大黄素干预大鼠慢性胰腺炎胰腺纤维化进展的研究

目的研究大黄素对大鼠慢性胰腺炎模型胰腺纤维化的干预作用及可能机制。方法胰管内注射三硝基苯磺酸(TNBS)制备大鼠慢性胰腺炎模型,用不同剂量(20、40、80 mg/kg)的大黄素鼻饲干预,生理盐水作为对照。放射免疫法检测血清透明质酸(HA)和层粘连蛋白(LN)水平;观察大鼠胰腺组织的病理学变化,并应用 Van Gieson 染色分析胰腺胶原纤维含量;Western 印迹分析检测大鼠胰腺组织中的转化生长因子(TGF)-β_1蛋白含量。结果 (1)小剂量、中剂量、大剂量大黄素处理组血清透明质酸水平分别为87μg/L±22μg/L、78μg/L±25μg/L、62μg/L±19μg/L,均显著低于模型对照组(113μg/L±27μg/L,均 P<0.05);血清层粘连蛋白水平分别为67μg/L±14μg/L、57μg/L±12μg/L和44μg/L±10μg/L,均显著低于模型对照组(86μg/L±17μg/L,均 P<0.05);(2)大黄素处理组胰腺纤维化程度轻于模型组,且随大黄素剂量的增加纤维化程度呈减轻趋势,大剂量大黄素组纤维化减轻程度与模型对照组相比,差异有统计学意义(P<0.05);(3)胰腺胶原纤维阳性染色所占面积,小剂量、中剂量、大剂量大黄素组分别为39%±7%、38%±4%、36%±5%,大剂量大黄素组纤维化程度轻于模型对照组(42%±6%),差异有统计学意义(P<0.05);(4)TGF-β_1蛋白表达量,小剂量、中剂量、大剂量大黄素组分别为44.3%±2.1%、39.2%±1.8%、28.8%±1.6%,与模型对照组(60.7%±1.7%)相比,大剂量大黄素组低于模型对照组(P<0.05);大剂量大黄素组与中、小剂量组比较,差异均有统计学意义(均 P<0.05)。结论大黄素具有抗大鼠慢性胰腺炎模型的胰腺纤维化作用,此作用与 TGF-β_1蛋白表达有关。

Effect of emodin on pancreatic fibrosis: experiment with rats

OBJECTIVE: To study the effect of emodin on pancreatic fibrosis and potential mechanism thereof. METHODS: Fifty SD rats were randomly divided into 5 equal groups: normal control group, model control group, low-dose emodin-treated group, mediate-dose emodin-treated group, and high-dose emodin-treated group. The rats of the latter 4 groups underwent infusion of trinitrobenzene sulfonic acid (TNBS) into the pancreatic duct so as to establish models of pancreatic fibrosis. The emodin-treated rats were fed with different doses of emodin (20, 40, and 80 mg/kg body weight), while the normal and model control groups received 0.9% sodium chloride solution instead. Twenty-eight days later the rats were killed, blood samples were collected, and their pancreases were taken out. The serum levels of hyaluronic acid (HA) and laminin (LN) were determined by radioimmunoassay. The histopathological alterations were studied by optical microscopy. The expression of collagen was examined by Van Gieson staining. Western blotting was used to detect the protein expression of transforming growth factor-beta(1) (TGF-beta(1)). RESULTS: (1) The serum level of HA of the low-dose, mediate-dose, and high-dose emodin-treated groups were 87 microg/L +/- 22 microg/L, 78 microg/L +/- 25 microg/L, and 62 microg/L +/- 19 microg/L respectively, all significantly lower than that of the model control group (113 microg/L +/- 27 microg/L, P < 0.05 or < 0.01). The serum levels of laminin in the low-dose, mediate-dose, and high-dose emodin-treated groups were 67 microg/L +/- 14 microg/L, 57 microg/L +/- 12 microg/L, and 44 microg/L +/- 10 microg/L respectively, all significantly lower than that of the model control group (86 microg/L +/- 17 microg/L, P < 0.05 or P < 0.01); (2) The degrees of fibrosis of the emodin-treated groups were obviously ameliorated in comparison with the model control group, the higher the dose of emodin the more improved the pathological changes, especially in the high-dose emodin-treated group (P < 0.05). (3) The percentages of collagen positive cells of the low-dose, mediate-dose, and high-dose emodin-treated groups were 39% +/- 7%, 38% +/- 4%, and 36% +/- 5% respectively, all lower than that of the model control group (42% +/- 6%), with a significant difference between the high-dose emodin-treated group and the model control group (P < 0.05). (4) The protein content of TGF-beta(1) of the low-dose, mediate-dose, and high-dose emodin-treated groups were 44.3% +/- 2.1%, 39.2% +/- 1.8%, and 28.8% +/- 1.6% respectively, all significantly lower than that of the model control group (60.7% +/- 1.7%, all P < 0.05), and the protein content of TGF-beta(1) of the high-dose emodin-treated group was significantly lower than those of the other 2 emodin-treated groups (both P < 0.05). CONCLUSION: Emoidn has an anti-fibrosis effect on pancreatic fibrosis, which maybe related to the content of TGF-beta(1) protein.