Figure 4

Effect of EGCG IL-6, IL-8 and TNF-α gene expression and production in IL-1β-stimulated human OA chondrocytes. Chondrocytes were pretreated with EGCG (10 to 100 μM) for 2 h and stimulated with IL-1β for (a, b) 8 h or (c, d, e, and f) 24 h. Gene expression for IL-6, IL-8 and TNF-α was determined by quantitative RT-PCR normalized to GAPDH and then compared with the levels present in un-stimulated chondrocytes. Levels of IL-6, IL-8 and TNF-α in the culture supernatants were quantified by sandwich ELISA. Value represents Mean ± SE of three different patients. # represents P < 0.05 Vs control; * P < 0.05 Vs IL-1β stimulated chondrocytes. EGCG, epigallocatechin-3-gallate; IL-interleukin; TNF, tumor necrosis factor.