嗜酸乳杆菌对小鼠结肠炎的疗效及结肠黏膜转录因子表达的影响

Administration of Lactobacillus plantarum reduces TNBS-induced colitis in mice

AIM: To determine the effect of administration of Lactobacillus plantarum (LP) on established colitis in mice and to explore possible mechanisms involved.

METHODS: A model of colitis was induced by intracolonic injection of 2,4,6-trinitrobenzene sulfonic acid sodium salt (TNBS) in adult Balb/c mice. The mice were then treated with LP (10⁹ CFU) or vehicle for three weeks. After treatment, all mice were killed and colonic damage was evaluated both histologically and biochemically, including determination of the activity of myeloperoxidase (MPO) activity, and the levels of leukotriene B4 (LTB4), tumor necrosis factor α (TNF-α) and interferon-γ (IFN-γ) in colon tissue.

RESULTS: LP therapy resulted in amelioration of colitis induced with TNBS in mice when compared with control mice without undergoing LP treatment. This anti-inflammatory effect of LP was evidenced by a significant reduction of macroscopic and microscopic colonic damage scores (1.11 ± 0. 61 vs 4.62 ± 0. 40, P < 0.05; 1.48 ± 0.40 vs 5.39 ± 1.12, P < 0.05). Moreover, a reduction of neutrophil infiltrate in LP-treated mice was confirmed biochemically by a significant reduction of the activity of colonic MPO (25.14 U/g ± 5.22 U/g vs 90.3 U/g ± 7.70 U/g, P < 0.05), a marker of neutrophil infiltration, in comparison with non-treated colitic mice. In addition, treatment with LP resulted in a lower colonic content of LTB4 and in a significant reduction of proinflammatory factors, such as TNF-α and IFN-γ, when compared with control mice (3.13 ng/g ± 0.10 ng/g vs 8.43 ng/g ± 0. 49 ng/g, P < 0.05; 205 ng/g ± 68 ng/g vs 375 ng/g ± 79 ng/g, P < 0.05; 446 ng/g ± 116 ng/g vs 603 ng/g ± 109 ng/g, P < 0.05).

CONCLUSION: Administration of LP is effective in accelerating the recovery of experimental colitis in mice possibly by reducing leukocyte accumulation and proinflammatory cytokine expression.