Possible actions (stimulatory or inhibitory) of green tea bioactive component (EGCG) in osteoblasts (OB) and osteoclasts (OC). Green tea bioactive components appear to promote bone formation by decreasing oxidative stress (ROS) and pro-inflammatory mediators (TNF-α, COX-2), and by increasing OB activity and survival (HSP27, TGFβ, Runx2, Wnt), resulting in enhanced mineralization (Runx2, osteocalcin, osterix, ALP). Green tea bioactive components suppress bone resorption by inhibiting OC formation (MMP) via increasing OC apoptosis (caspases, Fenton) that results in suppressing osteoclastogenesis. In addition, EC is involved in stimulating osteoblastogenesis, while T-cells and DC are involved in suppressing osteoclastogenesis.