Targeting apoptosis is a promising approach to inhibit the abnormal cell proliferation of cancer progression. Existing anti-apoptotic drugs, many derived from chemical substances, have often failed to combat cancer development and progression. Therefore, identification of apoptosis-inducing anticancer agents from plant-derived sources has become a key aim in cancer research. The present study was designed to explore the regulation of apoptosis by Tabebuia pallida (T. pallida) using an Ehrlich Ascites Carcinoma (EAC) mouse model and compositional analysis by LC-ESI-MS/MS. Dried and powdered T. pallida leaves (TPL), stem bark (TPSB), root bark (TPRB) and flowers (TPF) were extracted with 80% methanol. Using cultured EAC cells and EAC-bearing mice with and without these extracts, anticancer activities were studied by assessing cytotoxicity and tumor cell growth inhibition, changes in life span of mice, and hematological and biochemical parameters. Apoptosis was analyzed by microscopy and expression of selected apoptosis-related genes (Bcl-2, Bcl-xL, NFκ-B, PARP-1, p53, Bax, caspase-3 and -8) using RT-PCR. LC-ESI-MS analysis was performed to identify the major compounds from the most active extracts. In EAC mice compared with untreated controls, the TPL extract exhibited the highest cytotoxicity with significant tumor cell growth inhibition (p< 0.001), reduced ascites by body weight (p< 0.01), increased the life span (p<0.001), normalized blood parameters (RBC/WBC counts), and increased the levels of superoxide dismutase and catalase. TPL-treated EAC cells showed apoptotic characteristics of membrane blebbing, chromatin condensation and nuclear fragmentation, and caspase-3 activation, compared with untreated EAC cells. Moreover, annexin V-FITC and propidium iodide signals were greatly enhanced in response to TPL treatment, indicating apoptosis induction. Pro- and anti-apoptotic signaling after TPL treatment demonstrated up-regulated p53, Bax and PARP-1, and down-regulated NFκ-B, Bcl-2 and Bcl-xL expression, suggesting that TPL shifts the balance of pro- and anti-apoptotic genes towards cell death. LC-ESI-MS data of TPL showed a mixture of glycosides, lapachol, and quercetin antioxidant and its derivatives that were significantly linked to cancer cell targets. In conclusion, the TPL extract of T. pallida possesses significant anticancer activity. The tumor suppressive mechanism is due to apoptosis induced by activation of antioxidant enzymes and caspases and mediated by a change in the balance of pro- and anti-apoptotic genes that promotes cell death.

中文翻译：

---

展开EAC细胞中抗病原菌富集叶的凋亡机制。

靶向凋亡是抑制癌症进展的异常细胞增殖的有前途的方法。现有的抗凋亡药物（许多源自化学物质）通常无法抵抗癌症的发展和进展。因此，从植物来源中鉴定出诱导凋亡的抗癌剂已成为癌症研究的主要目标。本研究的目的是探索使用埃氏腹水癌（EAC）小鼠模型对浅色烟草（Taberbuia pallida）（T. pallida）的凋亡进行调控，并通过LC-ESI-MS / MS进行成分分析。用80％甲醇提取干燥和粉状的淡色丁香叶（TPL），茎皮（TPSB），根皮（TPRB）和花（TPF）。使用培养的EAC细胞和带有或不带有这些提取物的带有EAC的小鼠，通过评估细胞毒性和肿瘤细胞生长抑制作用，小鼠寿命的变化以及血液学和生化参数研究了抗癌活性。通过显微镜检查细胞凋亡，并使用RT-PCR分析所选凋亡相关基因（Bcl-2，Bcl-xL，NFκB，PARP-1，p53，Bax，caspase-3和-8）的表达。进行了LC-ESI-MS分析，以从活性最高的提取物中鉴定出主要化合物。在EAC小鼠中，与未处理的对照组相比，TPL提取物表现出最高的细胞毒性，并具有显着的肿瘤细胞生长抑制作用（p <0.001），体重减轻的腹水（p <0.01），寿命延长（p <0.001），血液正常化参数（RBC / WBC计数），并增加了超氧化物歧化酶和过氧化氢酶的水平。经TPL处理的EAC细胞表现出膜起泡的凋亡特征，与未处理的EAC细胞相比，染色质浓缩和核碎裂以及caspase-3活化。此外，响应TPL处理，膜联蛋白V-FITC和碘化丙啶信号大大增强，表明细胞凋亡诱导。TPL治疗后的促凋亡信号和抗凋亡信号表明p53，Bax和PARP-1上调，而NFκB，Bcl-2和Bcl-xL表达下调，这表明TPL改变了促凋亡和促凋亡的平衡-凋亡基因导致细胞死亡。TPL的LC-ESI-MS数据显示，糖苷，拉帕酚和槲皮素抗氧化剂及其衍生物的混合物与癌细胞靶标显着相关。总之，淡色锥虫的TPL提取物具有显着的抗癌活性。