Ginger extract suppresses the activations of NF-κB and Wnt pathways and protects inflammatory arthritis

Abstract

Objective: Rheumatoid arthritis (RA) is a disabling inflammatory disorder. Ginger is used for food and medicine to treat arthralgia, sprains, and muscle aches. Anti-inflammatory effects of ginger have been observed. The aim of our study was to detect the effects of ginger on experimentally induced inflammatory arthritis.

Methods: Female Wistar albino rats (n = 21) were randomly separated into three groups (control, arthritis, and arthritis + ginger). Arthritis was generated by an appropriate method using type 2 collagen and Freund's adjuvant (collagen-induced arthritis model). The ginger group was treated starting at the first collagen injection with ginger root extract for 32 days by oral gavage (50 mg/kg/daily). Interleukin (IL)-6, IL-17, tumor necrosis factor-α (TNF-α), sclerostin, dickkopf-related protein-1 (DKK-1), and obestatin serum levels were studied by enzyme-linked immunosorbent assay method. Tissue TNF-α, IL-17, cyclooxygenase-2 (COX-2), and nuclear factor kappa B (NF-κB) levels were detected using the Western blot method.

Results: Mean arthritis score and serum levels of TNF-α, IL-6, and IL-17 were significantly decreased in ginger group than in the arthritis group. Increased sclerostin serum level and decreased DKK-1 serum levels were detected in ginger group compared with arthritis group. The decreases of IL-17, TNF-α, COX-2, and NF-κB tissue levels were statistically significant in the ginger group compared with arthritis group. Histopathological evaluation of the ginger group showed a decrease in the inflammation score compared to arthritis group.

Conclusion: It can be concluded that ginger has protective properties in the development of inflammatory arthritis. The antiarthritic acts of ginger are related to NF-κB activity and Wnt pathway. Thus, it may be suggested that ginger is a candidate to research in human RA treatment.

Figure 1.

The effect of ginger extracts on histopathological changes (H&E × 200) in rats with collagen-induced arthritis. (a) Normal perisynovial tissue and cartilage-bone appearance in the control group. (b) Obvious perisynovial inflammation and destruction of cartilage-bone in the arthritis group. (c) Decreased perisynovial inflammation and synovial hyperplasia in the ginger group.

Figure 2.

The effect of ginger extracts on protein levels of tumor necrosis factor alpha (TNF-α; a), interleukin 17 (IL-17; b), nuclear factor-kappa B (NF-κB; c), and cyclooxygenase-2 (COX-2; d) in rats with collagen-induced arthritis. The intensity of the bands was quantified by densitometric analysis, and β-actin was included to ensure equal protein loading. Data are expressed as percent of control value. Each bar represents the mean ± standard error. Blots were repeated at least three times. *P < .05, **P < .01, ***P < .001 as compared with control group; ^# P < .05, ^## P < .01 as compared with arthritis group.