Herbal formulation "turmeric extract, black pepper, and ginger" versus Naproxen for chronic knee osteoarthritis: A randomized, double-blind, controlled clinical trial

Phytother Res. 2020 Aug;34(8):2067-2073. doi: 10.1002/ptr.6671. Epub 2020 Mar 16.


Osteoarthritis is the most common articular disease that can lead to chronic pain and severe disability. Curcumin-an effective ingredient in turmeric with anti inflammatory property-plays an important role in protecting the joints against destructive factors. Gingerols and piperine, are the effective ingredients of ginger and black pepper, which may potentially enhance and sustain the effect of curcumin in this direction. To determine the effect of cosupplementation with turmeric extract, black pepper, and ginger on prostaglandin E2 (PGE2 ) in patients with chronic knee osteoarthritis, compared with Naproxen. Sixty patients with two different levels of knee osteoarthritis (Grade 2 and 3) were studied. Individuals were randomly assigned to receive daily turmeric extract, ginger, and black pepper together or Naproxen capsule for 4 weeks. PGE2 was evaluated by ELISA method. 24-hr recall was also assessed. All of participants completed the study. PGE2 decreased significantly in both groups (p < .001), but there was no significant differences between groups. The results of this study indicated that intake of the selected herbs twice a day for 4 weeks may improve the PGE2 levels in patients with chronic knee osteoarthritis similar to Naproxen drug.

Keywords: Naproxen; black pepper; ginger; knee osteoarthritis; prostaglandin E2; turmeric extract.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Anti-Inflammatory Agents, Non-Steroidal / pharmacology
  • Anti-Inflammatory Agents, Non-Steroidal / therapeutic use*
  • Chronic Disease
  • Curcuma / chemistry*
  • Curcumin / chemistry*
  • Double-Blind Method
  • Female
  • Humans
  • Male
  • Middle Aged
  • Naproxen / pharmacology
  • Naproxen / therapeutic use*
  • Osteoarthritis, Knee / drug therapy*
  • Piper nigrum / chemistry*
  • Plant Extracts / chemistry*
  • Zingiber officinale / chemistry*


  • Anti-Inflammatory Agents, Non-Steroidal
  • Plant Extracts
  • Naproxen
  • turmeric extract
  • Curcumin