Rooibos (Aspalathus linearis) has cardioprotective properties against isoproterenol-induced hypertrophy in H9c2 cardiomyoblasts. Improving mitochondrial and antioxidant activity

Abstract

Systemic hypertension is one of the risk factors for cardiovascular disease (CVD), a global health concern. The left ventricle experiences severe stress from prolonged high blood pressure, which can cause left ventricular hypertrophy and eventually lead to left ventricular failure. The majority of pharmaceutical therapies are expensive and have long-term negative effects, particularly for patients who live in low-resource environments. In order to help manage CVD, efforts are being made to find more natural and reasonably priced adjuvant medicines. The purpose of this study was to assess Aspalathus linearis (Rooibos, RB)'s ability to prevent isoproterenol-induced hypertrophy in H9c2 cardiomyoblasts. Isoproterenol (50 mM, 24 h), RB (100 mg/mL, 24 h), co-treatment with isoproterenol (50 mM, 24 h), and control (2 % FBS media, 24 h) were the treatments administered to cardiomyoblasts. We performed the following tests: Western blots, high-resolution respirometry, lipid peroxidation assay (TBARS), antioxidant assays (SOD and CAT), cell viability assay (MTT), cell size (light microscopy), and an ATP assay. Isoproterenol decreased mitochondrial routine respiration, decreased SOD and CAT activities, increased oxidative stress through an increase in lipid peroxidation, decreased cell size and viability, complex-I linked OXPHOS and complex-II's contribution to the ETS via the S-pathway, and increased complex-IV activity without adversely affecting ATP levels. When RB and isoproterenol were administered together, cell size decreased, antioxidant enzyme activity improved, rotundine respiration increased, and complex-I increased the expression of total Akt and decreased the expression of total NFAT, while also linking OXPHOS and decreasing the cytochrome-c response. According to our research, RB might be used as an adjunct therapy to treat left ventricular hypertrophy. In this situation, RB's protective impact is attributed to its strong antioxidant properties and ability to rescue mitochondrial dysfunction.