Lim Ji Young, Kim Wookyoung, Ha Ae Wha
Department of Food Science and Nutrition, Dankook University, Cheonan 31116, Korea.
Department of Food Science and Nutrition, Natural Nutraceuticals Industrialization Research Center, Dankook University, Cheonan 31116, Korea.
Nutr Res Pract. 2023 Apr;17(2):192-205. doi: 10.4162/nrp.2023.17.2.192. Epub 2022 Aug 23.
BACKGROUND/OBJECTIVES: It is known that the renin-angiotensin system (RAS) in the brain could regulate cognitive functions as well as blood pressure. Inhibition of RAS for the improvement of cognitive function may be a new strategy, but studies so far have mostly reported on the effects of RAS inhibition by drugs, and there is no research on cognitive improvement through RAS inhibition of food ingredients. Therefore, this study investigated the effect of curcumin on blood pressure and cognitive function and its related mechanism in spontaneously hypertensive rat/Izm (SHR/Izm).
MATERIALS/METHODS: Six-week-old SHR/Izm rats were divided into 5 groups: control group (CON), scopolamine group (SCO, drug for inducing cognitive deficits), positive control (SCO and tacrine [TAC]), curcumin 100 group (CUR100, SCO + Cur 100 mg/kg), and curcumin 200 group (CUR200, SCO + Cur 200 mg/kg). Changes in blood pressure, RAS, cholinergic system, and cognitive function were compared before and after cognitive impairment.
The SCO group showed increased blood pressure and significantly reduced cognitive function based on the y-maze and passive avoidance test. Curcumin treatments significantly improved blood pressure and cognitive function compared with the SCO group. In both the CUR100 and CUR200 groups, the mRNA expressions of angiotensin-converting enzyme (ACE) and angiotensin II receptor type1 (AT1), as well as the concentrations of angiotensin II (Ang II) in brain tissue were significantly decreased. The mRNA expression of the muscarinic acetylcholine receptors (mAChRs) and acetylcholine (ACh) content was significantly increased, compared with the SCO group.
The administration of curcumin improved blood pressure and cognitive function in SCO-induced hypertensive mice, indicating that the cholinergic system was improved by suppressing RAS and AT1 receptor expression and increasing the mAChR expression.
背景/目的：已知大脑中的肾素-血管紧张素系统（RAS）可调节认知功能和血压。抑制RAS以改善认知功能可能是一种新策略，但迄今为止的研究大多报道了药物抑制RAS的效果，尚无关于通过食物成分抑制RAS改善认知功能的研究。因此，本研究探讨了姜黄素对自发性高血压大鼠/Izm（SHR/Izm）血压和认知功能及其相关机制的影响。
材料/方法：将6周龄的SHR/Izm大鼠分为5组：对照组（CON）、东莨菪碱组（SCO，诱导认知缺陷的药物）、阳性对照组（SCO和他克林[TAC]）、姜黄素100组（CUR100，SCO + 100 mg/kg姜黄素）和姜黄素200组（CUR200，SCO + 200 mg/kg姜黄素）。比较认知障碍前后血压、RAS、胆碱能系统和认知功能的变化。
基于Y迷宫和被动回避试验，SCO组血压升高，认知功能显著降低。与SCO组相比，姜黄素治疗显著改善了血压和认知功能。在CUR100组和CUR200组中，血管紧张素转换酶（ACE）和血管紧张素II 1型受体（AT1）的mRNA表达以及脑组织中血管紧张素II（Ang II）的浓度均显著降低。与SCO组相比，毒蕈碱型乙酰胆碱受体（mAChRs）的mRNA表达和乙酰胆碱（ACh）含量显著增加。
给予姜黄素可改善SCO诱导的高血压小鼠的血压和认知功能，表明通过抑制RAS和AT1受体表达并增加mAChR表达可改善胆碱能系统。
