嗜酸乳杆菌胞壁粗提物及DNA对溃疡性结肠炎小鼠模型的作用

Treatment with Lactobacillus acidophilus cell wall extract and DNA improves experimental acute colitis in mice

目的:观察嗜酸乳杆菌BCW和DNA对实验性结肠炎的治疗作用.方法:40只♀BABLc小鼠随机分为正常组、嗜酸乳杆菌BCW组、嗜酸乳杆菌DNA组和生理盐水组,除正常组小鼠外,其余各组自由饮用1.5%DSS7d建立小鼠结肠炎模型,从实验第1天开始,给予嗜酸乳杆菌BCW(20μg10g)、嗜酸乳杆菌DNA(0.2μg10g)和生理盐水(0.2mL10g)灌肠7d,观察小鼠每天的体质量变化粪便性状和粪便隐血情况;实验结束时处死动物,观察结肠大体观,测量全段结肠长度并称其质量;HE染色观测结肠炎症情况,评价嗜酸乳杆菌BCW和DNA对小鼠急性结肠炎的影响.结果:饮用DSS小鼠体质量逐渐下降,DAI积分增高,结肠黏膜出现糜烂或溃疡,腺体破坏,大量炎性细胞浸润.与生理盐水组比较,嗜酸乳杆菌BCW和DNA能减缓小鼠体质量的下降(2.94g±0.78g,3.37g±1.08gvs6.96g±1.39g,P<0.05),降低小鼠DAI积分(4.27±0.41,4.62±0.56vs6.85±0.94,P<0.05),在组织学方面能阻止DSS导致的结肠缩短(8.62cm±1.31cm,8.15cm±0.97cmvs6.63cm±1.38cm,P<0.05)及肠质量指数的增加(1.63%±0.27%,1.68%±0.29%vs2.12%±0.22%,P<0.05),减轻黏膜损伤,恢复腺体及绒毛的排列,减轻炎性细胞的浸润.结论:嗜酸乳杆菌BCW和DNA能有效地缓解小鼠急性结肠炎炎症,减轻组织损伤.

AIM： To investigate the effect of treatment with Lactobacillus acidophilus （L.acidophilus） cell wall extract （BCW） and DNA on experimental colitis in mice. METHODS： Forty 6-8-wk-old specific pathogenfree female BALBc mice were randomly divided into four groups： normal group, L.acidophilus BCW-treated group, L.acidophilus DNA-treated group, and control group. Except the normal group, other groups of mice were subjected toinduction of experimental colitis with 1.5% DSS in drinking water for 7 d and then treated with L.acidophilus BCW （20 μg10 g）, L.acidophilus DNA （0.2 μg10 g）, and physiological saline （0.2 mL10 g）, respectively. The changes in body weight, fecal traits, and faecal occult bleeding were recorded each day. All animals were killed on day 8 to isolate the whole colon for examination of length and wet weight. Hematoxylin and eosin staining of colonic sections was performed. The effect of treatment with L.acidophilus BCW and DNA on experimental colitis was then evaluated. RESULTS： Compared with the control group, weight loss was significantly improved （2.94 g ± 0.78 g, 3.37 g ± 1.08 g vs 6.96 g ± 1.39 g, both P 0.05） and DAI score was signifi cantly decreased （4.27 ± 0.41, 4.62 ± 0.56 vs 6.85 ± 0.94, both P 0.05） in mice treated with both L.acidophilus BCW and DNA. Treatment with L.acidophilus BCW and DNA prevented the shortening of colon length （8.62 cm ± 1.31 cm, 8.15 cm ± 0.97 cm vs 6.63 cm ± 1.38 cm, both P 0.05）, increased the colon body weight index （1.63% ± 0.27%, 1.68% ± 0.29% vs 2.12% ± 0.22%, both P 0.05）, improved mucosal damage and inflammatory infiltration, and protected mucosal glands and villi. CONCLUSION： Treatment with L.acidophilus cell wall extract and DNA can improve DSS-induced experimental colitis in mice.