摘要
目的探讨黄芩素对2,4,6-三硝基苯磺酸(TNBS)诱导的小鼠肠炎实验模型的作用及机制。方法将BALB/c小鼠随机分成3组(n=10):正常对照组、模型组(TNBS)和黄芩素组(TNBS+黄芩素20 mg·kg-1)。黄芩素组于造模前2 d ig给予黄芩素,每天1次,共9 d。测量结肠长度,并取结肠组织进行HE染色,进行组织损伤和炎症细胞浸润评分;ELISA测定结肠组织中肿瘤坏死因子α(TNF-α)含量。体外制备细菌脂多糖(LPS)诱导的RAW264.7炎症细胞模型,黄芩素(10,25和50 mmol·L-1)给药干预,Griess试剂法测定上清中一氧化氮(NO)含量;荧光定量PCR检测炎症介质TNF-α、白细胞介素6(IL-6)、IL-1β、诱导型NO合酶(i NOS)、环氧合酶2(COX-2)和单核细胞趋化蛋白1(MCP-1)m RNA表达;Western蛋白印迹法检测磷脂酰肌醇3-激酶/蛋白激酶B/NF-κB(PI3K/AKT/NF-κB)通路磷酸化蛋白(p-PI3K,p-AKT,p-p65和p-IκBa)表达。结果与正常对照组相比,模型组小鼠结肠缩短,组织病理损伤,炎症细胞浸润,组织TNF-α含量增高;黄芩素给药组上述症状得到显著改善(P<0.05)。与细胞对照组相比,LPS模型组细胞NO分泌、炎症介质(TNF-α,IL-6,IL-1β,i NOS,COX-2和MCP-1)m RNA表达及PI3K/AKT/NF-κB通路磷酸化蛋白表达均增高(P<0.05,P<0.01);与模型组比较,黄芩素给药组上述指标均降低(P<0.05,P<0.01)。结论黄芩素可减轻TNBS诱导的小鼠实验性肠炎的症状,作用机制可能与抑制PI3K/AKT/NF-κB通路的激活从而抑制炎症介质的表达和减少炎症因子释放有关。
OBJECTIVE To explore the effect and mechanisms of baicalein on 2,4,6-trinitrobenzene sulfonic acid（TNBS）-induced experimental colitis in mice. METHODS BALB/c mice were randomly placed into three groups（n=10）： normal control group, TNBS group, and TNBS＋baicalein（20 mg·kg-1, once per day） group. Mouse colitis was induced by intrarectal injection of TNBS. Baicalein was administered by oral gavage two days prior to TNBS treatment and until the end of the study（a total of 9 d）. The colon length was measured before HE staining was performed for histological damage assessment. The remaining colon pieces were col ected to measure the content of tumor necrosis factor-α（TNF-α）. Lipopolysaccharide（LPS）-stimulated RAW264.7 mouse macrophage was used as a cell model to determine the content of nitric oxide（NO） in cell culture medium, the m RNA levels of TNF-α, interleukin-6（IL-6）, IL-1β,inducible nitric oxide synthase（i NOS）, cyclooxygenase 2（COX-2） and monocyte chemoattractant protein-1（MCP-1）, and the protein expression of phosphatidylinositol 3-kinase/protein kinase B/nuclear factor-κB（PI3K/AKT/NF-κB） pathway. RESULTS Baicalein significantly attenuated TNBS-induced colon shortening and histological injury（P〈0.05）, which was correlated with the decline in the content of TNF-α in the colon.According to the in vivo results, baicalein exposure down-regulated the secretion of NO and the m RNA expression of pro-inflammatory mediators（i NOS, COX-2, MCP-1, TNF-α, IL-1β and IL-6） in LPS-stimulated RAW264.7 cells（P〈0.05, P〈0.01）. Additionally, the phosphorylation/activation of LPS-stimulated PI3K/AKT/NF-κB pathway was inhibited by baicalein treatment. CONCLUSION The beneficial effect of baicalein in TNBS-induced experimental colitis may be due to PI3K/AKT/NF-κB signaling inhibition.
出处
《中国药理学与毒理学杂志》
CAS
CSCD
北大核心
2017年第6期541-546,共6页
Chinese Journal of Pharmacology and Toxicology
基金
国家自然科学基金(81273572)
国家自然科学基金(81530069)~~
