The results of this study indicate that equol has beneficial effects on structural as well as molecular skin parameters and encourages further investigations to decipher the epigenetic regulation of skin ageing and interactions of equol.
Neuropeptide Y (NPY)-Y2 receptors are G-protein coupled receptors and, upon activation, induce opening of potassium channels or closing of calcium channels. They are generally presynaptically located. Depending on the neuron in which they are expressed they mediate inhibition of release of NPY and of the neuron's classical transmitter GABA, glutamate or noradrenaline, respectively. Here we provide evidence that Y2 receptor binding is inhibited dose-dependently by GTPγS along Schaffer collaterals, the stria terminalis and the fimbria indicating that Y2 receptors are functionally coupled to G-proteins along these fiber tracts. Double immune fluorescence revealed coexistence of Y2-immunoreactivity with β-tubulin, a marker for axons in the stria terminalis, but not with synaptophysin labeling presynaptic terminals, supporting the localization of Y2 receptors along axonal tracts. After kainic acid-induced seizures in rats, GTPγS-induced inhibition of Y2 receptor binding is facilitated in the Schaffer collaterals but not in the stria terminalis. Our data indicate that Y2 receptors are not only located at nerve terminals but also along fiber tracts and are there functionally coupled to G-proteins.
Introduction: Topical investigations have demonstrated that oxidative stress and inflammation play key roles in biological aging and determine incidence and course of age-related diseases. Lifestyle and environmental factors hugely impact epigenetic regulation and DNA stability with telomere attrition and epigenetic instability providing a potential record of the cumulative burden of endogenous and exogenous oxidative noxae. Certain physiologically active plant components exhibit antioxidative activities affecting epigenetic regulation of inflammation response and DNA repair.Methods: Against this background, the present study investigated green tea polyphenol epigallocatechin gallate (EGCG) in the context of telomere regulation in Caco-2 colorectal adenocarcinoma cells vs. ES-1 primary skin fibroblasts. Cell lines were treated with 20 and 200 µM EGCG for 36, 72 and 144 hours, respectively. Telomerase activity, relative telomere length as well as methylation status of hTERT and c-Myc from different culture conditions were assessed. Malondialdehyde (MDA) served as a surrogate marker of potential pro-oxidative effects of EGCG in a physiologically relevant tissue model.Results: EGCG incubation was associated with telomere shortening and decreased telomerase activity in Caco-2 cells, and relatively longer telomeres along with increased methylation of six 5'—C—phosphate—G—3' (CpG) sites in the promoter region of human Telomerase Reverse Transcriptase (hTERT) in fibroblasts. At low concentrations, EGCG significantly decreased oxidative damage to lipids in Caco-2 cells and attenuated H2O2 induced oxidation at higher concentrations.Conclusion: These results suggest differential EGCG-mediated telomeric modulation in cancer vs. primary cells and a specific antioxidant activity of EGCG against oxidative damage to lipids in abnormal cells.Keywords: Caco-2, epigallocatechin gallate, telomeres, hTERT, DNA methylation, telomerase, oxidative stress, malondialdehyde
Objective: In vitro and in vivo studies in rodents have demonstrated many health promoting properties of individual phytochemicals including antioxidative and chemopreventive effects. Recently combination of substances is claimed to enhance activity.The objective of this study was to investigate health benefits of a daily consumption of a combination of a large variety of phytochemicals (TimeBlock ® ). To assess potential changes we analyzed specific biomarkers that are associated with aging, oxidative stress and DNA stability: Methylation of LINE-1, c-Myc, IL-6, MLH1, DNMT1, ITGA2B and telomere length. Methods:For this study 110 healthy participants of both sexes between 31-76 years were recruited, 101 subjects were included in further analysis. A small reference group (n=20) without intervention within the same age interval served as control. Participants received a plant based dietary supplement (TimeBlock ® ) for 6 months by oral administration. Ingredients included extracts from green tea (EGCG), wheatgrass (tocotrienols), barley grass (folic acid), tomatoes (lycopene), tagetes (zeaxanthin, lutein), algae, shiitake mushrooms (vitamin D) and grape seeds (resveratrol). Capillary blood samples were collected from all participants before administration and within 6 days after the end of the study period following DNA extraction, bisulfite conversion and qPCR as well as high resolution melting curve analysis addressing analysis of LINE-1, c-Myc, IL-6, MLH1, DNMT1, ITGA2B and telomere length. Nutrition, lifestyle and health status were assessed with a standardized food and lifestyle questionnaire. Results and discussion:Our results confirmed the positive effect of plant derived antioxidants on telomeres and inflammation frequency. An age-specific drift of analyzed markers could be observed. While methylation of c-Myc-a key factor in telomerase regulation-was not affected by administration, total telomere length showed a significant increase, which we suggest to be linked with an increased cell turnover and accelerated apoptosis of senescent or mutated cells without enhancing telomerase activity. Further, methylation of mismatch repair protein gene MLH1 showed a strong negative correlation with telomere length, supporting the influence of MMR on telomere regulation. Conclusion:The results of the present study indicate that a combined administration of a variety of phytochemicals can be a potential preventive and therapeutic agent, as each substance exhibits different modes of action and in combination, health promoting effects could be potentiated. Addressing different mechanisms of aging, specific phytochemicals could be used as new therapeutic approach against age-related diseases.
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