Effect Of Acanthus Ilicifolius Alkaloid A And Its Acetylated Derivatives On Liver Fibrosis In Rats And Its Molecular Mechanisms

Objective: To study the effect and mechanisms of Acanthus ilicifoliusalkaloid A (4-hydroxy-2(3H)-benzoxazolon, HBOA) and its acetylatedderivatives on the hepatic fibrosis induced by porcine serum (PS) in rats.Methods: The Spraque-Dawley (SD) rats were randomly divided intohepatic fibrosis group and normal control group (NC). The rats in the hepaticfibrosis group were induced by intraperitoneal injection of0.5mL sterile PStwice a week for twelve weeks to induced hepatic fibrosis, and the rats in the NCgroup were intraperitoneally injected equal nomal saline. After the formation ofhepatic fibrosis was confirmed by pathology at the end of the eighth week, therats of hepatic fibrosis were randomly divided into five subgroups: modelcontrol group (MC), colchicine group which as positive control group, HBOAgroup,4-acetoxy-2(3H)-benzoxazolone (TC-2) group and3-acetyl-4-acetoxy-2-benzoxazolone (TC-3) group. The rats in colchicine, HBOA, TC-2and TC-3groups were intragastrically administered their respective drug once daily for4consecutive weeks. At the same time, the rats in NC and MC groups wereintragastrically administered o.6%CMC-Na solution.24hours after the lastadministration of drug, all the animals were sacrificed, blood and liver samples were collected further analysis. The serum alanine aminotransferase (ALT) andaspartate aminotransferase (AST) levels were measured. The content of lipidperoxidation (MDA) in liver tissue were evaluated. The degree of hepaticfibrosis was observed with masson’s stain. The expression of platelet-derivedgrowth factor-BB (PDGF-BB), platelet-derived growth factor receptor-beta(PDGFRβ), mitogen-activated protein kinase3(Mapk3), extracellular signalregulated kinase1(ERK1) and peroxisome proliferator-activated receptor-γ(PPARγ) in liver tissue were assayed by reverse transcription polymerase chainreaction (RT-PCR). The production of transforming growth factor-β1(TGF-β1)and α-smooth muscle actin (α-SMA) in liver tissue were determined byimmunohistochemistry.Results: Compared with the MC group, the activities of serum AST andALT and the content of liver MDA in HBOA, TC-2and TC-3groups weredecreased significantly (P<0.05or P<0.01). The result of masson’s stain showedthat HBOA, TC-2and TC-3could reduce the degree of hepatic fibrosis (P<0.05or P<0.01) induced by PS. The result of RT-PCR showed that the expression ofliver PDGF-BB, PDGFRβ, Mapk3mRNA in HBOA, TC-2and TC-3groupswere decreased significantly (P<0.05or P<0.01) and the expression of liverPPARγ mRNA in HBOA, TC-2and TC-3groups was increased significantly(P<0.05) compared with the MC group. However, compared with the MC group,no significant difference was found on the expression of liver ERK1mRNA inHBOA, TC-2and TC-3groups. The result of immunohistochemistry showedthat the production of liver TGF-β1and α-SMA proteins in HBOA, TC-2andTC-3groups were decreased significantly (P<0.05or P<0.01) compared withthe MC group. There were no significant difference on serum biochemicalindicators, liver tissue collagen and other indicators content of rats between HBOA, TC-2and TC-3groups.Conclusion: HBOA and its acetylated derivatives can intervene inPS-induced liver fibrosis in rats, in which potential mechanisms may be relatedwith inhibiting lipid peroxidation, inhibiting the expression of PDGF-BB,PDGFRβ, Mapk3mRNA and increasing the expression of PPARγ mRNA,decreasing the production of TGF-β1and preventing the activation of hepaticstellate cell (HSC). These may account for their hepatoprotective effect onhepatic fibrosis induced by PS.