminoid complex extract from turmeric rhizome with turmeric volatile oil (CuraMed®) and its combination with boswellic acid extract from Indian frankincense root (Curamin®) vs placebo for the treatment of 40- to 70-year-old patients with osteoarthritis (OA).

Methods: The effects of CuraMed® 500-mg capsules (333 mg curcuminoids) and Curamin® 500-mg capsules (350 mg curcuminoids and 150 mg boswellic acid) taken orally three times a day for 12 weeks in 201 patients was investigated in a three-arm, parallel-group, randomized, double-blinded, placebo-controlled trial. Primary outcome efficacy measures included OA physical function performance-based tests, the WOMAC recommended index of joint pain, morning stiffness, limitations of physical function, and the patients' global assessment of disease severity.

Results: Favorable effects of both preparations compared to placebo were observed after only 3 months of continuous treatment. A significant effect of Curamin® compared to placebo was observed both in physical performance tests and the WOMAC joint pain index, while superior efficacy of CuraMed vs placebo was observed only in physical performance tests. The effect size compared to placebo was comparable for both treatment groups but was superior in the Curamin® group. The treatments were well tolerated.

Conclusions: Twelve-week use of curcumin complex or its combination with boswellic acid reduces pain-related symptoms in patients with OA. Curcumin in combination with boswellic acid is more effective. Combining Curcuma longa and Boswellia serrata extracts in Curamin® increases the efficacy of OA treatment presumably due to synergistic effects of curcumin and boswellic acid.

Trial registration: This trial is registered at the database www.clinicaltrials.gov . https://clinicaltrials.gov/ct2/show/NCT02390349?term=EuroPharma&rank=1 . Study registration number: NCT02390349 .

Fig. 1

CONSORT Diagram - participant flow chart. ITT – intention to treat analysis, which includes all patients who completed the tests. DEA – dropouts excluded analysis, which includes only patients who completed all tests during all 3 visits

Fig. 2

The changes with time in the maximum number of chair stand repetitions possible in a 30-s period at weeks 0, 4, and 12 in the Curamin, CuraMed and placebo treatment groups. Within-group improvements (*p < 0.05, **p < 0.01, ***p < 0.001) in physical performance tests at the end of the study (visit 3) compared to baseline (week 0)

Fig. 3

The changes with time in a fast-paced walking test timed over 4 × 10 m for a total 40 m at weeks 0, 4, and 12 in the Curamin, CuraMed and placebo treatment groups. Within-group improvements (*p < 0.05, **p < 0.01, ***p < 0.001) in physical performance tests at the end of the study (visit 3) compared to baseline (week 0)

Fig. 4

The changes with time in the time required to rise from a chair, walk 3 m, turn, and walk back to the chair at weeks 0, 4, and 12 in the Curamin, CuraMedand placebo treatment groups. Within-group improvements (*p < 0.05, **p < 0.01, ***p < 0.001) in physical performance tests at the end of the study (visit 3) compared to baseline (week 0)

Fig. 5

The changes with time in the time required to ascend and descend a flight of stairs at weeks 0, 4, and 12 in the Curamin, CuraMed and placebo treatment groups. Within-group improvements (*p < 0.05, **p < 0.01, ***p < 0.001) in physical performance tests at the end of the study (visit 3) compared to baseline (week 0)