Vascular Responses to Extractable Fractions of Ilex paraguariensis in Rats Fed Standard and High-Cholesterol Diets
- 1 October 2005
- journal article
- research article
- Published by SAGE Publications in Biological Research For Nursing
- Vol. 7 (2), 146-156
- https://doi.org/10.1177/1099800405280521
Abstract
The authors investigated the vasorelaxant properties of the aqueous (Aq-EF) and acid n-butanolic (acn-BuOH) extractable fractions from Ilex paraguariensis leaves. Perfusion pressure was evaluated using isolated and perfused mesenteric arterial beds (MABs) from rats fed hypercholesterolemic and standard diets. Extract-induced vasorelaxation in the presence and absence of various inhibitors was examined following precontraction of the MABs with methoxamine (30 μM) solution. In hypercholesterolemic-diet rats, relaxation in intact MABs was significantly decreased with ac-n-BuOH-EF bolus (300, 600, 900 μg) in comparison to those in standard-diet rats. After the endothelium was stripped from the MABs, the vascular responses to ac-n-BuOH-EF and 900 μg bolus of Aq-EF were significantly changed. Treatment of the MABs with an inhibitor of nitric oxide synthase, NG -nitro-L-arginine methylester hydrochloride (L-NAME, 10 mM), did not change either ac-n-BuOH-EF- or Aq-EF-induced vasodilation except for the 900 g bolus of Aq-EF. The guanilate cyclase inhibitor methylene blue (100 μM) did not affect vasodilation for either fraction in the MABs from the hypercholesterolemic-diet rats. The chronic oral administration of I. paraguariensis extract in hypercholesterolemic-diet rats resulted in a significant reduction in serum levels of cholesterol and triglycerides. These results suggest that I. paraguariensis ac-n-BuOH-EF and Aq-EF induce vasodilation in standard-diet rats in a dose-dependent manner and that the hypercholesterolemic diet substantially reduced the effect of ac-n-BuOH-EF on precontracted MABs.Keywords
This publication has 38 references indexed in Scilit:
- Impaired renal vascular endothelial function in vitro in experimental hypercholesterolemiaAtherosclerosis, 2001
- Anti-hypercholesterolaemia, Antioxidant Activity and Free Radical Scavenger Effects of Traditional Chinese Medicine Prescriptions Used for StrokeJournal of Pharmacy and Pharmacology, 2000
- Antioxidant Effects of an Aqueous Extract of Ilex paraguariensisBiochemical and Biophysical Research Communications, 2000
- Pharmacodynamics and Pharmacokinetics of the HMG-CoA Reductase InhibitorsClinical Pharmacokinetics, 1997
- Nitric oxide production and endothelium‐dependent vasorelaxation induced by wine polyphenols in rat aortaBritish Journal of Pharmacology, 1997
- Antioxidant Effects of Ilex Paraguariensis: Induction of Decreased Oxidability of Human LDLin VivoBiochemical and Biophysical Research Communications, 1996
- Endothelium-Dependent Vasorelaxation Caused by Various Plant ExtractsJournal of Cardiovascular Pharmacology, 1995
- Endothelium-dependent relaxation of coronary arteries by noradrenaline and serotoninNature, 1983
- Coronary Artery Spasm Induced in Atherosclerotic Miniature SwineScience, 1983
- The obligatory role of endothelial cells in the relaxation of arterial smooth muscle by acetylcholineNature, 1980