| Baicalin belong to the flavonoids, is the active ingredient of skullcap.Several physiological roles, for example, anti-inflammatory, antibacterial,anti-oxidation, scavenging free radicals, have been found. Recently, somestudies have shown that baicalin can also protect liver.Acute liver injury refers to the clinical disease with abnormal liverfunction as the main manifestation. The occurrence is acute, and most of themhave a clear incentive. The disease always occurred with fever and jaundice asclinical symptoms. Severe or persistent liver injury can ultimately lead toacute liver failure. The virus infection, drug factor, excessive alcohol intakeand trauma factor are common causes. Recent years, with the improvement ofpeople’s living standard and the level of medical, the excessive of foodadditives, excessive alcohol consumption, drug abuse and increase of types ofclinical medicine, the incidence of liver injury also increased year by year.Hepatic oval cell (HOC) as a type of liver stem cells, with the potentialof bidirectional differentiation, is very important in the treatment of liverdisease. It has got the attention of scholars at home and abroad in recent years.In the normal tissue, cell proliferation and growth should be coexistedwith the aging and death. The form of cell death can be divided into threecategories: apoptosis, autophagic cell death and necrosis. The first two kindsalso known as programmed cell death (PCD). Autophagy is a hotspot ofresearch at home and abroad in recent years, the research of its role inmammals and the relations with diseases of each system has made significantprogress. Autophagy is the unique life phenomenon of eukaryotes. It candepredate damaged macromolecules by lysosomal, clear defect organelles anduseless protein intracellular, etc. Autophagy plays an important role in theoccurrence, development and treatment of the nervous system, the immune system and the digestive system diseases.Objective: Eestablish the rat model of acute liver injury with HOCproliferation, research the effect of baicalin on HOC proliferation anddifferentiation in acute liver injury in rats, and the effect on apoptosis andautophagy of injuried liver tissue, explore the effect of baicalin on acute liverinjury and the mechanism.Methods:96healthy SD rats (weight200g±20g) were randomly dividedinto normal control group, model group, baicalin low-dose group and baicalinhigh-dose group，marked by K,M,BL and BH,randomly divided into foursubgroups. M group was given2-acetamidofluorene (2-AAF) solution bygavage,4days,15mg/kg.d, and lined2/3partial liver resection at the5th day.BL group and BH group were fed2-AAF solution4days and gave baicalinsolution (BL50mg/kg.d, BH100mg/kg.d) by gavage in the same time. Thenlined2/3partial liver resection at the5th day, and gave baicalin solution bygavage until put to death. Rats of each group were sacrificed and drawn at thefirst day,7th day,14th day and21st day after the operation.Haematoxylin-eosin (H-E) staining was used to observe the microstructu-re of the tissue under the microscope. Immunohistochemistry (IHC) was usedto assay c-kit, AFP and CK19expression in liver tissue. Immunofluorescencetechnic (IFT) was used to assay OV6expression in the liver tissue. DoubleIFT was used to assay EpCAM and PCNA expression. Detect the hepatocyteapoptosis with the TdT-mediated dUTP nick end labeling (TUNEL) method.Western blot was used to assay Beclin1and microtubule-associated protein1light chain3beta (LC3B) expression. Detected serum alanine transaminase(ALT),aspartate transaminase (AST), alkaline phosphatase (ALP) and albumin(ALB) content with the colorimetry.Results:⑴Liver function results showed: compared with M group, theAST, ALT and ALP of baicalin intervention group were reduced (P<0.05), theALB were elevated (P<0.05). Compared with BL group, the AST, ALT andALP of BH group was lower (P<0.05).⑵H-E staining showed: we could findHOC proliferation in liver.It suggested we successfully established the acute liver injury model with HOC proliferation in rats.⑶HOC markers c-kitexpression(IHC)and OV6expression(IFT), were both increased significantlyat7-14days, and reached the peak at the14th day.The expression of eachgroup was different (P<0.05). Compared with M group, the expression ofbaicalin intervention group decreased (P<0.05). With the does increased, theexpression decreased more obvious (P<0.05).⑷PCNA-positive rate, assayedby double IFT, was the highest at the first day, and decreased over time.Theexpression of each group was different (P<0.05).Compared with M group,PCNA-positive rate of BH group was decreased (P<0.05).There was nodifference between M and BL group (P>0.05).⑸HOC liver cell and bile ductcell phenotype marker expression were different in each group (P<0.05).Compared with M group, the AFP of baicalin intervention group wasdecreased (P<0.05), and the CK19was increased (P<0.05).⑹The cellapoptotic was different in each group (P<0.05). Compared with M group, theapoptotic of baicalin intervention group were decreased (P<0.05). With thedoes increased, the decrease was more obvious (P<0.05).⑺The autophagymarkers, examined by Western blot, showed: LC3B and Beclin1expressionwere different in each group (P<0.05).They showed an upward trend in modelgroup. With baicalin intervention, they showed upward trend after theoperative, and gradually decreased from the7th day.There was differencebetween M group and baicalin intervention group (P<0.05). Compared withBL group, the downward trend of BH group was more obvious (P<0.05).Conclusions: Baicalin have the effect of liver protective in acute liverinjury rats, and can inhibit the excessive proliferation of HOC after liverinjury, and induce the differentiation of HOC to mature liver cells and bileduct cells. Baicalin can inhibit the cell apoptosis and autophagy of acuteinjuried liver in rats, which may be the mechanism of baicalin to protect theacute injuried liver. |
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