Effects of berberine on colon dermal cell apoptosis in mice with ulcerative colitis based on JAK/STAT signaling pathway / 中国药理学通报

Aim To analyze the effects of berberine on the apoptosis of colon epithelial cells and polymorpho-nuclear neutrophils ( PMNs) in mice with ulcerative colitis ( UC ) by regulating JAK/STAT signaling pathway. Methods The UC mouse models were established by dextran sulfate sodium ( DSS) method and were randomly divided into control group, UC group, low-dose, middle-dose and high-dose berberine groups and positive drug group ( mesalazine enteric-coated tablet group) . In addition, the mice were randomly di¬vided into UC group, high-dose berberine group, AG490 group, and high-dose berberine + AG490 group. Levels of serum tumor necrosis factor a (TNF-α) and interleukin 6 (IL-6) and colon epithelial cell apoptosis and PMN apoptosis were compared among the groups. Western blot was used to detect the expres¬sions of colon tissue apoptosis-related and JAK/STAT signaling pathway-related proteins. Results The lev¬els of serum TNF-α and IL-6, apoptosis rate of colon epithelial cell and protein expressions of Fas, FasL, Bax, caspase-3, p-JAK2/JAK2 and p-STAT3/STAT3 in each dose berberine group and positive drug group were significantly lower than those in UC group (P < 0.05), and the above indicators in berberine groups were reduced gradually (P <0.05) . The PMN apoptosis rate and Bcl-2 protein expression were significantly higher in each dose berberine group and positive drug group than those in UC group (P <0. 05) , and the two indicators increased gradually in berberine groups ( P < 0.05). AG490 could reverse the above effects of berberine ( P < 0. 05 ). Conclusions Berberine can inhibit the apoptosis of colon epithelial cell and promote the apoptosis of PMN in UC mice by regulating the JAK/STAT signaling pathway, and then play a role in the treatment of UC.

A 75 kDa glycoprotein isolated from Cudrania tricuspidata Bureau induces colonic epithelial proliferation and ameliorates mouse colitis induced by dextran sulfate sodium / 中国天然药物

Cudrania tricuspidata Bureau (CTB), a species of the Moraceae plant, has been used as a bruise recovery treatment. This study aimed to determine whether the 75 kDa phytoglycoprotein extracted from CTB has a regulatory effect on the proliferation of human colon epithelial cells and the pathological process of inflammatory bowel disease (IBD). We found that CTB glycoprotein significantly induces the proliferation of human colon epithelial HT-29 cells by activating protein kinase C. CTB glycoprotein stimulated the phosphorylation of c-Jun N-terminal kinase and transcription factor nuclear factor-κB, which are responsible for the expression of cell-cycle-related proteins (CDK2, CDK4, cyclin D1 and cyclin E) during its promotion of cell proliferation. Experimental colitis was induced in mice by adding dextran sulfate sodium to their drinking water at a concentration of 4% (W/V) for seven days. We found that CTB glycoprotein ameliorates the pathological process of IBD and lowers the disease activity index score, which was composed of body weight change, diarrhea, and hematochezia in ICR mice treated with dextran sulfate sodium. Hence, we suggest that CTB glycoprotein has the ability to prevent IBD by promoting cell proliferation signaling events via the activation of PKC, JNK and NF-κB in colon epithelial cells.

Falcarindiol from Angelica koreana Down-regulated IL-8 and Up-regulated IL-10 in Colon Epithelial Cells

Angelica koreana is an important medicinal plant for some locals in East Asia including Korea. A few reports have shown the efficacy of its phytochemical constituents. We have isolated and purified one compound falcarindiol (FAL) from the methanolic extract of A. koreana roots. At concentrations from to 1 µM to 25 µM, the FAL isolated from the roots of A. koreana exerted no significant cytotoxicity and down-regulated LPS-stimulated pro-inflammatory cytokine IL-8 in colon epithelial cells, while up-regulating anti-inflammatory cytokine IL-10. In addition, the FAL decreased the expression of LPS-induced inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 protein by Western blot analysis. Colon epithelial cells play pivotal roles in regulating the colon immune system and thus FAL is expected to be candidate agent as therapeutic potential for the treatment of inflammatory bowel disease (IBD) by modulating LPS-induced inflammation in colon epithelial cells.

Calpains are Involved in Entamoeba histolytica-Induced Death of HT-29 Colonic Epithelial Cells

Entamoeba histolytica is an enteric tissue-invading protozoan parasite that can cause amebic colitis and liver abscess in humans. E. histolytica has the capability to kill colon epithelial cells in vitro; however, information regarding the role of calpain in colon cell death induced by ameba is limited. In this study, we investigated whether calpains are involved in the E. histolytica-induced cell death of HT-29 colonic epithelial cells. When HT-29 cells were co-incubated with E. histolytica, the propidium iodide stained dead cells markedly increased compared to that in HT-29 cells incubated with medium alone. This pro-death effect induced by ameba was effectively blocked by pretreatment of HT-29 cells with the calpain inhibitor, calpeptin. Moreover, knockdown of m- and micro-calpain by siRNA significantly reduced E. histolytica-induced HT-29 cell death. These results suggest that m- and micro-calpain may be involved in colon epithelial cell death induced by E. histolytica.