Clonorchis sinensis is one of the most prevalent parasitic helminths in Korea. Although cholangiocarcinoma can be induced by C. sinensis infection, the underlying mechanism is not clearly understood. To assess the role of C. sinensis infection in carcinogenesis, an in vitro system was established using the human epithelial cell line HEK293T. In cells exposed to the excretory/secretory products (ESP) of C. sinensis and the carcinogen dimethylnitrosamine (DMN), cellular proliferation and the proportion of cells in the G2/M phase increased. Moreover, the expression of the cell cycle proteins E2F1, p-pRb, and cyclin B was dramatically increased when ESP and DMN were added together. Similarly, the transcription factor E2F1 showed its highest level of activity when ESP and DMN were added simultaneously. These findings indicate that DMN and ESP synergistically affect the regulation of cell cycle-related proteins. Our results suggest that exposure to C. sinensis and a small amount of a carcinogen such as DMN can promote carcinogenesis in the bile duct epithelium via uncontrolled cellular proliferation and the upregulation of cell cycle-related proteins.
Animals ; Carcinogens/*metabolism/*toxicity ; Cell Cycle/drug effects ; Cell Line ; Cell Proliferation ; Clonorchis sinensis/*metabolism ; Dimethylnitrosamine/*toxicity ; Epithelial Cells/*drug effects ; Humans

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.
Animals ; Antioxidants ; pharmacology ; Chemical and Drug Induced Liver Injury ; drug therapy ; Dimethylnitrosamine ; toxicity ; Female ; Glutathione ; metabolism ; Male ; Protective Agents ; pharmacology ; Rats ; Rats, Wistar ; Silybin ; Silymarin ; pharmacology

OBJECTIVETo study the role of hepatic sinusoidal endothelium injury during hepatic fibrogenesis induced by dimethylnitrosamine (DMN) in rats.

METHODSHepatic fibrosis of rats was induced by administration of DMN intraperitoneally three times a week for 4 weeks. The animals were harvested on day 2 and week 1, 2, 3, 4, 5, 6, 8, 12, and 24. The formation of liver fibrosis and hepatic sinusoid capillarization were successively observed by morphological observation and other methods.

RESULTSTwo days after treated with DMN, there was no obvious changes in the liver, but the fenestration of the sinusoidal endothelial cells decreased, and it became more obvious after one week. After four weeks, there was a large necrotic area and a number of pseudolobes appeared. The HA in the serum was lower than that of control (231.30 ng/ml +/- 143.80 ng/ml vs 56.50 ng/ml +/- 18.10 ng/ml; t=3.14, P<0.05), but the hydroxyproline content was obviously higher than that of control (223.04 microg/g +/- 37.09 microg/g vs 61.55 microg/g +/- 20.85 microg/g; t=8.28, P<0.05). Hepatic sinusoid capillarization was gradually formed and defenestration of the hepatic sinusoidal endothelium preceded the appearance of serious hepatocellular damage, hepatic fibrosis and basement membrane.

CONCLUSIONSThe damage and phenotypic alteration of the hepatic sinusoidal endothelium may be a vital issue triggering the liver fibrosis induced by DMN.

Actins ; analysis ; Animals ; Dimethylnitrosamine ; toxicity ; Endothelium, Vascular ; pathology ; physiopathology ; Fibrosis ; chemically induced ; Immunohistochemistry ; Liver ; blood supply ; chemistry ; pathology ; Male ; Muscle, Smooth ; chemistry ; Rats ; Rats, Wistar ; Time Factors ; von Willebrand Factor ; analysis

OBJECTIVETo observe the pharmacological effect of Cordyceps polysaccharide on dimethylnitrosamine (DMN)-induced liver fibrosis in rats.

METHODDMN rat liver fibrosis model was established and divided into the normal group (N, n = 6), the model group (M, n = 11), the Cordyceps polysaccharide group (C, n = 8) and the colchicine group (Q, n = 9). During the modeling for four weeks, Cordyceps polysaccharide (60 mg x kg(-1)) and colchicine (0.1 mg x kg(-1)) were orally administered for three weeks, while the model and normal groups were given disinfected water of the same amount.

OBSERVATIONserum ALT, AST, GGT and Alb, TBil content; content of hydroxyproline (Hyp) in liver tissues; liver pathology and collagen staining; SOD activity and MDA, GSH, GSH-Px in liver tissues; protein expression of proliferating cell nuclear antigen (PCNA) in liver tissues.

RESULTSerum ALT, AST, GGT, TBil significantly increased, and A1b decreased significantly in the model group. Hepatic Hyp significantly increased in the model group, whereas the index remarkably decreased in the Cordyceps polysaccharide group and the colchicine group. HE staining: the structure of normal hepatic lobules was damaged, with hepatocytes tumefaction and proliferation of connective tissues in portal tracts in the model group, while the Cordyceps polysaccharide group and the colchicine group recorded notable reduction in above pathological changes. Collagen staining: the model group showed hepatic lobule fibrous septum and many intact pseudolobules; while the Cordyceps polysaccharide group and the colchicine group witnessed decrease in collagen deposition. The model group showed significant decrease in SOD, GSH-Px and GSH and increase in MDA, whereas the Cordyceps polysaccharide group and the colchicine group recorded notable growth in GSH and GSH-Px. The model group showed significant decrease in protein expression of PCNA in liver tissues, while the Cordyceps polysaccharide group and the colchicine group showed significant reduction.

CONCLUSIONCordyceps polysaccharide can significantly inhibit DMN-induced liver fibrosis and lipid peroxidation in rats.

Alanine Transaminase ; blood ; Animals ; Aspartate Aminotransferases ; blood ; Blotting, Western ; Collagen ; metabolism ; Cordyceps ; chemistry ; Dimethylnitrosamine ; toxicity ; Drug Administration Schedule ; Glutathione ; metabolism ; Glutathione Peroxidase ; Hydroxyproline ; Immunohistochemistry ; Lipid Peroxidation ; drug effects ; Liver ; drug effects ; metabolism ; pathology ; Liver Cirrhosis, Experimental ; blood ; etiology ; prevention & control ; Male ; Malondialdehyde ; metabolism ; Phytotherapy ; Polysaccharides ; administration & dosage ; pharmacology ; Proliferating Cell Nuclear Antigen ; metabolism ; Rats ; Rats, Wistar ; Superoxide Dismutase ; metabolism ; gamma-Glutamyltransferase ; blood

Matrine (MT), the effective component of Sophora flavescens Ait, has been shown to have anti-inflammation, immune-suppressive, anti-tumor, and anti-hepatic fibrosis activities. However, the pharmacological effects of MT still need to be strengthened due to its relatively low efficacy and short half-life. In the present study, we report a more effective thio derivative of MT, MD-1, and its inhibitory effects on the activation of hepatic stellate cells (HSCs) in both cell culture and animal models. Cytological experiments showed that MD-1 can inhibit the proliferation of HSC-T6 cells with a half-maximal inhibitory concentration (IC50) of 62 μmol/L. In addition, MD-1 more strongly inhibits the migration of HSC-T6 cells compared to MT and can more effectively induce G0/G1 arrest and apoptosis. Investigating the biological mechanisms underlying anti-hepatic fibrosis in the presence of MD-1, we found that MD-1 can bind the epidermal growth factor receptor (EGFR) on the surface of HSC-T6 cells, which can further inhibit the phosphorylation of EGFR and its downstream protein kinase B (Akt), resulting in decreased expression of cyclin D1 and eventual inhibition of the activation of HSC-T6 cells. Furthermore, in rats with dimethylnitrosamine (DMN)-induced hepatic fibrosis, MD-1 slowed the development and progression of hepatic fibrosis, protecting hepatic parenchymal cells and improving hepatic functions. Therefore, MD-1 is a potential drug for anti-hepatic fibrosis.
Alkaloids ; pharmacology ; Animals ; Cell Line ; Cyclin D1 ; metabolism ; Dimethylnitrosamine ; toxicity ; Enzyme Activation ; drug effects ; ErbB Receptors ; metabolism ; G1 Phase Cell Cycle Checkpoints ; drug effects ; Hepatic Stellate Cells ; metabolism ; pathology ; Liver Cirrhosis ; chemically induced ; metabolism ; pathology ; prevention & control ; Phosphorylation ; drug effects ; Proto-Oncogene Proteins c-akt ; metabolism ; Quinolizines ; pharmacology ; Rats