Objective:To evaluate the effect of hydroxysafflor yellow A(HSYA)on thioacetamide-induced liver fibrosis.Methods:Thioacetamide was administered to rats intraperitoneally in doses of 200 mg/kg twice a week for 12 weeks...Objective:To evaluate the effect of hydroxysafflor yellow A(HSYA)on thioacetamide-induced liver fibrosis.Methods:Thioacetamide was administered to rats intraperitoneally in doses of 200 mg/kg twice a week for 12 weeks.Thioacetamide-intoxicated rats were given silymarin(50 mg/kg)or HSYA(5 mg/kg)orally every day for 8 weeks.Liver enzymes,fibrosis markers,histological changes as well as immunohistochemistry of TNF-α,IL-6,p21,α-SMA,and caspase-3 were examined.The effect of HSYA on HSC-T6 activation/proliferation and apoptosis was also determined in vitro.Results:HSYA decreased liver enzymes,TNF-α,IL-6,and p21 expressions,hepatic PDGF-B,TIMP-1,TGF-β1,and hydroxyproline levels,as well as fibrosis score(S2 vs.S4)compared to the thioacetamide group.HSYA also downregulatedα-SMA while increasing caspase-3 expression.Surprisingly,at 500μg/mL,HSYA had only a slightly suppressive effect on HSC proliferation,with a 9.5%reduction.However,it significantly reduced TGF-β1,inhibitedα-SMA expression,induced caspase-3 expression,and promoted cell senescence.Conclusions:HSYA may be a potential therapeutic agent for delaying and reversing the progression of liver fibrosis.More research on HSYA at higher doses and for a longer period is warranted.展开更多
Objective:To investigate and compare the hepatoprotective effects of crude ethanolic and aqueous extracts of Phyllanthus acidus（L.） Skeels（P.acidus） leaves on acetaminophen（APAP） and thioacetamide（TAA） induced...Objective:To investigate and compare the hepatoprotective effects of crude ethanolic and aqueous extracts of Phyllanthus acidus（L.） Skeels（P.acidus） leaves on acetaminophen（APAP） and thioacetamide（TAA） induced liver toxicity in wistar rats.Silymarin was the reference hepatoprotective agent.Methods:In two different sets of experiments,the P.acidus extracts （200 and 400 mg/kg,body weight） and silymarin（100 mg/kg,body weight） were given orally for 7 days and a single dose of APAP（2 g/kg,per oral） or TAA（100 mg/kg,subcutaneous） were given to rats.The level of serum aspartate transaminase（AST）,alanine transaminase（ALT）,alkaline phosphatase（ALP）,total bilirubin and total protein were monitored to assess hepatotoxicity and hepatoprotection.Results:APAP or TAA administration caused severe hepatic damage in rats as evident from significant rise in serum AST,ALT,ALP,total bilirubin and concurrent depletion in total serum protein.The P.acidus extracts and silymarin prevented the toxic effects of APAP or TAA on the above serum parameters indicating the hepatoprotective action.The aqueous extract was found to be more potent than the corresponding ethanolic extract against both toxicants.The phenolic and flavonoid content（175.02±4.35 and 74.68±1.28,respectively） and 2,2-diphenyl-1- picrylhydrazil（DPPH）[IC<sub>50</sub>=（33.2±0.31）μg/mL]scavenging potential was found maximum with aqueous extract as compared to ethanolic extract.Conclusions:The results of present study suggests that the aqueous extract of P.acidus leaves has significant hepatoprotective activity on APAP and TAA induced hepatotoxicity,which might be associate with its high phenolic and flavonoid content and antioxidant properties.展开更多
Objective:To investigate the antifibrotic effects of Chrysanthemum indicum ethanol extract(CIEE)against activated hepatic stellate cells(HSC)and thioacetamide(TAA)-induced hepatofibrosis in rats.Methods:Cell viability...Objective:To investigate the antifibrotic effects of Chrysanthemum indicum ethanol extract(CIEE)against activated hepatic stellate cells(HSC)and thioacetamide(TAA)-induced hepatofibrosis in rats.Methods:Cell viability and proliferation of HSC-T6 cells were measured using MTT assay.Primary HSCs were used to study morphology.TAA(200 mg/kg)was used to induced hepatic fibrosis in rats.CIEE(100 and 500 mg/kg)and silymarin(50 mg/kg)were administered orally.Liver functions including alanine transaminase,aspartate transaminase,glutathione,and hydroxyproline levels were measured using commercial kits.Liver sections and fibrotic biomarker expression were measured using hematoxylin and eosin staining and real-time polymerase chain reaction.Results:In vitro study revealed that CIEE(0.1,0.25,and 0.5 mg/mL)inhibited the proliferation of activated HSCs exposed to transforming growth factor(TGF)-β and restored the activated primary HSC morphology.In in vivo studies,TAA-induced increase in liver/body weight ratio(5.46±0.26)was significantly reduced(4.13±0.22)by CIEE(P<0.05 at 500 mg/kg).CIEE(100 and 500 mg/kg)improved the liver functions by significantly attenuating changes in alanine transaminase,aspartate transaminase,glutathione,and hydroxyproline levels(P<0.05).Further,CIEE(100 and 500 mg/kg)ameliorated the histological changes in liver tissue and TGF-β expression significantly(P<0.05)in TAA-induced rats.Conclusions:CIEE significantly protects against TAA-induced liver damage in rats and can be used in the treatment of liver fibrosis.展开更多
AIM:To examine whether the administration of atorvastatin and rosuvastatin would prevent experimentallyinduced hepatic cirrhosis in rats.METHODS:Liver cirrhosis was induced by injections of thioacetamide(TAA).Rats wer...AIM:To examine whether the administration of atorvastatin and rosuvastatin would prevent experimentallyinduced hepatic cirrhosis in rats.METHODS:Liver cirrhosis was induced by injections of thioacetamide(TAA).Rats were treated concurrently with TAA alone or TAA and either atorvastatin(1,10 and 20 mg/kg) or rosuvastatin(1,2.5,5,10 and 20 mg/kg) given daily by nasogastric gavage.RESULTS:Liver fibrosis and hepatic hydroxyproline content,in the TAA-treated group was significantly higher than those of the controls [11.5 ± 3.2 vs 2.6 ± 0.6 mg/g protein(P = 0.02)].There were no differences in serum aminotransferase levels in the TAA controls compared to all the groups treated concomitantly by statins.Both statins used in our study did not prevent liver fibrosis or reduce portal hypertension,and had no effect on hepatic oxidative stress.Accordingly,the hepatic level of malondialdehyde was not lower in those groups treated by TAA + statins compared to TAA only.In vitro studies,using the BrdU method have shown that atorvastatin had no effect of hepatic stellate cells proliferation.Nevertheless,statin treatment was not associated with worsening of liver damage,portal hypertension or survival rate.CONCLUSION:Atorvastatin or rosuvastatin did not inhibit TAA-induced liver cirrhosis or oxidative stress in rats.Whether statins may have therapeutic applications in hepatic fibrosis due to other etiologies deserve further investigation.展开更多
Objective:To evalueate hepatoprotective effects Feronia elephantum(F.elephantum)correa against thioacctamide(TA)induced liver necrosis in diabetic rats.Methods:Male wistar rats were made diabetic with alloxan(160 mg/k...Objective:To evalueate hepatoprotective effects Feronia elephantum(F.elephantum)correa against thioacctamide(TA)induced liver necrosis in diabetic rats.Methods:Male wistar rats were made diabetic with alloxan(160 mg/kg)on day 0 of the study.They were intoxicated with hepatotoxicant(thioacetamide,300 mg/kg,ip)on day 9 of study to produce liver necrosis.Effects of 7 day daily once administration(day 2 to day 9)of EF(400 and 800 mg/kg,po)were evaluated on necorosis of liver in terms of mortality,liver volume,liver weight,serum aspartate aminotransferase(AST)and serum alanine transaminase(ALT),and histopathology of liver sections(for signs of necorosis and inflammation)on day-9 of the study.Separate groups of rats with treated only with alloxan(DA control),thioacetamide(TA control)and both(TA+DA control)were maintained.Results:FE significantly lowered the mortality rate and showed improvement in liver function parameters in TA-induced diabetic rats without change in liver weight,volume and serum glucose levels.Conclusions:FE showed promising activity against TA-induced liver necorsis in diabetic rats and so might be useful for prevention of liver complications in DM.展开更多
Objective:To evaluate the protective effect of Pisonia aculeata(P.aculeata) on thioacetamide induced hepatotoxicity in rats.Methods:Male Wistar rats were administered 250 or 500 mg/kg p.o.of P.aculeata extract for 21 ...Objective:To evaluate the protective effect of Pisonia aculeata(P.aculeata) on thioacetamide induced hepatotoxicity in rats.Methods:Male Wistar rats were administered 250 or 500 mg/kg p.o.of P.aculeata extract for 21 days and simultaneously administered thioacetamide(TAA) 50 mg/kg bw s.c.1 h alter the respective assigned treatments every 72 h.At the end of all experimental methods,all the animals were sacrificed by cervical decapitation.Blood samples were collected.Serum was separated and analyzed for various biochemical parameters.Results:TAA induced a significant rise in aspartate amino transferase(AST),alanine amino transferase(ALT),alkaline phosphatase(ALP),total bilirubin,gamma glutamate transpeptidase(GGTP),lipid peroxidase(LPO)with a reduction of total protein,superoxide dismutase(SOD),catalase,glutathione peroxidase(GPx) and glutathione S-transferase(GST).Treatment of rats with different does of plant extract(250 and 500 mg/kg) significantly(P<0.001) altered serum marker enzymes and antioxidant levels to near normal against TAA treated rats.The activity of the extract at a dose of 300 tug/kg was comparable to the standard drug,silymarin(50 mg/kg.p.o.).Conclusions:It can be concluded that P.aculeata extract possesses a remarkable hepaloprolective and antioxidant activity against TAA induced hepatotoxicitv.Wore research is required lo derive an optimal therapeutic dose.展开更多
Objective:To identify the phytochemical constituents of Amorphopkallus campanulatus(A. campanulatus) tuber and to evaluate its antioxidant potential through in vitro and in vivo models. Methods:Phytochemical screening...Objective:To identify the phytochemical constituents of Amorphopkallus campanulatus(A. campanulatus) tuber and to evaluate its antioxidant potential through in vitro and in vivo models. Methods:Phytochemical screening and in vitro antioxidant activities of A.campanulatus tuber n-hexane extract(ACHE) and methanolic extract(ACME) were evaluated using DPPH,hydroxyl radical,reducing power and total antioxidant capacity assays.The total phenolic and flavonoid contents were also investigated.The protective potential of two different doses of ACME(125 and 250 mg/kg) was also evaluated against thioaeetamide(TAA) induced oxidative stress in rats. Silymarin used as a standard drug control.Hepatotoxicitv was assessed by quantifying the serum levels of aspartate aminotransferase(AST),alanine aminotransferase(AIT),alkaline phosphatase (ALP) and lactate dehydrogenase(LDH).The antioxidant potential of ACME were also evaluated by the estimation of catalase(CAT),glutathione peroxidase(GPx),glutathione reductase (OR),glutathione-S-transferase(GST),reduced glutathione(GSH) and lipid peroxidation (Thiobarbituric acid reactive substances) in hepatic and renal tissues.Histopathologic changes of liver were also evaluated.Results:In vitro studies revealed that ACME has higher antioxidant and radical scavenging activity than ACHE,which may be attributed to its higher phenolic and flavonoid content.ACME significandy prevented the elevation of serum AST,ALT.ALP,LDH,and tissue malondialdehyde levels(P 【 0.05).Hepatic and renal GSH.GST.GR,GPx,and catalase levels were remarkably increased by the treatment with the extract.Quantification of histopathological changes also supported the dose dependent protective effects of ACME.Conclusions:The results do suggest that A.campanulatus tuber could be considered as a potential source of natural antioxidant.展开更多
AIM: To study the effect of dichloromethylene diphos-phonate (DMDP), a selective Kupffer cell toxicant in reference to liver damage and postnecrotic liver regeneration in rats induced by sublethal dose thioacetamide (...AIM: To study the effect of dichloromethylene diphos-phonate (DMDP), a selective Kupffer cell toxicant in reference to liver damage and postnecrotic liver regeneration in rats induced by sublethal dose thioacetamide (TA). METHODS: Rats, intravenously (iv ) pre-treated with a single dose of DMDP (10 mg/kg), were intraperitoneally (ip ) injected with TA 6.6 mmol/kg (per 500 mg/kg body weight). Hepatocytes were isolated from rats at 0, 24, 48 and 72 h following TA intoxication and blood and liver samples were obtained. To evaluate the mecha-nisms involved in the postnecrotic regenerative state, DNA distribution and ploidy time course were assayed in isolated hepatocytes. Circulating cytokine tumor necrosis factor-alpha (TNF-α) was assayed in serum and determined by reverse transcriptase-polymerase chain reaction in liver extract. RESULTS: The effect of DMDP induced noticeable changes in postnecrotic regeneration, causing an increased percentage of hepatocytes in the cell cycle S phase. The increase at 24 h in S1 population in rats pretreated with DMDP + TA was significantly (P < 0.05) different compared with that of the TA group (18.07% vs 8.57%). Hepatocytes increased their proliferation as a result of these changes. Also, TNF-α expression and serum level were increased in rats pre-treated with DMDP. Thus, DMDP pre-treatment reduced TA-induced liver injury and accelerated postnecrotic liver regeneration. CONCLUSION: These results demonstrate that Kupffer cells are involved in TA-induced liver, as well as in post-necrotic proliferative liver states.展开更多
Background and aims:Combination therapy is a promising new strategy that has been proposed to increase the efficacy of cancer treatment.We aimed to investigate the anti-cancer activity of rifampicin monotherapy and it...Background and aims:Combination therapy is a promising new strategy that has been proposed to increase the efficacy of cancer treatment.We aimed to investigate the anti-cancer activity of rifampicin monotherapy and its combination with doxorubicin against hepatocellular carcinoma(HCC).Materials and methods:The in vitro half maximal inhibitory concentration(IC50)and selectivity index(SI)of the drugs under investigation against HepG2 and human lung fibroblast(WI38)cell lines were determined.For the in vivo experiment,male Sprague-Dawley albino rats were injected with thioacetamide at 200 mg/kg twice a week for 90 days;HCC development was confirmed histopathologically.Following HCC induction,the rats were treated with intraperitoneal doxorubicin,rifampicin,or their combination for 45 or 90 days.After sacrifice,the livers were examined histopathologically.The levels of aminotransferases,albumin,bilirubin,malondialdehyde,superoxide dismutase(SOD),catalase(CAT),total antioxidant capacity(TAC),and nitric oxide were measured by spectrophotometry.Alphafetoprotein,cancer antigen 19-9,tumor necrosis factor-alpha,interleukin-6,Bcl-2-associated X protein,caspase 3,caspase 8,and p53 were estimated using ELISA.Results:In vitro,the combination of doxorubicin and rifampicin showed the highest SI of 3.43.In vivo,among the measured markers,the levels of TAC,CAT,SOD,and p53 decreased(P<0.001)and the rest of the measured marker levels increased(P<0.001)in the HCC-bearing rats;after treatment in all groups,all these changes improved toward normal in a time-dependent manner.The combination of doxorubicin and rifampicin optimized the effects of the two individual drugs and exerted the best antioxidant effects.Conclusions:In general,compared with rifampicin or doxorubicin alone,combination therapy has favorable outcomes.Based on our results,the combination of rifampicin and doxorubicin might be applicable for HCC chemotherapy.展开更多
AIM:To determine the molecular mechanisms involved in experimental hepatic fibrosis prevention by caffeine(CFA).METHODS:Liver fibrosis was induced in Wistar rats by intraperitoneal thioacetamide or bile duct ligation ...AIM:To determine the molecular mechanisms involved in experimental hepatic fibrosis prevention by caffeine(CFA).METHODS:Liver fibrosis was induced in Wistar rats by intraperitoneal thioacetamide or bile duct ligation and they were concomitantly treated with CFA(15 mg/kg per day).Fibrosis and inflammatory cell infiltrate were evaluated and classified by Knodell index.Inflammatory infiltrate was quantified by immunohistochemistry(anti-CD11b).Gene expression was analyzed by quantitative reverse transcription-polymerase chain reaction for collagenⅠ?(Col-1),connective tissue growth factor(CTGF),transforming growth factorβ1(TGF-β1),tumor necrosis factor alpha(TNF-α),interleukin-1(IL-1),IL-6,superoxide dismutase(SOD)and catalase(CAT).Activation of Nrf2 and Snail-1 was analyzed by Westernblot.TNF-αexpression was proved by enzyme-linked immunosorbant assay,CAT activity was performed by zymography.RESULTS:CFA treatment diminished fibrosis index in treated animals.The Knodell index showed both lower fibrosis and necroinflammation.Expression of profibrogenic genes CTGF,Col-1 and TGF-β1 and proinflammatory genes TNF-α,IL-6 and IL-1 was substantially diminished with CFA treatment with less CD11b positive areas.Significantly lower values of transcriptional factor Snail-1 were detected in CFA treated rats compared with cirrhotic rats without treatment;in contrast Nrf2was increased in the presence of CFA.Expression of SOD and CAT was greater in animals treated with CFA showing a strong correlation between mRNA expression and enzyme activity.CONCLUSION:Our results suggest that CFA inhibits the transcriptional factor Snail-1,down-regulating profibrogenic genes,and activates Nrf2 inducing antioxidant enzymes system,preventing inflammation and fibrosis.展开更多
Objective:To assess the In vivo anlioxid Fanl and hepaloproleclive activity of metlianolic exlracl of Daucus carota(D.carota) seeds in experimental animals.Methods:Methanolic extracts of D.carota seeds is used for hep...Objective:To assess the In vivo anlioxid Fanl and hepaloproleclive activity of metlianolic exlracl of Daucus carota(D.carota) seeds in experimental animals.Methods:Methanolic extracts of D.carota seeds is used for hepatoproleclion assessment.Oxidative stress were induced in rats by thioacetamide 100 nig/kg s.c.in four groups of rats(two test,standard and toxic control). Two test groups received D.carota seeds extract[DCSE) at doses of 200 mg/kg and 400 mg/kg. Standard group received silymarin(25 mg/kg) and toxic control received only thioacetamide. Control group received only vehicle.On the 8th day animals were sacrificed and liver enzyme like serum glutamic pyruvic transaminase(SGPT),serum glutamic-oxaloacetic transaminase(SCOT) and alkaline phosphatase(ALP)were estimated in blood serum and antioxidant enzyme like superoxide disnuituse(SOD),cululase(CAT),glutathione reductase(CKD),glutathione peroxidase(GPX),glutalhione-S-transferase(GST)and lipid peroxidation(LPO)were estimated in liver homogcnatc.Results:A significant decrease in SGPT,SCOT and ALP levels was observed in all drug treated groups as compared to thioacetamide group(P<0.001) and in case of antioxidant enzyme a significant(P<0.001) increase in SOD.CAT,GRD,GPX and GST was observed in all dmg treated groups as compared with thioacetamide group.But in case of LPO a significant(P <0.001) reduction was observed as compared to toxic control group.Conclusions:DCSE has contributed lo the reduction of oxidative stress and the protection of liver in experimental rals.展开更多
BACKGROUND Severe acute liver failure(SALF) is a rare, but high-mortality, rapidly evolving syndrome that leads to hepatocyte degeneration with impaired liver function.Thioacetamide(TAA) is a known xenobiotic, which p...BACKGROUND Severe acute liver failure(SALF) is a rare, but high-mortality, rapidly evolving syndrome that leads to hepatocyte degeneration with impaired liver function.Thioacetamide(TAA) is a known xenobiotic, which promotes the increase of the formation of reactive oxygen species. Erythroid 2-related factor 2(Nrf2) activates the antioxidant protection of cells. Studies have evidenced the involvement of inflammatory mediators in conditions of oxidative stress.AIM To evaluate the antioxidant effects of glutamine on Nrf2 activation and NFκBmediated inflammation in rats with TAA-induced IHAG.METHODS Male Wistar rats(n = 28) were divided into four groups: control,control+glutamine, TAA, and TAA + glutamine. Two TAA doses(400 mg/kg)were administered intraperitoneally, 8 h apart. Glutamine(25 mg/kg) was administered at 30 min, 24 h, and 36 h. At 48 h, blood was collected for liver integrity analysis [aspartate aminotransferase(AST), alanine aminotransferase(ALT), and alkaline phosphatase(ALP)]. The liver was harvested for histology and assessment of oxidative stress [thiobarbituric acid-reactive substances(TBARS), catalase(CAT), glutathione peroxidase(GPx), glutathione S-transferase(GST), glutathione(GSH), Nrf2, Kelch-like ECH-associated protein 1(Keap1),NADPH quinone oxidoreductase1(NQO1), superoxide dismutase(SOD)] and inflammatory process.RESULTS TAA caused disruption of the hepatic parenchyma, with inflammatoryinfiltration, massive necrosis, and ballooning degeneration. Glutamine mitigated this tissue damage, with visible regeneration of hepatic parenchyma; decreased TBARS(P < 0.001), GSH(P < 0.01), IL-1β, IL6, and TNFα levels(P <0.01) in hepatic tissue; and decreased blood levels of AST, ALT, and ALP(P <0.05). In addition, CAT, GPx, and GST activities were restored in the glutamine group(P<0.01, P <0.01, and P <0.001, respectively vs TAA alone). Glutamine increased expression of Nrf2(P < 0.05), NQO1, and SOD(P < 0.01), as well as levels of IL-10(P <0.001), while decreasing expression of Keap1, TLR4, NFκB(P < 0.001), COX-2 and iNOS,(P < 0.01), and reducing NO_2 and NO_3 levels(P < 0.05).CONCLUSION In the TAA experimental model of IHAG, glutamine activated the Nrf2 pathway,thus promoting antioxidant protection, and blunted the NFκB-mediated pathway, reducing inflammation.展开更多
AIM To examine the effects of aspirin and enoxaparin on liver function, coagulation index and histopathology in a rat model of liver fibrosis.METHODS Forty-five male Sprague-Dawley rats were randomly divided into the ...AIM To examine the effects of aspirin and enoxaparin on liver function, coagulation index and histopathology in a rat model of liver fibrosis.METHODS Forty-five male Sprague-Dawley rats were randomly divided into the control group(n = 5) and model group(n = 40). Thioacetamide(TAA) was used to induce liver fibrosis in the model group. TAA-induced fibrotic rats received TAA continuously(n = 9), TAA + low-dose aspirin(n = 9), TAA + high-dose aspirin(n = 9) or TAA + enoxaparin(n = 9) for 4 wk. All rats were euthanized after 4 wk, and both hematoxylin-eosin and Masson staining were performed to observe pathological changes in liver tissue. RESULTS Liver fibrosis was assessed according to the METAVIR score. Compared with untreated cirrhotic controls, a significant improvement in fibrosis grade was observed in the low-dose aspirin, high-dose aspirin and enoxaparin treated groups, especially in the high-dose aspirin treated group. Alanine aminotransferase and total bilirubin were higher, albumin was lower and both prothrombin time and international normalized ratio were prolonged in the four treatment groups compared to controls. No significant differences among the four groups were observed.CONCLUSION Aspirin and enoxaparin can alleviate liver fibrosis in this rat model.展开更多
AIM To investigate the potential effect of inhibitors of phosphodiesterase-5(PDE-5) for therapy of portal hypertension in liver cirrhosis.METHODS In the rat model of thioacetamide-induced liver fibrosis/cirrhosis the ...AIM To investigate the potential effect of inhibitors of phosphodiesterase-5(PDE-5) for therapy of portal hypertension in liver cirrhosis.METHODS In the rat model of thioacetamide-induced liver fibrosis/cirrhosis the nitric oxide-cyclic guanosine monophosphate(NO-cGMP) pathway was investigated. Expression and localization of PDE-5, the enzyme that converts vasodilating cGMP into inactive 5'-GMP, was in the focus of the study. Hepatic gene expression of key components of the NO-cGMP pathway was determined by qRT-PCR: Endothelial NO synthase(eNOS), inducible NO synthase(iNOS), soluble guanylate cyclase subunits α1 and β1(sGCa1, sGCb1), and PDE-5. Hepatic PDE-5 protein expression and localization were detected by immunohistochemistry. Serum cGMP concentrations were measured using ELISA. Acute effects of the PDE-5 inhibitor Sildenafil(0.1 mg/kg or 1.0 mg/kg) on portal and systemic hemodynamics were investigated using pressure transducers.RESULTS Hepatic gene expression of eNOS(2.2-fold; P = 0.003), sGCa1(1.7-fold; P = 0.003), sGCb1(3.0-fold; P = 0.003), and PDE-5(11-fold; P = 0.003) was increased in cirrhotic livers compared to healthy livers. Overexpression of PDE-5(7.7-fold; P = 0.006) was less pronounced in fibrotic livers. iNOS expression was only detected in fibrotic and cirrhotic livers. In healthy liver, PDE-5 protein was localized primarily in zone 3 hepatocytes and to a lesser extent in perisinusoidal cells. This zonation was disturbed in cirrhosis: PDE-5 protein expression in perisinusoidal cells was induced approximately 8-fold. In addition, PDE-5-expressing cells were also found in fibrous septa. Serum cGMP concentrations were reduced in rats with cirrhotic livers by approximately 40%. Inhibition of PDE-5 by Sildenafil caused a significant increase in serum cGMP concentrations [+ 64% in healthy rats(P = 0.024), + 85% in cirrhotic rats(P = 0.018)]. Concomitantly, the portal venous pressure was reduced by 19% in rats with liver cirrhosis. CONCLUSION Overexpression and abrogated zonation of PDE-5 likely contribute to the pathogenesis of cirrhotic portal hypertension. PDE-5 inhibition may therefore be a reasonable therapeutic approach for portal hypertension.展开更多
Objective: To evaluate the antioxidant, immunomodulatory and anti-inflammatory activities of pyrrolidine dithiocarbamate and saxagliptin in rats with thioacetamide-induced ulcerative colitis. Methods: Animals were ora...Objective: To evaluate the antioxidant, immunomodulatory and anti-inflammatory activities of pyrrolidine dithiocarbamate and saxagliptin in rats with thioacetamide-induced ulcerative colitis. Methods: Animals were orally administered with a vehicle, sulfasalazine(500 mg/kg), pyrrolidine dithiocarbamate(100 mg/kg), and saxagliptin(10 mg/kg) for two weeks. Ulcerative colitis was induced by a single intrarectal instillation of thioacetamide on day 8. Colon samples were collected to assess mitogen-activated protein kinase(MAPK), phosphorylated extracellular signal-regulated kinase(ERK), c AMP response element-binding protein(CREB), interleukin-12(IL-12), caspase-3, β-defensin, inducible nitric oxide synthase(i NOS) and glucagon like peptide-1(GLP-1). Moreover, histopathological examination was performed. Results: Rats treated with thioacetamide caused increases in colonic MAPK, phosphorylated ERK, CREB, caspase-3, IL-12, β-defensin, i NOS, as well as decreases in body weight and GLP-1. In addition, distortion of colonic structure was found by histopathological examination. Pyrrolidine dithiocarbamate and saxagliptin mitigated colitis severity by improving body weight decrease and GLP-1, and reducing colonic MAPK, phosphorylated ERK, CREB, caspase-3, IL-12, β-defensin and i NOS. Conclusions: Pyrrolidine dithiocarbamate and saxagliptin are efficient against thioacetamide induced colitis through improving inflammatory and oxidative changes.展开更多
BACKGROUND Recently,the exclusive use of mesenchymal stem cell(MSC)-secreted molecules,named as the secretome,have been evaluated for overcoming the limitations of cell-based therapy while maintaining its advantages.A...BACKGROUND Recently,the exclusive use of mesenchymal stem cell(MSC)-secreted molecules,named as the secretome,have been evaluated for overcoming the limitations of cell-based therapy while maintaining its advantages.AIM To improve cell-free therapy by adding disease-specificity through stimulation of MSCs using disease-causing materials.METHODS We collected the secretory materials(named as inducers)released from AML12 hepatocytes that had been pretreated with thioacetamide(TAA)and generated the TAA-induced secretome(TAA-isecretome)after stimulating adipose-derived stem cells with the inducers.The TAA-isecretome was intravenously administered to mice with TAA-induced hepatic failure and those with partial hepatectomy.RESULTS TAA-isecretome infusion showed higher therapeutic potential in terms of(1)restoring disorganized hepatic tissue to normal tissue;(2)inhibiting proinflammatory cytokines(interleukin-6 and tumor necrosis factor-α);and(3)reducing abnormally elevated liver enzymes(aspartate aminotransferase and alanine aminotransferase)compared to the naïve secretome infusion in mice with TAA-induced hepatic failure.However,the TAA-isecretome showed inferior therapeutic potential for restoring hepatic function in partially hepatectomized mice.Proteomic analysis of TAA-isecretome identified that antioxidant processes were the most predominant enriched biological networks of the proteins exclusively identified in the TAA-isecretome.In addition,peroxiredoxin-1,a potent antioxidant protein,was found to be one of representative components of TAA-isecretome and played a central role in the protection of TAA-induced hepatic injury.CONCLUSION Appropriate stimulation of adipose-derived stem cells with TAA led to the production of a secretome enriched with proteins,especially peroxiredoxin-1,with higher antioxidant activity.Our results suggest that appropriate stimulation of MSCs with pathogenic agents can lead to the production of a secretome specialized for protecting against the pathogen.This approach is expected to open a new way of developing various specific therapeutics based on the high plasticity and responsiveness of MSCs.展开更多
AIM:To propose an alternative model of hepatic encephalopathy(HE) in mice,resembling the human features of the disease.METHODS:Mice received two consecutive intraperitoneal injections of thioacetamide(TAA) at low dosa...AIM:To propose an alternative model of hepatic encephalopathy(HE) in mice,resembling the human features of the disease.METHODS:Mice received two consecutive intraperitoneal injections of thioacetamide(TAA) at low dosage(300 mg/kg).Liver injury was assessed by serum transaminase levels(ALT) and liver histology(hematoxylin and eosin).Neutrophil infiltration was estimated by confocal liver intravital microscopy.Coagulopathy was evaluated using prolonged prothrombin and partial thromboplastin time.Hemodynamic parameters were measured through tail cuff.Ammonia levels were quantified in serum and brain samples.Electroencephalography(EEG) and psychomotor activity score were performed to show brain function.Brain edema was evaluated using magnetic resonance imaging.RESULTS:Mice submitted to the TAA regime developed massive liver injury,as shown by elevation of serum ALT levels and a high degree of liver necrosis.An intense hepatic neutrophil accumulation occurred in response to TAA-induced liver injury.This led to mice mortality and weight loss,which was associated with severe coagulopathy.Furthermore,TAA-treated mice presented with increased serum and cerebral levels of ammonia,in parallel with alterations in EEG spectrum and discrete brain edema,as shown by magnetic resonance imaging.In agreement with this,neuropsychomotor abnormalities ensued 36 h after TAA,fulfilling several HE features observed in humans.In this context of liver injury and neurological dysfunction,we observed lung inflammation and alterations in blood pressure and heart rate that were indicative of multiple organ dysfunction syndrome.CONCLUSION:In summary,we describe a new murine model of hepatic encephalopathy comprising multiple features of the disease in humans,which may provide new insights for treatment.展开更多
Several mixed ligand Cu(II), Zn(II) complexes using (benzylidenethiourea) (obtained by the condensation of benzaldehyde and thiourea) as the primary ligand and (acetamide or thioacetamide) as an additional ligand were...Several mixed ligand Cu(II), Zn(II) complexes using (benzylidenethiourea) (obtained by the condensation of benzaldehyde and thiourea) as the primary ligand and (acetamide or thioacetamide) as an additional ligand were synthesized and characterized analytically and spectroscopically, magnetic susceptibility and molar conductance measurements ,as well as by UV-Vis. and IR spectroscopy. The interaction of the complexes with calf thymus (CT)DNA was studied using absorption spectra, while the concentration of DNA in gel electrophoresis remained constant at 10 μl. They exhibit absorption hypochromicity increased during the binding of the complexes to calf thymus DNA. The complexes show enhanced antimicrobial activities complexes with the free ligand. A theoretical treatment of the formation of complexes in the gas phase was studied, this was done using the HYPERCHEM-6 program for the Molecular mechanics and Semi-empirical calculations.展开更多
基金funded by Theodore Bilharz Research Institute (grant number:ID-MS-99/A,Principal investigator:Naglaa M.El-Lakkany).
文摘Objective:To evaluate the effect of hydroxysafflor yellow A(HSYA)on thioacetamide-induced liver fibrosis.Methods:Thioacetamide was administered to rats intraperitoneally in doses of 200 mg/kg twice a week for 12 weeks.Thioacetamide-intoxicated rats were given silymarin(50 mg/kg)or HSYA(5 mg/kg)orally every day for 8 weeks.Liver enzymes,fibrosis markers,histological changes as well as immunohistochemistry of TNF-α,IL-6,p21,α-SMA,and caspase-3 were examined.The effect of HSYA on HSC-T6 activation/proliferation and apoptosis was also determined in vitro.Results:HSYA decreased liver enzymes,TNF-α,IL-6,and p21 expressions,hepatic PDGF-B,TIMP-1,TGF-β1,and hydroxyproline levels,as well as fibrosis score(S2 vs.S4)compared to the thioacetamide group.HSYA also downregulatedα-SMA while increasing caspase-3 expression.Surprisingly,at 500μg/mL,HSYA had only a slightly suppressive effect on HSC proliferation,with a 9.5%reduction.However,it significantly reduced TGF-β1,inhibitedα-SMA expression,induced caspase-3 expression,and promoted cell senescence.Conclusions:HSYA may be a potential therapeutic agent for delaying and reversing the progression of liver fibrosis.More research on HSYA at higher doses and for a longer period is warranted.
文摘Objective:To investigate and compare the hepatoprotective effects of crude ethanolic and aqueous extracts of Phyllanthus acidus（L.） Skeels（P.acidus） leaves on acetaminophen（APAP） and thioacetamide（TAA） induced liver toxicity in wistar rats.Silymarin was the reference hepatoprotective agent.Methods:In two different sets of experiments,the P.acidus extracts （200 and 400 mg/kg,body weight） and silymarin（100 mg/kg,body weight） were given orally for 7 days and a single dose of APAP（2 g/kg,per oral） or TAA（100 mg/kg,subcutaneous） were given to rats.The level of serum aspartate transaminase（AST）,alanine transaminase（ALT）,alkaline phosphatase（ALP）,total bilirubin and total protein were monitored to assess hepatotoxicity and hepatoprotection.Results:APAP or TAA administration caused severe hepatic damage in rats as evident from significant rise in serum AST,ALT,ALP,total bilirubin and concurrent depletion in total serum protein.The P.acidus extracts and silymarin prevented the toxic effects of APAP or TAA on the above serum parameters indicating the hepatoprotective action.The aqueous extract was found to be more potent than the corresponding ethanolic extract against both toxicants.The phenolic and flavonoid content（175.02±4.35 and 74.68±1.28,respectively） and 2,2-diphenyl-1- picrylhydrazil（DPPH）[IC<sub>50</sub>=（33.2±0.31）μg/mL]scavenging potential was found maximum with aqueous extract as compared to ethanolic extract.Conclusions:The results of present study suggests that the aqueous extract of P.acidus leaves has significant hepatoprotective activity on APAP and TAA induced hepatotoxicity,which might be associate with its high phenolic and flavonoid content and antioxidant properties.
文摘Objective:To investigate the antifibrotic effects of Chrysanthemum indicum ethanol extract(CIEE)against activated hepatic stellate cells(HSC)and thioacetamide(TAA)-induced hepatofibrosis in rats.Methods:Cell viability and proliferation of HSC-T6 cells were measured using MTT assay.Primary HSCs were used to study morphology.TAA(200 mg/kg)was used to induced hepatic fibrosis in rats.CIEE(100 and 500 mg/kg)and silymarin(50 mg/kg)were administered orally.Liver functions including alanine transaminase,aspartate transaminase,glutathione,and hydroxyproline levels were measured using commercial kits.Liver sections and fibrotic biomarker expression were measured using hematoxylin and eosin staining and real-time polymerase chain reaction.Results:In vitro study revealed that CIEE(0.1,0.25,and 0.5 mg/mL)inhibited the proliferation of activated HSCs exposed to transforming growth factor(TGF)-β and restored the activated primary HSC morphology.In in vivo studies,TAA-induced increase in liver/body weight ratio(5.46±0.26)was significantly reduced(4.13±0.22)by CIEE(P<0.05 at 500 mg/kg).CIEE(100 and 500 mg/kg)improved the liver functions by significantly attenuating changes in alanine transaminase,aspartate transaminase,glutathione,and hydroxyproline levels(P<0.05).Further,CIEE(100 and 500 mg/kg)ameliorated the histological changes in liver tissue and TGF-β expression significantly(P<0.05)in TAA-induced rats.Conclusions:CIEE significantly protects against TAA-induced liver damage in rats and can be used in the treatment of liver fibrosis.
文摘AIM:To examine whether the administration of atorvastatin and rosuvastatin would prevent experimentallyinduced hepatic cirrhosis in rats.METHODS:Liver cirrhosis was induced by injections of thioacetamide(TAA).Rats were treated concurrently with TAA alone or TAA and either atorvastatin(1,10 and 20 mg/kg) or rosuvastatin(1,2.5,5,10 and 20 mg/kg) given daily by nasogastric gavage.RESULTS:Liver fibrosis and hepatic hydroxyproline content,in the TAA-treated group was significantly higher than those of the controls [11.5 ± 3.2 vs 2.6 ± 0.6 mg/g protein(P = 0.02)].There were no differences in serum aminotransferase levels in the TAA controls compared to all the groups treated concomitantly by statins.Both statins used in our study did not prevent liver fibrosis or reduce portal hypertension,and had no effect on hepatic oxidative stress.Accordingly,the hepatic level of malondialdehyde was not lower in those groups treated by TAA + statins compared to TAA only.In vitro studies,using the BrdU method have shown that atorvastatin had no effect of hepatic stellate cells proliferation.Nevertheless,statin treatment was not associated with worsening of liver damage,portal hypertension or survival rate.CONCLUSION:Atorvastatin or rosuvastatin did not inhibit TAA-induced liver cirrhosis or oxidative stress in rats.Whether statins may have therapeutic applications in hepatic fibrosis due to other etiologies deserve further investigation.
文摘Objective:To evalueate hepatoprotective effects Feronia elephantum(F.elephantum)correa against thioacctamide(TA)induced liver necrosis in diabetic rats.Methods:Male wistar rats were made diabetic with alloxan(160 mg/kg)on day 0 of the study.They were intoxicated with hepatotoxicant(thioacetamide,300 mg/kg,ip)on day 9 of study to produce liver necrosis.Effects of 7 day daily once administration(day 2 to day 9)of EF(400 and 800 mg/kg,po)were evaluated on necorosis of liver in terms of mortality,liver volume,liver weight,serum aspartate aminotransferase(AST)and serum alanine transaminase(ALT),and histopathology of liver sections(for signs of necorosis and inflammation)on day-9 of the study.Separate groups of rats with treated only with alloxan(DA control),thioacetamide(TA control)and both(TA+DA control)were maintained.Results:FE significantly lowered the mortality rate and showed improvement in liver function parameters in TA-induced diabetic rats without change in liver weight,volume and serum glucose levels.Conclusions:FE showed promising activity against TA-induced liver necorsis in diabetic rats and so might be useful for prevention of liver complications in DM.
文摘Objective:To evaluate the protective effect of Pisonia aculeata(P.aculeata) on thioacetamide induced hepatotoxicity in rats.Methods:Male Wistar rats were administered 250 or 500 mg/kg p.o.of P.aculeata extract for 21 days and simultaneously administered thioacetamide(TAA) 50 mg/kg bw s.c.1 h alter the respective assigned treatments every 72 h.At the end of all experimental methods,all the animals were sacrificed by cervical decapitation.Blood samples were collected.Serum was separated and analyzed for various biochemical parameters.Results:TAA induced a significant rise in aspartate amino transferase(AST),alanine amino transferase(ALT),alkaline phosphatase(ALP),total bilirubin,gamma glutamate transpeptidase(GGTP),lipid peroxidase(LPO)with a reduction of total protein,superoxide dismutase(SOD),catalase,glutathione peroxidase(GPx) and glutathione S-transferase(GST).Treatment of rats with different does of plant extract(250 and 500 mg/kg) significantly(P<0.001) altered serum marker enzymes and antioxidant levels to near normal against TAA treated rats.The activity of the extract at a dose of 300 tug/kg was comparable to the standard drug,silymarin(50 mg/kg.p.o.).Conclusions:It can be concluded that P.aculeata extract possesses a remarkable hepaloprolective and antioxidant activity against TAA induced hepatotoxicitv.Wore research is required lo derive an optimal therapeutic dose.
基金financially supported by University Grants Commission(UGC),New Delhi,India[F.No.37-265/2009(SR)]Financial assistance from UGC as Research Fellowship in Sciences for Meritorious Students to P.N. ANSIL
文摘Objective:To identify the phytochemical constituents of Amorphopkallus campanulatus(A. campanulatus) tuber and to evaluate its antioxidant potential through in vitro and in vivo models. Methods:Phytochemical screening and in vitro antioxidant activities of A.campanulatus tuber n-hexane extract(ACHE) and methanolic extract(ACME) were evaluated using DPPH,hydroxyl radical,reducing power and total antioxidant capacity assays.The total phenolic and flavonoid contents were also investigated.The protective potential of two different doses of ACME(125 and 250 mg/kg) was also evaluated against thioaeetamide(TAA) induced oxidative stress in rats. Silymarin used as a standard drug control.Hepatotoxicitv was assessed by quantifying the serum levels of aspartate aminotransferase(AST),alanine aminotransferase(AIT),alkaline phosphatase (ALP) and lactate dehydrogenase(LDH).The antioxidant potential of ACME were also evaluated by the estimation of catalase(CAT),glutathione peroxidase(GPx),glutathione reductase (OR),glutathione-S-transferase(GST),reduced glutathione(GSH) and lipid peroxidation (Thiobarbituric acid reactive substances) in hepatic and renal tissues.Histopathologic changes of liver were also evaluated.Results:In vitro studies revealed that ACME has higher antioxidant and radical scavenging activity than ACHE,which may be attributed to its higher phenolic and flavonoid content.ACME significandy prevented the elevation of serum AST,ALT.ALP,LDH,and tissue malondialdehyde levels(P 【 0.05).Hepatic and renal GSH.GST.GR,GPx,and catalase levels were remarkably increased by the treatment with the extract.Quantification of histopathological changes also supported the dose dependent protective effects of ACME.Conclusions:The results do suggest that A.campanulatus tuber could be considered as a potential source of natural antioxidant.
文摘AIM: To study the effect of dichloromethylene diphos-phonate (DMDP), a selective Kupffer cell toxicant in reference to liver damage and postnecrotic liver regeneration in rats induced by sublethal dose thioacetamide (TA). METHODS: Rats, intravenously (iv ) pre-treated with a single dose of DMDP (10 mg/kg), were intraperitoneally (ip ) injected with TA 6.6 mmol/kg (per 500 mg/kg body weight). Hepatocytes were isolated from rats at 0, 24, 48 and 72 h following TA intoxication and blood and liver samples were obtained. To evaluate the mecha-nisms involved in the postnecrotic regenerative state, DNA distribution and ploidy time course were assayed in isolated hepatocytes. Circulating cytokine tumor necrosis factor-alpha (TNF-α) was assayed in serum and determined by reverse transcriptase-polymerase chain reaction in liver extract. RESULTS: The effect of DMDP induced noticeable changes in postnecrotic regeneration, causing an increased percentage of hepatocytes in the cell cycle S phase. The increase at 24 h in S1 population in rats pretreated with DMDP + TA was significantly (P < 0.05) different compared with that of the TA group (18.07% vs 8.57%). Hepatocytes increased their proliferation as a result of these changes. Also, TNF-α expression and serum level were increased in rats pre-treated with DMDP. Thus, DMDP pre-treatment reduced TA-induced liver injury and accelerated postnecrotic liver regeneration. CONCLUSION: These results demonstrate that Kupffer cells are involved in TA-induced liver, as well as in post-necrotic proliferative liver states.
文摘Background and aims:Combination therapy is a promising new strategy that has been proposed to increase the efficacy of cancer treatment.We aimed to investigate the anti-cancer activity of rifampicin monotherapy and its combination with doxorubicin against hepatocellular carcinoma(HCC).Materials and methods:The in vitro half maximal inhibitory concentration(IC50)and selectivity index(SI)of the drugs under investigation against HepG2 and human lung fibroblast(WI38)cell lines were determined.For the in vivo experiment,male Sprague-Dawley albino rats were injected with thioacetamide at 200 mg/kg twice a week for 90 days;HCC development was confirmed histopathologically.Following HCC induction,the rats were treated with intraperitoneal doxorubicin,rifampicin,or their combination for 45 or 90 days.After sacrifice,the livers were examined histopathologically.The levels of aminotransferases,albumin,bilirubin,malondialdehyde,superoxide dismutase(SOD),catalase(CAT),total antioxidant capacity(TAC),and nitric oxide were measured by spectrophotometry.Alphafetoprotein,cancer antigen 19-9,tumor necrosis factor-alpha,interleukin-6,Bcl-2-associated X protein,caspase 3,caspase 8,and p53 were estimated using ELISA.Results:In vitro,the combination of doxorubicin and rifampicin showed the highest SI of 3.43.In vivo,among the measured markers,the levels of TAC,CAT,SOD,and p53 decreased(P<0.001)and the rest of the measured marker levels increased(P<0.001)in the HCC-bearing rats;after treatment in all groups,all these changes improved toward normal in a time-dependent manner.The combination of doxorubicin and rifampicin optimized the effects of the two individual drugs and exerted the best antioxidant effects.Conclusions:In general,compared with rifampicin or doxorubicin alone,combination therapy has favorable outcomes.Based on our results,the combination of rifampicin and doxorubicin might be applicable for HCC chemotherapy.
基金Supported by Conacyt grant No.25474 to Juan ArmendárizBorunda
文摘AIM:To determine the molecular mechanisms involved in experimental hepatic fibrosis prevention by caffeine(CFA).METHODS:Liver fibrosis was induced in Wistar rats by intraperitoneal thioacetamide or bile duct ligation and they were concomitantly treated with CFA(15 mg/kg per day).Fibrosis and inflammatory cell infiltrate were evaluated and classified by Knodell index.Inflammatory infiltrate was quantified by immunohistochemistry(anti-CD11b).Gene expression was analyzed by quantitative reverse transcription-polymerase chain reaction for collagenⅠ?(Col-1),connective tissue growth factor(CTGF),transforming growth factorβ1(TGF-β1),tumor necrosis factor alpha(TNF-α),interleukin-1(IL-1),IL-6,superoxide dismutase(SOD)and catalase(CAT).Activation of Nrf2 and Snail-1 was analyzed by Westernblot.TNF-αexpression was proved by enzyme-linked immunosorbant assay,CAT activity was performed by zymography.RESULTS:CFA treatment diminished fibrosis index in treated animals.The Knodell index showed both lower fibrosis and necroinflammation.Expression of profibrogenic genes CTGF,Col-1 and TGF-β1 and proinflammatory genes TNF-α,IL-6 and IL-1 was substantially diminished with CFA treatment with less CD11b positive areas.Significantly lower values of transcriptional factor Snail-1 were detected in CFA treated rats compared with cirrhotic rats without treatment;in contrast Nrf2was increased in the presence of CFA.Expression of SOD and CAT was greater in animals treated with CFA showing a strong correlation between mRNA expression and enzyme activity.CONCLUSION:Our results suggest that CFA inhibits the transcriptional factor Snail-1,down-regulating profibrogenic genes,and activates Nrf2 inducing antioxidant enzymes system,preventing inflammation and fibrosis.
文摘Objective:To assess the In vivo anlioxid Fanl and hepaloproleclive activity of metlianolic exlracl of Daucus carota(D.carota) seeds in experimental animals.Methods:Methanolic extracts of D.carota seeds is used for hepatoproleclion assessment.Oxidative stress were induced in rats by thioacetamide 100 nig/kg s.c.in four groups of rats(two test,standard and toxic control). Two test groups received D.carota seeds extract[DCSE) at doses of 200 mg/kg and 400 mg/kg. Standard group received silymarin(25 mg/kg) and toxic control received only thioacetamide. Control group received only vehicle.On the 8th day animals were sacrificed and liver enzyme like serum glutamic pyruvic transaminase(SGPT),serum glutamic-oxaloacetic transaminase(SCOT) and alkaline phosphatase(ALP)were estimated in blood serum and antioxidant enzyme like superoxide disnuituse(SOD),cululase(CAT),glutathione reductase(CKD),glutathione peroxidase(GPX),glutalhione-S-transferase(GST)and lipid peroxidation(LPO)were estimated in liver homogcnatc.Results:A significant decrease in SGPT,SCOT and ALP levels was observed in all drug treated groups as compared to thioacetamide group(P<0.001) and in case of antioxidant enzyme a significant(P<0.001) increase in SOD.CAT,GRD,GPX and GST was observed in all dmg treated groups as compared with thioacetamide group.But in case of LPO a significant(P <0.001) reduction was observed as compared to toxic control group.Conclusions:DCSE has contributed lo the reduction of oxidative stress and the protection of liver in experimental rals.
文摘BACKGROUND Severe acute liver failure(SALF) is a rare, but high-mortality, rapidly evolving syndrome that leads to hepatocyte degeneration with impaired liver function.Thioacetamide(TAA) is a known xenobiotic, which promotes the increase of the formation of reactive oxygen species. Erythroid 2-related factor 2(Nrf2) activates the antioxidant protection of cells. Studies have evidenced the involvement of inflammatory mediators in conditions of oxidative stress.AIM To evaluate the antioxidant effects of glutamine on Nrf2 activation and NFκBmediated inflammation in rats with TAA-induced IHAG.METHODS Male Wistar rats(n = 28) were divided into four groups: control,control+glutamine, TAA, and TAA + glutamine. Two TAA doses(400 mg/kg)were administered intraperitoneally, 8 h apart. Glutamine(25 mg/kg) was administered at 30 min, 24 h, and 36 h. At 48 h, blood was collected for liver integrity analysis [aspartate aminotransferase(AST), alanine aminotransferase(ALT), and alkaline phosphatase(ALP)]. The liver was harvested for histology and assessment of oxidative stress [thiobarbituric acid-reactive substances(TBARS), catalase(CAT), glutathione peroxidase(GPx), glutathione S-transferase(GST), glutathione(GSH), Nrf2, Kelch-like ECH-associated protein 1(Keap1),NADPH quinone oxidoreductase1(NQO1), superoxide dismutase(SOD)] and inflammatory process.RESULTS TAA caused disruption of the hepatic parenchyma, with inflammatoryinfiltration, massive necrosis, and ballooning degeneration. Glutamine mitigated this tissue damage, with visible regeneration of hepatic parenchyma; decreased TBARS(P < 0.001), GSH(P < 0.01), IL-1β, IL6, and TNFα levels(P <0.01) in hepatic tissue; and decreased blood levels of AST, ALT, and ALP(P <0.05). In addition, CAT, GPx, and GST activities were restored in the glutamine group(P<0.01, P <0.01, and P <0.001, respectively vs TAA alone). Glutamine increased expression of Nrf2(P < 0.05), NQO1, and SOD(P < 0.01), as well as levels of IL-10(P <0.001), while decreasing expression of Keap1, TLR4, NFκB(P < 0.001), COX-2 and iNOS,(P < 0.01), and reducing NO_2 and NO_3 levels(P < 0.05).CONCLUSION In the TAA experimental model of IHAG, glutamine activated the Nrf2 pathway,thus promoting antioxidant protection, and blunted the NFκB-mediated pathway, reducing inflammation.
文摘AIM To examine the effects of aspirin and enoxaparin on liver function, coagulation index and histopathology in a rat model of liver fibrosis.METHODS Forty-five male Sprague-Dawley rats were randomly divided into the control group(n = 5) and model group(n = 40). Thioacetamide(TAA) was used to induce liver fibrosis in the model group. TAA-induced fibrotic rats received TAA continuously(n = 9), TAA + low-dose aspirin(n = 9), TAA + high-dose aspirin(n = 9) or TAA + enoxaparin(n = 9) for 4 wk. All rats were euthanized after 4 wk, and both hematoxylin-eosin and Masson staining were performed to observe pathological changes in liver tissue. RESULTS Liver fibrosis was assessed according to the METAVIR score. Compared with untreated cirrhotic controls, a significant improvement in fibrosis grade was observed in the low-dose aspirin, high-dose aspirin and enoxaparin treated groups, especially in the high-dose aspirin treated group. Alanine aminotransferase and total bilirubin were higher, albumin was lower and both prothrombin time and international normalized ratio were prolonged in the four treatment groups compared to controls. No significant differences among the four groups were observed.CONCLUSION Aspirin and enoxaparin can alleviate liver fibrosis in this rat model.
文摘AIM To investigate the potential effect of inhibitors of phosphodiesterase-5(PDE-5) for therapy of portal hypertension in liver cirrhosis.METHODS In the rat model of thioacetamide-induced liver fibrosis/cirrhosis the nitric oxide-cyclic guanosine monophosphate(NO-cGMP) pathway was investigated. Expression and localization of PDE-5, the enzyme that converts vasodilating cGMP into inactive 5'-GMP, was in the focus of the study. Hepatic gene expression of key components of the NO-cGMP pathway was determined by qRT-PCR: Endothelial NO synthase(eNOS), inducible NO synthase(iNOS), soluble guanylate cyclase subunits α1 and β1(sGCa1, sGCb1), and PDE-5. Hepatic PDE-5 protein expression and localization were detected by immunohistochemistry. Serum cGMP concentrations were measured using ELISA. Acute effects of the PDE-5 inhibitor Sildenafil(0.1 mg/kg or 1.0 mg/kg) on portal and systemic hemodynamics were investigated using pressure transducers.RESULTS Hepatic gene expression of eNOS(2.2-fold; P = 0.003), sGCa1(1.7-fold; P = 0.003), sGCb1(3.0-fold; P = 0.003), and PDE-5(11-fold; P = 0.003) was increased in cirrhotic livers compared to healthy livers. Overexpression of PDE-5(7.7-fold; P = 0.006) was less pronounced in fibrotic livers. iNOS expression was only detected in fibrotic and cirrhotic livers. In healthy liver, PDE-5 protein was localized primarily in zone 3 hepatocytes and to a lesser extent in perisinusoidal cells. This zonation was disturbed in cirrhosis: PDE-5 protein expression in perisinusoidal cells was induced approximately 8-fold. In addition, PDE-5-expressing cells were also found in fibrous septa. Serum cGMP concentrations were reduced in rats with cirrhotic livers by approximately 40%. Inhibition of PDE-5 by Sildenafil caused a significant increase in serum cGMP concentrations [+ 64% in healthy rats(P = 0.024), + 85% in cirrhotic rats(P = 0.018)]. Concomitantly, the portal venous pressure was reduced by 19% in rats with liver cirrhosis. CONCLUSION Overexpression and abrogated zonation of PDE-5 likely contribute to the pathogenesis of cirrhotic portal hypertension. PDE-5 inhibition may therefore be a reasonable therapeutic approach for portal hypertension.
文摘Objective: To evaluate the antioxidant, immunomodulatory and anti-inflammatory activities of pyrrolidine dithiocarbamate and saxagliptin in rats with thioacetamide-induced ulcerative colitis. Methods: Animals were orally administered with a vehicle, sulfasalazine(500 mg/kg), pyrrolidine dithiocarbamate(100 mg/kg), and saxagliptin(10 mg/kg) for two weeks. Ulcerative colitis was induced by a single intrarectal instillation of thioacetamide on day 8. Colon samples were collected to assess mitogen-activated protein kinase(MAPK), phosphorylated extracellular signal-regulated kinase(ERK), c AMP response element-binding protein(CREB), interleukin-12(IL-12), caspase-3, β-defensin, inducible nitric oxide synthase(i NOS) and glucagon like peptide-1(GLP-1). Moreover, histopathological examination was performed. Results: Rats treated with thioacetamide caused increases in colonic MAPK, phosphorylated ERK, CREB, caspase-3, IL-12, β-defensin, i NOS, as well as decreases in body weight and GLP-1. In addition, distortion of colonic structure was found by histopathological examination. Pyrrolidine dithiocarbamate and saxagliptin mitigated colitis severity by improving body weight decrease and GLP-1, and reducing colonic MAPK, phosphorylated ERK, CREB, caspase-3, IL-12, β-defensin and i NOS. Conclusions: Pyrrolidine dithiocarbamate and saxagliptin are efficient against thioacetamide induced colitis through improving inflammatory and oxidative changes.
基金Supported by National Research Foundation of Korea,No.NRF-2015R1C1A1A02036931
文摘BACKGROUND Recently,the exclusive use of mesenchymal stem cell(MSC)-secreted molecules,named as the secretome,have been evaluated for overcoming the limitations of cell-based therapy while maintaining its advantages.AIM To improve cell-free therapy by adding disease-specificity through stimulation of MSCs using disease-causing materials.METHODS We collected the secretory materials(named as inducers)released from AML12 hepatocytes that had been pretreated with thioacetamide(TAA)and generated the TAA-induced secretome(TAA-isecretome)after stimulating adipose-derived stem cells with the inducers.The TAA-isecretome was intravenously administered to mice with TAA-induced hepatic failure and those with partial hepatectomy.RESULTS TAA-isecretome infusion showed higher therapeutic potential in terms of(1)restoring disorganized hepatic tissue to normal tissue;(2)inhibiting proinflammatory cytokines(interleukin-6 and tumor necrosis factor-α);and(3)reducing abnormally elevated liver enzymes(aspartate aminotransferase and alanine aminotransferase)compared to the naïve secretome infusion in mice with TAA-induced hepatic failure.However,the TAA-isecretome showed inferior therapeutic potential for restoring hepatic function in partially hepatectomized mice.Proteomic analysis of TAA-isecretome identified that antioxidant processes were the most predominant enriched biological networks of the proteins exclusively identified in the TAA-isecretome.In addition,peroxiredoxin-1,a potent antioxidant protein,was found to be one of representative components of TAA-isecretome and played a central role in the protection of TAA-induced hepatic injury.CONCLUSION Appropriate stimulation of adipose-derived stem cells with TAA led to the production of a secretome enriched with proteins,especially peroxiredoxin-1,with higher antioxidant activity.Our results suggest that appropriate stimulation of MSCs with pathogenic agents can lead to the production of a secretome specialized for protecting against the pathogen.This approach is expected to open a new way of developing various specific therapeutics based on the high plasticity and responsiveness of MSCs.
基金CNPq,Fapemig,PRONEX and CAPES for financial support.
文摘AIM:To propose an alternative model of hepatic encephalopathy(HE) in mice,resembling the human features of the disease.METHODS:Mice received two consecutive intraperitoneal injections of thioacetamide(TAA) at low dosage(300 mg/kg).Liver injury was assessed by serum transaminase levels(ALT) and liver histology(hematoxylin and eosin).Neutrophil infiltration was estimated by confocal liver intravital microscopy.Coagulopathy was evaluated using prolonged prothrombin and partial thromboplastin time.Hemodynamic parameters were measured through tail cuff.Ammonia levels were quantified in serum and brain samples.Electroencephalography(EEG) and psychomotor activity score were performed to show brain function.Brain edema was evaluated using magnetic resonance imaging.RESULTS:Mice submitted to the TAA regime developed massive liver injury,as shown by elevation of serum ALT levels and a high degree of liver necrosis.An intense hepatic neutrophil accumulation occurred in response to TAA-induced liver injury.This led to mice mortality and weight loss,which was associated with severe coagulopathy.Furthermore,TAA-treated mice presented with increased serum and cerebral levels of ammonia,in parallel with alterations in EEG spectrum and discrete brain edema,as shown by magnetic resonance imaging.In agreement with this,neuropsychomotor abnormalities ensued 36 h after TAA,fulfilling several HE features observed in humans.In this context of liver injury and neurological dysfunction,we observed lung inflammation and alterations in blood pressure and heart rate that were indicative of multiple organ dysfunction syndrome.CONCLUSION:In summary,we describe a new murine model of hepatic encephalopathy comprising multiple features of the disease in humans,which may provide new insights for treatment.
文摘Several mixed ligand Cu(II), Zn(II) complexes using (benzylidenethiourea) (obtained by the condensation of benzaldehyde and thiourea) as the primary ligand and (acetamide or thioacetamide) as an additional ligand were synthesized and characterized analytically and spectroscopically, magnetic susceptibility and molar conductance measurements ,as well as by UV-Vis. and IR spectroscopy. The interaction of the complexes with calf thymus (CT)DNA was studied using absorption spectra, while the concentration of DNA in gel electrophoresis remained constant at 10 μl. They exhibit absorption hypochromicity increased during the binding of the complexes to calf thymus DNA. The complexes show enhanced antimicrobial activities complexes with the free ligand. A theoretical treatment of the formation of complexes in the gas phase was studied, this was done using the HYPERCHEM-6 program for the Molecular mechanics and Semi-empirical calculations.
