Identification of two herbal compounds with potential cholesterol-lowering activity.

Low-density lipoprotein receptor (LDLR) plays a pivotal role in the control of plasma LDL-cholesterol level. This occurs predominantly at the transcriptional level through two gene regulation elements, named SRE: sterol-responsive element and SIRE: sterol-independent responsive element. We have developed a high-throughput screening using LDLR promoter activation-based assay to search for cholesterol-lowering compounds from a Chinese herb-based natural compound library. With this approach, we identified two compounds, named Daphnetoxin and Gniditrin, from Chinese herb Daphne giraldii Nitsche, which could activate LDLR promoter. Characterization of these compounds showed that they increased the level of LDLR mRNA and consequently up-regulate LDLR expression. The structures of these compounds are different from well-known LDLR promoter activating compounds such as GW707. The results suggested that these herbal compounds could represent good candidates for development of new classes of cholesterol-lowering drugs.