| Alcohol drinks play important roles in our daily life. However, due to the excessive use, alcohol has brought about many adverse effects on human health. Among them, one of the most serious problems is alcoholic liver disease, which has become a sore point for countries all over the world. In this research, we used ultra-fined ginseng powders as experimental raw materials to study the ginsenosides, the main active compounds of ginseng, and their protective effects against ethanol-induced hepatocellular injury, which would provide the information on the potential role of ultra-fined ginseng powders in the prevention and treatment of alcoholic liver disease.The ginsenoside sample was obtained by freeze drying, after being extracted by the water bath reflux method with 70% alcohol solution and purified with D101 macroporous resin. Then seven major ginsenosides in the sample were determined by the high-performance liquid chromatography. The DPPH radical scavenging activity, ABTS radical scavenging activity and oxygen radical absorbance capacity of the sample were assessed by in vitro antioxidant assays. The results show the purity of the sample is over 86.84%. In terms of the antioxidant activity, the sample shows weak potential in DPPH radical scavenging (about 1/16 of Trolox). However, the ABTS radical scavenging activity is stronger, about 54.64% of Trolox and oxygen radical absorbance capacity of the sample is higher than Trolox, about 1.88 times of Trolox. These data demonstrate that ginsenosides exert their antioxidant activity mainly through providing hydrogen ions to free radicals and stopping chain reactions.The cell model of alcoholic liver disease was built by inducing HepG2 cells with ethanol and the optimal concentration of ethanol was set to 100 mM according to the result of MTS assay. When testing the cytotoxic effects of the sample on HepG2 cells, we found that incubation of the cells with ginsenosides within the concentrations of 100 μg/mL shows no cytotoxicity to cells. Furthermore, the protective effect of ginsenosides against ethanol-induced cell injury in HepG2 cell was demonstrated by the fact that when the cells were pretreated with the sample before being incubated with ethanol, the AST and ALT activities in the cell medium would be lower compared with the only-ethanol-treated group.To further research the mechanisms of the protection, we examined the effects of ginsenosides on the activities of the antioxidant enzymes (SOD, CAT, and GSH-PX), the content of MDA, the level of ROS and the release of TNF-a in the cell model with ethanol-induced hepatocellular injury. The results show that the sample can effectively restore the activities of antioxidant enzymes and reduce the levels of MDA and ROS in the cells and the amount of TNF-a in the medium, which exhibit its strong antioxidant and anti-inflammatory properties. In addition, the outcome of Western Blot shows that the inhibition of NF-κB cell signaling pathway by the sample plays an important role in the hepatoprotective abilities of ginsenosides.Finally, we evaluated the activities of ginsenosides against ethanol-induced injury in liver from the perspective of the regulation of fat metabolism. The effects of the sample on the cellular TG content, the formation of lipid droplets and the AMPK/SREBP-1c cell signaling pathway were measured. The results indicate that the ginsenosides can effectively reduce the TG storage and the excessive formation of lipid droplets in HepG2 cells. Moreover, the ginsenosides are able to modulate the AMPK/SREBP-lc cell signaling pathway. The treatment stimulates the AMPKa Thr172 phosphorylation, which activates AMPK and spurs the SREBP-lc Ser372 phosphorylation, which prevents SREBP-lc from entering the cell nucleus to regulate gene transcription. All these actions seem to ameliorate the disorders of lipid metabolism in HepG2 cells with ethanol-induced injury.In conclusion, all above results indicate that the ginsenosides extracted from ultra-fined ginseng powders possess moderate antioxidant activity. And they can protect hepatocytes against ethanol-induced injury by the regulation of oxidative stress response and lipid metabolism. |
PDF Full Text Request