沙棘熊果酸对H_(22)荷瘤小鼠抑瘤活性及其机制的探讨

Antitumor Activity and Mechanism of Ursolic Acid Extracted from Hippophae rhamnoides L. on H_(22) Tumor Bearing Mice

建立小鼠H_(22)移植瘤模型,观察沙棘(Hippophae rhamnoides L.)熊果酸(ursolic acid,UA)对小鼠H_(22)移植瘤的抑制作用并探讨其可能的作用机制。根据公式计算抑瘤率及脏器指数;苏木精-伊红染色法(hematoxylin-eosin staining,HE)观察各组小鼠肿瘤组织病理学变化;酶联免疫吸附法检测荷瘤小鼠血浆中白细胞介素-12(interleukin-12,IL-12)、肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)水平;免疫组化法测定肿瘤组织中基质金属蛋白酶-2(matrix metalloproteinase-2,MMP-2)的表达;免疫印迹法检测肿瘤组织中血管内皮生长因子(vascular endothelial growth factor,VEGF)及Ras蛋白表达量。结果表明,沙棘熊果酸能明显改善H_(22)荷瘤小鼠的一般状况;抑制移植瘤的生长,抑瘤率分别为17.46%、35.11%、55.22%;与模型组相比,沙棘熊果酸能明显升高TNF-α、IL-12的水平(P<0.05),降低MMP-2的阳性表达,下调VEGF、Ras蛋白过表达,且呈现剂量效应关系。其机制可能与其提高血中IL-12等抗肿瘤活性细胞因子的浓度诱导细胞免疫,提高机体免疫力,抑制肝癌细胞外基质降解以及新生血管形成有关。

By establishing H22 transplanted tumor model in mice,observe the inhibitory effect of ursolic acid (UA) extracted from hippophae rhamnoides L. on H22 transplanted tumor in mice and explore its possible mechanism.The inhibition rate and organ index were calculated according to the formula. Hematoxylin-eosin staining (HE) staining was used to observe the histopathological changes of tumor tissues in mice, and the levels of interleukin-12 (IL-12) and tumor necrosis factor-α(TNF-α) in the plasma of the tumor bearing mice were detected by enzyme linked immunosorbent assay. Immunohistochemical staining had been used to detect the positive level of matrix metalloproteinase -2 (MMP-2) in neoplasm tissues. And the expression of vascular endothelial growth factor (VEGF) and Ras protein in tumor tissues was detected by Western blot. The results showed that Hippophae rhamnoides L. abstract ursolic acid could obviously improve the general condition of H22 tumor bearing mice. Restrain the growth of neoplasm in H22 tumor bearing mice, and theneoplasm suppressor rate was 17.46 %, 35.11 % and 55.22 % successively. Compared with the model group, ursolic acid extracted from Hippophae rhamnoides L.could significantly increase the levels of TNF-α and IL-12 (P<0.05), reduced the positive expression of MMP-2, and down regulated the overexpression of VEGF and Ras, and showed a dose effect relationship.Its mechanism might be related to increasing the concentration of anti tumor active cytokines such as IL-12 in blood to induce cell immunity, improve the immunity of the body, inhibit the degradation of the extracellular matrix of liver cancer and the formation of neovascularization.