Hot-water extract of defatted Perilla frutescens seed residue suppresses osteoclast differentiation and improves...

The defatted residue of Perilla frutescens seeds, a by-product of edible oil production, remains largely underutilized in food applications. This study investigated the effects of a hot-water extract derived from this residue on osteoclast differentiation and bone-related changes. In bone marrow-derived macrophages, the extract inhibited receptor activator of nuclear factor-κB ligand-induced osteoclast differentiation, as evidenced by the reduced formation of tartrate-resistant acid phosphatase-positive multinucleated cells and decreased tartrate-resistant acid phosphatase activity, without significantly affecting cell viability. In ovariectomized mice, the extract increased trabecular region length and cortical bone thickness. In a separate experiment, it enhanced femoral mechanical strength in a three-point bending test. High-performance liquid chromatography analysis identified rosmarinic acid and salviaflaside in the extract. These findings suggest that defatted Perilla frutescens seed residue may be a functional resource for improving bone health.