Ameliorative potential of astaxanthin in isoproterenol-induced heart failure in rats via the regulation of the renin-angiotensin system.

Heart failure (HF) is a condition in which the heart cannot pump blood effectively to the body. Isoproterenol (ISO) induces HF in rodents by affecting the renin-angiotensin system (RAS). Astaxanthin (AST) is known to have protective effects on the cardiovascular system. However, clear evidence showing that AST improves HF through RAS regulation has not yet been report-ed. This study aimed to investigate the role of AST in ISO-induced HF in rats. HF was induced by intraperitoneal (i.p.) injection of ISO (5 mg/kg/day) for seven consecutive days. AST (25 and 50 mg/kg), aliskiren (30 mg/kg), ramipril (4 mg/kg), and telmisartan (8 mg/kg) were administered orally for 21 days, starting from the last dose of ISO (day 8). Changes in systolic and diastolic blood pressure and heart rate associated with HF were measured on days 0, 7, 14, 21, and 28. Additionally, changes in heart-to-body weight ratio, serum creatine kinase-MB (CK-MB), serum angiotensin-converting enzyme (ACE) ac-tivity, plasma renin activity (PRA), tissue hydroxyproline, and lactate dehydro-genase (LDH) activity, along with histopathological alterations, were evaluated. The administration of AST and RAS-modulating agents reduced ISO-induced changes in cardiac function and biochemical markers. It also demonstrated car-dioprotective effects. Therefore, AST may be useful for treating cardiotoxic HF due to its RAS-regulatory actions. However, further studies are needed to con-firm this therapeutic potential across different HF models and animal species.