Effects of dietary supplementation with a standardized aqueous extract of Terminalia chebula fruit (AyuFlex(®)) on joint mobility, comfort, and functional capacity in healthy overweight subjects: a randomized placebo-controlled clinical trial

BACKGROUND: Joint and connective tissue integrity, comfort and function are paramount to optimal performance in exercise, recreational and occupational activities. The fruit of Terminalia chebula has been used extensively in various traditional health systems for different ailments, with additional preclinical and clinical data demonstrating antioxidant and anti-inflammatory potential. The aim of this study was to evaluate the effects of a standardized aqueous extract of Terminalia chebula fruit (AyuFlex®) dietary supplementation on joint mobility, comfort, and functional capacity in healthy overweight subjects. METHODS: One-hundred and five (105) overweight, apparently healthy male and female subjects (35–70 years of age) were pre-screened and randomized to one of three groups for 84 days: placebo, AyuFlex1 (250 mg twice daily) or AyuFlex2 (500 mg twice daily) in a randomized, double-blind, placebo-controlled design. A two-week placebo lead-in period was used to improve data quality/validity. All subjects had no knee joint discomfort at rest, but experienced knee joint discomfort only with activity/exercise of at least 30 on 100 mm Visual Analog Scale (VAS). Primary outcome measures included symptoms of joint health and function as measured by modified-Knee Injury & Osteoarthritis Outcomes Score (mKOOS) global & modified-Western Ontario and McMaster Universities Arthritis Index (mWOMAC) subscales (discomfort, stiffness and function). Secondary outcomes included VAS questionnaires on overall/whole-body joint health, low back health, knee mobility, willingness and ability to exercise, 6-min walk test for distance and range of motion (ROM) of pain-free knee flexion/extension. Tertiary outcome measures included inflammatory (high sensitivity C-reactive protein (hsCRP), tumor necrosis factor (TNF)-α) and extracellular matrix (ECM)/Connective Tissue (COMP) biomarkers, and safety (vital signs and blood markers) & tolerability (Adverse Event (AE)/ side effect profiles). RESULTS: Compared to placebo, at day 84 AyuFlex® treatment significantly: 1) improved mKOOS global scores in AyuFlex1 + AyuFlex2 (P = 0.023), and improved total and physical function subscale of mWOMAC relative to baseline, 2) improved VAS scores for Knee Discomfort with activity/exercise in AyuFlex1 + AyuFlex2 (P = 0.001) relative to baseline, 3) improved VAS scores for whole-body joint function in AyuFlex1 + AyuFlex2 (P < 0.029) relative to baseline, 4) improved VAS score for decreased knee joint soreness following leg extension challenge for AyuFlex1 (P = 0.022) and AyuFlex2 (P = 0.043) relative to baseline, 5) improved 6-min walk performance distance covered (P = 0.047) and VAS discomfort (P = 0.026) post-6 min walk in AyuFlex1 + AyuFlex2 relative to baseline, 6) and tended to decrease COMP levels in AyuFlex1 + AyuFLex2 (P = 0.104) relative to baseline. All biomarkers of safety remained within normative limits during the study. Low back health tended to improve in the AyuFlex1 and AyuFlex2 group, but failed to reach significance relative to placebo group. CONCLUSIONS: AyuFlex® improved mKOOS global scores, knee joint discomfort with activity/exercise, 6-min walk test distance covered and discomfort post-6 min walk test, overall whole-body joint function, knee soreness following leg extension resistance exercise in a healthy, overweight population, without AE. Differences between 250 mg/BID and 500 mg/BID were non-significant for most of the outcome measures, validating the efficacy of the lower dose. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT02589249; October 26, 2015.