Background: Chronic treatment with the dietary flavonoid quercetin is known to lower blood pressure and restore endothelial dysfunction in animal models of hypertension. This study investigated the direct effects of quercetin on vascular response in chronic 2-kidney, 1-clip (2K1C) renal hypertensive rats. The effects of antioxidant vitamin ascorbic acid on the vasoreactivity were also examined.
Methods: 2K1C renal hypertension was induced by clipping the left renal artery; age-matched rats that received sham treatment served as controls. Thoracic aortae were mounted in tissue baths for the measurement of isometric tension.
Results: Relaxant responses to acetylcholine were significantly attenuated in 2K1C rats in comparison with sham rats. Quercetin or ascorbic acid augmented acetylcholine-induced relaxation in 2K1C rats, whereas no significant differences were noted in sham rats. The relaxation response to sodium nitroprusside was comparable between 2K1C and sham rats, and sodium nitroprusside-induced relaxation was not altered by quercetin or ascorbic acid in either group. The contractile response to phenylephrine was significantly enhanced in 2K1C rats compared with sham rats. Phenylephrine-induced contraction was inhibited by pretreatment with quercetin or ascorbic acid in 2K1C rats, whereas neither chemical affected responses in sham rats. N(w)-nitro-L-arginine methyl ester markedly augmented the contractile response to phenylephrine in sham rats, whereas no significant differences were observed in 2K1C rats. Quercetin or ascorbic acid did not affect phenylephrine-induced contraction in the presence of N(w)-nitro-L-arginine methyl ester in either 2K1C or sham rats.
Conclusion: Acute exposure to quercetin appears to improve endothelium-dependent relaxation and inhibit the contractile response, similar to the effect of ascorbic acid in 2K1C hypertension. These results partially explain the vascular beneficial effects of quercetin in renal hypertension.
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http://dx.doi.org/10.1016/j.krcp.2015.12.003 | DOI Listing |
BMC Plant Biol
January 2025
Department of Crop Sciences, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA.
Purpose: This study explored how exogenous silicon (Si) affects growth and salt resistance in maize.
Methods: The maize was cultivated in sand-filled pots, incorporating varied silicon and salt stress (NaCl) treatments. Silicon was applied at 0, 2, 4, 6, and 8 mM, and salt stress was induced using 0, 60 and120 mM concentrations.
Anal Chem
January 2025
State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, P. R. China.
Human cells generate a bulk of aldehydes during lipid peroxidation (LPO), influencing critical cellular processes, such as oxidative stress, protein modification, and DNA damage. Enals, highly reactive α,β-unsaturated aldehydic metabolites, are implicated in various human pathologies, especially neurodegenerative disorders, cancer, and cardiovascular diseases. Despite their importance, endogenous enals remain poorly characterized, primarily due to their instability and low abundance.
View Article and Find Full Text PDFLuminescence
January 2025
Pharmaceutical Chemistry Department, Faculty of Pharmacy, Misr International University, Cairo, Egypt.
Affordable and eco-friendly green spectrofluorometric (FL) methods can enhance the safety and cost-effectiveness of quality assurance and control in ascorbic acid (ASA) formulations. However, most current techniques for ASA analysis have faced challenges like complexity, delayed response times, low throughput, time-consuming procedures, and requirements for expensive equipment and hazardous chemicals for analyte modification. The study is aimed at producing natural carbon quantum dots (NACQDs) from pumpkin seed peels (PSPs), a natural waste material, using a rapid microwave-assisted method.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Biochemistry, Bahauddin Zakariya University, Multan, 60800, Pakistan.
Liver cancer is globally the most frequent fatal malignancy, and its identification is critical for making clinical decisions about treatment options. Pathological diagnostics and contemporary imaging technologies provide insufficient information for tumor identification. Hydrogen peroxide (HO), an emerging biomarker is a powerful oxidant found in the tumor microenvironment, and stimulates the invasion, proliferation, and metastasis of liver cancer cells.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Mechanical and Industrial Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India.
ZnO-doped CuO nanocomposites (CuO-ZnO NPs) of 1, 3, and 5 mol% were prepared by the solution combustion method using ODH as a fuel (Oxlyl-hydrazide) at 500 °C and calcining at 1000 °C for two hours and the Structural, photocatalytic, and electrochemical properties were investigated by experimental and theoretical methods. X-ray diffraction (XRD) patterns revealed a crystallite size (D) range of 25 to 31 nm for pure CuO and 1, 3, and 5 mol% CuO-ZnO NPs. According to calculations, the optical energy band gap (Eg) of the NPs is between 2.
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