Abstract:
The fruit of
Pandanus tectorius (PTF) has a long history of use as a folk medicine to treat hyperlipidemia in Hainan province, South China. Our previous studies have shown that the
n-butanol extract of PTF is rich in caffeoylquinic acids and has an adequate therapeutic effect on dyslipidemic animals induced by high-fat diet. In this work, seven caffeoylquinic acids isolated from PTF were screened for the lipid-lowering activity in HepG2 hepatoma cells. Oil-Red O staining, microscopy and intracellular triglyceride (TG) and total cholesterol (TC) quantification showed that 3-
O-caffeoylquinic acid (3-CQA), 3, 5-di-
O-caffeoylquinic acid (3, 5-CQA), and 3, 4, 5-tri-
O-caffeoylquinic acid (3, 4, 5-CQA) significantly inhibited lipid accumulation induced by oleic acid and decreased intracellular levels of TC and TG in a dose-dependent manner. These three caffeoylquinic acids showed no significant cytotoxicity at concentrations of 1-50 μmol·L
-1 as determined by MTT assay. Realtime quantitative PCR revealed that 3-CQA and 3, 5-CQA significantly increased the expression of lipid oxidation-related genes PPAR
α, CPT-1 and ACOX1 while 3-CQA, 3, 5-CQA and 3, 4, 5-CQA decreased the expression of lipogenic genes SREBP-1c, SREBP-2, HMGR, ACC, FAS. Overall, 3-CQA, 3, 5-CQA and 3, 4, 5-CQA may be the principal hypolipidemic components in PTF which can decrease intracellular lipid accumulation through up-regulating the expression of lipid oxidative genes and down-regulating the expression of lipogenic genes.