Yan Zhou

Xuzhou Medical College, Suchow, Jiangsu Sheng, China

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Publications (2)4.55 Total impact

  • [show abstract] [hide abstract]
    ABSTRACT: Berberine (BBR) is an isoquinoline alkaloid isolated from several Chinese herbal medicines, such as Coptis chinensis, Berberis aristata, and Coptis japonica. It exhibits a lipid-lowering effect by up-regulating hepatic low density lipoprotein receptor (LDLR) expression. However, the plasma concentration of BBR is very low after oral administration for the reason that BBR is poorly absorbed and rapidly metabolized. Therefore, it is hard to explain the pharmacological effects of BBR in vivo. Here, RT-PCR, Western blotting and Oil Red O staining were used to investigate the effects of four BBR metabolites on LDLR expression and lipid accumulation in human hepatoma Hep G2 cells. Our results suggested that BBR increased LDLR mRNA and protein levels in a time- and dose-dependent manner. Four metabolites of BBR, Jatrorrhizin, Columbamine, Berberubine and Demethyleneberberine, were found to be able to up-regulate LDLR mRNA and protein expression. Moreover, almost all the metabolites had potent effects on inhibiting cellular lipid accumulation. These results suggest that both BBR and its metabolites exhibit lipid-lowering effects by up-regulating LDLR expression, and BBR and its metabolites might be the in vivo active forms of BBR produced after oral administration. This study provides information to help us understand the mechanisms underlying the hypolipidemic effects of BBR in vivo.
    Fitoterapia 12/2013; · 2.23 Impact Factor
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    ABSTRACT: Rhizoma Coptidis (Huanglian in Chinese) is commonly used in Chinese folk medicine to treat diarrhea, diabetes, hypertension, hyperlipidemia and tumours. This herb has increasingly gained attention because of its use as a hypolipidemic herb. Berberine (BBR) is the most important constituent of Rhizoma Coptidis that contribute to the pharmacological efficacy of the herb. Pharmacokinetic studies have indicated that BBR has poor oral bioavailability. Interestingly, several reports show that absorbed BBR is extensively metabolized in rats and humans. We speculate that the BBR metabolites might be responsible for the pharmacological effects. The aim of this study is to examine BBR metabolites for their triglyceride (TG)-lowering activities and the molecular mechanism to clarify BBR genuine effective forms in vivo. Four BBR metabolites were examined their TG-lowering effects with a commercial triglyceride assay kit. Real-time PCR and Western blotting were used to confirm genes and proteins of interest, respectively. Among those BBR metabolites, M2 exhibited the more potential effects on TG-lowering and AMP-activated protein kinase (AMPK) activation in Hep G2 cells as compared with BBR. Moreover, BBR and M2 inhibited gene expressions of acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), glycerol-3-phosphate acyltransferase (GPAT) and 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR), but motivated gene expression of medium chain acyl-CoA dehydrogenase (mCAD) significantly. The results suggested that the TG-lowering effects of BBR and M2 might be partially mediated by the up-regulation of lipolysis gene expressions and down-regulation of lipogenesis gene expressions through activation of the AMPK signaling pathway. BBR and its metabolites might be in vivo active forms of oral doses of BBR, and M2 might be a promising drug candidate against hyperlipidemia.
    Journal of ethnopharmacology 07/2013; · 2.32 Impact Factor