Monascus-fermented red mold dioscorea protects mice against alcohol-induced liver injury, whereas its metabolites ankaflavin and monascin regulate ethanol-induced peroxisome proliferator-activated receptor-γ and sterol regulatory element-binding transcrip

2017 ◽  
Vol 98 (5) ◽  
pp. 1889-1898 ◽  
Author(s):  
Chih-Fu Cheng ◽  
Tzu-Ming Pan
2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Chia Ju Chang ◽  
Thing-Fong Tzeng ◽  
Shorong-Shii Liou ◽  
Yuan-Shiun Chang ◽  
I-Min Liu

The aim of this study was to investigate the antiobesity and antihyperlipidaemic effects of myricetin. Myricetin exhibited a significant concentration-dependent decrease in the intracellular accumulation of triglyceride in 3T3-L1 adipocytes. The high-fat diet (HFD)-fed rats were dosed orally with myricetin or fenofibrate, once daily for eight weeks. Myricetin (300 mg kg−1per day) displayed similar characteristics to fenofibrate (100 mg kg−1per day) in reducing lowered body weight (BW) gain, visceral fat-pad weights and plasma lipid levels of HFD-fed rats. Myricetin also reduced the hepatic triglyceride and cholesterol contents, as well as lowered hepatic lipid droplets accumulation and epididymal adipocyte size in HFD-fed rats. Myricetin and fenofibrate reversed the HFD-induced down-regulation of the hepatic peroxisome proliferator activated receptor (PPAR)α. HFD-induced decreases of the hepatic protein level of acyl-CoA oxidase and cytochrome P450 isoform 4A1 were up-regulated by myricetin and fenofibrate. The elevated expressions of hepatic sterol regulatory element binding proteins (SREBPs) of HFD-fed rats were lowered by myricetin and fenofibrate. These results suggest that myricetin suppressed BW gain and body fat accumulation by increasing the fatty acid oxidation, which was likely mediated via up-regulation of PPARαand down-regulation of SREBP expressions in the liver of HFD-fed rats.


2002 ◽  
Vol 61 (3) ◽  
pp. 371-374 ◽  
Author(s):  
Sander Kersten

Dietary fatty acids have numerous effects on cellular function, many of which are achieved by altering the expression of genes. The present paper reviews recent data on the mechanisms by which fatty acids influence DNA transcription, and focus specifically on the importance of three transcription factors: peroxisome proliferator-activated receptor α; liver X receptor α; sterol regulatory element-binding protein 1c. These data indicate that fatty acids induce or inhibit the mRNA expression of a variety of different genes by acting both as agonists and as antagonists for nuclear hormone receptors.


2020 ◽  
Vol 107 (1) ◽  
pp. 67-81
Author(s):  
L. Yahaghi ◽  
Parichehreh Yaghmaei ◽  
N. Hayati-Roodbari ◽  
S. Irani ◽  
A. Ebrahim-Habibi

AbstractPurposeBetanin is a betacyanin with antioxidant and anti-inflammatory activities whose effects were investigated in a nonalcoholic steatohepatitis (NASH) model.Main methodsNinety-six male naval medical research institute (NMRI) mice were divided into eight groups (n = 12) including normal control, high fat diet (HFD), Sham, and positive control treated with trans-chalcone. Three experimental groups were treated with 5 mg/kg, 10 mg/kg or 20 mg/kg betanin, and a betanin protective group was also defined.ResultsFour weeks of HFD treatment resulted in steatohepatitis with associated fibrosis. Significant increase was observed in serum levels of triglycerides (TG), total cholesterol (TC), glucose, insulin, leptin, liver enzymes, malondialdehyde (MDA), furthermore insulin resistance and (sterol regulatory element-binding protein-1c) SREBP-1c were detected. Levels of high-density lipoprotein cholesterol (HDL-C), adiponectin, superoxide dismutase (SOD), catalase (CAT), and PPAR-α (peroxisome proliferator-activated receptor-α) considerably decreased. Treatment by betanin, particularly the 20 mg/kg dosage, attenuated these changes.ConclusionBetanin is a potential treating agent of steatohepatitis and works through up-regulation of PPAR-α, down-regulation of SREBP-1c, modification of adipokine levels and modulation of lipid profile.


2007 ◽  
Vol 21 (11) ◽  
pp. 2698-2712 ◽  
Author(s):  
Bhaskar Ponugoti ◽  
Sungsoon Fang ◽  
Jongsook Kim Kemper

Abstract Insulin inhibits transcription of cholesterol 7α-hydroxylase (Cyp7a1), a key gene in bile acid synthesis, and the hepatic nuclear factor-4 (HNF-4) site in the promoter was identified as a negative insulin response sequence. Using a fasting/feeding protocol in mice and insulin treatment in HepG2 cells, we explored the inhibition mechanisms. Expression of sterol regulatory element-binding protein-1c (SREBP-1c), an insulin-induced lipogenic factor, inversely correlated with Cyp7a1 expression in mouse liver. Interaction of HNF-4 with its coactivator, peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α), was observed in livers of fasted mice and was reduced after feeding. Conversely, HNF-4 interaction with SREBP-1c was increased after feeding. In vitro studies suggested that SREBP-1c competed with PGC-1α for direct interaction with the AF2 domain of HNF-4. Reporter assays showed that SREBP-1c, but not of a SREBP-1c mutant lacking the HNF-4 interacting domain, inhibited HNF-4/PGC-1α transactivation of Cyp7a1. SREBP-1c also inhibited PGC-1α-coactivation of estrogen receptor, constitutive androstane receptor, pregnane X receptor, and farnesoid X receptor, implying inhibition of HNF-4 by SREBP-1c could extend to other nuclear receptors. In chromatin immunoprecipitation studies, HNF-4 binding to the promoter was not altered, but PGC-1α was dissociated, SREBP-1c and histone deacetylase-2 (HDAC2) were recruited, and acetylation of histone H3 was decreased upon feeding. Adenovirus-mediated expression of a SREBP-1c dominant-negative mutant, which blocks the interaction of SREBP-1c and HNF-4, partially but significantly reversed the inhibition of Cyp7a1 after feeding. Our data show that SREBP-1c functions as a non-DNA-binding inhibitor and mediates, in part, suppression of Cyp7a1 by blocking functional interaction of HNF-4 and PGC-1α. This mechanism may be relevant to known repression of many other HNF-4 target genes upon feeding.


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