In vitro and some animal models have shown that quercetin, a polyphenol derived from plants, has a wide range of biological actions including anti-carcinogenic, anti-inflammatory and antiviral activities; as well as attenuating lipid peroxidation, platelet aggregation and capillary permeability. This review focuses on the physicochemical properties, dietary sources, absorption, bioavailability and metabolism of quercetin, especially main effects of quercetin on inflammation and immune function. According to the results obtained both in vitro and in vivo, good perspectives have been opened for quercetin. Nevertheless, further studies are needed to better characterize the mechanisms of action underlying the beneficial effects of quercetin on inflammation and immunity.
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.
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.
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.
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.
The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/5791518001210633.
Adult stem cells are known to have a reduced restorative capacity as we age and are more vulnerable to oxidative stress resulting in a reduced ability of the body to heal itself. We have previously reported that a proprietary nutraceutical formulation, NT-020, promotes proliferation of human hematopoietic stem cells in vitro and protects stem cells from oxidative stress when given chronically to mice in vivo. Because previous reports suggest that the blue green algae, Aphanizomenon flos-aquae (AFA) can modulate immune function in animals, we sought to investigate the effects of AFA on human stem cells in cultures.
Two AFA products were used for extraction: AFA whole (AFA-W) and AFA cellular concentrate (AFA-C). Water and ethanol extractions were performed to isolate active compounds for cell culture experiments. For cell proliferation analysis, human bone marrow cells or human CD34+ cells were cultured in 96 well plates and treated for 72 hours with various extracts. An MTT assay was used to estimate cellproliferation.
We report here that the addition of an ethanol extract of AFA-cellular concentrate further enhances the stem cell proliferative action of NT-020 when incubated with human adult bone marrow cells or human CD34+ hematopoietic progenitors in culture. Algae extracts alone had only moderate activity in these stem cell proliferation assays.
This preliminary study suggests that NT-020 plus the ethanol extract of AFA cellular concentrate may act to promote proliferation of human stem cell populations.