Cholestasis is a liver disease characterized by the accumulation of toxic bile salts, bilirubin, and cholesterol, resulting in hepatocellular damage. Recent findings have revealed several key steps of cholestasis liver injury including the toxicity of bile acids and accumulation of proinflammatory mediator. In this study, we investigated the protective effect of bicyclol in cholestasis caused by bile duct ligation (BDL), as well as relevant mechanisms. Bicyclol attenuated liver damage in BDL mice by increasing the levels of hydrophilic bile acid such as α-MCA and β-MCA, regulating bile acid-related pathways and improving histopathological indexes. High-mobility group box 1 (HMGB1) is an extracellular damage-associated molecular pattern molecule which can be used as biomarkers of cells and host defense. Bicyclol treatment decreased extracellular release of HMGB1. In addition, HMGB1 is also involved in regulating autophagy in response to oxidative stress. Bicyclol promoted the lipidation of LC3 (microtubule-associated protein 1 light chain 3)-Ⅱ to activate autophagy. The nuclear factor, E2-related factor 2 (Nrf2) and its antioxidant downstream genes were also activated. Our results indicate that bicyclol is a promising therapeutic strategy for cholestasis by regulating the bile acids and autophagy-mediated HMGB1/p62/Nrf2 pathway.

To investigate the preventive and therapeutic effects of rapamycin (RAPA) on autoimmune hepatitis and liver fibrosis induced by concanavalin A (ConA) and possible mechanisms. Female C57BL/6 mice aged 8 weeks were randomly divided into normal control group, ConA model group, and ConA+RAPA treatment group. The serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured; hematoxylin-eosin and Masson staining and Knodell HAI and Ishak scoring systems were used to evaluate the degrees of liver inflammation and fibrosis. Gradient centrifugation was used to separate mononuclear cells, flow cytometry was used to measure CD4(+)/CD8(+) ratio, and intracellular cytokine staining was performed to measure the levels of interferon-γ (IFN-γ), interleukin-4 (IL-4), interleukin-10 (IL-10), and transforming growth factor β (TGF-β) in immune cells. The t-test was used for data comparison between groups. The RAPA treatment group showed a significant reduction in serum ALT level compared with the ConA model group (P < 0.05). Liver inflammatory injury was reduced significantly, and there was no obvious fibrous tissue proliferation. The level of TGF-β in mononuclear cells was reduced significantly, and the treatment group had a significantly lower level of TGF-β than the model group (8.91%±1.25% vs 16.65%±2.05%, P < 0.05). The proportions of CD4(+) and CD8(+)T cells in the liver were reduced, and the treatment group had significantly lower proportions of CD4(+) and CD8(+)T cells than the model group (proportion of CD4(+)T cells: 4.09%±1.20% vs 8.91%±0.69%, P < 0.05; proportion of CD8(+)T cells: 3.28%±0.66% vs 9.68%±1.46%, P < 0.05). The proportion of Th1 cells was reduced, and the treatment group had a significantly lower proportion of Th1 cells than the model group (1.02%±0.06% vs 2.83%±0.21%, P < 0.05); the proportions of Th3 and Tr1 regulatory T cells were increased, and the treatment group had significantly higher proportions of Th3 and Tr1 regulatory T cells than the model group (proportion of Th3 regulatory T cells: 59.53%±9.82% vs 47.13%±4.79%, P < 0.05; proportion of Tr1 regulatory T cells: 10.63%±2.27% vs 7.09%±1.66%, P < 0.05), but the proportion of Th2 cells showed no significant difference between the two groups (P > 0.05). RAPA can promote the differentiation of Th3/Tr1 cells, reduce the expression of TGF-β in mononuclear cells, slow down the progression of chronic hepatitis induced by ConA into liver fibrosis, and thus prevent liver fibrosis.

目前, 肠道菌群已成为一个当今研究的热点问题之一. 脂肪性肝病是指由于各种原因引起的肝细胞内脂肪堆积过多的病变, 引起肝的正常结构、生理及生化功能受损, 最终出现临床症状的一类疾病总称, 一般包括非酒精性脂肪性肝病和酒精性肝病两大类. 肠道菌群和肠道通透性的变化可以通过肠-肝轴进一步影响脂肪性肝病的发展. 同样, 在脂肪性肝病的发生发展过程中, 肠道菌群的也发生不同程度的改变. 本文主要介绍肠-肝轴与脂肪性肝病的关系、脂肪性肝病进展过程中肠道菌群的变化及益生菌在脂肪性肝病治疗中的应用新进展.