Ya-yun Liu,Jiao-jiao You,Wei Xu,Ting Zhai,Chun-yuan Du,Yong Chen,Feng-mei Han
Objective The present work was to investigate the protective effects of the aqueous extract of Gynura procumbens (GPAE) against nonalcoholic steatohepatitis (NASH) in mice and NCTC-1469 cells. Methods C57BL/6J mice were fed with methionine and choline-deficient (MCD) diet and administered simultaneously with GPAE (500 and 1000 mg/kg/d, respectively) by gavage for six weeks. The biomarkers of NASH in serum and liver were determined. NCTC-1469 cells were pretreated with 0.25 mmol/L palmitic acid (PA) plus 0.5 mmol/L oleic acid (OA) for 24 h or treated with adenovirus expressing short-hairpin RNA against CFLAR (Ad-shCFLAR) for 24 h and then treated with GPAE (80 and 160 µg/mL, respectively) for 24 h, and the content of cellular biomarkers of NASH was detected. Results In mice treated with MCD , GPAE could decrease the levels of serum ALT , AST, the content of hepatic TG , TC and MDA , repress the activities and protein expression of CYP2E1 and CYP4A and the phosphorylation of JNK, increase the activities of HO-1, CAT and GSH-Px, up-regulate the mRNA expression of PPARα, FABP5, CPT1α, ACOX, SCD-1, mGPAT, MTTP and the protein expression of CFLAR and NRF2. In NCTC-1469 cells treated with PA and OA, GPAE could decrease the content of cellular TG and ROS , promote the uptake of 2-NBDG, up-regulate the protein expression of CFLAR and NRF2. In NCTC-1469 cells treated with Ad-sh CFLAR , GPAE up-regulated the mRNA and protein expression of CFLAR, down-regulated the phosphorylation of JNK, and increased the protein expression of NRF2 and pIRS1 . Conclusion These results indicated that the activation on CFLAR-JNK pathway might be the main anti-NASH mechanism of GPAE, which on the one hand promote the β-oxidation and efflux of fatty acids in liver, and finally reduce hepatic lipid accumulation , on the other hand increase the activities of anti-oxidant enzymes and inhibit the activities of ROS generation enzymes by activating NRF2, and therefore attenuates hepatic oxidative stress damage.
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.