Currently, HMG-CoA reductase inhibitors (statins) are the primary drugs to treat hypercholesterolemia. This class of drugs potently lowers serum LDL-cholesterol mainly through increased hepatic LDL receptor (LDLR) expression by activation of LDLR transcription. Statins effectively reduce elevated LDL-c and lessen the risk of coronary heart disease and related cardiovascular events. However, despite the success with statin treatments, a significant number of hypercholesterolemic patients do not achieve an acceptable plasma cholesterol level by a single drug therapy, and some patients do not tolerate statins owing to symptoms of muscle pain and muscle weakness caused by statins dose-dependently. Thus, in these cases, combination therapy by two agents with different modes of action might result in a better cholesterol-lowering effect with an improved efficacy of statins. We have identified Berberine (BBR), a compound originally isolated from the Chinese herb Hunglian as a novel upregulator of hepatic LDLR. We demonstrated that BBR strongly increased the hepatic LDLR expression by increasing the LDLR mRNA stability. We also demonstrated the effectiveness of BBR in reducing plasma cholesterol and LDL-c in hypercholesterolemic patients without side effects in a placebo-controlled clinical study. Recently, we have further identified that the BBR-containing medicinal plant extract goldenseal is a potent lipid-lowering natural product. Goldenseal strongly increases LDLR expression in HepG2 cells and effectively lowers plasma cholesterol and LDL-c in hyperlipidemic hamsters. Based upon these mechanistic and clinical studies, we hypothesize that BBR and its natural product goldenseal are promising candidates for statin combination therapy in treating hypercholesterolemic patients. The overall objectives of this new R21 proposal are to explore potential applications of the pure compound BBR and the crude extract goldenseal in combination therapy with current cholesterol lowering drug statins.
The specific aims of this new proposal are to: 1) Use the human ApoB/CETP double trasnsgenic mice, which have a lipid profile similar to humans, as an vivo animal model to determine if the herbal medicine goldenseal or the pure compound BBR is capable of potentiating the lipid lowering effects of fluvastatin and ameliorating the side effects of fluvastatin in damaging hepatic functions; and 2) We will examine the effects of BBR and goldenseal on fluvastatin pharmacokinetics to determine whether drug interactions occur in animals co-administered with statin and BBR. These proposed studies are exploratory and highly innovative. The success of these studies will ultimately benefit patients by offering more choices for their individual needs in reducing plasma cholesterol levels to prevent atherosclerotic cardiovascular disease. ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Center for Complementary & Alternative Medicine (NCCAM)
Type
Exploratory/Developmental Grants (R21)
Project #
1R21AT003195-01A2
Application #
7304583
Study Section
Special Emphasis Panel (ZAT1-DB (26))
Program Officer
Moen, Laura K
Project Start
2008-03-15
Project End
2010-02-28
Budget Start
2008-03-15
Budget End
2009-02-28
Support Year
1
Fiscal Year
2008
Total Cost
$210,000
Indirect Cost
Name
Palo Alto Institute for Research & Edu, Inc.
Department
Type
DUNS #
624218814
City
Palo Alto
State
CA
Country
United States
Zip Code
94304
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Singh, Amar Bahadur; Li, Hai; Kan, Chin Fung Kelvin et al. (2014) The critical role of mRNA destabilizing protein heterogeneous nuclear ribonucleoprotein d in 3' untranslated region-mediated decay of low-density lipoprotein receptor mRNA in liver tissue. Arterioscler Thromb Vasc Biol 34:8-16
Dong, Bin; Kan, Chin Fung Kelvin; Singh, Amar B et al. (2013) High-fructose diet downregulates long-chain acyl-CoA synthetase 3 expression in liver of hamsters via impairing LXR/RXR signaling pathway. J Lipid Res 54:1241-54
Li, Hai; Liu, Jingwen (2012) The novel function of HINFP as a co-activator in sterol-regulated transcription of PCSK9 in HepG2 cells. Biochem J 443:757-68
Wu, Minhao; Dong, Bin; Cao, Aiqin et al. (2012) Delineation of molecular pathways that regulate hepatic PCSK9 and LDL receptor expression during fasting in normolipidemic hamsters. Atherosclerosis 224:401-10
Dong, Bin; Wu, Minhao; Cao, Aiqin et al. (2011) Suppression of Idol expression is an additional mechanism underlying statin-induced up-regulation of hepatic LDL receptor expression. Int J Mol Med 27:103-10
Cao, Aiqin; Wu, Minhao; Li, Hai et al. (2011) Janus kinase activation by cytokine oncostatin M decreases PCSK9 expression in liver cells. J Lipid Res 52:518-30
Wu, Minhao; Cao, Aiqin; Dong, Bin et al. (2011) Reduction of serum free fatty acids and triglycerides by liver-targeted expression of long chain acyl-CoA synthetase 3. Int J Mol Med 27:655-62
Dong, Bin; Wu, Minhao; Li, Hai et al. (2010) Strong induction of PCSK9 gene expression through HNF1alpha and SREBP2: mechanism for the resistance to LDL-cholesterol lowering effect of statins in dyslipidemic hamsters. J Lipid Res 51:1486-95
Li, Hai; Liu, Jingwen (2010) Identification of heterogeneous nuclear ribonucleoprotein K as a transactivator for human low density lipoprotein receptor gene transcription. J Biol Chem 285:17789-97

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