Osteoblasts always express and secrete several cytokines, which
bind to receptors in osteoclasts and affect osteoclast activity in bone remodeling.
RANKL and IL-6 are two essential bone-resorbing factors
expressed in osteoblasts. After the addition of 0.3mMH2O2, the expressions
of RANKL and IL-6 increased. However, when pretreated with Rb2
of 0.1 μM, 1 μM and 10 μM, the elevated expressions of RANKL and IL-6
were, in part, inhibited (Fig. 5).