Artemisia absinthium (AA): a novel potential complementary and alternative medicine for breast cancer.

forrás: https://www.ncbi.nlm.nih.gov/pubmed/22311047


2016-09-30 12:24:02


Natural products have become increasingly important in pharmaceutical discoveries, and traditional herbalism has been a pioneering specialty in biomedical science. The search for effective plant-derived anticancer agents has continued to gain momentum in recent years. The present study aimed to investigate the role of crude extracts of the aerial parts of Artemisia absinthium (AA) extract in modulating intracellular signaling mechanisms, in particular its ability to inhibit cell proliferation and promote apoptosis in a human breast carcinoma estrogenic-unresponsive cell line, MDA-MB-231, and an estrogenic-responsive cell line, MCF-7. Cells were incubated with various concentrations of AA, and anti-proliferative activity was assessed by MTT assays, fluorescence microscopy after propidium iodide staining, western blotting and cell cycle analysis. Cell survival assays indicated that AA was cytotoxic to both MDA-MB-231 and MCF-7 cells. The morphological features typical of nucleic staining and the accumulation of sub-G1 peak revealed that the extract triggered apoptosis. Treatment with 25 μg/mL AA resulted in activation of caspase-7 and upregulation of Bad in MCF-7 cells, while exposure to 20 μg/mL AA induced upregulation of Bcl-2 protein in a time-dependent response in MDA-MB-231 cells. Both MEK1/2 and ERK1/2 was inactivated in both cell lines after AA treatment in a time-dependent manner. These results suggest that AA-induced anti-proliferative effects on human breast cancer cells could possibly trigger apoptosis in both cell lines through the modulation of Bcl-2 family proteins and the MEK/ERK pathway. This might lead to its possible development as a therapeutic agent for breast cancer following further investigations.


Suppression of human monocyte tissue factor induction by red wine phenolics and synthetic derivatives of resveratrol

forrás: http://www.ncbi.nlm.nih.gov/pubmed/16507316


2014-10-28 13:42:48


Prevention of cardiovascular disease through nutritional supplements is growing in popularity throughout the world. Multiple epidemiologic studies found that moderate consumption of alcohol, particularly red wine, lowers mortality rates from coronary heart diseases (CHD). Chronic inflammation and atherosclerosis associated with CHD culminate in aberrant intravascular expression of tissue factor (TF), which triggers blood coagulation leading to thrombosis, a major cause for heart attack. We showed earlier that two red wine phenolics, resveratrol and quercetin, suppressed TF induction in endothelial cells. In the present study, we investigated efficacy of seven resveratrol derivatives, which were shown to be effective in regulating cancer cell growth in vitro at much lower concentrations than the parent compound resveratrol, in inhibiting TF induction in peripheral blood mononuclear cells (PBMCs). We also tested possible synergistic effects of resveratrol and quercetin with the other major red wine phenolics in suppression of lipopolysaccharide-induced TF expression in human PBMCs. We found that several resveratrol derivatives were 2- to 10-fold more efficient than resveratrol in inhibiting TF induction. Our study found no evidence for synergism among red wine polyphenolics. These data suggest that structural alterations of resveratrol can be effective in producing potent antithrombotic agents that will have therapeutic potential in the improvement of cardiovascular health and prevention of CHD. Among major red wine phenolics, quercetin appears to be the predominant suppressor of TF induction.


Resveratrol induces gastric cancer cell apoptosis via reactive oxygen species, but independent of sirtuin1

forrás: http://www.ncbi.nlm.nih.gov/pubmed/22211760


2014-10-28 13:38:15


The currently available chemotherapeutic regimens against gastric cancer are not very effective, leading to high recurrence and poor survival. Resveratrol is a naturally occurring polyphenol with potent apoptosis-inducing activity. However, the mechanism underlying its actions remains unknown. In the present study, human gastric adenocarcinoma SGC7901 cells were treated with resveratrol (0, 25, 50, 100 and 200 μmol/L) for 48 h, and cellular apoptosis DNA damage were determined. In certain experiments, cells were incubated with superoxide dismutase (100 U/mL), catalase (300 U/mL) or sirtinol (10 μmol/L) to determine the role of reactive oxygen species (ROS) and sirtuin1 in resveratrol-induced cellular apoptosis. Treatment with resveratrol (50-200 μmol/L) for 48 h significantly induced apoptosis and DNA damage in human gastric cancer SGC7901 cells. This was due to the increased generation of ROS following resveratrol treatment because incubation of cells with superoxide dismutase (100 U/mL) or catalase (300 U/mL) attenuated resveratrol-induced cellular apoptosis. Interestingly, treatment with resveratrol (25-200 μmol/L) did not affect the level and activity of sirtuin1, whereas the sirtuin1 inhibitor sirtinol (10 μmol/L) significantly reduced sirtuin1 activity. Furthermore, treatment with sirtinol (10 μmol/L) did not have any effect on apoptosis induced by resveratrol. These data provide evidence that resveratrol induces apoptosis via ROS, but independent of sirtuin1, in the human gastric cancer cell line SGC7901.


Luteolin inhibits human prostate tumor growth by suppressing vascular endothelial growth factor receptor 2-mediated angiogenesis.

forrás: http://www.ncbi.nlm.nih.gov/pubmed/23300633


2014-04-15 12:46:52


Abstract

Angiogenesis, the formation of new blood vessels from pre-existing vascular beds, is essential for tumor growth, invasion, and metastasis. Luteolin is a common dietary flavonoid found in fruits and vegetables. We studied the antiangiogenic activity of luteolin using in vitro, ex vivo, and in vivo models. In vitro studies using rat aortic ring assay showed that luteolin at non-toxic concentrations significantly inhibited microvessel sprouting and proliferation, migration, invasion and tube formation of endothelial cells, which are key events in the process of angiogenesis. Luteolin also inhibited ex vivo angiogenesis as revealed by chicken egg chorioallantoic membrane assay (CAM) and matrigel plug assay. Gelatin zymographic analysis demonstrated the inhibitory effect of luteolin on the activation of matrix metalloproteinases MMP-2 and MMP-9. Western blot analysis showed that luteolin suppressed VEGF induced phosphorylation of VEGF receptor 2 and their downstream protein kinases AKT, ERK, mTOR, P70S6K, MMP-2, and MMP-9 in HUVECs. Proinflammatory cytokines such as IL-1β, IL-6, IL-8, and TNF-α level were significantly reduced by the treatment of luteolin in PC-3 cells. Luteolin (10 mg/kg/d) significantly reduced the volume and the weight of solid tumors in prostate xenograft mouse model, indicating that luteolin inhibited tumorigenesis by targeting angiogenesis. CD31 and CD34 immunohistochemical staining further revealed that the microvessel density could be remarkably suppressed by luteolin. Moreover, luteolin reduced cell viability and induced apoptosis in prostate cancer cells, which were correlated with the downregulation of AKT, ERK, mTOR, P70S6K, MMP-2, and MMP-9 expressions. Taken together, our findings demonstrate that luteolin inhibits human prostate tumor growth by suppressing vascular endothelial growth factor receptor 2-mediated angiogenesis.

 

 


Enhancement of recombinant myricetin on the radiosensitivity of lung cancer A549 and H1299 cells.

forrás: http://www.ncbi.nlm.nih.gov/pubmed/24650056


2014-04-15 12:41:59


Abstract

OBJECTIVE:

Myricetin, a common dietary flavonoid is widely distributed in fruits and vegetables, and is used as a health food supplement based on its immune function, anti-oxidation, anti-tumor, and anti-inflammatory properties. The aim of this study was to investigate the effects of myricetin on combination with radiotherapy enhance radiosensitivity of lung cancer A549 and H1299 cells.

METHODS:

A549 cells and H1299 cells were exposed to X-ray with or without myricetin treatment. Colony formation assays, CCK-8 assay, flow cytometry and Caspase-3 level detection were used to evaluate the radiosensitization activity of myricetin on cell proliferation and apoptosis in vitro. Nude mouse tumor xenograft model was built to assessed radiosensitization effect of myricetin in vivo.

RESULTS:

Compared with the exposed group without myricetin treatment, the groups treated with myricetin showed significantly suppressed cell surviving fraction and proliferation, increased the cell apoptosis and increased Caspase-3 protein expression after X-ray exposure in vitro. And in vivo assay, growth speed of tumor xenografts was significantly decreased in irradiated mice treated with myricetin.

CONCLUSIONS:

The study demonstrated both in vitro and in vivo evidence that combination of myricetin with radiotherapy can enhance tumor radiosensitivity of pulmonary carcinoma A549 and H1299 cells, and myricetin could be a potential radiosensitizer for lung cancer therapy.

VIRTUAL SLIDES:

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/5791518001210633.

 


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