Pomegranate (Punica Granatum L.) Peel Hydroalcoholic Extract Supplementation Reduces Pain and Improves Clinical Symptoms of Knee Osteoarthritis: A Randomized Double-Blind Placebo Controlled Study

Osteoarthritis (OA) is a degenerative joint disease with several pathological mechanisms. The intervention that provides for reduced pain and disability with fewer side effects may help improve OA. Pomegranate peel is known to have powerful antioxidant and anti-inflammatory properties due to its great amount of polyphenols. The objective of this study was to evaluate the effects of the pomegranate peel extract on clinical signs and symptoms of knee OA. This randomized, doubleblind placebo-controlled clinical trial was conducted amongst 60 women in the age range of 38 - 60 years who were referred to the physical medicine and rehabilitation department of the Tabriz University of Medical Sciences in Tabriz, Iran (Sep 2014 - Feb 2015). The participants were allocated using the block randomization method in one of two study arms. The intervention and control groups received 500 mg of pomegranate peel, hydro alcoholic extract (n = 30) and placebo (n = 30), twice daily for 8 weeks, along with standard drug therapy. The primary outcome measure was the change in mean, Knee injury and osteoarthritis outcome score (KOOS) and the secondary outcome measure was the visual analog scale score. There were no significant differences between the two groups in the mean of age, body mass index (BMI), disease duration and parity before intervention (P > 0.05). The mean of KOOS increased from 46.15 ± 16.82 to 57.57 ± 15.61 after 12 weeks (P < 0.001) as compared to the placebo group 50.83 ± 18.83 declining to 56.10 ± 18.07 (P < 0.001). The VAS score declined significantly in both treatment and control groups compared with baselines (P < 0.005). These changes in the intervention group were significantly greater than those in the control group after adjusting for baseline values, weight changes, energy intake, physical activity, disease duration and parity (P < 0.05). This study presented some effects of the pomegranate peel extract in reducing pain and improving clinical signs and symptoms in women with knee OA and might be considered as a complementary medicine in treating OA.