Acylated ghrelin limits fat accumulation and improves redox state and inflammation markers in the liver of high-fat-fed rats

Obesity (Silver Spring). 2014 Jan;22(1):170-7. doi: 10.1002/oby.20454. Epub 2013 Jun 13.

Abstract

Objective: Obesity commonly causes hepatic lipid accumulation that may favor oxidative stress and inflammation with negative clinical impact. Acylated ghrelin (A-Ghr) modulates body lipid distribution and metabolism, and it may exert antioxidant effects in vitro as well as systemic anti-inflammatory effects in vivo. The impact of A-Ghr on liver triglyceride content, redox state and inflammation markers in diet-induced obesity was investigated.

Design and methods: A-Ghr (200-μg/injection: HFG) or saline (HF) were administered subcutaneously twice-daily for 4 days to 12-week-old male rats fed a high-fat diet for 1 month (n = 8-10/group).

Results: Compared to lean animals, liver triglyceride accumulation occurred in HF despite enhanced phosphorylation of the lipid oxidation regulator AMPK and preserved mitochondrial enzyme activities. High triglycerides were accompanied by pro-oxidant changes in redox state and proinflammatory changes in NF-kB and TNF-alpha. A-Ghr limited liver triglyceride excess (P < 0.05 HF > HFG > Control) with concomitant activation of glutathione peroxidase and normalized redox state and cytokines. A-Ghr-induced liver changes were associated with higher plasma adiponectin and lower circulating fatty acids (P < 0.05 HFG vs.

Hf) conclusions: A-Ghr limits liver triglyceride accumulation and normalizes tissue redox state and inflammation markers in diet-induced obese rats. These results suggest a favorable impact of A-Ghr on hepatic complications of diet-induced obesity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adiponectin / blood
  • Animals
  • Anti-Inflammatory Agents / pharmacology
  • Antioxidants / pharmacology
  • Diet, High-Fat / adverse effects*
  • Fatty Acids / blood
  • Ghrelin / pharmacology*
  • Glutathione Peroxidase / metabolism
  • Inflammation / metabolism*
  • Lipid Metabolism / drug effects*
  • Liver / drug effects*
  • Liver / metabolism
  • Male
  • NF-kappa B / metabolism
  • Obesity / pathology
  • Oxidation-Reduction / drug effects
  • Oxidative Stress / drug effects
  • Rats
  • Rats, Wistar
  • Reactive Oxygen Species / metabolism
  • Triglycerides / metabolism
  • Tumor Necrosis Factor-alpha / metabolism

Substances

  • Adiponectin
  • Anti-Inflammatory Agents
  • Antioxidants
  • Fatty Acids
  • Ghrelin
  • NF-kappa B
  • Reactive Oxygen Species
  • Triglycerides
  • Tumor Necrosis Factor-alpha
  • Glutathione Peroxidase