Ritian Jin,Jude Juventus Aweya,Rong Lin,Wuyin Weng,Jiaqi Shang,Dangfeng Wang,Yiling Fan,Shen Yang
VLATSGPG (VLA) was a DPP-IV inhibitory peptide isolated from salmon ( Salmo Salar ) skin. Here, we demonstrated that VLA inhibited the activation of PERK through the AKT signaling pathway. Furthermore, we investigated the effect of VLA on free fatty acid (FFA)-induced lipid accumulation disorder and inflammation in HepG2 cells, elucidating the potential regulatory mechanism in this nonalcoholic fatty liver disease cell model. VLA reduced the mRNA expression of adipogenic factors FAS, ACC, and SCD-1 through the PERK/eIF2α pathway and the level of apolipoprotein B-100 secretion. These may contribute to the reducing FFA-induced lipid accumulation in cells and reducing intracellular lipid levels. In addition, VLA increased IκBα mRNA expression via the PERK/IκBα pathway, inhibited the NF-κB p65 activation, and thus inhibited cell inflammation.
Yan Yan,Yuan Haisheng,Yang Fan,Na Heiya,Yu Xiuling,Liu Jingran,Wang Yuzhen
Non-alcoholic fatty liver disease (NAFLD) is becoming a significant global public health threat. Seabuckthorn ( Hippophae rhamnoides L.) has been used in traditional Chinese medicine (TCM). The hypolipidemic effects of Seabuckthorn polysaccharides (SP) against high-fat diets (HFD)-induced NAFLD were systematically explored and compared with that of Bifidobacterium lactis V9 ( B. Lactis V9). Results showed that HFD-induced alanine transaminase (ALT) and aspartate aminotransferase (AST) levels decreased by 2.8-fold and 4.5-fold, respectively, after SP supplementation. Moreover, the alleviating effect on hepatic lipid accumulation is better than that of B. Lactis V9. The ACC and FASN mRNA levels were significantly reduced by 1.8 fold ( P < 0.05) and 2.3 folds ( P < 0.05), respectively, while the CPT1α and PPARα mRNA levels was significantly increased by 2.3 fold ( P < 0.05) and 1.6 fold ( P < 0.05), respectively, after SP administration. SP activated phosphorylated-AMPK and inhibited PPARγ protein expression, improved serum oxidative stress and inflammation ( P < 0.05). SP supplementation leads to increased hepatic expression of nuclear factor erythroid 2-related factor 2 (Nrf-2), heme oxygenase-1 (HO-1) and Superoxide dismutase-2 (SOD-2). Furthermore, SP treatment improved HFD-induced intestinal dysbiosis. Lentisphaerae , Firmicutes , Tenericutes and Peptococcus sp., RC9_gut_group sp., and Parabacteroides sp. of the gut microbiota were significantly associated with hepatic steatosis and indicators related to oxidative stress and inflammation. Therefore, SP can mitigate hepatic lipid accumulation by regulating Nrf-2/HO-1 signaling pathways and gut microbiota. This study offers new evidence supporting the use of SP as a prebiotic treatment for NAFLD.