Epiberberine

Epiberberine reduces serum cholesterol in diet-induced dyslipidemia Syrian golden hamsters via network pathways involving cholesterol metabolism.[Pubmed: 26593426 ]

Eur J Pharmacol. 2016 Mar 5;774:1-9.

This study aimed to evaluate the cholesterol-lowering effect of Epiberberine in dyslipidemia Syrian golden hamsters induced by high fat and high cholesterol (HFHC) diet and its regulation mechanism on some key genes involved in cholesterol metabolism.
METHODS AND RESULTS:
Hamsters were divided into six groups: normal control group (NC), HFHC group, simvastatin (Sim) and three doses of Epiberberine group. The body weight, organs weight and serum lipid levels, as well as total cholesterol (TC) and total bile acids (TBA) levels in liver and feces were determined. Furthermore, the antidyslipidemia effect of Epiberberine on key genes involved in cholesterol biosynthesis, uptake, conversion and elimination such as 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), low density lipoprotein receptor (LDL receptor), 7-alpha-hydroxylase (CYP7A1) and apical sodium dependent bile acid transporter (ASBT) were investigated. The results showed that Epiberberine at high dosage significantly reduced serum TC, low density lipoprotein cholesterol (LDL-c) and TBA levels by 20.2%, 22.3% and 43.8%, respectively, and increased TBA and TC levels in feces. Epiberberine inhibited HMGCR mRNA and protein expressions and slightly reduced the protein level of ASBT, as well as dramatically up-regulated mRNA and protein expressions of CYP7A1 and LDL receptor.
CONCLUSIONS:
These findings suggested that the antidyslipidemia effects of Epiberberine can be achieved via inhibiting the synthesis of cholesterol, promoting the uptake and conversion of TC in liver and increasing the excretion of TC and TBA in feces. Thus, Epiberberine should be considered as one of the promising natural drugs for the treatment of dyslipidemia.

Anti-Alzheimer and antioxidant activities of Coptidis Rhizoma alkaloids.[Pubmed: 19652386]

Biol Pharm Bull. 2009 Aug;32(8):1433-8.

Coptidis Rhizoma and its isolated alkaloids are reported to possess a variety of activities, including neuroprotective and antioxidant effects.
METHODS AND RESULTS:
Thus, the anti-Alzheimer and antioxidant effects of six protoberberine alkaloids (berberine, palmatine, jateorrhizine, Epiberberine, coptisine, and groenlandicine) and one aporphine alkaloid (magnoflorine) from Coptidis Rhizoma were evaluated via beta-site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1), acetylcholinesterase (AChE), and butyrylcholinesterase (BChE) assays, along with peroxynitrite (ONOO(-)) scavenging and total reactive oxygen species (ROS) inhibitory assays. Six protoberberine alkaloids exhibited predominant cholinesterases (ChEs) inhibitory effects with IC(50) values ranging between 0.44-1.07 microM for AChE and 3.32-6.84 microM for BChE; only Epiberberine (K(i)=10.0) and groenlandicine (K(i)=21.2) exerted good, non-competitive BACE1 inhibitory activities with IC(50) values of 8.55 and 19.68 microM, respectively. In two antioxidant assays, jateorrhizine and groenlandicine exhibited significant ONOO(-) scavenging activities with IC(50) values of 0.78 and 0.84 microM, respectively; coptisine and groenlandicine exhibited moderate total ROS inhibitory activities with IC(50) values of 48.93 and 51.78 microM, respectively. These results indicate that Coptidis Rhizoma alkaloids have a strong potential of inhibition and prevention of Alzheimer's disease (AD) mainly through both ChEs and beta-amyloids pathways, and additionally through antioxidant capacities. In particular, groenlandicine may be a promising anti-AD agent due to its potent inhibitory activity of both ChEs and beta-amyloids formation, as well as marked ONOO(-) scavenging and good ROS inhibitory capacities.
CONCLUSIONS:
As a result, Coptidis Rhizoma and the alkaloids contained therein would clearly have beneficial uses in the development of therapeutic and preventive agents for AD and oxidative stress-related disease.

Identification of metabolites of epiberberine in rat liver microsomes and its inhibiting effects on CYP2D6.[Pubmed: 25612454]

Zhongguo Zhong Yao Za Zhi. 2014 Oct;39(19):3855-9.

Epiberberine, one of the most important isoquinoline alkaloid in Coptidis Rhizoma, possesses extensive pharmacological activities. In this paper, the liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to study phase I and phase II metabolites.
METHODS AND RESULTS:
A Thermo HPLC system (including Surveyor AS, Surveyor LC Pump, Surveyor PDA. USA) was used. The cocktail probe drugs method was imposed to determine the content change of metoprolol, dapsone, phenacetin, chlorzoxazone and tolbutamide simultaneously for evaluating the activity of CYP2D6, CYP3A4, CYP1A2, CYP2E1 and CYP2C9 under different concentrations of Epiberberine in rat liver microsomes. The result showed that Epiberberine may have phase I and phase II metabolism in the rat liver and two metabolites in phase I and three metabolites in phase II are identified in the temperature incubation system of in vitro liver microsomes. Epiberberine showed significant inhibition on CYP2D6 with IC50 value of 35.22 μmol L(-1), but had no obvious inhibiting effect on the activities of CYP3A4, CYP1A2, CYP2E1 and CYP2C9.
CONCLUSIONS:
The results indicated that Epiberberine may be caused drug interactions based on CYP2D6 enzyme. This study aims to provide a reliable experimental basis for its further research and development of Epiberberine.

Anti-adipogenic effect of epiberberine is mediated by regulation of the Raf/MEK1/2/ERK1/2 and AMPKα/Akt pathways.[Pubmed: 26119076 ]

Arch Pharm Res. 2015 Jun 29.

It has been reported that alkaloids derived from Coptis chinensis exert anti-adipogenic activity on 3T3-L1 adipocytes by downregulating peroxisome proliferation-activity receptor-γ (PPAR-γ) and CCAAT/enhancer binding protein-α (C/EBP-α). However, the signaling-based mechanism of the inhibitory role of Epiberberine in the early stages of 3T3-L1 adipocyte differentiation is uncharacterized.
METHODS AND RESULTS:
Here, we show that Epiberberine had inhibitory effects on adipocyte differentiation and significantly decreased lipid accumulation by downregulating an adipocyte-specific transcription factor, sterol regulatory element-binding protein-1 (SREBP-1). Furthermore, we observed that Epiberberine markedly suppressed the differentiation-mediated phosphorylation of components of both the Raf/mitogen-activated protein kinase 1 (MEK1)/extracellular signal-regulated protein kinase 1/2 (ERK1/2) and AMP-activated protein kinase-α1 (AMPKα)/Akt pathways. In addition, gene expression of fatty acid synthase (FAS) was significantly inhibited by treatment with Epiberberine during adipogenesis. These results indicate that the anti-adipogenic mechanism of Epiberberine is associated with inhibition of phosphorylation of Raf/MEK1/ERK1/2 and AMPKα/Akt, followed by downregulation of the major transcription factors of adipogenesis, such as PPAR-γ, C/EBP-α, and SREBP-1, and FAS.
CONCLUSIONS:
Taken together, this study suggests that the anti-adipogenic effect of Epiberberine is mediated by downregulation of the Raf/MEK1/ERK1/2 and AMPKα/Akt pathways during 3T3-L1 adipocyte differentiation. Moreover, the anti-adipogenic effects of Epiberberine were not accompanied by modulation of β-catenin.

Anal Chem. 2015 Jan 6;87(1):730-7.

Selective lighting up of epiberberine alkaloid fluorescence by fluorophore-switching aptamer and stoichiometric targeting of human telomeric DNA G-quadruplex multimer.[Pubmed: 25429435 ]

Aptamers, that exist naturally in living cells as functional elements and can switch nonfluorescent natural targets to fluorophores, are very useful in developing highly sensitive and selective biosensors and screening functional agents.
METHODS AND RESULTS:
This work demonstrates that human telomeric G-quadruplex (HTG) can serve as a potential fluorophore-switching aptamer (FSA) to target a natural isoquinoline alkaloid. We found that, among the G-quadruplexes studied here and the various structurally similar alkaloids including Epiberberine (EPI), berberine (BER), palmatine (PAL), jatrorrhizine (JAT), coptisine (COP), worenine (WOR), sanguinarine (SAN), chelerythrine (CHE), and nitidine (NIT), only the HTG DNA, especially with a 5'-TA-3' residue at the 5' end of the G-quadruplex tetrad (5'-TAG3(TTAG3)3-3', TA[Q]) as the minimal sequence, is the most efficient FSA to selectively light up the EPI fluorescence. Compared to the 5' end flanking sequences, the 3' end flanking sequences of the tetrad contribute significantly less to the recognition of EPI. The binding affinity of EPI to TA[Q] (K(d) = 37 nM) is at least 20 times tighter than those of the other alkaloids. The steady-state absorption, steady-state/time-resolved fluorescence, and NMR studies demonstrate that EPI most likely interact with the 5' end flanking sequence substructure beyond the core [Q] and the G-quadruplex tetrad in a much more specific manner than the other alkaloids. The highly selective and tight binding of EPI with the FSA and significantly enhanced fluorescence suggest the potential development of a selective EPI sensor (detection limit of 10 nM). More importantly, EPI, as the brightest FSA emitter among the alkaloids, can also serve as an efficient conformation probe for HTG DNA and discriminate the DNA G-quadruplex from the RNA counterpart. Furthermore, EPI can bind stoichiometrically to each G-quadruplex unit of long HTG DNA multimer with the most significant fluorescence enhancement, which has not been achieved by the previously reported probes.
CONCLUSIONS:
Our work suggests the potential use of EPI as a bioimaging probe and a therapeutic DNA binder.