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

Abstract

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. 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). 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. 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.