Norepinephrine-augmenting lipolytic effectors from Astilbe thunbergii rhizomes

An EtOAc-soluble fraction from a 80% Me2CO extract of the rhizomes of Astilbe thunbergii enhanced norepinephrine-induced lipolysis in rat fat cells, while an EtOAc-insoluble fraction had no effect. The active substances isolated from the EtOAc-soluble fraction of the rhizomes were identified as eucryphin (1), bergenin (2), and astilbin (3), which enhanced norepinephrine-induced lipolysis at concentrations of 10-1000 microgram/mL, while they themselves did not cause lipolysis. Furthermore, these compounds slightly stimulated adrenocorticotrophic hormone-induced lipolysis and inhibited insulin-induced lipogenesis from glucose.