Hyuganatsu orange (Citrus tamurana Hort. Ex Tanaka) contains a water soluble substance that suppresses bone loss in ovariectomized rats.

We investigated whether Hyuganatsu orange (Citrus tamurana Hort. ex Tanaka) contains water and acetic-acid soluble substances that increase bone mineral density (BMD) in ovariectomized rats. In in vivo study, femoral BMD can significantly increased. In in vitro study, tartrate-resistant acid phosphatase (TRAP) positive cells significantly decreased. We speculate that Hyuganatsu orange contains biologically active substances other than hesperidin that increase BMD.