Effects of Essential Oil of Blepharocalyx salicifolius on Cardiovascular Function of Rats

Abstract

Some studies reported that herbal interventions with Blepharocalyx salicifolius minimized the high blood pressure in animals. Thus the aim of this study was to evaluate the cardiovascular effects of essential oil from the leaves of the plant. Wistar Kyoto (WKY) and Spontaneously Hypertensive Rats (SHR) with 60 days old were subjected to daily injection of essential oil (10 mg/Kg ip.). At the end of 30 days, the animals were anesthetized, the carotid artery was catheterized to hemodynamic measurements and total blood was collected by puncturing. The cardiovascular measurements performed were systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate, myocardial contractility parameters, angiotensin converting enzyme (ACE) activity and myosin ATPase. The hearts were dissected for left ventricle removal, the papillary muscle was used to assess myocardial contractility and tissue to myosin ATPase and ACE activity determinations. The oil was obtained by hydrodistillation in a Clevenger apparatus and analyzed by GC‐FID and GC‐MS. Molecular modelling studies were performed on components of essential oil of B. salicifolium and Angiotensin I‐Converting Enzyme (ACE‐I) in order to support the understanding of the biological activity. The project was approved by the Ethics Committee for Animal Use from UNIPAMPA under number 05/2016. We identified 34 compounds in the essential oil, the sesquiterpenes representing the largest fraction of the essential oil with 55.9% of constitution, and the main component was the spathulenol with 11.6%. We observed an antihypertensive effect attributed the decrease in SBP and DBP (12% and 23%) in SHR treated with essential oil. The myocardial contractility parameters evaluated by isometric force, sarcoplasmic reticulum activity, inotropic response to the calcium, assessment β‐adrenergic response and strength of tetanic contractions, and serum ACE activity were not modified by the essential oil treatment. However, the myosin ATPase activity was increased 51.6% in SHR and the cardiac ACE activity was decreased 41.5% in SHR and 49% in WKY. Molecular modelling studies were performed on the four main components of essential oil, such as limoneme, viridoflorol, santoline triene and spathulenol. The data suggest the spathulenol, that was the higher concentration component in essential oil, could be the main compound inducing the of ACE‐I activity inhibition. The results obtained in this study reveal the antihypertensive action of B. salicifolius essential oil in SHR and the potential interaction with Renin Angiotensin System without impairment of cardiac function.Support or Funding InformationPPSUS/FAPERGSThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.