Alpinia zerumbet leaf extract reverses hypertension and improves adverse remodeling in the left ventricle and aorta in spontaneously hypertensive rats

Alpinia zerumbet, a plant native to East Asia, is widely found on the Brazilian coast, where it is used in folk medicine as an antihypertensive, diuretic, and anxiolytic. This study investigated the effects of the hydroalcoholic extract obtained from Alpinia zerumbet leaves (AZE) on cardiovascular changes and oxidative status in spontaneously hypertensive rats (SHR). SHR and Wistar-Kyoto male rats, 90 days old, treated or not with AZE (50 mg/kg/day in drinking water) for six weeks, were used in this study. Blood pressure (BP) was assessed weekly by tail plethysmography. At the end of treatment, the animals were anesthetized with thiopental (70 mg/kg, ip), blood was collected through abdominal aorta puncture, the thoracic aorta and left ventricle were isolated for morphometric analysis and immunostaining of NOX-4, SOD-2, 8-isoprostane, and angiotensin II AT1 receptors (AT1R), and the mesenteric arterial bed (MAB) was isolated for the assessment of vascular function. Oxidative damage in lipids and proteins and the enzymatic antioxidant activity were evaluated in plasma samples by spectrophotometry. AZE normalized BP in SHR. Although the treatment did not improve the MAB vascular dysfunction, it reversed the cardiovascular remodeling in the aorta and left ventricle. In addition, AZE improved antioxidant activity in plasma and SOD-2 immunostaining in the thoracic aorta and left ventricle, decreased protein carbonylation in plasma, and reduced 8-isoprostane, NOX-4, and AT1R immunostaining in the cardiovascular system. The results suggested that AZE reversed hypertension and cardiovascular remodeling in SHR, which was associated with lower oxidative stress and AT1R.