Green tea could improve elderly hypertension by modulating arterial stiffness, the activity of the renin/angiotensin/aldosterone axis, and the sodium–potassium pumps in old male rats

Abstract

Hypertension is a major health problem common in the elderly people. Green tea is a popular beverage recommended in folk medicine for lowering blood pressure. However, the molecular mechanisms involved in the antihypertensive effects of green tea are not fully understood. Therefore, the aim of this study was to investigate the antihypertensive effects of green tea on high‐salt diet‐induced hypertension in old male rats. Forty old male rats were divided into five groups: control, hypertensive, and hypertensive–green tea (2, 4, and 6 g/kg). Heart rate (HR) and systolic blood pressure (SBP) were measured. Cardiac and renal histology were also performed. Lipid profile, NO, angiotensin II (Ang II), and aldosterone were determined, and the expression of eNOS, ATIR and ATIIR, aldosterone receptor, and Atp1a1 were measured. Green tea could significantly decrease HR and SBP, lipid profiles, renin–angiotensin II–aldosterone system activity, and Ang II signaling in kidney tissue of hypertensive rats (p < .01). It also increased Atp1a1, Nrf2, and eNOS expression along with antioxidant enzymes activity and NO concentration (p < .05) and decreased NF‐ĸB and iNOS expression and IL‐1β levels in the heart, kidneys, and aorta of rats with hypertension. It can be concluded that green tea can improve salt‐induced blood pressure by modulating the function of the renin—angiotensin–aldosterone system, enhancing the synthesis of nitric oxide in the endothelium, increasing antioxidant activity and suppressing inflammation in the heart and kidney, improving the expression of the sodium–potassium pump, and reduction in serum lipids and glucose in aged male rats. Practical applications The results of this study showed that green tea could improve hypertension in elderly rats by modulating (1) the expression of the sodium–potassium pump in the heart, kidney, and aortic tissues, (2) the activity of the renin–angiotensin II–aldosterone system in kidney, (3) enhancing antioxidant and anti‐inflammatory activities in the heart, aorta, and kidneys, (4) enhancing the synthesis of nitric oxide in the endothelium, and (5) lowering lipid profile. The results of these studies show that the consumption of green tea and its products can be a good candidate for the prevention of cardiovascular diseases such as hypertension in the elderly. In addition, attention to its bioactive compounds can be considered by researchers as an independent therapeutic strategy or adjunctive therapy for the treatment of hypertension.

Tea Consumption and New-Onset Acute Kidney Injury: The Effects of Milk or Sweeteners Addition and Caffeine/Coffee

“…AKI, a syndrome characterized by an abrupt loss of kidney function, is usually associated with a focal mismatch between impaired delivery of oxygen and nutrients to the nephron and incremental renal energy and oxygen requirements, and most of the AKI events are attributed to ischemic injuries [5,6]. Tea and its bioactive components could modulate the function of the renin-angiotensin-aldosterone system, enhance the synthesis of endothelial nitric oxide, increase antioxidant activity and inhibit inflammation, and improve the expression of renal sodium-potassium pump, and therefore, reduce renal oxygen consumption, improve hemodynamic recovery during reperfusion, and decrease the susceptibility to AKI during acute injury in the general population [29][30][31].…”

Protective effects and molecular mechanisms of tea polyphenols on cardiovascular diseases

“…The structure, quantity, and type of diet can also influence the occurrence of cardiovascular events (52,53). For example, a high-salt diet can exacerbate vasoconstriction, leading to elevated blood pressure and plasma cholesterol and contributing to the development of AS (52)(53)(54)(55).…”

“…The structure, quantity, and type of diet can also influence the occurrence of cardiovascular events (52,53). For example, a high-salt diet can exacerbate vasoconstriction, leading to elevated blood pressure and plasma cholesterol and contributing to the development of AS (52)(53)(54)(55). Sugar can increase blood viscosity and slow blood flow, which, combined with damage to the vascular endothelium, causes the generation of a large number of atherosclerotic plaques that block blood vessels and trigger the occurrence of acute cardiovascular events (56,57).…”

“…In addition, tannins in tea have been shown to have a hypotensive effect on rats ( 78 ). Gao et al ( 52 , 53 ) found that green tea had an antihypertensive effect on hypertension induced by a high salt diet in aged male rats, and its main mechanism of action included inhibiting the activity of the renin-angiotensin II-aldosterone system, altering the expression of sodium-potassium pumps in heart, kidney and aortic tissues and increasing the synthesis of nitric oxide in endothelial cells.…”

Evaluation of Expression of Cytochrome P450 Aromatase and Inflammatory, Oxidative, and Apoptotic Markers in Testicular Tissue of Obese Rats (Pre)Treated with Garlic Powder

“…Terefore, these interconnected pathways and mediators involved in them are very appropriate therapeutic goals to improve obesity and its infertility complications. Increasing physical activity through regular exercise and lifestyle changes through diet correction and the use of herbal products are very simple strategies that are highly regarded [23][24][25][26][27][28][29].…”