Beneficial effects of hyperoside on bone metabolism in ovariectomized mice

Hyperoside, an active flavonoid glycoside isolated from many traditional Chinese medicines, has received much attention because of its potential role in osteoporosis treatment. In the present study, we investigated the antiosteoporotic role and mechanism of hyperoside on ovariectomized (OVX) mice. Sixty female Kunming mice received one of three treatments orally for 12 weeks: estradiol valerate (0.3 mg/kg body weight/day), hyperoside (20, 40, or 80 mg/kg body weight/day), or vehicle. We found that hyperoside was effective in preventing osteoporosis by increasing bone mineral density, restoring trabecular bone micro-architecture, and enhancing bone strength. Meanwhile, the activities of bone resorption markers, including tartrate-resistant acid phosphatase 5b (TRAP-5b) and C-terminal telopeptide of type I collagen (CTX), were significantly decreased, while the bioactivity of bone formation markers, osteocalcin (OC) and bone-specific alkaline phosphatase (BALP), were significantly increased. Mechanistically, hyperoside reduced the expression of receptor activator of nuclear factor-kappa B ligand (RANKL), TNF-receptor-associated factor 6 (TRAF6), phosphorylated inhibitor of nuclear factor-kappa B a (I kappa B alpha), NF-kappa B p65, and nuclear factor of activated T cell cytoplasmic 1 (NFATc1) and promoted the expression of osteoprotegerin (OPG). Therefore, the function of hyperoside might be related to the inhibition of the TRAF-6 mediated RANKL/RANK/NF-kappa B signaling pathway and the elevation of the OPG/RANKL ratio. These data demonstrated that hyperoside has potential applications as a drug for osteoporosis treatment.