Abstract 225: Treatment with LCZ696, an Orally Active Angiotensin Receptor Neprilysin Inhibitor Prevents Ischemic Brain Damage

Abstract

Objective: Recent accumulating evidence suggests that an orally active angiotensin II receptor-neprilysin inhibitor, LCZ696, was supposed to be superior compared to angiotensin II receptor blocker (ARB), valsartan alone in treating cardiovascular disease. We previously reported that ARBs prevent ischemic brain damage using middle cerebral artery occlusion (MCAO) mouse model. Moreover, natriuretic peptides such as atrial natriuretic peptide (ANP) or brain natriuretic peptide (BNP) increased by neprilysin inhibitor are also reported to protect brain damage. Therefore, we investigate the possible protective effects of valsartan (VAL) compared with LCZ696 (LCZ) (VAL+ neprilysin inhibitor; 1:1) on the prevention of ischemic damage after stroke. Methods: Focal brain ischemia was induced by MCAO with the intraluminal filament technique in 10-week male C57BL/6J mice. Mice were treated with VAL (3 mg/kg) or LCZ (6 mg/kg) orally as powder in gelatin mini-capsules daily for 2 weeks before MCAO. Ischemic area was evaluated by triphenyl tetrazolium chloride staining, cerebral blood flow (CBF) by laser-Doppler flowmetry, oxidative stress by dihydroethidium staining. Results: Telemetry method showed that systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) did not change before and after treatments. Protective effect of LCZ treatment on ischemic brain damage in each brain section seemed to be more marked than that of VAL treatment. The average ischemic area ratio showed a significant reduction in VAL and LCZ groups compared with CON group. CBF in the peripheral region around ischemic core was significantly improved after treatments. Moreover, VAL and LCZ treatments significantly decreased the increase of superoxide anion production in the cortex of ischemic side. However, significant differences of CBF and superoxide anion production were not observed in VAL and LCZ. Conclusions: Both valsartan and LCZ696 treatments exerted preventive effects on ischemic stroke. The preventive effect of LCZ696 seemed more prominent than VAL. LCZ696 could be a novel powerful approach to protect brain after stroke. Further investigation has been performed to clarify the protective effect of LCZ696 on ischemic brain damage.