O tratamento com bagaço de uva (Vitis vinifera) melhora os parâmetros morfológicos cardíacos em ratos espontaneamente hipertensos

Abstract

The properties of the bioactive compounds present in winery waste, including grape pomace, have beneficial effects in both the prevention and treatment of various comorbidities due to their antihypertensive, antioxidant and anti-inflammatory effects. The aim of this study was to evaluate the potential effects of treatment with grape pomace (Vitis vinifera, Syrah grape variety) on blood pressure levels and on changes associated with cardiac hyperplasia, hypertrophy and fibrosis. Normotensive male rats (Wistar) and hypertensive male rats (SHR), aged 8 to 10 weeks (250-300g), were used. During treatment (14 days), the animals in the control group (Wistar and SHR, n=5) received a standard diet every day, while the animals in the treated group (SHR UVA, n=5) received a special diet enriched with grape pomace (300 mg/kg/day). Mean arterial pressure (mmHg) was assessed by a non-invasive method, using caudal plethysmography, on days 0 and 14 of treatment. Histological analyses of the staining were carried out by quantifying the number of cardiomyocytes, number of intercellular spaces, cardiomyocyte diameter, total interstitial collagen deposition, and its subtypes I and III. All procedures were approved by the Ethics Committee (CEUA/UFMT/nº 23108.010699/2023- 18). The results showed that on day 0 the average blood pressure of the hypertensive groups was higher (137.7±1.74 SHR control and 144.9±2.8 SHR UVA), compared to the normotensive group (108.6±2.16 mmHg). At the end of the treatment with grape pomace, it was noted that the treated hypertensive group showed a reduction in blood pressure compared to the SHR control group (117.3±1.09 vs 136.2±0.29 mmHg, respectively). There were no changes in the number of cardiomyocytes and the number of intercellular spaces between the groups evaluated. However, SHR animals showed an increase in the diameter (mm) of cardiomyocytes compared to the normotensive group (11.0±0.02 vs 9.78±0.02 respectively). Treatment with grape pomace was able to reverse this parameter in the SHR rats (9.44±0.18). Analyses of total interstitial collagen (%) showed greater deposition of interstitial collagen in the control SHR group compared to the normotensive control group (33.62±1.77 vs. 23.94±2.29 respectively), and after treatment with grape pomace, the treated group showed a reduction in deposited collagen (30.19±0.50) compared to the control hypertensive group. In the collagen I and III subtyping, it was observed that the control SHR rats showed greater deposition of type I collagen compared to the Wistar group, and treatment with grape pomace reduced the deposition of type I collagen in the hypertensive rats, without normalizing this parameter. Therefore, these results indicate that bioactive natural products, such as grape pomace, may represent promising alternatives in pharmacotherapy for the treatment of arterial hypertension and other cardiovascular comorbidities.