Catechins Blunt the Effects of oxLDL and its Primary Metabolite Phosphatidylcholine Hydroperoxide on Endothelial Dysfunction Through Inhibition of Oxidative Stress and Restoration of eNOS in Rats
KIDNEY & BLOOD PRESSURE RESEARCH
Authors: Chang, Hao-Hsiang; Chien, Chen-Yen; Chen, Kuo-Hsin; Huang, Shih-Chung; Chien, Chiang-Ting
Abstract
Background/Aims: We explored the effects of catechins (decaffeinated green tea extracts containing (-)-epicatechin, (-)-epigallocatechin, (-)-epicatechin gallate and (-)-epigallocatechin gallate) on atherosclerosis risk factors, oxidized low-density lipoprotein (oxLDL) and its primary metabolite, phosphatidylcholine hydroperoxide (PCOOH) induced oxidative injury in cultured endothelial cell line and rats. Methods: We used endothelial cell line and male Wistar rats to determine the effect of catechins on oxLDL or PCOOH induced oxidative injury including apoptosis, H2O2 level, vascular responses and urinary 8-isoprostane and nitrite/nitrate concentration. Plasma catechins concentration was determined by a CoulArray HPLC. Responses of aortic and renal vasoconstriction were evaluated by a transonic meter and a full-field laser perfusion imager. Results: PCOOH administration significantly increased H2O2 amounts and cell apoptosis and decreased endothelial nitric oxide synthase (eNOS) expression in the cultured endothelial cells. Catechins pretreatment significantly reduced PCOOH-elevated H2O2 amounts, endothelial cell apoptosis and partly recovered eNOS expression. Intravenous administration of oxLDL, PCOOH or H2O2, not native LDL, significantly decreased renal and aortic blood flow associated with enhanced ICAM-1 expression and 4-hydroxynoneal (4-HNE) accumulation, and decreased eNOS expression in the male Wistrar rats. One hour after oral intake of green tea extracts, 4 peaks of catechins were found in the rat plasma. The increased plasma catechins significantly inhibited oxLDL-, PCOOH-or H2O2-induced renal and aortic vasoconstriction, decreased urinary 8-isoprostane levels, renal ICAM-1 expression and 4-HNE accumulation, and restored nitrite/nitrate amounts and eNOS activity. Conclusions: Our data suggests that catechins pretreatment decrease PCOOH-induced endothelial apoptosis and arterial vasoconstriction through the action of H2O2 inhibition and eNOS restoration. (C) 2017 The Author(s) Published by S. Karger AG, Basel
Erythropoietin protects the subventricular zone and inhibits reactive astrogliosis in kaolin-induced hydrocephalic rats
CHILDS NERVOUS SYSTEM
Authors: Suryaningtyas, Wihasto; Arifin, Muhammad; Rantam, Fedik Abdul; Bajamal, Abdul Hafid; Dahlan, Yoes Prijatna; Ugrasena, I. Dewa Gede; Maliawan, Sri
Abstract
PurposeTo elucidate the potential role of erythropoietin (EPO) as a neuroprotective agent against reactive astrogliosis and reducing the thinning rate of subventricular zone (SVZ) in kaolin-induced hydrocephalic rats.MethodThirty-six ten-week-old Sprague-Dawley rats were used in this study. Hydrocephalus was induced with 20% kaolin suspension injected into the cistern of thirty rats and leaving the six rats as normal group. The hydrocephalic rats were randomly divided into hydrocephalic and treatment group. The treatment group received daily dose of recombinant human erythropoietin (rhEPO) from day 7 to day 21 after induction. The animals were sacrificed at 7 (only for hydrocephalic group) and 14 or 21 (for both groups) days after induction. Brain was removed and was prepared for histological analysis by hematoxylin and eosin staining as well as immunohistochemistry for 4-HNE, GFAP, Iba-1, and Ki-67.ResultsHistopathological analysis showed that animals treated with rhEPO had a reduced astrocyte reactivity displayed by lower GFAP expression. Hydrocephalic rats received rhEPO also displayed reduced microglial activation shown by lower Iba-1 protein expression. Exogenous rhEPO exerted its protective action in reducing astrogliosis by inhibiting lipid peroxidation that was documented in this study as lower expression of 4-HNE than non-treated group. The SVZ thickness was progressively declining in hydrocephalus group, while the progression rate could be reduced by rhEPO.ConclusionErythropoietin has a potential use for inhibiting lipid peroxidation, and reactive astrogliosis in hydrocephalic animal model. The reduced thinning rate of SVZ demonstrated that EPO also had effect in reducing the hydrocephalus progressivity. Further research is warranted to explore its efficacy and safety to use in clinical setting.