Isolation and identification of anti-osteoclastogenesis active compounds from Ilex kaushue leaves

Kudingcha is a herbal tea with a strong bitter taste and a hint of sweetness made from the leaves of the plants of the Ilex genus. In Southeast Asia, including Vietnam and China, it is used as a folk medicine because of its thirst-quenching, expectorant, vision-restoring, and detoxifying properties. In this study, 13 compounds, including seven saponins and four caffeoylquinic acids, were isolated from an Ilex kaushue extract and found to inhibit osteoclast differentiation. Among the isolated compounds, a novel saponin inhibited osteoclast differentiation in a concentration-dependent manner. Furthermore, the ethyl acetate-soluble fraction, which inhibited osteoclastogenesis more strongly than other fractions, increased bone strength in SAMP6 mice. These results indicate that Kudingcha has the potential to be used as a functional food against osteoporosis.