Avaliação do efeito do carvacrol (2-metil-5-(1-metiletil)-fenol) sobre as alterações cardíacas e renais em ratos espontaneamente hipertensos

Abstract

Systemic arterial hypertension is a chronic cardiovascular disease characterized by a sustained increase in blood pressure and is associated with progressive damage to the function and structure of target organs, such as the heart and kidney, which undergo structural and functional changes. The development of hypertension has been associated with oxidative stress, a mechanism that causes tissue damage in multiple systems and organs, also affecting the target organs of hypertension. Thus, seeking alternatives for substances that have antihypertensive and antioxidant activity, and that improve the damage to the target organs of hypertension, should be explored. In this context, carvacrol, a phenolic monoterpene, present in some aromatic plants, presents among its important properties the vasorelaxant, antihypertensive and antioxidant activity. Therefore, the objective of this study was to evaluate the effects of treatment with carvacrol on cardiac and renal changes in spontaneously hypertensive rats. The animals were divided into five groups: normotensive control wistar kyoto (WKY-CTL) and hypertensive (SHR-CTL); and hypertensive patients treated with carvacrol 50 mg/kg (SHR-C50), carvacrol 100 mg/kg (SHR-C100) and resveratrol 10 mg/kg (SHR-RE10). All rats were treated orally once a day for twenty-eight days. The experimental protocols were approved by CEUA-UFPB nº 6638150621. The treatment did not affect the weight of the animals during the twenty-eight days. In the indirect blood pressure measurement trial, the SHR-C50, SHR-C100 and SHR-RE10 groups had reduced systolic blood pressures compared to the start of treatment, when compared to the SHR-CTL. Carvacrol (50 mg/kg) was able to reduce the heart mass index when compared to SHR-CTL. Through the echocardiogram, it was possible to observe that carvacrol did not induce structural changes in the heart. The electrocardiogram showed that the duration of the QRS interval in the SHR-CTL group was longer than in the WKY group, and carvacrol was not able to reverse the duration of the QRS interval. The duration of the QT interval showed no difference between the studied groups. The SHR-CTL group showed an increase in renal mass index when compared to the WKY-CTL. However, treatment with carvacrol failed to reduce this index. In the urea and plasma creatinine assays, the animals of the evaluated groups did not show differences in creatinine. However, urea was increased in the SHR-CTL group when compared to the WKY-CTL, and carvacrol was able to reduce this parameter when compared to the SHR-CTL. However, treatment with resveratrol decreased plasma urea concentrations compared to SHR-CTL. The hypertensive groups showed higher collagen deposition in cardiac tissue and kidney. Carvacrol and resveratrol treatment was able to reduce collagen deposition compared to SHR-CTL. In heart and kidney tissue sections, carvacrol significantly reduced the basal fluorescence of the DHE probe when compared to SHR-CTL. Thus, these results demonstrate that treatment with carvacrol was efficient in reducing blood pressure, in addition to improving cardiac and renal fibrosis, renal function, and oxidative stress.