α-Tocotrienol inhibits osteoclastic bone resorption by suppressing RANKL expression and signaling and bone resorbing activity

► α-TT but not α-TP inhibits RANKL expression in osteoblasts. ► α-TT inhibits RANKL-induced osteoclastogenesis by suppressing c-Fos expression in precursors. ► α-TT suppresses RANKL-induced ERK and delayed NF-κB activation. ► α-TT but not α-TP reduces bone-resorbing activity of mature osteoclasts.