Protective Effect of Ginger (Zingiber officinale Roscoe) Extract against Oxidative Stress and Mitochondrial Apoptosis Induced by Interleukin-1ß in Cultured Chondrocytes.

ABSTRACT

AIMS: The protective effects of ginger (Zingiber officinale Roscoe) extract on IL-1ß-mediated oxidative stress and mitochondrial apoptosis were investigated in C28I2 human chondrocytes. METHODS: The effects of various concentrations of ginger extract on C28I2 human chondrocyte viability were evaluated in order to obtain noncytotoxic concentrations of the drug by methylthiotetrazole assay. The cells were pretreated with 5 and 25 µg/mL ginger extract for 24 h, followed by incubation with IL-1ß (10 ng/mL) for 24 h. The effects of ginger extract on IL-1ß-induced intracellular reactive oxygen species (ROS) production and lipid peroxidation were examined. The mRNA expressions of antioxidant enzymes including catalase, superoxide dismutase-1, glutathione peroxidase-1, glutathione peroxidase-3, and glutathione peroxidase-4 were evaluated by reverse transcription polymerase chain reaction. The protein expressions of Bax, Bcl-2, and caspase-3 were analyzed by Western blotting. RESULTS: No cytotoxicity was observed at any concentration of ginger extract in C28I2 cells. Ginger extract pretreatment remarkably increased the gene expression of antioxidant enzymes and reduced the IL-1ß-induced elevation of ROS, lipid peroxidation, the Bax/Bcl-2 ratio, and caspase-3 activity. CONCLUSIONS: Ginger extract could considerably reduce IL-1ß-induced oxidative stress and consequent mitochondrial apoptosis as the major mechanisms of chondrocyte cell death. These beneficial effects of ginger extract may be due to its antioxidant properties. It may be considered as a natural herbal product to prevent OA-induced cartilage destruction in the clinical setting.