title: Inhibitory effect of Piper betel leaf extracts on copper-mediated LDL oxidation and oxLDL-induced lipid accumulation via inducing reverse cholesterol transport in macrophages.
abstract: Piper betel leaf (PBL) has the biological capabilities of detoxification and can work as an anti-inflammatory agent and an anti-oxidant. In this study, we evaluated the anti-oxidative activity of the extract of Piper betel leaves (PBLs) on the basis of Cu(2+)-mediated oxidation, and its ability to prevent foam cell formation in a model for oxidised low density lipoprotein (oxLDL)-induced lipid accumulation in macrophages. Our data demonstrated that PBLs were able to inhibit LDL oxidation in vitro and are able to reduce the lipid accumulation in macrophages. We showed the underlying mechanisms to be the following: PBLs up-regulated the protein levels of the class A and class B scavenger receptors, the membrane lipid transporter ABCA1, and its upstream regulator Liver X receptor (LXR) in the macrophages exposed to oxLDL. The results suggested that PBLs activated the reverse cholesterol transport mechanism to enhance the metabolism of the oxLDL that could prevent both lipid accumulation and foam cell formation and further minimise the possible damage of vessels caused by the oxLDL.
authors.affiliation: Institute of Biochemistry and Biotechnology, College of Medicine, Chung Shan Medical University, Taichung, Taiwan. 128729@cch.org.tw
authors.forename: Gwo-Chin
authors.initials: GC
authors.lastname: Ma
authors.forename: Pei-Fang
authors.initials: PF
authors.lastname: Wu
authors.forename: Hsien-Chun
authors.initials: HC
authors.lastname: Tseng
authors.forename: Charng-Cherng
authors.initials: CC
authors.lastname: Chyau
authors.forename: Hsiu-Chin
authors.initials: HC
authors.lastname: Lu
authors.forename: Fen-Pi
authors.initials: FP
authors.lastname: Chou
mesh_terms: D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002784:Cholesterol / Q000378:metabolism*; D003300:Copper / Q000378:metabolism; D005487:Foam Cells / Q000187:drug effects / Q000378:metabolism; D050356:Lipid Metabolism / Q000187:drug effects*; D008077:Lipoproteins, LDL / Q000378:metabolism*; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D010084:Oxidation-Reduction; D031701:Piper / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry
chemical_list: D008077:Lipoproteins, LDL; D010936:Plant Extracts; C099252:oxidized low density lipoprotein; D003300:Copper; D002784:Cholesterol
keywords: Atherosclerosis; Oxidised low density lipoprotein; Piper betel leaf; Reverse cholesterol transport