Fig. 1
CIA induction and EGCG administration in CII-immunized DBA/1 J mice. a Effects of EGCG on arthritis score of CIA mice. DBA1/J mice (DBA-1) were untreated or immunized with 100ug CII in complete CFA. A booster injection of 100 ug of CII was given on day 14 to induce CIA in mice. Beginning on day 21 post CII immunization, 10 mg/kg EGCG was administered orally using oral gavage for nine successive times every two days over the course of three weeks. PBS was given to the CIA control group over the same time period. Mice were sacrificed on day 49 for immunophenotypic analysis and histopathological examination, *P < 0.05, **P < 0.01. N = 4 to 5 mice per group for each experiment, with a total of 14 mice per group; *P < 0.05; **P < 0.01. N = 14 mice for each group. Data shown is representative of three independent experiments. b Effects of EGCG on paw swelling of CIA mice. Mice were untreated DBA-1 or immunized with CII as described above and treated with PBS (vehicle) or EGCG. All data are shown as mean ± SEM of three independent experiments. N = 4 to 5 mice per group for each experiment, with a total of 14 mice per group. c Representative photographs depicting vehicle-fed (upper) and EGCG-fed CIA mice (lower) on day 49 after 1st immunization. d Histopathology of paw and knee joints from representative CIA mice treated with vehicle (left) or EGCG (right). Joints were harvested on day 49 and joints were decalcified and stained with H&E (original magnification × 40). Five mice were examined per group. e Values of histological scores are shown as mean ± SEM derived from five mice per group for synovial inflammatory infiltrate, cartilage degradation and bone erosion. f Serum titers of CII-specific IgG2a were detected by ELISA in the individual EGCG (n = 14) or vehicle-fed mice (n = 14). Serum samples were obtained on day 49 post first CII immunization. The results were calculated in arbitrary units and are expressed as mean ± SD of three independent experiments, ∗∗P < 0.01