Efficacy and mechanism of action of turmeric supplements in the treatment of experimental arthritis

Abstract

Objective. Scientific evidence is lacking for the antiarthritic efficacy of turmeric dietary supplements that are being promoted for arthritis treatment. Therefore, we undertook studies to determine the antiarthritic efficacy and mechanism of action of a well-characterized turmeric extract using an animal model of rheumatoid arthritis (RA).Methods. The composition of commercial turmeric dietary supplements was determined by highperformance liquid chromatography. A curcuminoidcontaining turmeric extract similar in composition to these supplements was isolated and administered intraperitoneally to female Lewis rats prior to or after the onset of streptococcal cell wall-induced arthritis. Efficacy in preventing joint swelling and destruction was determined clinically, histologically, and by measurement of bone mineral density. Mechanism of action was elucidated by analysis of turmeric's effect on articular transcription factor activation, microarray analysis of articular gene expression, and verification of the physiologic effects of alterations in gene expression. Results.A turmeric fraction depleted of essential oils profoundly inhibited joint inflammation and periarticular joint destruction in a dose-dependent manner. In vivo treatment prevented local activation of NF-B and the subsequent expression of NF-B-regulated genes mediating joint inflammation and destruction, including chemokines, cyclooxygenase 2, and RANKL. Consistent with these findings, inflammatory cell influx, joint levels of prostaglandin E 2 , and periarticular osteoclast formation were inhibited by turmeric extract treatment.Conclusion. These translational studies demonstrate in vivo efficacy and identify a mechanism of action for a well-characterized turmeric extract that supports further clinical evaluation of turmeric dietary supplements in the treatment of RA.The use of botanical remedies for arthritis treatment is promoted in the US by the lay press and high-profile medical practitioners (1,2). Interest in the use of nonpharmaceutical arthritis treatments has grown with the withdrawal of Food and Drug Administrationapproved antiinflammatory drugs (3). However, scientific data are almost uniformly lacking concerning the antiarthritic efficacy and mechanism of action of popular botanical remedies (4,5). The rational medicinal use of botanical dietary supplements is further complicated by the fact that the composition of over-the-counter botanical dietary supplements is not strictly regulated (4,5). Unfortunately, in the medical literature, the chemical composition and biologic activity of botanicals that are tested for antiarthritic efficacy are frequently also not well characterized (6-9). Therefore, benchmarks are lacking for assessing the potential suitability of commercially available botanical supplements or phytomedicines. 3452Turmeric is one such botanical supplement whose use against arthritis, supported almost exclusively by its traditional, centuries-old use as an antiinflammatory agent in Ayurvedic medicine, has been heavily prom...

In vivo delivery of lentiviral vectors expressing vasoactive intestinal peptide complementary DNA as gene therapy for collagen‐induced arthritis

“…However very few studies (using gene therapy or any other treatment strategy) have demonstrated regression of established arthritis (16,17,43,44), and to date, total regression of established severe disease has not been achieved with any RA treatment.…”

Biological and therapeutic activities, and anticancer properties of curcumin

“…Funk et al (36) documented the effectiveness of an extract devoid of essential oils in preventing joint inflammation, while a hydroalcoholic extract of turmeric was demonstrated to inhibit joint inflammation and periarticular tissue destruction in a dose-dependent manner (37).…”

Curcumin-loaded colloidal carrier system: formulation optimization, mechanistic insight, ex vivo and in vivo evaluation

“…plant-based agents are being promoted for the management of arthritis. 4 Curcumin (CR), the yellow coloring agent found in turmeric (Curcuma longa, family Zingiberaceae), is a diferuloylmethane [1,7-Bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione] and has been used for centuries as a spice in the Indian subcontinent. 5 It has been reported to have a wide range of activities like anti-inflammatory, anti-oxidant, anti-parasitic, anti-mutagenic, anti-cancer, and anti-arthritic (both in vitro and in vivo), as suggested by many studies.…”