ABSTRACT
<p><b>OBJECTIVE</b>Elevation of reactive oxygen species (ROS), especially the level of superoxide is a key event in many forms of cardiovascular diseases. To study the mechanism of tea polyphenols against cardiovascular diseases, we observed the expressions of ROS-related enzymes in endothelial cells.</p><p><b>METHODS</b>Tea polyphenols were co-incubated with bovine carotid artery endothelial cells (BCAECs) in vitro and intracellular NADPH oxidase subunits p22phox and p67phox, SOD-1, and catalase protein were detected using Western blot method.</p><p><b>RESULTS</b>Tea polyphenols of 0.4 microg/mL and 4.0 microg/mL (from either green tea or black tea) down-regulated NADPH oxidase p22phox and p67phox expressions in a dose-negative manner (P < 0.05), and up-regulated the expressions of catalase (P < 0.05).</p><p><b>CONCLUSIONS</b>Tea polyphenols regulate the enzymes involved in ROS production and elimination in endothelial cells, and may be beneficial to the prevention of endothelial cell dysfunction and the development of cardiovascular diseases.</p>
Subject(s)
Animals , Cattle , Camellia sinensis , Chemistry , Carotid Arteries , Cell Biology , Catalase , Cells, Cultured , Down-Regulation , Endothelial Cells , Metabolism , Flavonoids , Pharmacology , Membrane Transport Proteins , NADPH Dehydrogenase , NADPH Oxidases , Phenols , Pharmacology , Phosphoproteins , Polyphenols , Reactive Oxygen Species , Metabolism , Superoxide Dismutase , Superoxide Dismutase-1 , Up-RegulationABSTRACT
<p><b>OBJECTIVE</b>To investigate the relationship between fasting serum levels of leptin, glucose, insulin resistance, lipids in simple obese children.</p><p><b>METHODS</b>Fasting serum levels of leptin and insulin (Fins) were measured by RIA in 42 obese and 42 normally-weighted children matched on age, sex and height, and their total cholesterol (TC), triglyceride (TG), high density lipoprotein-cholesterol (HDL-C) were analyzed with enzymatic methods. HOMA-IR and LDL-C were calculated.</p><p><b>RESULTS</b>Serum level of leptin was (2.74 - 45.12) micro g/L and (0.53 - 10.18) micro g/L in obese and normally-weighted children, respectively, with an average level of leptin (log) significantly higher in obese group than that in control group (P < 0.001). Serum level of leptin was positively correlated with BMI, WHR and percentage of body fat. Of obese children, 83% were leptin resistant. Serum levels of TC, TG, LDL-C and insulin were significantly higher in obese leptin-resistant group than those in normally-weighted control group, but no significant difference in them between obese leptin-sensitive group and its normally-weighted control group was observed. Significantly higher serum levels of TG and lower HDL-C were observed in obese leptin-resistant group, as compared with those in obese leptin-sensitive group.</p><p><b>CONCLUSIONS</b>A big difference in serum level of leptin between obese and normally-weighted children was found, suggesting most obese children were resistant to endogenous leptin. Leptin resistance correlated significantly with the risk of metabolic syndrome and cardiovascular disease, indicating serum level of leptin could be used as an indicator in screening obese children at high risk.</p>