Effect of probiotics on pro-inflammatory cytokines and NF-kappaB activation in ulcerative colitis

Abstract

Aim: To demonstrate the therapeutic effect of probiotics in patients with ulcerative colitis (UC), and their effect on inflammatory mediators and nuclear factor (NF)-kappaB activation in these patients.

Methods: Thirty patients with mild to moderate UC were randomly classified into two groups: sulfasalazine group, who received sulfasalazine 2400 mg/d; and probiotic group, who received sulfasalazine 2400 mg/d with probiotic. The patients were investigated before and after 8 wk of treatment with probiotic (Lactobacillus delbruekii and Lactobacillus fermentum). Colonic activity of myeloperoxidase (MPO) was assayed with UV spectrophotometry, the colonic content of interleukin (IL)-6 was determined by enzyme-linked immunosorbent assay (ELISA), fecal calprotectin was determined by ELISA, and expression of NF-kappaB p65 and tumor necrosis factor (TNF)-alpha proteins in colonic tissue was identified by immunohistochemistry and reverse transcription polymerase chain reaction, respectively.

Results: At the start of the study, colonic mucosal injury and inflammation were demonstrated in UC patients by hematoxylin and eosin staining, and an increase in colonic MPO activity, fecal calprotectin, and expression of colonic TNF-alpha and NF-kappaB p65 proteins. The use of probiotic for 8 wk significantly ameliorated the inflammation by decreasing the colonic concentration of IL-6, expression of TNF-alpha and NF-kappaB p65, leukocyte recruitment, as demonstrated by a decrease in colonic MPO activity, and the level of fecal calprotectin compared to sulfasalazine group and the control group (P < 0.05).

Conclusion: Oral supplementation with probiotics could be helpful in maintaining remission and preventing relapse of UC.

Figures

Figure 1

Hematoxylin and eosin staining of colonic tissue (HE, × 250). A: Control group showed no damage; B: Patients before treatment showed necrotic destruction of the epithelium, inflammatory cellular infiltration, and ulceration of the mucosa and submucosa; C: Sulfasalazine group showed attenuation of the extent and severity of the histological signs; D: Probiotic group showed inhibition of the extent of inflammation, and prevention of mucosal injury.

Figure 2

Myeloperoxidase activity (g/U), interleukin-6 level (pg/mL), and fecal calprotectin (g/kg) in colon of ulcerative colitis patients and controls. Data are presented as mean ± SD. aP < 0.05 vs sulfasalazine; cP < 0.05 vs patients; eP < 0.05 vs interleukin-6 level of the probiotics. MPO: Myeloperoxidase; IL-6: Interleukin-6; FC: Fecal calprotectin.

Figure 3

Immunohistochemical staining for nuclear factor-κB p65 (Brown staining, SP × 700). A: Section of colon from controls showing normal structure and architecture; B: Section of colon from ulcerative colitis patients before treatment showing extensive nuclear factor (NF)-κB (brown) expression; C: Section of colon from sulfasalazine group showing limited NF-κB (brown) expression; D: Section of colon from probiotic group showing minimal NF-κB (brown) expression.

Figure 4

Expression of tumor necrosis factor-α mRNA. Lane 1: Control group; Lane 2: Probiotic group; Lane 3: Sulfasalazine group; Lane 4: Ulcerative colitis patients before treatment. TNF-α: Tumor necrosis factor-α.