Red Araça (Psidium cattleianum) Extract Prevents Right Ventricular Hypertrophy in Experimental Pulmonary Arterial Hypertension.

Background: Pulmonary artery hypertension (PAH) is characterised by progressive pulmonary vascular remodelling and increased pulmonary vascular resistance, leading to right ventricular (RV) dysfunction and failure. Red araça (Psidium cattleianum) extract is derived from native Brazilian fruit rich in phenolic compounds with recognised antioxidant and anti-inflammatory properties. Objectives: The present study aimed to evaluate the preventive effects of red araça extract administration on RV remodelling and pulmonary arteriole alterations in rats with MCT-induced PAH. Methods: Male Wistar rats were divided into three groups: control, monocrotaline (MCT), and MCT + red araça extract. PAH was induced by a single intraperitoneal injection of MCT (60 mg/kg), and the treated group received red araça extract (5 mL/kg/day) by gavage for 21 days. Echocardiographic, hemodynamic, morphometric, molecular, and histological analyses were subsequently performed. Results: The MCT group exhibited increased pulmonary vascular resistance and RV hypertrophy, impaired RV function, elevated TLR4 and xanthine oxidative (XO) protein expression, elevated Akt activation, and marked increase in pulmonary arteriole wall thickness. Treatment with red araça extract prevented RV hypertrophy, reduced total pulmonary vascular resistance, preserved Akt activation similar to control, and decreased TLR4 and XO protein expression in the RV. In addition, administration of red araça extract prevented the increase in pulmonary arteriolar wall thickness. Conclusions: Collectively, these findings suggest that red araça extract attenuates cardiopulmonary alterations associated with experimental PAH, possibly involving modulation of the expression of proteins related to cardiac hypertrophy and inflammation.