Figure 1.

Study design of the AIA experiment. Male C57BL/6 mice aged 10–12 weeks were immunized at each side of the knee articular cavity on day 0, and second immunizations were performed on day 21. From day 2 to day 31 after immunization, mice were administered with oral gavage Tan IIA once a day consecutively, as described in the Materials and Methods. Body weight and knee joint diameter were measured every 5 days. Blood samples for proinflammatory cytokine analysis were collected on days 40, 48, 56, and 80. The mice were euthanized at day 80, and bone, spleen, liver, and serum samples were collected. Histopathological analysis was performed on the bones of knee joints. Spleen and liver indices were calculated by weighing spleen and liver. Serum samples were subjected to ELISA assay.