Soy Isoflavones and Bone Health: Focus on the RANKL/RANK/OPG Pathway

Figure 1

Aging, estrogen deficiency, vitamin D deficiency, and recent fracture are related to osteoporotic fractures incidence. The balance of the OPG and RANKL is vital in bone homeostasis. RANKL binds to RANK, allowing the activation osteoclasts. Mature osteoclast adheres to the bone surface and promotes bone resorption. Soy isoflavones supplementation decrease RANKL/OPG ratio by reducing RANKL and increasing OPG. OPG is bound to RANKL and subsequently inhibits RANK activation. It stops the activation of osteoclasts and decreases osteoclastogenesis. Thus the subsequent bone formation begins. (RANK: receptor activator of NF-κB; RANKL: receptor activator of NF-κB ligand; OPG: osteoprotegerin).