Anti-Tumor Action, Clinical Biochemistry Profile and Phytochemical Constituents of a Pharmacologically Active Fraction of <i>S</i>. <i>crispus</i> in NMU-Induced Rat Mammary Tumour Model

Cancer patients seek alternative remedies such as traditional medicinal plants for safe and effective treatment and help overcome the side effects of conventional therapy. Current knowledge indicates that extracts of Strobilanthes crispus of the Acanthaceae family exhibit potent anticancer properties in vitro and are non-toxic in vivo. S. crispus was also reported to be protective against chemical hepatocarcinogenesis. We previously showed that a bioactive fraction of S. crispus leaves also synergized with tamoxifen to cause apoptosis of human breast cancer cell lines without damaging non-malignant epithelial cells. The present study aimed to evaluate the antitumor effect of S. crispus dichloromethane fraction (F3) using N-methyl-N-Nitrosourea (NMU)-induced rat mammary tumor model. Tumor regression was observed in 75% of the rats following 8-week oral administration of F3 with no secondary tumour formation and no signs of anemia or infection. However, no improvement in the liver and renal function profiles was observed. Major constituents of F3 were identified as lutein, 131-hydroxy-132-oxo-pheophytin a, campesterol, stigmasterol, β-sitosterol, pheophytin a and 132-hydroxy-pheophytin a. These compounds however, may not significantly contribute to the antitumor effect of F3.癌症患者常寻求替代疗法，例如传统药用植物，以获取安全有效的治疗手段并缓解常规疗法带来的不良反应。现有研究表明，爵床科（Acanthaceae）皱叶马蓝（Strobilanthes crispus）提取物在体外展现出强效抗癌活性，且在体内无毒性。另有研究显示，该植物还可对化学性肝癌发生起到防护作用。本团队此前研究表明，皱叶马蓝叶片中的某一活性组分可与他莫昔芬（tamoxifen）产生协同作用，诱导人乳腺癌细胞系发生凋亡，且不会损伤非恶性上皮细胞。本研究旨在利用N-甲基-N-亚硝基脲（N-methyl-N-Nitrosourea, NMU）诱导的大鼠乳腺肿瘤模型，评估皱叶马蓝二氯甲烷组分（F3）的抗肿瘤效果。经8周口服给药F3后，75%的大鼠出现肿瘤消退，且未观察到继发性肿瘤形成，亦无贫血或感染迹象。但该给药方案未对大鼠的肝肾功能指标产生改善作用。经鉴定，F3的主要成分为叶黄素（lutein）、131-羟基-132-氧代脱镁叶绿素a、菜油甾醇（campesterol）、豆甾醇（stigmasterol）、β-谷甾醇（β-sitosterol）、脱镁叶绿素a（pheophytin a）以及132-羟基脱镁叶绿素a。然而，上述化合物或许并未对F3的抗肿瘤活性起到显著贡献。