Department for Life Quality Studies, Alma Mater Studiorum-University of Bologna, Corso d'Augusto 237, 47921 Rimini, Italy.
Department of Life Sciences and Biotechnologies, University of Ferrara, 44121 Ferrara, Italy.
J Ethnopharmacol. 2015 Mar 13;162:261-9. doi: 10.1016/j.jep.2014.12.010. Epub 2015 Jan 2.
The decoction of the roots of Hemidesmus indicus is widely used in the Indian traditional medicine for many purposes and poly-herbal preparations containing Hemidesmus are often used by traditional medical practitioners for the treatment of cancer. In the context of anticancer pharmacology, anti-angiogenic therapy has become an effective strategy for inhibiting new vessel formation and contrast tumor growth. These considerations are supported by the evidence that most tumors originate in hypoxic conditions and limitation of oxygen diffusion stimulates the formation of tumor abnormal microvasculature. Aim of this study was to evaluate the in vitro anti-angiogenic potential of Hemidesmus indicus (0.31-0.93 mg/mL) on human umbilical vein endothelial cells and delineate the main molecular mechanisms involved in its anti-angiogenic activity both in normoxia and hypoxia.
The decoction of Hemidesmus indicus was subjected to an extensive HPLC phytochemical characterization. Its in vitro anti-angiogenic potential was investigated in normoxia and hypoxia. Cell proliferation, apoptosis induction, and inhibition of endothelial cell migration and invasion were analyzed by flow cytometry. The endothelial tube formation assay was evaluated in matrix gel. The capillary tube branch points formed were counted using a Motic AE21 microscope and a VisiCam videocamera. The regulation of key factors of the neovascularization process such as VEGF, HIF-1α and VEGFR-2 was explored at mRNA and protein level by real time PCR and flow cytometry, respectively.
Treatment with Hemidesmus resulted in a significant inhibition of cell proliferation and tube formation in both normoxia and hypoxia. Hemidesmus differently regulated multiple molecular targets related to angiogenesis according to oxygen availability. In normoxia, the inhibition of VEGF was the main responsible for its anti-angiogenic effect; the angiogenesis inhibition induced in hypoxia was regulated by a more complex mechanism involving firstly HIF-1α inhibition, and then VEGF and VEGFR-2 down-regulation. Additionally, the inhibition of endothelial cell migration and invasion by Hemidesmus was more pronounced in normoxia than in hypoxia, possibly due to the physiological enhanced induction of invasion characteristic of hypoxia.
Our results indicate that Hemidesmus might represent a promising therapeutic strategy for diseases in which the inhibition of angiogenesis could be beneficial, such as cancer. The antiangiogenic activity of Hemidesmus is based on multiple interactions with critical steps in the angiogenic cascade. VEGF expression stimulated by HIF-1α as well as endothelial cell migration and differentiation represent important targets of Hemidesmus action and might contribute to its cancer therapeutic efficacy that is presently emerging and offer a scientific basis for its use in traditional medicine.
在印度传统医学中，通脱木的根被广泛用于多种用途，含有通脱木的复方制剂常被传统医学从业者用于治疗癌症。在抗癌药理学中，抗血管生成治疗已成为抑制新血管形成和对比肿瘤生长的有效策略。大多数肿瘤起源于缺氧环境的证据以及氧气扩散限制刺激肿瘤异常微血管形成，支持了这一观点。本研究旨在评估通脱木（0.31-0.93mg/ml）在人脐静脉内皮细胞中的体外抗血管生成潜力，并描绘其在常氧和缺氧条件下抗血管生成活性的主要分子机制。
通脱木提取物进行了广泛的 HPLC 植物化学表征。在常氧和缺氧条件下，研究了其体外抗血管生成潜力。通过流式细胞术分析细胞增殖、凋亡诱导以及内皮细胞迁移和侵袭抑制。在基质凝胶中评估内皮管形成试验。使用 Motic AE21 显微镜和 VisiCam 摄像机计数形成的毛细血管分支点。通过实时 PCR 和流式细胞术分别在 mRNA 和蛋白水平上研究了新血管生成过程中关键因子（如 VEGF、HIF-1α 和 VEGFR-2）的调节。
通脱木处理可显著抑制常氧和缺氧条件下的细胞增殖和管形成。通脱木根据氧气可用性，对与血管生成相关的多种分子靶标进行了不同的调节。在常氧条件下，VEGF 的抑制是其抗血管生成作用的主要原因；在缺氧条件下诱导的血管生成抑制是通过更复杂的机制调节的，首先是 HIF-1α 的抑制，然后是 VEGF 和 VEGFR-2 的下调。此外，通脱木对内皮细胞迁移和侵袭的抑制在常氧条件下比在缺氧条件下更为明显，这可能是由于缺氧的生理增强诱导了侵袭特征。
我们的结果表明，通脱木可能是一种有前途的治疗策略，可用于抑制血管生成有益的疾病，如癌症。通脱木的抗血管生成活性基于与血管生成级联中关键步骤的多种相互作用。由 HIF-1α 刺激的 VEGF 表达以及内皮细胞迁移和分化是通脱木作用的重要靶点，可能有助于其癌症治疗效果的出现，并为其在传统医学中的应用提供科学依据。
