Pterosin Sesquiterpenoids from Pteris cretica as Hypolipidemic Agents via Activating Liver X Receptors

Four new pterosin sesquiterpenoids (1-4), a new ent-kaurane diterpenoid (17), and 18 known compounds were isolated from the aerial parts of Pteris cretica L. The structures of the isolates were elucidated based on spectroscopic data analysis, and their absolute configurations were determined by comparison of experimental and calculated electronic circular dichroism spectra. The compounds were evaluated for lipid-lowering effects in 3T3-L1 adipocytes. Compounds 4, 8, 17, and 22 were more potent than the positive control, berberine, in decreasing triglycerides activity, with compound 4 exerting the most potent activity. Compound 4 activated LXRα/β in a HEK 293T cell-based reporter gene assay. Molecular dynamic simulations revealed that compound 4 activates liver X receptors (LXRs) through hydrogen bonding with the residues of LXRα/β, suggesting that compound 4 reduces total triglycerides through the regulation of LXRα/β.