Treatment of mice with dextran sulfate sodium-induced colitis with human interleukin 10 secreted by transformed Bifidobacterium longum.

Ulcerative colitis (UC) is an inflammatory bowel disease (IBD) the etiology of which has not yet been fully clarified. Cytokine interleukin-10 (IL-10) plays a central role in downregulating inflammatory cascade in UC and is likely a candidate for therapeutic intervention. However, its intravenous administration is costly and inconvenient. Therefore, we established a novel IL-10 delivery system by transforming a hIL-10-containing plasmid into B. longum (BL-hIL-10) and investigated its effects on 5% dextran sulfate sodium (DSS)-induced ulcerative colitis in mice and the possible underlying mechanism. Our results show that (1) hIL-10 was expressed and secreted into the culture supernatant of BL-hIL-10 after L-arabinose induction in vitro as examined by Western blot, enzyme-linked immunosorbent assay (ELISA) and RT-PCR; (2) addition of BL-hIL-10 culture supernatant had no cytotoxic effect and morphological alteration, but significantly inhibited the enhancement of proinflammatory cytokines by lipopolysaccharide (LPS) in THP-1 cells; (3) oral administration of BL-hIL-10 alleviated colitis syndrome of the model mice, attenuated colitis-activated NF-κB pathway measured by DNA-binding assay and colitis-elevated expression of proinflammatory cytokines examined with CCK cytotoxic kits, and upregulated CD4+CD25+Foxp3+ Treg in blood and mesenteric lymph nodes measured by flow cytometry. In conclusion, BL-hIL-10 as a novel oral hIL-10 delivery system has been successfully established and oral administration of BL-hIL-10 alleviated inflammatory damage of colonic tissue in the model mice by blocking the colitis-activated NF-κB pathway and upregulating CD4+CD25+Foxp3+ Treg in blood and mesenteric lymph nodes in mice.

Polydatin ameliorates DSS-induced colitis in mice through inhibition of nuclear factor-kappaB activation.

Nuclear factor- κB (NF- κB) plays a pivotal role in the regulation of immune and inflammatory responses. The real-time expression level of NF- κB reflects the development of ulcerative colitis (UC). Polydatin has vast pharmacological activities, including inhibiting the production of inflammatory mediators, inducing the production of antioxidants, regulating immune function, etc. The purpose of this study was to investigate the potential inhibitory effects of polydatin on NF- κB pathway activation in a mouse UC model. The results showed that polydatin treatment downregulated NF- κB p65 activity and expression, blocked the expression of TNF- α, IL-6 and IL-1 ß at both mRNA and protein levels, decreased myeloperoxidase (MPO) activity, and alleviated inflammatory damage of colitis in mice with UC (p < 0.05), suggesting that the anti-inflammation effects of polydatin can be attributed, at least partially, to the blocking of the NF- κB pathway.

Anti-oxidant effects of resveratrol on mice with DSS-induced ulcerative colitis.

BACKGROUND AND AIMS: Oxidant/antioxidant balance is suggested to be an important factor for the recurrence and progression of ulcerative colitis (UC). The aim of the study is to investigate the potential protective role of resveratrol (Res) against dextran sodium sulfate (DSS)-induced oxidative damage in colon of mice with UC. METHODS: UC was induced in mice by oral administration of synthetic DSS (molecular weight 5000) for 7 days. Mice were divided into normal group, colitis control group, low-dose Res-treated group (RLD-treated group), and high-dose Res-treated group (RHD-treated group). Inhibitory effects of concomitant treatment with Res were assessed daily using a Disease Activity Index (DAI) and severity of histological changes. MDA, MPO, SOD and GSH-PX activity of colonic tissue were determined in colon samples by chemical colorimetry. TNF-alpha, IL-8, IFN-gamma, p22(phox) and gp91(phox) expression levels were detected using quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR), ELISA, and Western blot analysis. RESULT: Administration of Res significantly inhibited the severity of UC compared to the colitis control group. Colonic tissue MDA and MPO activities decreased significantly in Res-treated groups compared to colitis control groups. Furthermore, colonic tissue SOD and GSH-Px activities increased significantly in Res-treated groups compared to colitis control groups. The expression levels of TNF-alpha, IL-8, IFN-gamma, p22(phox), and gp91(phox) also decreased significantly in the Res-treated group compared to the colitis control group. CONCLUSIONS: Oral administration of Res exerts marked inhibitory effects on UC in mice. Resveratrol may play an important role in preventing DSS-induced oxidative damage.