Study On Hepatoprotective Activity Of Chitooligosaccharide On Acute Alcoholic Liver Disease

With the development of the social economy and the increasing frequency of social activities,the proportion of binge drinking people has been rising,and the diseases and problems caused by alcohol have become increasingly serious.On the other hand,consumers are paying more attention to drinking health.Therefore,the sobering effect and prevention of alcoholic liver disease have become the research hotspots in recent years.Chitooligosaccharide(COS),a naturally-derived amino sugar oligomer,has the properties of material abundance,non-toxic,biodegradation,and non-pollution.It has been shown to have strong antioxidant activity and sobering and liver protection.In this study,chitooligosaccharide was used as raw materials,the in vitro antioxidant activity of chitooligosaccharide was studied,and its sobering effect was further explored,and the protective effects and related mechanisms of acute alcohol liver diseases were finally discussed,providing the theoretical foundation for developing the safe and effective liver protection products of chitooligosaccharide.The main research contents and conclusions of the study are as follows:1.Chitooligosaccharide was studied in vitro antioxidant activity.The ability of chitooligosaccharide to scavenge hydroxyl radicals(·OH)and DPPH free radicals was determined.The results showed that the clearance of ·OH and DPPH increased with increasing chitooligosaccharide concentration,indicating its good antioxidant activity.2.The sobering effect of chitooligosaccharide was further studied.By establishing a mouse hangover model,the mice were judged to be drunk by observing the disappearance of righting reflex.The mice were sacrificed 4 hours after drinking,and the serum ethanol,acetaldehyde,alanine aminotransferase(ALT)and aspartate aminotransferase(AST)contents were determined.Besides,the contents of alcohol dehydrogenase(ADH)and acetaldehyde dehydrogenase(ALDH)in the liver were also measured.The results showed that compared with the model group,the drunken proportions of the low-dose COS group,the medium high-dose COS group,and the high-dose COS group decreased by 14.28%,42.85% and 14.48%,respectively,and the hangover rate of the low-dose COS group reached 100%.However,the little effect of sobering was observed in the other groups.In addition,compared with the model group,the contents of ethanol,acetaldehyde,ALT,AST and ADH in the chitooligosaccharide group were significantly decreased,which indicated that chitooligosaccharide had sobering effect to some extent.3.The protective effect of chitooligosaccharide on acute alcoholic liver injury in mice was studied.The model of acute liver injury in mice was established.Liver histopathological examination was performed on the mice,and serum ALT,AST,total cholesterol(TC),triglyceride(TG),very low density lipoprotein(VLDL)content,liver coefficient,liver glutathione(GSH),superoxide dismutase(SOD)and malondialdehyde(MDA)was measured.The results showed that compared with the alcohol model group,the degree of liver tissue damage in the chitooligosaccharide group was reduced,and the levels of serum ALT,AST,TC,TG,VLDL decreased significantly in both positive control group and chitooligosaccharide group,also,the liver GSH content and SOD activity increased significantly,while the liver coefficient and MDA content decreased significantly,indicating that chitooligosaccharide had positive protective effect on acute alcoholic liver disease in mice.4.The mechanisms of protective effect of chitooligosaccharide in acute alcoholic liver injury were discussed.Reverse Transcription-Polymerase Chain Reaction(RT-PCR)and Western-blot was used to detect the related genes and protein expression in oxidative stress and microsomal alcohol oxidase(MEOS)pathway in liver.The results showed that chitooligosaccharide could restore the mRNA activity of heme oxygenase 1(HO-1)and NAD(P)H quinone oxidoreductase-1(NQO1),and down-regulate glycogen synthase kinase-3β(GSK-3β),extracellular signal-regulated kinases(ERK)and c-Jun N-terminal kinase(JNK)mRNA expression,which was also reflected on the HO-1 and ERK protein levels.And chitooligosaccharide could promote the overall expression of Nrf2.Therefore,the protective effect on the liver might be related to the induction of antioxidant genes and mitogen-activated protein kinase(MAPK)dependent oxidative stress.Alcohol could significantly increase the expression of cytochrome P-450 second family E subtype polypeptide 1(CYP2E1)mRNA,while chitooligosaccharide could significantly reduce the expression of CYP2E1,indicating that it was also associated with CYP2E1-dependent oxidative stress.