Institute of Chemical Biology, Henan University, Kaifeng 475004, China.
Acta Pharmacol Sin. 2013 Nov;34(11):1403-10. doi: 10.1038/aps.2013.90. Epub 2013 Aug 26.
To investigate the effects and the molecular mechanisms of fucoxanthin, a major carotenoid found in edible seaweed, on HeLa cells.
The cytotoxicity of fucoxanthin was evaluated using MTT assay. Cell cycle and apoptosis were evaluated using flow cytometric analysis. Autophagy was detected with acridine orange staining and transient transfection of the GFP-LC3 plasmid into the cells. Protein expression was detected with Western blotting.
Treatment of HeLa cells with fucoxanthin (10-80 μmol/L) for 48 h caused dose-dependent cytotoxicity with an IC50 value of 55.1±7.6 μmol/L. Fucoxanthin (10, 20, and 40 μmol/L) dose-dependently induced G0/G1 arrest, but did not change the apoptosis of HeLa cells. The same concentrations of fucoxanthin dose-dependently increased the protein expression of LC3 II (the autophagosome marker) and Beclin 1 (the initiation factor for autophagosome formation) in HeLa cells. Moreover, fucoxanthin dose-dependently decreased the levels of phosphorylated Akt and its downstream proteins p53, p70S6K, and mTOR, and increases the expression of PTEN in HeLa cells. Pretreatment of HeLa cells with 3-methyladenine (5 mmol/L) blocked the cytotoxic effect of fucoxanthin as well as fucoxanthin-induced autophagy.
Fucoxanthin exerts autophagy-dependent cytotoxic effect in HeLa cells via inhibition of Akt/mTOR signaling pathway.
研究在可食用海藻中发现的主要类胡萝卜素岩藻黄质对 HeLa 细胞的作用及其分子机制。
通过 MTT 法评估岩藻黄质的细胞毒性。通过流式细胞术分析评估细胞周期和细胞凋亡。使用吖啶橙染色和 GFP-LC3 质粒瞬时转染检测自噬。用 Western blot 检测蛋白表达。
HeLa 细胞用岩藻黄质（10-80μmol/L）处理 48 h 可引起剂量依赖性细胞毒性，IC50 值为 55.1±7.6μmol/L。岩藻黄质（10、20 和 40μmol/L）可剂量依赖性诱导 G0/G1 期阻滞，但不改变 HeLa 细胞的凋亡。相同浓度的岩藻黄质可剂量依赖性增加 HeLa 细胞中 LC3 II（自噬体标志物）和 Beclin 1（自噬体形成的起始因子）的蛋白表达。此外，岩藻黄质可剂量依赖性降低 HeLa 细胞中磷酸化 Akt 及其下游蛋白 p53、p70S6K 和 mTOR 的水平，并增加 PTEN 的表达。用 3-甲基腺嘌呤（5mmol/L）预处理 HeLa 细胞可阻断岩藻黄质的细胞毒性作用以及岩藻黄质诱导的自噬作用。
岩藻黄质通过抑制 Akt/mTOR 信号通路在 HeLa 细胞中发挥自噬依赖性细胞毒性作用。
