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Objective To establish a mouse model of diethylnitrosamine(DEN)-induced hepatocellular carcinoma (HCC),and to explore the effects of two different diet formulas on the establishment of DEN-induced HCC model.Methods SPF C57BL/6 mice (8 males and 8 females) were injected intraperitoneally with 25 mg/kg DEN at day 14 to establish a HCC model.The mice were divided into two groups after weaning.One group was fed with the SPF class rodents cereal-based diet,another group was fed with AIN-93G formula diet.The mice were sacrificed at the age of 9 months.The livers were weighed and the growth of liver cancer was observed and recorded.Results All the mice in the cereal-based diet group developed HCC as expected.The body weight and liver mass of the mice in the AIN-93G diet group were significantly lower than that of the cereal-based diet group.The incidence of HCC,and the number and size of tumor nodules were also significantly lower in the AIN-93G diet group than that in the cereal-based diet group.Conclusions DEN-induced HCC model has been successfully established in mice fed with cereal-based diet,while mice fed with AIN93-G diet prevented the development of DEN-induced HCC,and their body weight was decreased significantly,suggesting that dietary factors play a key role in establishment of animal disease models.
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Objective To investigate the role of macrophage?derived Act1 (nuclear factor kappa B activator 1) in the inflammatory bowel disease. Methods Genetically engineered mice carrying targeted suppression of Act1 in the mac?rophages (Anti?Act1) were used for the dextran sodium sulfate (DSS)?induced ulcerative colitis. The severity of colitis was assessed by weight loss, stool consistency, fecal blood index, colorectal length and H&E histology. The infiltration of CD45 + leukocytes and CD68 + macrophages in the inflammatory intestine was observed by immunohistochemical staining and expression levels of mRNA for inflammatory cytokines in colon tissues were analyzed by RT?qPCR. Results As com?pared with C57 mice, the anti?Act1 mice exhibited less severe acute colitis following DSS treatment, with reduced CD45 +leukocyte and CD68 + macrophage infiltrates in the colon tissue. Inflamed colons of the anti?Act1 mice expressed lower mR?NA levels of TNF?α, IL?1βand IL?6. Conclusions Targeted suppression of Act1 in the macrophages ameliorates dextran sodium sulfate?induced intestinal inflammation.
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Objective:To compare the anti-obesity effect of green tea and black tea polyphenols and investigate their molecular mechanisms. Method:Rats were divided randomly into four groups:control group,high-fat group,high-fat diet with green tea polyphenols(GTP) supplement group,and high-fat diet with black tea polyphenols(BTP) supplement group. Body weight was determined every 2 w. After 3 months,the changes of epididymal fat tissues weight and serum lipids were observed. Expressions of those genes associated with adipocyte differentiation in epididymal fat tissues of rats were measured by real-time transcription-polymerase chain reaction,including pref-1,aP2,TNF-?,leptin,PPAR-?,C/EBP-? . Results:Both GTP and BTP prevented the increase of body weight and fat induced by high-fat diet and profoundly down-regulated those adipocyte-specific genes,including aP2,TNF-?and leptin. In addition,GTP also up-regulated the pre-adipocye marker — pref-1 and reduced the expression of transcription factor,peroxisome proliferators-activated receptor(PPAR-?) . Conclusion:Tea polyphenols could prevent obesity by reversing the adipocyte differentiation,and GTP possessed stronger inhibitory effect than BTP.
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Objective: To investigate the effect of (-) epigallocatechin gallate (EGCG) and black tea polyphenols on the lipid metabolism related gene expression profile of human hepatocellular carcinoma HepG2 cells. Method: The total RNA was isolated from HepG2 cells treated with EGCG (5? mol/L), black tea polyphenols (5?g/ml) or 0.1%DMSO (control) for 8 h and was hybridized to Human 14k cDNA microarray for gene expression profile analysis. Real-time RT-PCR was conducted to confirm microarray data. Results: A total of 13 and 29 genes related to lipid metabolism showed differential change after EGCG or black tea polphenols treatment respectively, of which six genes showed consistent expression. The results of real-time PCR were consistent with the microarray data. Conclusion: The mechanism(s) by which EGCG and black tea polyphenols exerts its effects on lipid metabolism are comprehensive. The novel target identified in this study may provide new evidence for further investigation in the hypolipidemic effects of tea polyphenols.