Ng Pei Ying, Chye Soi Moi, Ng Chew Hee, Koh Rhun Yian, Tiong Yee Lian, Pui Liew Phing, Tan Yong Hui, Lim Crystale Siew Ying, Ng Khuen Yen
School of Health Sciences, International Medical University, Kuala Lumpur, Malaysia.
School of Postgraduate Studies, International Medical University, Kuala Lumpur, Malaysia. Email:
Asian Pac J Cancer Prev. 2017 Apr 1;18(4):917-926. doi: 10.22034/APJCP.2017.18.4.917.
Background: Clinacanthus nutans (C.nutans) is a plant consumed as a cancer treatment in tropical Asia. Despite the availability of numerous anecdotal reports, evaluation of active anticancer effects has remained elusive. Therefore we here examined antiproliferative, reactive oxygen species (ROS)-inducing and apoptosis mechanisms of whole plant extracts in different cancer cell lines. Methods: Antiproliferative actions of five solvent extracts (hexane, chloroform, ethyl acetate, methanol and water) of C.nutans were tested on non-small cell lung cancer (A549), nasopharygeal cancer (CNE1) and liver cancer (HepG2) cells using MTT assay. The most potent anticancer extract was then assessed by flow cytometry to study cell cycle changes . Intracellular levels of ROS were quantified by DCFH-DA assay. Involvement of the caspase pathway in induction of apoptosis was assessed using caspase assay kits. GC-MS analysis was performed to identify phytoconstituents in the extracts. Results: Hexane and chloroform extracts were antiproliferative against all three cell lines, while the ethyl acetate extract, at 300 μg/mL, was antiproliferative in the CNE1 but not A549 and HepG2 cases. Methanol and water extracts did not inhibit cancer cell proliferation. The most potent anticancer hexane extract was selected for further testing. It induced apoptosis in all three cell lines as shown by an increase in the percentage of cell in sub-G1 phase. Dose-dependent increase in ROS levels in all three cell lines indicated apoptosis to be possibly modulated by oxidative stress. At high concentrations (>100 μg/mL), hexane extracts upregulated caspases 8, 9 and 3/7 across all three cell lines. GC-MS analysis of the hexane extract revealed abundance of 31 compounds. Conclusion : Among the five extracts of C.nutans, that with hexane extract demonstrated the highest antiproliferative activity against all three cancer cell lines tested. Action appeared to be via ion of intracellular ROS, and induction of apoptosis via intrinsic and extrinsic caspase pathways.
鳄嘴花是一种在亚洲热带地区被用作癌症治疗的植物。尽管有大量的传闻报道，但对其抗癌活性的评估仍不明确。因此，我们在此研究了全植物提取物在不同癌细胞系中的抗增殖、诱导活性氧（ROS）和凋亡机制。方法：使用MTT法检测鳄嘴花的五种溶剂提取物（己烷、氯仿、乙酸乙酯、甲醇和水）对非小细胞肺癌（A549）、鼻咽癌（CNE1）和肝癌（HepG2）细胞的抗增殖作用。然后通过流式细胞术评估最有效的抗癌提取物，以研究细胞周期变化。通过DCFH-DA法对细胞内ROS水平进行定量。使用caspase检测试剂盒评估caspase途径在凋亡诱导中的作用。进行GC-MS分析以鉴定提取物中的植物成分。结果：己烷和氯仿提取物对所有三种细胞系均有抗增殖作用，而乙酸乙酯提取物在300μg/mL时对CNE1有抗增殖作用，但对A549和HepG2无作用。甲醇和水提取物不抑制癌细胞增殖。选择最有效的抗癌己烷提取物进行进一步测试。它诱导所有三种细胞系发生凋亡，表现为亚G1期细胞百分比增加。所有三种细胞系中ROS水平的剂量依赖性增加表明凋亡可能由氧化应激调节。在高浓度（>100μg/mL）下，己烷提取物在所有三种细胞系中上调caspase 8、9和3/7。己烷提取物的GC-MS分析显示有31种化合物。结论：在鳄嘴花的五种提取物中，己烷提取物对所有三种测试癌细胞系表现出最高的抗增殖活性。其作用似乎是通过细胞内ROS的产生以及通过内在和外在caspase途径诱导凋亡。
