Psidium guajava leaves extract alters colonic microbiome composition and reduces intestinal sodium absorption in rats exposed to a high-sodium diet.

Objectives: High sodium intake is a major risk factor for hypertension and renal diseases. Previous studies have shown that a suspension of ethanolic extract of Psidium guajava (guava) leaves (PsE) has antihypertensive effects in rats on a high-sodium diet (HSD), but some mechanisms to that remain unexplored. This study explored whether oral PsE treatment affects sodium handling by the intestine and alters the gut microbiome in HSD-fed rats.

Antihypertensive effect of a nanoemulsion of leaves extract in sodium-dependent hypertensive rats.

(DC) is an important botanical source of Brazilian green propolis and have many compounds with potential antihypertensive activity. However, little is known about the specific antihypertensive properties of DC, or the mechanisms involved. Here we aimed to chemically characterise an ethanolic DC extract (eDC), test its antihypertensive properties and the involvement of neurogenic mechanisms using an animal model of salt-dependent hypertension.

Nutraceuticals in the management of autonomic function and related disorders: A comprehensive review.

Nutraceuticals have been described as phytocomplexes when derived from foods of plant origin or a pool of secondary metabolites when derived from foods of animal origin, which are concentrated and administered in an appropriate form and can promote beneficial health effects in the prevention/treatment of diseases. Considering that pharmaceutical medications can cause side effects, there is a growing interest in using nutraceuticals as an adjuvant therapeutic tool for several disorders involving autonomic dysfunction, such as obesity, atherosclerosis and other cardiometabolic diseases. This review summarizes and discusses the evidence from the literature on the effects of various nutraceuticals on autonomic control, addressing the gut microbiota modulation, production of secondary metabolites from bioactive compounds, and improvement of physical and chemical properties of cell membranes.

Protein disulfide isomerase-mediated transcriptional upregulation of Nox1 contributes to vascular dysfunction in hypertension.

Nox1 signaling is a causal key element in arterial hypertension. Recently, we identified protein disulfide isomerase A1 (PDI) as a novel regulatory protein that regulates Nox1 signaling in VSMCs. Spontaneously hypertensive rats (SHR) have increased levels of PDI in mesenteric resistance arteries compared with Wistar controls; however, its consequences remain unclear.

Exercise-induced neuroplasticity in autonomic nuclei restores the cardiac vagal tone and baroreflex dysfunction in aged hypertensive rats.

Aging is accompanied by considerable deterioration of homeostatic systems, such as autonomic imbalance characterized by heightened sympathetic activity, lower parasympathetic tone, and depressed heart rate (HR) variability, which are aggravated by hypertension. Here, we hypothesized that these age-related deficits in aged hypertensive rats can be ameliorated by exercise training, with benefits to the cardiovascular system. Therefore, male 22-mo-old spontaneously hypertensive rats (SHRs) and age-matched Wistar Kyoto (WKY) submitted to moderate-intensity exercise training (T) or kept sedentary (S) for 8 wk were evaluated for hemodynamic/autonomic parameters, baroreflex sensitivity, cardiac sympathetic/parasympathetic tone and analysis of dopamine β-hydroxylase (DBH+) and oxytocin (OT+) pathways of autonomic brain nuclei.

Biofunctionalization of surfaces to minimize undesirable effects in cardiovascular assistance devices.

Background: The reactivity of blood with non-endothelial surface is a challenge for long-term Ventricular Assist Devices development, usually made with pure titanium, which despite of being inert, low density and high mechanical resistance it does not avoid the thrombogenic responses. Here we tested a modification on the titanium surface with Laser Induced Periodic Surface Structures followed by Diamond Like Carbon (DLC) coating in different thicknesses to customize the wettability profile by changing the surface energy of the titanium.

Methods: Four different surfaces were proposed: (1) Pure Titanium as Reference Material (RM), (2) Textured as Test Sample (TS), (3) Textured with DLC 0.

Short exposure to high salt in drinking solution leads to a cardiovascular phenotype of hypertension without changes in the blood volume of rats.

New Findings: What is the central question of this study? Is the cardiovascular phenotype of high blood pressure observed in rats salt loaded with 2% NaCl in drinking solution a blood volume-dependent hypertension? What is the main finding and its importance? Animals exposed to 2% NaCl drinking solution develop hypertension, with dominance of sympathetic outflow and high [Na ] in the cerebrospinal fluid, but without changes in the blood volume. The phenotype of salt-dependent hypertension might be related to accumulation of [Na ] in the cerebrospinal fluid, which makes it an interesting animal model in which to study the neuronal pathways involved in control of the circulation in osmotic challenge conditions.

Abstract: Evidence suggests that hypertension induced by high salt intake is correlated with an autonomic imbalance that favours sympathetic hyperactivity and an increase in vascular resistance, indicating a neurogenic component to this pathology.

Effects of Psidium guajava L. leaves extract on blood pressure control and IL-10 production in salt-dependent hypertensive rats.

Psidium guajava (guava) leaves extract displays anti-hypertensive properties by mechanisms not yet fully understood. Here, we investigated whether sympathetic drive and immune signaling mechanisms are involved with the antihypertensive effect of the guava extract in a model of salt-dependent hypertension. Raw guava extract (rPsE) was characterized by colorimetric and UPLC-MS techniques.

The gut-brain axis and sodium appetite: Can inflammation-related signaling influence the control of sodium intake?

Sodium is the main cation present in the extracellular fluid. Sodium and water content in the body are responsible for volume and osmotic homeostasis through mechanisms involving sodium and water excretion and intake. When body sodium content decreases below the homeostatic threshold, a condition termed sodium deficiency, highly motivated sodium seeking, and intake occurs.

Exercise training rescues the electrical activity of liver-projecting DMNV neurones in response to oxytocin in spontaneously hypertensive rats.

A neural circuit between the paraventricular nucleus of the hypothalamus (PVN) and the dorsal motor nucleus of the vagus (DMNV) constitutes part of an important parasympathetic autonomic pathway that controls hepatic glucose production. Intracerebroventricular injection of insulin activates oxytocinergic neurones in the PVN and elicits the release of oxytocin into the circulation, which plays an important role in the metabolism of glucose. Moreover, the central action of insulin can reduce the concentration of glucose in blood taken from the hepatic vein of Wistar rats via activation of vagal efferent nerves to the liver.

Swimming training improves cardiovascular autonomic dysfunctions and prevents renal damage in rats fed a high-sodium diet from weaning.

New Findings: What is the central question of this study? How does swimming exercise training impact hydro-electrolytic balance, renal function, sympathetic contribution to resting blood pressure and cerebrospinal fluid (CSF) [Na ] in rats fed a high-sodium diet from weaning? What is the main finding and its importance? An exercise-dependent reduction in blood pressure was associated with decreased CSF [Na ], sympathetically driven vasomotor tonus and renal fibrosis indicating that the anti-hypertensive effects of swimming training in rats fed a high-sodium diet might involve neurogenic mechanisms regulated by sodium levels in the CSF rather than changes in blood volume.

Abstract: High sodium intake is an important factor associated with hypertension. High-sodium intake with exercise training can modify homeostatic hydro-electrolytic balance, but the effects of this association are mostly unknown.

Central action of CART induces neuronal activation in the paraventricular and dorsomedial hypothalamus of diet-induced obese and lean mice.

The cocaine- and amphetamine-regulated transcript (CART) is a peptide commonly studied in the feeding behavior, but it exerts an important role in the autonomic and cardiovascular control as well. It is known that exogenous administration of CART in the central nervous system can elicit increase in blood pressure of both conscious and anesthetized rodents, but little is known whether these central effects might differ between lean and obese animals. We have recently shown that diet-induced obese mice that developed hypertension presented an upregulation of CART levels in the dorsomedial nucleus of hypothalamus, while obese normotensive ones had not.

The role of insulin at brain-liver axis in the control of glucose production.

Glucose is an essential metabolic substrate for all mammalian cells, and its availability in the circulation is carefully controlled to avoid wide variations. Different mechanisms are involved in the glucose disposal, such as an adequate pancreatic and hepatic function. Insulin is the main hormone in glycemic control, and its action occurs directly in the cells, as well as in the liver, in an indirect way, to ultimately control the glycemia.

Salt-induced sympathoexcitation involves vasopressin V1a receptor activation in the paraventricular nucleus of the hypothalamus.

A high-salt diet can lead to hydromineral imbalance and increases in plasma sodium and osmolality. It is recognized as one of the major contributing factors for cardiovascular diseases such as hypertension. The paraventricular nucleus (PVN) plays a pivotal role in osmotically driven sympathoexcitation and high blood pressure, the precise mechanisms of which are not fully understood.