CYP1A1 and arthritic joint disease: As shown in Fig. 8, tetrandrine and DIM markedly increased the number of CYP1A1-positive cells, decreased the number of p-Syk positive cells and osteoclasts in the tibias (Fig. 8a, b), reduced the TRAP5b activity in the serum (Fig. 8c), increased the values of BMD, BV/TV and Tb.Th in the tibias, and decreased the Tb.Sp values of arthritis rats (Fig. 8d).