Administration of FLL to OVX rats improves bone quality through inhibiting NF-κB activation and then scavengering abundant ROS via preventing Nox4 expression as well as resuming mitochondria function, suggesting FLL may serve as a natural antioxidant agent against osteoporosis by a direct regulation of Nox4/ROS/NF-κB signaling in OVX rats. The gene discussed is NOX4; the disease is osteoporosis.