Effect of cardamonin on the vascular contraction in hypertensive rats

• Grant number: 13/16249-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2013
• End date: May 31, 2015
• Field of knowledge: Biological Sciences - Pharmacology - Cardiorenal Pharmacology
• Principal Investigator: Eliana Hiromi Akamine
• Grantee: Anna Ariadne Luiza Massella Patsea
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

In the spontaneously hypertensive rats (SHRs), the endothelial dysfunction is characterized by increased contractile factor production, mainly cyclooxygenase (COX)-derived factors, which oppose to the relaxant effect of nitric oxide. The increase in COX product formation may be due to the elevated intracellular calcium ([Ca2+]i), which leads to the high availability of arachidonic acid (AA), the COX substrate. Compounds that act on the endothelial factors are possibly useful tools to modulate the endothelial function in pathological conditions, such as hypertension. Cardamonin was isolated from plants of zingiberaceous specie and belongs to the chalcone family, which involves compounds that have antioxidant and anti-inflammatory properties. In vascular myocytes of normontensive rats, cardamonin promoted relaxation and altered the ion channel physiology, such as the conductance of calcium channel. Considering that an increase of [Ca2+]i in endothelial cells from SHRs leads to a higher contractile factor release and that cardamonin may reduce the [Ca2+]i, we hypothesized that cardamonin may reduce the AA formation and, then, the formation of contractile factors and the endothelium-dependent contraction in SHRs. Therefore, the objectives of the present study are (i) to evaluate the effects of cardamonin on [Ca2+]i, (ii) the formation of contractile factors in endothelial cells, and (iii) the endothelium-dependent contraction in aortas of SHRs.