Monkfish Peptides Mitigate High Fat Diet-Induced Hepatic Steatosis in Mice

Abstract

Non-alcoholic fatty liver disease (NAFLD) is a hepatic metabolic syndrome usually accompanied by fatty degeneration and functional impairment. The aim of the study was to determine whether monkfish peptides (LPs) could ameliorate high-fat diet (HFD)-induced NAFLD and its underlying mechanisms. NAFLD was induced in mice by giving them an HFD for eight weeks, after which LPs were administered in various dosages. In comparison to the HFD control group: body weight in the LP-treated groups decreased by 23–28%; triacylglycerol levels in the blood decreased by 16–35%; and low-density lipoproteins levels in the blood decreased by 23–51%. Additionally, we found that LPs elevated the activity of hepatic antioxidant enzymes and reduced the inflammatory reactions within fatty liver tissue. Investigating the effect on metabolic pathways, we found that in LP-treated mice: the levels of phospho-AMP-activated protein kinase (p-AMPK), and phospho-acetyl CoA carboxylase (p-ACC) in the AMP-activated protein kinase (AMPK) pathway were up-regulated and the levels of downstream sterol regulatory element-binding transcription factor 1 (SREBP-1) were down-regulated; lipid oxidation increased and free fatty acid (FFA) accumulation decreased (revealed by the increased carnitine palmitoyltransferase-1 (CPT-1) and the decreased fatty acid synthase (FASN) expression, respectively); the nuclear factor erythroid-2-related factor 2 (Nrf2) antioxidant pathway was activated; and the levels of heme oxygenase-1 (HO-1) and nicotinamide quinone oxidoreductase 1 (NQO1) were increased. Overall, all these findings demonstrated that LPs can improve the antioxidant capacity of liver to alleviate NAFLD progression mainly through modulating the AMPK and Nrf2 pathways, and thus it could be considered as an effective candidate in the treatment of human NAFLD.

Eighteen Novel Bioactive Peptides from Monkfish (Lophius litulon) Swim Bladders: Production, Identification, Antioxidant Activity, and Stability

“…Presently, BPs have been produced from monkfish muscle and its processing by-products and showed significant bioactivities. For example, peptides fraction (MW < 1 kDa) from monkfish muscle could improve the antioxidant capacity of the liver to alleviate non-alcoholic fatty liver disease (NAFLD) progression mainly through modulating the intestinal flora and AMPK and Nrf2 pathways [ 42 , 43 , 44 ]. APs prepared from monkfish muscle hydrolysate, including EWPAQ, FLHRP, LMGQW, EDIVCW, MEPVW and YWDAW, could concentration-dependently scavenge free radicals and control lipid peroxidation [ 18 , 41 ].…”

Bioactive Peptides from Skipjack Tuna Cardiac Arterial Bulbs: Preparation, Identification, Antioxidant Activity, and Stability against Thermal, pH, and Simulated Gastrointestinal Digestion Treatments

“…Skin gelatin peptides of Pacific cod could reduce and repair ultraviolet (UV)-radiated skin injuries by enhancing the activity of antioxidant enzymes and holding back the levels of nuclear factor kappa-light chain enhancer of B cells (NF-κB) and pro-inflammatory cytokines [ 28 ]. Ye et al reported that BPs from monkfish muscle could mitigate high fat diet-induced hepatic steatosis in mice through up-regulating the content of phospho-AMP-activated protein kinase (p-AMPK), which further activate the nuclear factor erythroid-2-related factor 2 (Nrf2) pathway to increase the levels of heme oxygenase-1 (HO-1) and nicotinamide quinone oxidoreductase 1 (NQO1) [ 29 ]. Pentapeptide of LCGEC from tuna roe could activate the Nrf2 pathway to decrease the apoptosis of HaCaT cells induced by UV-B radiation.…”

Effects of low molecular weight peptides from monkfish (Lophius litulon) roe on immune response in immunosuppressed mice

“…Bioactive peptides containing 2–20 amino acids can exert various physiological effects, such as immunoregulation, antioxidant, antibacterial, antitumor, and hepato-protective impact ( 10 – 12 ). These peptides have been gaining increasing attention recently due to their bioactivity, high safety and bioavailability, and diverse physiological functions.…”

“…For example, Hu et al ( 11 ) prepared antioxidant peptides from the protein hydrolysate of monkfish muscle, while Tian et al ( 17 ) optimized the extraction factors of antioxidant peptides from monkfish muscle, and investigated their role in H 2 O 2 -induced lesion. Ye et al ( 12 ) investigated the amelioration effect of monkfish peptides toward high fat diet-induced hepatic steatosis in mice. However, there is no report on the preparation of immunomodulatory peptides from monkfish.…”