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Isolation and identification of two galangin metabolites from rat urine and determination of their in vitro hypolipidemic activity


Xuguang Zhang
Shouqian Cheng
Hailong Li
Xiaopo Zhang
Feng Chen
Youbin Li
Junqing Zhang
Yinfeng Tan

Abstract

Purpose: To investigate the lipid-lowering activity of two metabolites of galangin, namely, galangin-3-O-β-D-glucuronic acid (GG-1) and galangin-7-O-β-D-glucuronic acid (GG-2).
Methods: Female Sprague-Dawley rats were orally administered with galangin. The two metabolites of galangin were isolated from urine sample and purified using Sephadex LH-20 and semi-preparative high performance liquid chromatography (HPLC). The structures of the metabolites were identified by analyzing spectroscopic data. Hypolipidemic activity was evaluated in HepG2 cells. The down- or upregulation of lipogenic genes was detected using real-time quantitative polymerase chain reaction (qPCR).
Results: Both metabolites of galangin showed hypolipidemic activity. These  activities are closely associated with the down-regulation of lipogenic genes such as SREBP-1a, SREBP-1c, and SREBP-2 transcription factors, and the downstream genes such as FAS, ACC, and HMGR were revealed by realtime qPCR data.
Conclusion: The results show that both metabolites possess better lipid-lowering activities than galangin. These hypolipidemic activities are closely associated with inhibiting key genes or proteins that regulated the biosynthesis of both cholesterol and triglycerides.

Keywords: Galangin, Galangin-3-O-β-D-glucuronic acid, Galangin-7-O-β- D-glucuronic acid, Hypolipidemic, Lipogenic genes, Metabolites


Journal Identifiers


eISSN: 1596-9827
print ISSN: 1596-5996