ABSTRACT
BACKGROUND: Leaves of the natural plant lotus are used in traditional Chinese medicine and tea production. They are rich in flavonoids. METHODS: In this study, lotus leaf flavonoids (LLF) were applied to human lung cancer A549 cells and human small cell lung cancer cells H446 in vitro to verify the effect of LLF on apoptosis in these cells through the ROS/p38 MAPK pathway. RESULTS: LLF had no toxic effect on normal cells at concentrations up to 500 µg/mL, but could significantly inhibit the proliferation of A549 cells and H446 cells. Flow cytometry showed that LLF could induce growth in A549 cells. We also found that LLF could increase ROS and MDA levels, and decrease SOD activity in A549 cells. Furthermore, qRT-PCR and western blot analyses showed that LLF could upregulate the expression of p38 MAPK (p-p38 MAPK), caspase-3, caspase-9, cleaved caspase-3, cleaved caspase-9 and Bax and downregulate the expression of Cu/Zn SOD, CAT, Nrf2, NQO1, HO-1, and Bcl-2 in A549 cells. Results of HPLC showed that LLF mainly contain five active substances: kaemp-feritrin, hyperoside, astragalin, phloridzin, and quercetin. The apoptosis-inducing effect of LLF on A549 cells came from these naturally active compounds. CONCLUSIONS: We have shown in this study that LLF is a bioactive substance that can induce apoptosis in A549 cells in vitro, and merits further research and development.
Subject(s)
Humans , Flavonoids/pharmacology , Reactive Oxygen Species/metabolism , Apoptosis/drug effects , p38 Mitogen-Activated Protein Kinases/metabolism , Lotus/chemistry , Lung Neoplasms/pathology , Signal Transduction/drug effects , Plant Leaves/chemistry , Cell Proliferation , Phytochemicals/pharmacology , A549 Cells , Lung Neoplasms/drug therapyABSTRACT
AIM: To investigate the effects of silencing carbonic anhydrase 1 (CA1) on proliferation, apoptosis, invasion and migration of human lung cancer A549 cells. METHODS: CA1-specific siRNA (si-CA1 group) and negative control (si-NC group) were transfected into lung cancer A549 cells by lipofection. The A549 cells transfected with empty liposome were used as blank control group. Real-time quantitative PCR (qPCR) and Western blot (Western blot) were used to detect the expression of CA1 mRNA and protein. Cell counting kit method (CCK-8), flow cytometry and Transwell assay were used to detect proliferation and apoptosis of A549 cells, invasion and migration capabilities. RESULTS:qPCR and Western blot showed that the expression levels of CA1 mRNA and protein in A549 cells transfected with CA1 siRNA were significantly down-regulated (P0.05). CONCLUSION: Silencing CA1 can inhibit the proliferation, invasion and migration of lung cancer A549 cells and promote cell apoptosis.
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Aim: To study the induction of apoptotic effect of sodium selenite on human lung cancer A549 cells and its mechanisms. Methods: A549 cells were exposed to different concentrations of sodium selenite for 24 h. MTT assay was applied to determine A549 cell proliferation. Inverted fluorescence microscope was used to investigate the morphological changes in A549 cells. Flow cytometry analysis was applied to assess the apoptotic rates of A549 cells. Laser confocal microscope was employed to measure the reactive oxygen species (ROS) fluorescence intensity. A multi-detection reader was used to determine the antioxidant parameter. Western blot was utilized to detect the expression of Keapl, Nrf2, HO-1 and Nrf2 in cytoplasm and nucleus. Results: MTT results showed that sodium selenite inhibited the proliferation of A549 cells in a concentration-dependent manner. After treatment with sodium selenite for 24 h, the apoptotic rate of A549 cells was markedly increased through Hoechst 33342 staining and flow cytometry measurement. Sodium selenite significantly up-regulated ROS and malondialdehyde (MDA) content and down-regulated the levels of superoxide dismutase (SOD) and glutathione (GSH). Meanwhile, sodium selenite treatment also reduced the expressions of Keapl, Nrf2 and HO-1 at protein levels and inhibited Nrf2 protein nuclear translocation in A549 cells. Conclusions: Treatment with sodium selenite induces A549 cells apoptosis, which may contribute to the anti-proliferation activity, induction of apoptosis and regulation of oxidative stress reaction and Keapl/Nrf2/ARE antioxidative signaling pathway expression.
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OBJECTIVE:To study the inhibitory mechanism of timosaponin B-Ⅱ(TB-Ⅱ) on the proliferation and migration of human lung cancer A549 cells. METHODS:A549 cells were treated with TB-Ⅱ [0(blank control),1,10 and 100 μg/ml] for 48 h,and total RNA and total protein were extracted respectively. Real time fluorescence quantitative-PCR and Western blot were used to detect mRNA and protein levels of IL-18. IL-18 in A549 cells was silenced by transfection;the expression of IL-18 mRNA and protein were compared among untransfection group,negative control group and transfection group;and then human lung can-cer A549 cells with silenced gene were treated with 10 μg/ml TB-Ⅱ for 24,48 and 72 h. The activity of cell proliferation was de-tected with CCK-8,and the change of cell migration ability was observed by streak method. RESULTS:Compared with blank con-trol,the expression of IL-18 mRNA and protein in A549 cells all increased after treated with TB-Ⅱ(P<0.05 or P<0.01),and were positively correlated with concentration. Compared with untransfection group,the expression of IL-18 mRNA and protein de-creased in transfection group(P<0.01). Compared with untransfected cell treated with TB-Ⅱ,the viability and migration ability of A549 cells with transfection gene increased after treated with TB-Ⅱ for 72 h(P<0.01). CONCLUSIONS:TB-Ⅱ can inhibit the proliferation and migration of A549 cells by up-regulating IL-18 gene expression.
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OBJECTIVE:To study the effects of Thymalfasin for injection on the apoptosis of human lung cancer A549 cells. METHODS:After treated with 0(blank control),25,50,100,200 and 400 mg/L Thymalfasin for injection for 24,48 and 72 h, the cell proliferation inhibitory rate was analyzed with MTT and calculated. After treated with 0(blank control),50 and 100 mg/L Thymalfasin for injection for 48 h,cell apoptosis was detected by flow cytometry,and the expression of Caspase-3,Bcl-2 and Bax and the phosphorylation level of Akt were deteced by Western blot. RESULTS:Compared with blank control group,proliferation in-hibitory rate of A549 cells increased after treated with Thymalfasin for injection,in concentration and time-dependent manner(P<0.05). The apoptotic rate of A549 cells increased after treated with Thymalfasin for injection 50,100 mg/L for 48 h (P<0.05). The expression of Caspase-3 increased while the Bcl-2/Bax and phosphorylation level of Akt decreased in A549 cells after treated with Thymalfasin for injection 100 mg/L (P<0.05). CONCLUSIONS:Thymalfasin for injection can inhibit the proliferation of A549 cells by activating Caspase-3,decreasing Bcl-2/Bax ratio,inhibiting Akt signal pathway and induce the apoptosis of A549 cells.