海南砂仁挥发油对2,4-二硝基氯苯与乙酸诱发的大鼠溃疡性结肠炎的治疗作用

目的观察海南砂仁挥发油(VOA)对溃疡性结肠炎(UC)的治疗作用及其机制。方法采用2,4-二硝基氯苯(DNCB)与乙酸复合灌肠法制备UC大鼠模型。将SD大鼠分为正常对照组、UC组、UC+VOA(0.42,0.84和1.68g·kg-1)和UC+柳氮磺吡啶(SSZ)0.52g·kg-1治疗组。正常组和UC组ig生理盐水,治疗组ig相应药物,连续给药21d后处死大鼠进行结肠大体形态和组织病理学评分。用邻苯三酚自氧化法测定结肠组织中超氧化物岐化酶(SOD)活性,比色法测定谷胱甘肽过氧化物酶(GSH-Px)活性和一氧化氮合酶(NOS)含量,SABC免疫组织化学法检测结肠组织肿瘤坏死因子α(TNF-α)和核因子-κBp65(NF-κBp65)阳性细胞百分率。结果与正常组比较,UC大鼠结肠组织学评分升高;结肠出现黏膜层缺损、淋巴组织增生、腺体排列紊乱以及以淋巴细胞为主的炎症细胞浸润和血管扩张等病理变化。结肠组织SOD和GSH-Px活性明显降低,NOS显著升高,TNF-α和NF-κBp65免疫阳性细胞百分率明显增加。与UC组比较,VOA0.84和1.68g·kg-1治疗后,明显降低UC大鼠结肠形态和组织学评分,减轻结肠病理变化,使UC结肠组织SOD和GSH-Px升高,NOS降低,结肠组织TNF-α和NF-κBp65免疫阳性细胞明显减少。结论VOA可减轻UC大鼠结肠炎症反应和黏膜损伤,作用机制可能与其抑制TNF-α和NF-κBp65表达从而抑制炎症级联反应有关。

Therapeutic effect of volatile oil from A. longiligulare T.L.Wu on ulcerative colitis induced by 2,4-dinitrobenzene-1- chlorobenzene and acetic acid in rats

AIM To explore therapeutic effect of volatile oil from A. longiligulare T.L.Wu (VOA) on ulcerative colitis (UC) and its possible mechanisms. METHODS UC model was established by an enema of 2,4-dinitrobenzene-1-chlorobenzene (DNCB) and acetic acid. SD rats were randomly divided into 6 groups: normal control, UC model, UC+VOA (0.42, 0.84 and 1.68 g·kg^-1) and UC+sulfasalazine (SSZ) 0.52 g·kg^-1 treated groups. The rats were ig administered with normal saline in normal control and UC model groups, and rats in other 4 groups were ig given VOA or SSZ once a day for 21 d, respectively. All rats were sacrificed 21 d after drug administration and the macroscopic and histological changes in colons were evaluated. The activity of superoxide dismutase (SOD) from colon tissue was measured with pyrograllol auto-oxidation assay and spectrophotometric method was used to detect the activity of glutathione peroxidase (GSH-Px) and the contents of nitric oxide synthase (NOS). The percentage of tumor necrosis factor-α (TNF-α) and nuclear factor-κB p65 (NF-κBp65) positive cells in colon tissue was determined with immunohistochemical assay. RESULTS Compared with normal control group, the score of macroscopical and histological features in UC group was significantly increased. Colonic mucosal defect, lymphoid tissue hyperplasia, glandular disorders, a large number of lymphocyte-predominant inflammatory cell infiltration and vascular dilation could be observed. The SOD and GSH-Px activities were obviously lower, and NOS level was significantly higher in colon tissue. The TNT-α and NF-κBp65 expressions in colon tissue also increased. Compared with UC group, UC+VOA (0.84 and 1.68 g·kg^-1) reduced colon macroscopic and histological damage significantly, elevated the activities of SOD and GSH-Px, reduced the content of NOS and inhibited the protein expressions of TNT-α and NF-κBp65 in colon tissues. CONCLUSION VOA may reduce inflammatory reaction and protect mucosa from UC. The probable mechanism was that it can inhibit TNF-α and NF-κBp65, and then suppress the inflammatory cascade from UC.