The effects of phenolic glycosides from <i>Betula platyphylla</i> var. <i>japonica</i> on adipocyte differentiation and mature adipocyte metabolism

<p><i>Betula platyphylla</i> var. <i>japonica</i> (Betulaceae) has been used traditionally in Asian countries for the treatment of inflammatory diseases. A recent study has reported a phenolic compound, platyphylloside from <i>B. platyphylla</i>, that shows inhibition on adipocyte differentiation and induces lipolysis in 3T3-L1 cells. Based on this finding, we conducted phytochemical analysis of the EtOH extract of the bark of <i>B. platyphylla</i> var. <i>japonica,</i> which resulted in the isolation of phenolic glycosides (<b>1</b>–<b>4</b>). Treatment of the isolated compounds (<b>1</b>–<b>4</b>) during adipocyte differentiation of 3T3-L1 mouse adipocytes resulted in dose-dependent inhibition of adipogenesis. In mature adipocytes, arylbutanoid glycosides (<b>2</b>–<b>4</b>) induced lipolysis related genes HSL and ATGL, whereas catechin glycoside (<b>1</b>) had no effect. Additionally, arylbutanoid glycosides (<b>2</b>–<b>4</b>) also induced GLUT4 and adiponectin mRNA expression, indicating improvement in insulin signaling. This suggests that the isolates from <i>B. platyphylla</i> var. <i>japonica</i> exert benefial effects in regulation of adipocyte differentiation as well as adipocyte metabolism.</p>