CARDIOVASCULAR EFFECTS INDUCED BY LINALOOL AFTER SUBCHRONIC TREATMENT OF SPONTANEOUSLY HYPERTENSIVE RATS

IntroductionLinalool (LIN) is an alcoholic monoterpene with biological activities previously described. This study in order to evaluate the cardiovascular effects in vivo subchronic treatment of spontaneously hypertensive rats (SHR) is focusing on antihypertensive properties of linalool.MethodsAll experiments were performed with SHR aged 9–12 weeks and (−)‐linalool (≥ 97 % purity) was solubilized in cremophor in a ratio of 2:1 and diluted with physiological saline solution (100 mg/kg) and controls solutions captopril (30 mg/kg) and vehicle (saline + cremophor) were administered daily for 21 days by orogastric injections. Each 5 days the arterial pressure and the heart rate were measured by tail cuff method. At the end of treatment, mesenteric artery was isolated to reactivity tests and the heart was removed and placed in an oven to dry at 60° C, for 24 to 48 hours, to obtain the dry weight.ResultsAnimals treated with linalool, vehicle and captopril showed no statistically significant differences at the levels of water consumption and feeding and no difference in progressive increasing body weight between the three groups. None of the treated groups had significant changes in the values of heart rate. Animals treated with vehicle showed a progressive increase in the mean arterial pressure (MAP). Captopril induced a significant decrease at MAP, from the fifth day of treatment and (−)‐linalool was able to maintain the initial pressure values, avoiding the progression of hypertension and demonstrating a significant reduction in the blood pressure at fifteenth day. The subchronic treatment with linalool decreases the cardiac mass index similar to that found in animals treated with captopril when compared to the negative control group. Finally, linalool induced beneficial changes in vascular responsiveness.ConclusionThese results suggest that linalool, after 21 days of subchronic treatment of spontaneously hypertensive rats, demonstrated antihypertensive potential inducing the maintenance and decrease of the mean arterial pressure with no changes in heart rate, being able to reduce cardiac hypertrophy, to decrease vascular reactivity to a vasoconstrictor agent phenylephrine (PHE) and to increase pharmacological potency to a vasodilator agent sodium nitropusside (SNP).3012 ‐ ASPET Cardiovascular Pharmacology – General/OtherSupport or Funding InformationFundação de Amparo à Pesquisa do Estado da Bahia (FAPESB) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)