Protect Of Major Stilbene Compounds In Mulberry Twigs On Acute Liver Injury Induced By LPS/D-GalN

Acute liver injury,which can lead to high mortality in the clinic,is a multifactorial complex disease resulting from various etiologies.It is a new research strategy to explore active ingredients that have preventive and therapeutic effects on ALI from natural plants.Mulberry is one of the common traditional Chinese medicines.On one hand,what's well recorded in the ancient medical books like "New Materia Medica" and "Daily recipes" is the liverprotection effect of mulberry branches.On the other hand,modern pharmacology studies have proven that mulberry twigs have anti-inflammation,antioxidant effects etc.Though both the studies at home and abroad show that Mulberry extract has anti-inflammatory and antioxidant activity,further studies and more effort on the hepatoprotective effects of Mulberry extract and its main active ingredients are still heavily needed.Therefore,this experiment explored the mechanism of Mulberry extract and its main compounds on LPS/D-GalN-induced acute liver injury.The specific research contents and results are as follows,1.Mulberry extract prevents LPS/D-GalN-induced acute liver injuryThe results showed that Ext significantly improved the pathological changes of liver tissue induced by LPS/D-GalN in mice,and decreased the levels of ALT and AST in serum,increased the antioxidant enzyme activity of SOD and CAT in mice and decreased the levels of MDA.Furthermore,the Ext also significantly down-regulated MAPK signaling pathway and up-regulation of Keap1-Nrf2 signal pathway and antioxidant enzyme expression of HO-1 and NQO1.In conclusion,Ext can play its anti-inflammatory and antioxidant pharmacological activity by prevention of the activation of inflammation signal pathway and promotion the activation of screening oxidant stress to treat ALI.2.Content analysis of the main active compounds in the mulberry extractIn order further investigate the material basis of the mulberry twig extract,the content of the main active compounds was studied.Quantitative analysis of mulberry extract by HPLC,the content of stilbenes has a significant advantage over flavonoids,while the Oxy content is significantly higher than that of Res and MulA.Therefore,we choose Oxy for further research on the effect of liver protect.3.Oxy alleviates LPS/D-GalN-induced acute liver injuryThe research results showed that Oxy significantly ameliorated the pathological changes of liver tissue in mice induced by LPS/D-GalN,significantly reduced the elevated level of ALT and AST in ALI induced by LPS/D-GalN.At the same time,pretreatment with Oxy suppressed iNOS and decreases the MDA level in mouse serum.Pretreatment with Oxy reduced LPS/D-GalNsensitized depression of SOD and CAT and increased the level of T-AOC.Oxy significantly inhibited inflammation factor expression(IL-6,IL-1?,TNF?),suppressed the TLR4/NF-?B signaling pathway related protein expression.Oxy could activated Nrf2 separate from Keap1 and translocate it from the cytoplasm to the nucleus,increasing the expression of HO-1 and NQO1.Pretreatment with Oxy decreased LPS/D-GalN stimulated hepatocyte apoptosis by efficaciously raising the Bcl-2/ Bax ratio,inhibiting the activation of caspases,and activating the PI3K-Akt pathway.Our results demonstrate the hepatoprotective efficacy of Oxy is mainly due to the prevention of TLR4/NF-?B pathway activation,induced activation of Keap1-Nrf2 signaling pathway,and decreased hepatocyte apoptosis.4.Comparison of the protective effects of Oxy,Res and MulA on acute liver injuryIn order further explore the mechanism of Oxy on protection ALI,the structure-function relationship of the three stilbene compounds(Oxy,Res,MulA)in Mulberry extract was explored.The results showed that MulA was significantly superior to Oxy and Res in improving liver pathological changes induced by LPS/D-GalN in mice.Oxy,Res and MulA all significantly inhibited the elevation of ALT and AST caused by LPS/D-GalN,MulA>Res>Oxy(P<0.01).Oxy,Res and MulA all significantly increased activities of SOD and CAT,MulA>Res>Oxy(P<0.01).However,Res and Oxy were significantly better than MulA in inhibiting MDA production(P<0.05).Exploration of Oxy,Res and MulA inhibited the NF-?B signaling pathway by Western Blotting.The results showed that inhibition of MulA was significantly better than Oxy(P<0.01),and Oxy was significantly better than Res(P<0.01).Oxy,Res and MulA all promoted activation of Keap1-Nrf2 signaling pathway,MulA effect was significantly better than Oxy(p<0.01),and Oxy was significantly better than Res(P<0.01).However,Res was significantly better than Oxy and MulA(P<0.01)on inhibited the activation of caspase8.In summary,MulA compared with Res and Oxy having better protection on ALI induced by LPS /D-GalN.This study proved that mulberry twigs extract and its main stilbene compounds all have good hepatoprotective activity.This study provides a theoretical basis for the development of the mulberry resources,also provides a material basis for the research of liver-protecting functional foods.