白花蛇舌草总黄酮对实验性溃疡性结肠炎的作用及免疫学机制研究

Study on effect of total flavonoids of Oldenlendia difflusa on ulcerative colitis and its immunological mechanism

目的:观察不同剂量白花蛇舌草总黄酮(FOD)对溃疡性结肠炎(UC)模型小鼠结肠NF-κB及IL-8,TNF-α,IL-10表达的影响,探讨其抗UC的免疫学机制。方法:60只雄性昆明小鼠随机分成6组:对照组(Cont)蒸馏水灌胃,其余5组均自由饮用4%右旋葡聚糖硫酸钠(DSS)水溶液7 d以造成急性UC,同时给予下列药物灌胃:蒸馏水(DSS组),柳氮磺胺吡啶(SASP)500 mg·kg-1·d-1(DSS+SASP组),FOD 60 mg·kg-1·d-1(DSS+FOD-H组),FOD 40 mg·kg-1·d-1(DSS+FODM组),FOD 26.7 mg·kg-1·d-1(DSS+FOD-L组)。造模给药期间,每天对各组小鼠进行疾病活动指数(DAI)评分。造模7d后处死小鼠,取结肠组织标本,对结肠黏膜进行病理组织学损伤评估;用免疫组化法检测NF-κB p65的表达,ELISA法检测结肠组织中IL-8,TNF-α及IL-10的表达。结果:自由饮用4%DSS水溶液7 d可成功造成小鼠急性UC,与对照组比较,DSS组小鼠的DAI、结肠病理组织学损伤评分明显上升,结肠组织中NF-κB p65及IL-8,TNF-α表达显著增多,IL-10表达明显降低(P<0.05)。FOD可对抗DSS所致的小鼠急性UC,FOD以60,40 mg·kg-1·d-1预防给药7 d,可完全或部分对抗DSS引起的上述改变。与DSS组比较,DSS+FOD-H组、DSS+FOD-M组的DAI、结肠病理组织学损伤评分降低,IL-8,TNF-α及NF-κB p65表达下调,IL-10表达上调(P<0.05)。结论:FOD有明显的抗小鼠UC的作用,其机制可能与抑制NF-κB p65激活,从而减少促炎因子IL-8,TNF-α的表达,增加抗炎因子IL-10表达有关。

Objective： To observe the effect of total flavonoids of Oldenlendia difflusa（FOD） on NF-κB and IL-8, TNF-α, IL- 10 expressions of ulcerative colitis （UC） model rats, and explore its immunological mechanism of anti-UC. Method： Sixty Kunming male mice with the average weight of （20 ±2） g were randomly divided into six groups. The control group （cont） was orally adminis- tered with distilled water. Whereas the remaining five groups were fed with 4% dextran sulphate sodium （DSS） solution for seven days to induce acute UC, and orally administered with the following drugs ： distilled water （for the DSS group） , SASP at dose of 500 mg.kg^-1 .d ^-1 for theDSS＋SASPgroup, FOD at dose of 60 mg . kg i .d-1 for theDSS＋FOD-Hgroup, FODatdoseof40mg-kg^-1.d^-1 for the DSS ＋FOD-M group, and FOD at dose of 26. 7 mg . kg^-1. d^-1 for the DSS ＋ FOD-L group. During the modeling and drug administration, the mice were scored for DAI. Seven days later, the mice were put to death, and their colonic tissue samples were collected to evaluate colonic mucosal lesions. The NF-κB p65, IL-8, TNF-α, IL-10 expressions were tested by immunohistochemical staining and ELISA. Result： Seven-day feeding with 4% DSS solution could successfully induce acute UC in mice. Compared with the cont group, the DSS group showed significantly higher DAI and colonic mucosal lesions, remarkable increase in NF-κB p65, IL-8, TNF-α expression in colonic tissues, and notable decrease in IL-10 expression（P 〈 0. 05 ）. FOD could prevent acute UC in mice in- cluded by DSS. Seven-day administration of 60 mg ~ kg-1 . d -1 or 40 mg ~ kg 1 . d t FOD could completely or partially resist the a- bove mentioned changes caused by DSS. Compared with the DSS group, the DSS ＋ FOD-H group and the DSS ＋ FOD-M group showed reduction in colonic mucosal lesions, down-regulation in IL-8, TNF-c~ and NF-κB p65 expressions and up-regulation in IL-10 expres- sion （P 〈 0. 05）. Conclusion： FOD could significantly resist UC in mice. Its mechanism may be related to the inhibition of NF-κB p65 activation, the reduction of IL-8 and TNF-α expressions and the increase in the anti-inflammatory factor IL-10.