Identifying Natural Derived Upregulators of Human ApoA-I Expression via a Cell-Based Drug Screening System.

Apolipoprotein A-I (apoA-I), the major protein component of high-density lipoprotein, is instrumental in promoting efflux of cholesterol from extrahepatic tissues to the liver. It has been proposed that upregulation of apoA-I gene expression could have anti-atherosclerosis effects. For the purpose of screening human apoA-I expression upregulators, we established a cell-based drug screening model in vitro to identifying the effects of natural derived upregulators of apoA-I. In the work, human apoA-I promoter gene was cloned into pGL3B-neo vector containing luciferase gene and neomycin resistance gene. The recombinant reporter gene vector pGL3B-neo/apo was transfected into HepG2 cells, and therefore the stable cell line SApoA-I was obtained. These cells were treated with extracts from traditional Chinese herbs. The luciferase activities were detected to identify which ones can activate apoA-I promoter. Baicalein extracted from dried roots of Scutellaria baicalensis Georgi (Labiatae, Scutellaria) showed significant dose-dependent upregulatory activity in cell model, which might become an effective basic compound for developing novel HDL-raising drugs because of its effects on proteins involved in reverse cholesterol transport. [ABSTRACT FROM AUTHOR]