Antifibrotic Effect of Total Flavonoids of Astmgali Radix on Dimethylnitrosamine-lnduced Liver Cirrhosis in Rats

Objective：To study the effect of total flavonoids of Astmgali Radix（TFA）on liver cirrhosis induced with dimethylnitrosamine（DMN）in rats,and the effect on peroxisome proliferator-activated receptorγ（PPARγ）,uncoupling protein 2（UCP2）and farnesoid X receptor（FXR）.Methods：Fifty-three Sprague-Dawley rats were randomly divided into a control group（10 rats）and a DMN group（43 rats）.Rats in the DMN group were given DMN for 4 weeks and divided randomly into a model group（14 rats）,a low-dosage TFA group（14 rats）and a high-dosage TFA group（15 rats）in the 3rd week.Rats were given TFA for 4 weeks at the dosage of 15 and 30 mg/kg in the low-and high-TFA groups,respectively.At the end of the experiment blood and liver samples were collected.Serum liver function and liver tissue hydroxyproline content were determined.hematoxylin-eosin（HE）,Sirus red and immunohistochemical stainings of collagenⅠ,smooth muscle actin（α-SMA）was conducted in paraffinembedded liver tissue slices.Real time polymerase chain reaction（PCR）was adopted to determine PPARγ,UCP2 and FXR m RNA levels.Western blot was adopted to determine protein levels of collagenⅠ,α-SMA,PPARγ,UCP2 and FXR.Results：Compared with the model group,TFA increased the ratio of liver/body weight（low-TFA group P〈0.05,high-TFA group P〈0.01）,improved liver biochemical indices（P〈0.01 for ALT,AST,GGT in both groups,P〈0.05 for albumin and TBil in the high-TFA group）and reduced liver tissue hydroxproline content（P〈0.01 in both groups）in treatment groups significantly.HE staining showed that TFA alleviated liver pathological changes markedly and Sirus red staining showed that TFA reduced collagen deposition,alleviated formation and extent of liver pseudolobule.CollagenⅠandα-SMA immunohistochemical staining showed that staining area and extent markedly decreased in TFA groups compared with the model group.TFA could increase PPARγ,it regulated target UCP2,and FXR levels significantly compared with the model group（in the low-TFA group all P〈0.05,in the high group all P〈0.01）.Conclusions：TFA could improve liver function,alleviate liver pathological changes,and reduce collagen deposition and formation of liver pseudolobule in rats with liver cirrhosis.The antifibrotic effect of TFA was through regulating PPARγsignal pathway and the interaction with FXR.

Animal experiment and clinical study of effect of gamma-interferon on hepatic fibrosis

AIM To evaluate the antifibrotic effect ofdifferent doses of recombinant human Gamma-Interferon (IFN-γ) intwo rat models of hepaticfibrosis, and to observe its effect on moderatechronic hepatitis B virus fibrosis.METNODS Hepatic fibrosis was successfullyinduced in 150 and 196 rats by subcutaneousinjection of carbon tetrachloride (CCl4) andintraperitoneal injection of dimethylnitrosamine(DMN), respectively. Each of the two modeldose IFN-γ group (15 MU/kg per day, i.m. for 8group (1.67 MU/kg daily, i.m. for 8 weeks).Another group of 10 rats without any treatmentwas used as normal controls. At the end of theexperiment, semi-quantitative histopathologicalscores of inflammation and fibrosis, liver (αsmooth muscle actin (α-SMA) expression level,liver hydroxyl proline content and serumhyaluronic acid levels were compared. And 47medium chronic hepatitis B viral fibrosispatients were studied. They were given IFN-γtreatment, 100MU/day i.m. for the first threemonths and 100MU qod i.m. for the next sixmonths. Semi-quantitative pathological scoresof inflammation and fibrosis and serum hepaticfibrosis indices were compared within the 9months.RESULTS In animal experiment, thepathological fibrosis scores and liver hydroxylproline content were found to be significantlylower in rats treated with different doses of IFN-γ as compared with rats in fibrotic model groupinduced by either CCI4 or DMN, in a dose-dependent manner. For CCI4-induced model,pathological fibrosis scores in high, medium andIow doses IFN-γ groups were 5.10 ± 2.88, 7.70 ±3.53 and 8.00 ± 3.30, respectively, but the scorewas 14.60 ± 7.82 in fibrotic model group.Hydroxyl proline contents were 2.83 ± 1.18, 3.59± 1.22 and 4.80 ± 1.62, in the three IFN-γgroups, and 10.01 ± 3.23 in fibrotic model group.The difference was statistically significant(P＜0.01). Similar results were found in DMN-induced model. Pathological fibrosis scoreswere 6.30±0.48, 8.10 ±2.72 and 8.30 ±2.58, inhigh, medium and Iow doses IFN-γ groups, and12.60 ± 3.57 in fibrotic model group. Hydroxylproline contents were 2.72 ± 0.58, 3.14 ± 0.71and 3.62 ± 1.02, in the three IFN-γ groups, and12.79 ± 1.54 in fibrotic model group. Thedifference was statistically significant(P＜0.01). Serum hepatic fibrosis indicesdecreased significantly in the 47 patients afterIFN-γ treatment (HA: 433.38 ± 373.00 vs 281.57± 220.48; LN: 161.22± 41.02 vs 146.35 ± 44.67;PCⅢ: 192.59 ± 89.95 vs 156.98 ± 49.22; C-Ⅳ:156.30 ± 44.01 vs 139.14 ± 34.47) and thedifferences between the four indices weresignificant (P＜0.05). Thirty-three patientsCONCLUSION All the three doses of IFN-γ areeffective in treating rat liver fibrosis induced byeither CCl4 or DMN, the higher the dose, thebetter the effect. And IFN-γ is effective forpatients with moderate chronic hepatitis B viralfibrosis.

Umbilical cord-derived mesenchymal stem cells alleviate liver fibrosis in rats

AIM: To evaluate the efficacy of umbilical cord-derived mesenchymal stem cells(UC-MSCs) transplantation in the treatment of liver fibrosis.METHODS: Cultured human UC-MSCs were isolated and transfused into rats with liver fibrosis induced by dimethylnitrosamine(DMN). The effects of UC-MSCs transfusion on liver fibrosis were then evaluated by histopathology; serum interleukin(IL)-4 and IL-10 levels were also measured. Furthermore, Kupffer cells(KCs) in fibrotic livers were isolated and cultured to analyze their phenotype. Moreover, UC-MSCs were cocultured with KCs in vitro to assess the effects of UCMSCs on KCs' phenotype, and IL-4 and IL-10 levels were measured in cell culture supernatants. Finally, UCMSCs and KCs were cultured in the presence of IL-4 antibodies to block the effects of this cytokine, followed by phenotypical analysis of KCs.RESULTS: UC-MSCs transfused into rats were recruited by the injured liver and alleviated liver fibrosis, increasing serum IL-4 and IL-10 levels. Interestingly, UC-MSCs promoted mobilization of KCs not only in fibrotic livers, but also in vitro. Co-culture of UC-MSCs with KCs resulted in increased production of IL-4 and IL-10. The addition of IL-4 antibodies into the coculture system resulted in decreased KC mobilization.CONCLUSION: UC-MSCs could increase IL-4 and promote mobilization of KCs both in vitro and in vivo, subsequently alleviating the liver fibrosis induced by DMN.

Effects of Aqueous Extract of Plumbago zeylanica L. in the Reversal of DMN-induced Hepatic Fibrosis in Rat

[ Objectives ] This study was conducted to evaluate the action of the aqueous extract of a medicinal plant Plumbago zeylanica L. in the reversal of dime- thylnitrosamine （DMN） -induced hepatic fibrosis in rats, and to provide a scientific basis for the utilization of P. zeylanica in treatment of hepatic fibrosis. [Meth- ods ] Hepatic fibrosis in rats was induced by intraperitoneal injection of DMN. The rats were then given the aqueous extract of P. zeylanica at high, medium or low concentration by garage for five weeks. Serum level of alanine aminotransferase （ALT） was determined by lactate dehydrogenase （LDH）-release assay, and serum level of aspartate transaminase （AST） was measured by UV-malate dehydrogenase （MDH） assay. Serum levels of total bilirubin （TBIL）, direct bilirubin （DBIL） and indirect bilirubin （1BIL） were measured by vanadate oxidation assay. Four indices of hepatic fibrosis （hyaluronic acid, laminin, procollagen type III and colla- gen type IV） were determined by radioimmunoassay （RIA） assay. Morphological damage of liver tissue was observed by hematoxylin-eosin staining （H＆E stai- ning）. Immunohistochemical staining was performed to determine the location and area of deposited collagen type I, collagen type III and ct-smeoth muscle actin （a-SMA） in liver tissue. [ Results] Compared with the negative control （rats with diseased fiver and untreated with P. zeylanica aqueous extract）, the serum lev- els of ALT, AST, TBIL, DBIL and IBIL were significantly decreased by P. zeylanica aqueous extract; the levels of the four serum indices of hepatic fibrosis were also obviously reduced. H＆E staining showed that hepatic fibrosis in rats was obviously inhibited or even reversed by P. zeylanica aqueous extract. Immunohisto- chemical staining proved that the aqueous extract of P. zeylanica significantly reduced the area and coloration of collagen type I, collagen type III and ct-SMA in rat liver. [ Conclusions] The aqueous extract of P. zeylanica has a definite effect in reversal of DMN-indueed hepatic fibrosis in rat by promoting the recovery of liver function, reversal of histopathological changes and reducing fibrotic collagen.

Silibinin alleviates N-nitrosodimethylamine-induced glutathione dysregulation and hepatotoxicity in rats

The present study was designed to evaluate the hepatoprotective and antioxidant potentials of silibinin(SBN)against N-nitrosodimethylamine(DMN)-induced toxic insults in the rat liver.The liver damage was induced in Wistar albino rats by repeated administration of DMN(10 mg·kg-1 b.w.,i.p.)on 3 consecutive days per week for 3 weeks.SBN(100 mg·kg-1 b.w.,p.o.)was given daily to the DMN treated rats for two weeks.The marker enzymes of liver toxicity and second-line enzymic and non-enzymic antioxidants were evaluated in serum and liver tissues before and after SBN treatment.Histopathology of the liver was evaluated by H & E staining.The DMN treatment produced a progressive increase in all the serum marker enzymes(AST,ALT,ALP,LDH,and γ-GT),peaking on Day 21.This treatment produced highly significant decreases in all the second-line antioxidant parameters(GSH,GST,GR,GPx,and vitamins C and E).The SBN treatment significantly reversed the DMN-induced damages,towards normalcy.Histopathological studies confirmed the development of liver toxicity in DMN-treated rats,which was reversed by SBN treatment in corroboration with the aforementioned biochemical results,indicating the hepatoprotective and antioxidant properties of SBN.In conclusion,the DMN-induced degenerative changes in the liver were alleviated by SBN treatment and this protective ability may be attributed to its antioxidant,free radical scavenging,and membrane stabilizing properties.