Ginger extract components suppress induction of chemokine expression in human synoviocytes

Introduction: Ginger has a long history of medicinal use, particularly as an anti-inflammatory agent for a wide variety of diseases such as arthritis. Suppression of inflammation in arthritis is attributed to suppression of proinflarnmatory cytokines and chemokines produced by synoviocytes, chondrocytes, and leukocytes. Objective: This study aimed to elucidate the effect of a combination ginger extract and its individual components on chemokine expression in human synoviocytes. Methods: Human synoviocytes were incubated with 100 mug/mL combination ginger extract (GE) of Alpinia galanga (AG) and Zingiber officinale (ZO); AG extract alone; ZO extract alone; or control media, for I hour at 37degreesC, 5% CO2. Cells were next activated with 1 ng/mL of tumor necrosis factor alpha (TNF-alpha) for 1 hour to determine macrophage chemotactic factor (MCP-1) and interferon-gamma activated protein (IP-10) mRNA levels using reverse transcriptase polymerase chain reaction (RT-PCR). Secreted MCPA and IP-10 were quantified by enzyme-linked immunosorbent assay (ELISA) following a 24 hour incubation period. Results: The GE combination was consistently more effective in decreasing chemokine mRNA and chemokine secreted protein levels than its individual components ZO or AG. In comparison, ZO was more effective than AG in suppressing chemokine expression. Conclusion: The present study demonstrates that GE inhibits chemokine expression, and that the combination of ZO and AG components acts synergistically. This ginger formulation may be useful for suppressing inflammation due to arthritis.