非酒精性脂肪性肝炎发病机制的研究进展

Effect of Clematis polysaccharide on serum IL-17 and TNF-α levels and hepatic pathological changes in rats with non-alcoholic steatohepatitis

AIM: To investigate the effect of Clematis polysaccharide on serum levels of interleukin-17 (IL-17) and tumor necrosis factor alpha (TNF-α) and hepatic pathological changes in rats with non-alcoholic steatohepatitis (NASH), and to analyze the correlation between serum levels of IL-17 and TNF-α.

METHODS: A rat model of NASH was established by feeding SD rats a high-fat diet. The levels of fasting IL-17 and TNF-α were tested, and the liver fatty degeneration grade and liver inflammation grade were assessed for NASH model rats, NASH rats treated with Clematis polysaccharide, NASH rats treated with polyene phosphatidylcholine, and normal rats. The differences in fasting IL-17 and TNF-α levels and hepatic pathological changes among all groups were compared, and the correlation between serum levels of IL-17 and TNF-α was analyzed.

RESULTS: Compared with the model group, NASH rats treated with Clematis polysaccharide had milder liver fatty degeneration and liver inflammation (P < 0.05 for both) and lower serum levels of IL-17 and TNF-α (P < 0.01 for both). Compared with the polyene phosphatidylcholine group, NASH rats treated with Clematis polysaccharide had a similar liver fatty degeneration grade and liver inflammation grade, and similar serum IL-17 and TNF-α levels (P > 0.05 for all).

CONCLUSION: Clematis polysaccharide is effective in NASH rats, its therapeutic effect is equivalent to that of polyene phosphatidylcholine, and the underlying mechanism may be associated with reducing serum IL-17 and TNF-α levels, and improving hepatic pathological change.

Application of mesenchymal stem cells in digestive system diseases

Mesenchymal stem cells (MSCs) have the capacity of multipotent differentiation and the property of immunomodulation. MSCs have been widely used in digestive system disease research because of their advantageous characteristics such as homing to areas of inflammation or tumour tissue, anti-inflammation, high plasticity, absence of immunologic rejection, being easy to be isolated, and being convenient for the expression of exogenous genes. In this article, we will review the application of mesenchymal stem cells in digestive system diseases including caustic esophagus injury, reflux esophagitis, gastric ulcer, radioactive intestinal injury, severe acute pancreatitis, inflammatory bowel disease, nonalcoholic steatohepatitis, acute liver failure, hepatic fibrosis, autoimmune liver diseases, liver cirrhosis, esophageal cancer, gastric cancer, colon cancer, liver cancer, and pancreatic cancer.

Current progress in research of overlap syndrome of autoimmune liver diseases

Autoimmune liver diseases (AILDs) include autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC). Overlap syndrome (OS) of AILDs is a relatively infrequent disease that has the combined clinical, biochemical, serological, histological and radiological features of AIH and PBC or PSC, mainly comprising AIH-PBC and AIH-PSC overlap syndromes. The AIH-PBC overlap syndrome is common in adults, while the AIH-PSC overlap syndrome is predominantly found in children. Overlap syndromes have a progressive course and may finally lead to liver cirrhosis and liver failure without treatment. High-dose ursodeoxycholic acid (UDCA) combined with immunosuppressive therapy with corticosteroids and/or azathioprine (AZA) is usually used in both AIH-PBC and AIH-PSC overlap syndromes. At present, liver transplantation is the only option with known therapeutic benefit for end-stage patients.

Therapeutic effects of fistular onion stalk extract on nonalcoholic fatty liver in rats

AIM: To investigate the therapeutic effects of fistular onion stalk extract on nonalcoholic fatty liver (NAFL) in rats.

METHODS: Sixty-four Wistar rats were randomly divided into two groups: blank control group (n = 8) and fat milk group (n = 56). The fat milk group was intragastrically given fat milk once a day to induce NAFL. After induction of NAFL, eight rats from each group were killed. The remaining rats of the fat milk group were further randomly divided into six subgroups: model control subgroup, Jiaogulan subgroup, polyene phosphatidylcholine subgroup, and low-, medium- and high-dose fistular onion stalk extract subgroups. Except the model control subgroup, each of the other subgroups was given the corresponding drug. After 8 weeks, all the animals were sacrificed. The contents of plasma total triglyceride (TG), cholesterol (TC), high-density lipoprotein (HDL), and low-density lipoprotein (LDL) were determined. The levels of malondialdehyde (MDA) and superoxide dismutase (SOD) in liver tissue were measured by spectrophotometry. Enzyme-linked immunosorbent assay (ELISA) was used to determined the changes in the content of TNF-α in the liver.

RESULTS: Compared with the model control subgroup, serum lipid levels showed different degrees of improvement in the low-, medium- and high-dose fistular onion stalk extract, Jiaogulan and polyene phosphatidylcholine subgroups: the levels of TG, TC and LDL decreased significantly (TG: 0.57 mmol/L ± 0.05 mmol/L, 0.51 mmol/L ± 0.04 mmol/L, 0.58 mmol/L ± 0.05 mmol/L, 0.52 mmol/L ± 0.05 mmol/L and 0.50 mmol/L ± 0.03 mmol/L vs 0.73 mmol/L ± 0.06 mmol/L, all P < 0.01; TC: 2.04 mmol/L ± 0.18 mmol/L, 1.69 mmol/L ± 0.15 mmol/L, 2.03 mmol/L ± 0.41 mmol/L, 1.88 mmol/L ± 0.18 mmol/L and 1.70 mmol/L ± 0.39 mmol/L vs 3.42 mmol/L ± 0.42 mmol/L, all P < 0.01; LDL: 0.41 mmol/L ± 0.05 mmol/L, 0.36 mmol/L ± 0.12 mmol/L, 0.46 mmol/L ± 0.13 mmol/L and 0.40 mmol/L ± 0.15 mmol/L vs 0.81 mmol/L ± 0.24 mmol/L, all P < 0.01); the levels of MDA and TNF-α were reduced significantly (all P < 0.01); and SOD activity increased (61.79 U/mg ± 5.72 U/mg, 83.03 U/mg ± 7.47 U/mg, 70.51 U/mg ± 4.84 U/mg, 66.66 U/mg ± 9.23 U/mg and 73.12 ± 4.87 U/mg vs 49.50 U/mg ± 9.31 U/mg, all P < 0.01).

CONCLUSION: Fistular onion stalk extract may exert a protective effect on liver function by decreasing the levels of TG and TC and the activity of MDA and increasing the activity of SOD.