Figure 1.
Hematoxylin-eosin staining of hepatic tissues in each group of rats.
With the consumption of high-fat diet, hepatocellular steatosis, ballooning degeneration, lobular inflammation, spotty focal necrosis were gradually shown in the hepatic lobule, especially in zone 3 of acinus. At the end of 8th week, simple steatosis appeared with no inflammatory cell infiltration. At the end of 16th week, steatohepatitis established with inflammatory cell infiltration and spotty focal necrosis (B). At the end of 24th week, numerous polymorphs and mononuclear cells infiltration and portal inflammation were frequently observed (C). These changes were improved in the liver of simvastatin-treated rats (D). A: Control ×200; B: 16th week ×200; C: 24th week ×200; D: Simvastatin-treated group ×200.
Figure 2.
Sudan IV staining of hepatic tissues in each group of rats.
Hepatic steatosis emerged until 8th week and aggravated gradually with the consumption of high-fat diet (B). Panacinar steatosis was observed at the end of 24th week (C). These changes were improved in the liver of simvastatin-treated rats (D). A: Control ×200; B: 16th week ×200; C: 24th week ×200; D: Simvastatin-treated group ×200.
Figure 3.
Masson staining of hepatic tissues in each group of rats.
Slightly sinusoidal fibrosis appeared only in part of model rats until 16th week (B). At the end of 24th week, all model rats showed hepatic fibrosis in sinusoids, partly in portal area (C). These changes were improved in the liver of simvastatin-treated rats (D). A: Control ×200; B: 16th week ×200; C: 24th week ×200; D: Simvastatin-treated group ×200.
Figure 4.
Representative graphs and bar charts of hepatic mRNA and protein expressions of iNOS, eNOS, and Collagen І in each group of rats.
The hepatic protein expression of iNOS and eNOS were detected in the control group of rats, with little collagen I expression (A). With the consumption of high-fat diet, the iNOS and collagen I expressions were gradually increased (B, C, F, G), while eNOS expression was gradually decreased (D, E). Compared with rats in the 24th week group, simvastatin treatment could up-regulate eNOS expression (A, D, E) and down-regulate iNOS expression (B, C), followed by improved hepatic fibrosis, which represented by decreased collagen I expression (F, G). (# P<0.05, compared with the control group; * P<0.05, compared with 24th week group.).
Figure 5.
Representative graphs and bar charts of the mRNA and protein expressions of iNOS, eNOS, α-SMA, and Collagen І in LX-2 cells treated with TGF-β1 and simvastatin.
Most LX-2 cells obtained the quiescent phenotype after treated with ADM for three days. In LX-2 cells pre-treated with ADM, the mRNA and protein expressions of iNOS and eNOS were detected, with little α-SMA, and Collagen І expressions (A). TGF-β1 behaved as the most powerful activator of HSC and increased the iNOS expression and decreased the eNOS expression (B~E). Compared with the TGF-β1 group of LX-2 cells, LX-2 cells cultured with simvastatin alone or with both simvastatin and TGF-β1 had less iNOS, α-SMA, and Collagen І expressions (B, C, F~I) and more eNOS expression (D, E). (# P<0.05, compared with the control group; * P<0.05, compared with LX-2 cells treated with TGF-β1; ^ P<0.05, compared with LX-2 cells treated with simvastatin.).
Figure 6.
Representative graphs and bar charts of the mRNA and protein expressions of iNOS, eNOS, α-SMA, and Collagen І in LX-2 cells cultured with L-NAME and simvastatin.
L-NAME served as a NOS inhibitor, it inhibited both iNOS and eNOS expression (A~E) and induced more α-SMA, and Collagen І expressions (F~I). Simvastatin had antagonistic effect on the activation of LX-2 cells induced by L-NAME via increasing the eNOS expression (D, E). (# P<0.05, compared with the control group; * P<0.05, compared with LX-2 cells treated with L-NAME; ^ P<0.05, compared with LX-2 cells treated with simvastatin.).