scholarly journals Gallic Acid Improves Diabetic Steatosis by Downregulating MicroRNA-34a-5p through Targeting NFE2L2 Expression in High-Fat Diet-Fed db/db Mice

Antioxidants ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 92
Author(s):  
Ang-Tse Lee ◽  
Mon-Yuan Yang ◽  
Yi-Ju Lee ◽  
Tzu-Wei Yang ◽  
Chi-Chih Wang ◽  
...  

Type 2 diabetes mellitus (T2DM) has become epidemic worldwide and is strongly associated with nonalcoholic fatty liver disease (NAFLD). The molecular mechanisms of microRNAs in NAFLD and T2DM development and the corresponding therapies remain unclear. We performed microRNA microarray validation to determine whether hepatic miR-34a-5p was significantly upregulated in db/db mice fed with a high-fat diet (HFD), a mouse model of T2DM with steatohepatitis. The potential role of miR-34a-5p and gallic acid (GA) in regulating hepatic lipid metabolism and diabetic steatosis was explored. GA improved the activities of antioxidant enzymes and suppressed lipid accumulation in the HFD-induced steatotic liver of db/db mice. In vitro, the silencing of miR-34a-5p in hepatocyte HepG2 cells ameliorated high glucose + oleic acid/palmitic acid mixture–induced accumulation of cellular triglycerides. We identified nuclear factor erythroid-derived 2-like 2 (NFE2L2) as a direct target of miR-34a-5p. Reduction in intracellular triglyceride and the expression levels of sterol regulatory element-binding protein 1 and fatty acid synthase by GA were mediated by the inhibition of miR-34a-5p expression in HepG2 cells. The findings suggest that GA improves hepatic lipogenesis by downregulating miR-34a-5p by suppressing NFE2L2 expression, indicating the potential therapeutic role of GA or an NFE2L2-activating agent in diabetic fatty liver disease.

2015 ◽  
Vol 308 (2) ◽  
pp. E97-E110 ◽  
Author(s):  
Guangzhi Chen ◽  
Renfan Xu ◽  
Shasha Zhang ◽  
Yinna Wang ◽  
Peihua Wang ◽  
...  

Cytochrome P-450 epoxygenase-derived epoxyeicosatrienoic acids (EETs) exert diverse biological activities, which include potent vasodilatory, anti-inflammatory, antiapoptotic, and antioxidatant effects, and cardiovascular protection. Liver has abundant epoxygenase expression and high levels of EET production; however, the roles of epoxygenases in liver diseases remain to be elucidated. In this study, we investigated the protection against high-fat diet-induced nonalcoholic fatty liver disease (NAFLD) in mice with endothelial-specific CYP2J2 overexpression (Tie2-CYP2J2-Tr). After 24 wk of high-fat diet, Tie2-CYP2J2-Tr mice displayed attenuated NAFLD compared with controls. Tie2-CYP2J2-Tr mice showed significantly decreased plasma triglyceride levels and liver lipid accumulation, improved liver function, reduced inflammatory responses, and less increase in hepatic oxidative stress than wild-type control mice. These effects were associated with inhibition of NF-κB/JNK signaling pathway activation and enhancement of the antioxidant defense system in Tie2-CYP2J2-Tr mice in vivo. We also demonstrated that 14,15-EET treatment protected HepG2 cells against palmitic acid-induced inflammation and oxidative stress. 14,15-EET attenuated palmitic acid-induced changes in NF-κB/JNK signaling pathways, malondialdehyde generation, glutathione levels, reactive oxygen species production, and NADPH oxidase and antioxidant enzyme expression in HepG2 cells in vitro. Together, these results highlight a new role for CYP epoxygenase-derived EETs in lipotoxicity-related inflammation and oxidative stress and reveal a new molecular mechanism underlying EETs-mediated anti-inflammatory and antioxidant effects that could aid in the design of new therapies for the prevention and treatment of NAFLD.


Author(s):  
Basma S. Ismail ◽  
Eman S. Abdel-Reheim ◽  
Hanan A. Soliman ◽  
Basant Mahmoud

Liver is considered as significant organ within body. Aims: Our survey aimed in illustrating protective effectiveness of gallic acid (GA) against high fat regimen nonalcoholic fatty liver disease (NAFLD). Study design: In our study, Rats were classified into 3 groups; control, orally given fatty-sucrosed diet, gallic acid treated groups. Methodology: They were evaluated through measuring hepatic cholesterol and triglyceride, alanine and aspartate aminotransferases and gammaglutamyl-transferase; total, direct and indirect bilirubin; total protein, albumin and globulin; hepatic and adipose malondialdehyde, glutathione-S-transferase, superoxide dismutase, catalase, reduced glutathione and glutathione peroxidase activities; glucose, insulin, homeostasis model assessment of insulin resistance, leptin and adiponectin; tumor necrosis factor alpha, interleukin-17 and interleukin-1beta; fatty acid synthase, acetyl-Coenzyme A carboxylase-α  and HMGCoA reductase. Results: Our results demonstrated that GA ameliorated the elevated lipid, serum liver function enzymes, bilirubin and the decreased L.glycogen levels and serum protein profile. GA improved the hepatic and adipose antioxidants activities by decreasing MDA and increasing GST, SOD, Cat, GSH and GPx activities. GA ameliorated the elevated Glu, INS, HOMA-IR, LEP and the decreased adiponectin levels. Moreover, GA ameliorated the elevated TNF-α, IL-17, IL-1β, FAS, ACC-α and HMGCR levels. Liver and adipose histopathologies confirmed our results. Conclusion: Gallic acid intake exhibited a beneficial therapeutic effect on nonalcoholic fatty liver disease rats as anti-inflammatory and antioxidant agent.


2016 ◽  
Vol 252 ◽  
pp. e154 ◽  
Author(s):  
R. Kheder ◽  
J. Hobkir ◽  
M. Browning ◽  
C. Stover

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