Application of curcumin in rheumatic diseases

Curcumin is the main polyphenolic compound of the turmeric plant (Curcuma longa) which has been used for many years in the treatment of various medical conditions. Numerous experimental and pharmacological studies published in recent years show that curcumin, precisely because of its anti-inflammatory properties, can be very effective in the treatment of rheumatic diseases (1).

Curcumin and rheumatic diseases - clinical research so far

Rheumatic diseases, including rheumatoid arthritis and osteoarthritis, are inflammatory diseases that cause deformation of the joints and loss of their role, as well as deterioration of cartilage and bones (2). Osteoarthritis is the most common form of arthropathy, and it is characterized by the degeneration of articular cartilage and the loss of the role of cartilaginous structures that arise as a result of a combination of genetic, physiological and biochemical processes (3).

When we talk about the safety and effectiveness of curcumin in the treatment of rheumatoid arthritis, available research shows that this substance represents an excellent alternative to available drugs, especially if you take into account the fact that its effectiveness is comparable to certain non-steroidal anti-inflammatory drugs (1).

• Tako je cilj jedne randomizirane pilot studije bio utvrditi sigurnost upotrebe i učinkovitost kurkumina zasebno ili u kombinaciji s diklofenak natrijem u pacijenata s reumatoidnim artritisom. U studiji je bilo uključeno ukupno 55 pacijenata koji su bili podijeljeni u 3 skupine. Prva je skupina dobivala 500 mg kurkumina, druga je skupina dobivala diklofenak natrij u dozi od 50 mg, dok je treća skupina dobivala kombinaciju kurkumina i diklofenak natrija u spomenutim dozama. Promatrani parametri bili su: reduction of the point scale of disease activity (engl. Disease Activity Score, DAS) te bodovnih kriterija za reduction of joint sensitivity and swelling Američkog koledža za reumatologiju (engl. American College of Rheumatology, ACR). The results showed that the DAS score scale decreased in all groups, and the largest improvement in the DAS and ACR score scale was observed in the group that received only curcumin. Additionally, curcumin has been shown to be safe to use, with no reported side effects (4).
• Druga a randomized, double-blind, placebo-controlled study imala je za cilj utvrditi učinkovitost upotrebe kurkuminoida u pacijenata koji boluju od osteoartritisa koljena. U istraživanju je sudjelovalo 40 pacijenata s blagim do umjerenim oblikom osteoartritisa koljena koji su tijekom 6 tjedana svaki dan dobivali ukupno 1500 mg kurkuminoida raspoređenih u tri doze, odnosno placebo. Djelotvornost uzimanja kurkuminoida promatrana je kao promjena u WOMAC indeksu (engl. Western Ontario and McMaster Universities Osteoarthritis), VAS scale (English Visual Analogue Scale) and the LPFI index (English Lequesne´s pain functional index). The results showed that curcuminoid intake, compared to placebo, had a significant reduction in all three mentioned scales.A significant improvement in pain symptoms and knee function was also noted, and no significant side effects were observed (5).

Mechanism of action

Previous research involving patients with rheumatoid arthritis showed that taking curcumin resulted in suppression of Bcl-2 and Bcl-xL regulatory proteins, activation of Bax proteins, caspase-3 and -9, and degradation of poly (ADP ribose) polymerase (PARP) in synovial fibroblasts. Curcumin also inhibited the inflammatory response in synovial fibroblasts through suppression of COX-2, i.e. inhibition of prostaglandin E2 synthesis (6).

The results of another study showed that curcumin inhibited inflammatory processes by suppressing collagenase and stromelysin expression in HIG-82 synoviocytes (7).

Research has established that the anti-inflammatory effect of curcumin is manifested in the suppression of several inflammatory cytokines, such as TNF-α, interleukins (IL-1, -1β, -6 and -8) and cyclooxygenase-2 (COX-2) (2).

In one clinical study involving 50 patients with osteoarthritis, it was found that taking curcumin can prevent joint inflammation by suppressing enzymes (COX-2 and LOX) and inflammatory transcription factors (NF-κB and STAT3) (8).

Conclusion

Available drugs that are currently used in the treatment of rheumatic diseases are very effective, but due to their proven immunomodulatory effect, as well as their price, their use is limited. The effectiveness and safety of using curcumin makes it an excellent supportive therapy, and sometimes an alternative in the treatment of rheumatic diseases.

Author: Tena Škunca, mag. interior/ Vitaminoteka

Literature:

1. Fadus MC, et al. Curcumin: An age-old anti-inflammatory and anti-neoplastic agent, JTCM (2016), http://dx.doi.org/10.1016/j.jtcme.2016.08.002.

2. Shehzad A, Rehman G, Sup Lee Y. Curcumin in Inflammatory Diseases. BioFactors 2013; 39(1):69-77.

3. Shiozawa, S. and Tsumiyama, K. Pathogenesis of rheumatoid arthritis and c-Fos/AP-1. Cell Cycle 2009; 8, 1539–1543.

4. Chandran B, Goel A. A Randomized, Pilot Study to Assess the Efficacy and Safety of Curcumin in Patients with Active Rheumatoid Arthritis. Phytother Res (2012), doi: 10.1002/ptr.4639.

5. Panahi Y, Rahimnia AR, Sharafi M, Alishiri G, Saburi A, Sahebkar A. Curcuminoid Treatment for Knee Osteoarthritis: A Randomized Double-Blind Placebo-Controlled Trial. Phytother Res (2014), doi: 10.1002/ptr.5174.

6. Park, C., Moon, D.O., Choi, I.W., Choi, B.T., Nam, T.J., et al. Curcumin induces apoptosis and inhibits prostaglandin E(2) production in synovial fibroblasts of patients with rheumatoid arthritis. Int. J. Mol. Honey. 2007; 20, 365–372.

7. Jackson, J.K., Higo, T., Hunter, W.L., and Burt, H.M.The antioxidants curcumin and quercetin inhibit inflammatory processes associated with arthritis. Inflamm. Crisp. 2006; 55, 168–175.

8. Belcaro, G., Cesarone, M.R., Dugall, M., Pellegrini, L., Ledda, A., et al. Efficacy and safety of MerivaVR, a curcumin-phosphatidylcholine complex during extended administration in osteoarthritis patients. Alternate. Honey. Rev. 2010; 15, 337–344.