Guruvayoorappan Chandrasekharan, Kuttan Girija
Department of Immunology, Amala Cancer Research Center, Amala Nagar, Thrissur 680 555, Kerala, India.
J Exp Ther Oncol. 2007;6(3):241-50.
Angiogenesis is a crucial step essential for the growth, progression and metastasis of solid tumors. Substances produced by inflammatory cells, such as cytokines play an important role in the stimulation and progression of angiogenesis. In this study we investigated the anti-angiogenic effect of Biophytum sensitivum, using in vivo as well as in vitro models. In vitro antiangiogenic activity was studied using B16-F10 melanoma cell-induced capillary formation in C57BL/6 mice. Intraperitoneal administration of the extract at a concentration of 50 mg/kg significantly inhibited the tumor directed capillary formation induced by melanoma cells. The cytokine profile in the serum of these animals showed a drastically increased level of proinflammatory cytokines such as IL-1beta, IL-6, TNF-alpha, GM-CSF and the direct endothelial cell proliferating agent, VEGF. Administration of Biophytum extract could differentially regulate these cytokine's elevation. The differential elevation is further evidenced by the increased production of IL-2 and tissue inhibitor of metalloprotease-1 (TIMP-1) in the B16-F10 injected, extract treated animals. The extract of B. sensitivum at non-toxic concentrations (1 microg/ml, 5 microg/ml and 10 microg/ml) inhibited the VEGF-induced vessel sprouting in rat aortic ring assay. Moreover, B. sensitivum was able to inhibit the VEGF-induced proliferation, cell migration and capillary-like tube formation of primary cultured human endothelial cells. Furthermore B. sensitivum showed inhibitory effect on VEGF mRNA levels in B16-F10 melanoma cells. Hence the observed antiangiogenic activity of the plant B. sensitivum is exerted through its cytokine modulation activity and inhibitory activity against VEGF mRNA expression.
血管生成是实体瘤生长、进展和转移所必需的关键步骤。炎症细胞产生的物质,如细胞因子,在血管生成的刺激和进展中起重要作用。在本研究中,我们使用体内和体外模型研究了感应草的抗血管生成作用。使用B16-F10黑色素瘤细胞诱导C57BL/6小鼠的毛细血管形成来研究体外抗血管生成活性。以50mg/kg的浓度腹腔注射提取物可显著抑制黑色素瘤细胞诱导的肿瘤定向毛细血管形成。这些动物血清中的细胞因子谱显示促炎细胞因子如IL-1β、IL-6、TNF-α、GM-CSF以及直接的内皮细胞增殖剂VEGF的水平急剧升高。给予感应草提取物可差异调节这些细胞因子的升高。在注射B16-F10并经提取物处理的动物中,IL-2和金属蛋白酶组织抑制剂-1(TIMP-1)产量的增加进一步证明了这种差异升高。无毒浓度(1μg/ml、5μg/ml和10μg/ml)的感应草提取物在大鼠主动脉环试验中抑制了VEGF诱导的血管芽生。此外,感应草能够抑制VEGF诱导的原代培养人内皮细胞的增殖、细胞迁移和毛细血管样管形成。此外,感应草对B16-F10黑色素瘤细胞中的VEGF mRNA水平显示出抑制作用。因此,观察到的感应草的抗血管生成活性是通过其细胞因子调节活性和对VEGF mRNA表达的抑制活性来发挥的。