Barley Seedling Extracts Inhibit RANKL-Induced Differentiation, Fusion, and Maturation of Osteoclasts in the Early-to-Late Stages of Osteoclastogenesis

The number of patients with osteoporosis is increasing worldwide, and a decrease in bone mass is a main risk factor for fracture. The prevention of bone loss is critical for improving the quality of life for patients. However, the long-term use of antiosteoporotic agents is limited due to their side effects. Barley has been traditionally ingested for thousands of years as a safe, natural food with pharmaceutical properties, and its seedling can enhance the biological activity of the medicinal components found in food. This study aimed to clarify the antiresorptive activity of barley seedling and its mode of action. Barley seedling extracts (BSE) dose-dependently inhibited RANKL-induced osteoclast differentiation with alteration of IκB degradation, c-Fos, and NFATc1 molecules in the early-to-middle stages of osteoclastogenesis. In the late phase of osteoclastogenesis, BSE also prevented DC-STAMP and cathepsin K, which are required for cell fusion and bone degradation, such as osteoclast function. In conclusion, barley seedling from natural foods may provide long-term safety and be useful for the prevention or treatment of osteoclast-mediated bone metabolic diseases, including osteoporosis.