Chronic Administration of Red Yeast Rice Mitigates Endothelial Dysfunction in Spontaneously Hypertensive Rats by Inhibiting Oxidative Stress and Endothelial Nitric Oxide Synthase Uncoupling

• Published in: Current vascular pharmacology Vol. 22; no. 5; p. 355
• Main Authors: Tan, Jiunn Jye, Murugan, Dharmani Devi, Ling, Wei Chih, Lee, Siew-Keah, Kang, Waye Hann
• Format: Journal Article
• Language: English
• Published: United Arab Emirates 01.01.2024
• Subjects: Administration, Oral; Animals; Antihypertensive Agents - pharmacology; Antioxidants - pharmacology; Biological Products - pharmacology; Biopterins - analogs & derivatives; Biopterins - metabolism; Blood Pressure - drug effects; Cyclic GMP - metabolism; Disease Models, Animal; Endothelium, Vascular - drug effects; Endothelium, Vascular - metabolism; Endothelium, Vascular - physiopathology; Hypertension - drug therapy; Hypertension - enzymology; Hypertension - metabolism; Hypertension - physiopathology; Lovastatin - pharmacology; Male; Monascus - metabolism; Nitric Oxide - metabolism; Nitric Oxide Synthase Type III - metabolism; Oxidative Stress - drug effects; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Reactive Oxygen Species - metabolism; Signal Transduction - drug effects; Time Factors; Vasodilation - drug effects; Vasodilator Agents - pharmacology; vascular function; nitric oxide; functional food; Red yeast rice; hypertension; oxidative stress
• ISSN: 1875-6212
• DOI: 10.2174/0115701611295900240529104225

Hypertension is associated with endothelial dysfunction. An imbalance in the production of Nitric Oxide (NO) and Reactive Oxygen Species (ROS), leading to impaired NO-cyclic Guanosine Monophosphate (cGMP) pathway, contributes to this disorder. Red Yeast Rice (RYR), produced from the fermentation of rice with Monascus purpureus, is a traditional functional food originating from China. Although recognized for its anti-dyslipidemia properties, there has been growing evidence regarding the anti-hypertensive effects of RYR. However, these studies only focused on its direct and short-term effects. This study aims to investigate the vasoprotective effects of chronic oral RYR administration using Spontaneously Hypertensive Rats (SHR). SHR were randomly divided into 3 groups: SHR - Control; SHR - RYR extract (100 mg/kg/day); SHR - lovastatin (10 mg/kg/day). Wistar-Kyoto Rats (WKY) were used as normotensive controls. All animals were treated for 12 weeks by oral gavage. Systolic Blood Pressure (SBP) was measured weekly (tail-cuff method). Vascular reactivity was determined using isolated rat aortic rings in an organ bath. Aortic ROS, NO, tetrahydrobiopterin (BH4), and cGMP levels were evaluated. Administration of RYR attenuated SBP elevation and enhanced endothelium-dependent vasodilation in aortic rings. In addition, RYR decreased ROS production and significantly improved the level of vascular NO, BH4, and cGMP. In an SHR model, treatment with RYR for 12 weeks exerts an SBP lowering effect that can be attributed to improved vascular function via reduction of oxidative stress, decreased endothelial NO Synthase (eNOS) uncoupling and enhanced NO-cGMP pathway.