Department of Structural and Functional Biology, Biology Institute, University of Campinas, Brazil.
J Ethnopharmacol. 2013 Mar 7;146(1):300-10. doi: 10.1016/j.jep.2012.12.048. Epub 2013 Jan 10.
In Brazilian traditional medicine, Arctium lappa (Asteraceae), has been reported to relieve gastrointestinal symptoms.
In the present study, we investigated the effects of the lactone sesquiterpene onopordopicrin enriched fraction (ONP fraction) from Arctium lappa in an experimental colitis model induced by 2,4,6 trinitrobenzene sulfonic acid and performed experiments to elucidate the underlying action mechanisms involved in that effect.
ONP fraction (25 and 50 mg/kg/day) was orally administered 48, 24 and 1 h prior to the induction of colitis and 24 h after. The inflammatory response was assessed by gross appearance, myeloperoxidase (MPO) activity, tumor necrosis factor alpha (TNF-α) levels and a histological study of the lesions. We determined cyclooxygenase (COX)-1 and -2 protein expressions by western blotting and immunohistochemistry assays.
TNBS group was characterized by increased colonic wall thickness, edema, diffuse inflammatory cell infiltration, increased MPO activity and TNF-α levels. On the contrary, ONP fraction (25 and 50 mg/kg) treatment significantly reduced the macroscopic inflammation scores (p<0.05 and p<0.01, respectively) and morphological alterations associated with an increase in the mucus secretion. Similarly, the degree of neutrophil infiltration and the cytokine levels were significantly ameliorated. Moreover, COX-2 expression was up regulated in TNBS-treated rats. In contrast, ONP fraction (50 mg/kg) administration reduced COX-2 overexpression.
We have shown that the ONP fraction obtained from Arctium lappa exert marked protective effects in acute experimental colitis, confirming and justifying, at least in part, the popular use of this plant to treat gastrointestinal diseases.
在巴西传统医学中，牛蒡（菊科）被报道具有缓解胃肠道症状的作用。
本研究旨在研究 2,4,6-三硝基苯磺酸诱导的实验性结肠炎模型中，牛蒡中倍半萜内酯 onopordopicrin 富集部分（ONP 部分）的作用，并进行实验阐明其作用机制。
ONP 部分（25 和 50mg/kg/天）在诱导结肠炎前 48、24 和 1 小时以及 24 小时后口服给药。通过大体观察、髓过氧化物酶（MPO）活性、肿瘤坏死因子-α（TNF-α）水平和病变的组织学研究评估炎症反应。通过 Western blot 和免疫组织化学检测 COX-1 和 COX-2 蛋白表达。
TNBS 组表现为结肠壁增厚、水肿、弥漫性炎症细胞浸润、MPO 活性和 TNF-α水平增加。相反，ONP 部分（25 和 50mg/kg）治疗显著降低了宏观炎症评分（分别为 p<0.05 和 p<0.01）和与粘蛋白分泌增加相关的形态改变。同样，中性粒细胞浸润程度和细胞因子水平也得到显著改善。此外，COX-2 在 TNBS 处理的大鼠中表达上调。相反，ONP 部分（50mg/kg）给药降低了 COX-2 的过度表达。
我们表明，牛蒡的 ONP 部分在急性实验性结肠炎中表现出明显的保护作用，至少部分证实和证明了该植物用于治疗胃肠道疾病的广泛应用。
