Salviaflaside in water-soluble fraction of heated water extracted from defatted Perilla frutescens Britton var. japonica Hara seed residue suppresses osteoclast differentiation.

Polyphenols have physiological effects, such as antioxidant and anti-inflammatory effects, and have been reported to associated with osteoporosis and inflammatory diseases. Rosmarinic acid is a natural polyphenol contained in Lamiaceae herbs, such as perilla, sage, and sweet basil. Salviaflaside is a glycosidized compound of rosmarinic acid. It was one of the major components of the defatted Perilla frutescens Britton var. japonica Hara (egoma) seed residue extract. In this study, we investigated the anti-osteoporotic effects of the water-soluble layer fraction of egoma residue heated water extract (DPH-W) and salviaflaside on bone marrow-derived macrophages (BMMs). DPH-W reduced the number of tartrate-resistant acid phosphatase (TRAP) positive osteoclasts in BMM treated with receptor-activated nuclear factor kappa B ligand (RANKL). The mRNA expression levels of NFATc1 and CTSK, which are responsible for osteoclast differentiation and bone resorption, were suppressed. Salviaflaside decreased TRAP activity and suppressed the expression of osteoclast differentiation-related genes. Our findings indicate that egoma seed residue and salviaflaside may have potential as a useful therapeutic or prophylactic agent for the suppression of bone loss.