C-Phycoerythrin Prevents Chronic Kidney Disease-Induced Systemic Arterial Hypertension, Avoiding Oxidative Stress and Vascular Dysfunction in Remanent Functional Kidney.

Chronic kidney disease (CKD) is a burden in low- and middle-income countries, and a late diagnosis with systemic arterial hypertension (SAH) is the major complication of CKD. C-phycoerythrin (CPE) is a bioactive compound derived from Phormidium persicinum that presents anti-inflammatory and antioxidant effects in vitro and nephroprotective effects in vivo. In the current study, we determine the antihypertensive effect of CPE in a 5/6 nephrectomy-induced CKD model using twenty normotensives male Wistar rats, grouped into four groups (n = 5): sham; sham + CPE; 5/6 nephrectomy (NFx); and NFx + CPE. Treatment started a week post-surgery and continued for five weeks, with weekly hemodynamic evaluations. Following treatment, renal function, oxidative stress, and the expression of vascular dysfunction markers were assessed. The renal function analysis revealed CKD hyperfiltration, and the hemodynamic evaluation showed that SAH developed at the third week. AT1R upregulation and AT2R downregulation together with Mas1/p-Akt/p-eNOS axis were also observed. CPE treatment mitigated renal damage, preserved renal function, and prevented SAH with the modulation of the vasodilative AT1R, AT2R, and Mas1/pAKT/peNOS axis. This result reveals that CPE prevented CKD progression to SAH by avoiding oxidative stress and vascular dysfunction in the kidneys.

C-Phycocyanin Prevents Oxidative Stress, Inflammation, and Lung Remodeling in an Ovalbumin-Induced Rat Asthma Model.

Asthma is a chronic immunological disease related to oxidative stress and chronic inflammation; both processes promote airway remodeling with collagen deposition and matrix thickening, causing pulmonary damage and lost function. This study investigates the immunomodulation of C-phycocyanin (CPC), a natural blue pigment purified from cyanobacteria, as a potential alternative treatment to prevent the remodeling process against asthma. We conducted experiments using ovalbumin (OVA) to induce asthma in Sprague Dawley rats. Animals were divided into five groups: (1) sham + vehicle, (2) sham + CPC, (3) asthma + vehicle, (4) asthma + CPC, and (5) asthma + methylprednisolone (MP). Our findings reveal that asthma promotes hypoxemia, leukocytosis, and pulmonary myeloperoxidase (MPO) activity by increasing lipid peroxidation, reactive oxygen and nitrogen species, inflammation associated with Th2 response, and airway remodeling in the lungs. CPC and MP treatment partially prevented these physiological processes with similar action on the biomarkers evaluated. In conclusion, CPC treatment enhanced the antioxidant defense system, thereby preventing oxidative stress and reducing airway inflammation by regulating pro-inflammatory and anti-inflammatory cytokines, consequently avoiding asthma-induced airway remodeling.

Experimental Lab Tests on Rabbits for the Optimization and Redesign of Low-Cost Equipment for Automated Peritoneal Dialysis.

This work shows the experiences acquired by the experimental test performed to validate an automated peritoneal dialysis machine using rabbits with kidney damage to find improvements that can be made for future advances. These are listed to understand the direction of the development of the machine. The article shows the device's background and previous tests using a testbed. The rabbit anatomy was prepared for nephrectomy surgery. The tests were practiced by checking all of the APD machine's subsystems. The data were analyzed to develop improvements in the process. The results indicate the importance of the DPA machine as an alternative by implementing peristaltic pumps to substitute disposable cassettes. The identified improvements are the main objectives for research to continue improving the technology.

Sodium Hydrosulfide Reverts Chronic Stress-Induced Cardiovascular Alterations by Reducing Oxidative Stress.

ABSTRACT: Chronic stress induces a group of unrecognized cardiovascular impairments, including elevated hemodynamic variables and vascular dysfunction. Moreover, hydrogen sulfide (H 2 S), a gasotransmitter that regulates the cardiovascular system decreases under chronic stress. Thus, this study assessed the impact of sodium hydrosulfide (NaHS) (H 2 S donor) on chronic restraint stress (CRS)-induced cardiovascular changes. For that purpose, male Wistar rats were restrained for 2 hours a day in a transparent acrylic tube over 8 weeks. Then, body weight, relative adrenal gland weight, serum corticosterone, H 2 S-synthesizing enzymes, endothelial nitric oxide synthetize expression, reactive oxygen species levels, lipid peroxidation, and reduced glutathione-to-oxidized glutathione (GSH 2 :GSSG) ratio were determined in the thoracic aorta. The hemodynamic variables were measured in vivo by the plethysmograph method. The vascular function was evaluated in vitro as vasorelaxant responses induced by carbachol or sodium nitroprusside, and norepinephrine (NE)-mediated vasocontractile responses in the thoracic aorta. CRS increased (1) relative adrenal gland weight; (2) hemodynamic variables; (3) vasoconstrictor responses induced by NE, (4) reactive oxygen species levels, and (5) lipid peroxidation in the thoracic aorta. In addition, CRS decreased (1) body weight; (2) vasorelaxant responses induced by carbachol; (3) GSH content, and (4) GSH 2 :GSSG ratio. Notably, NaHS administration (5.6 mg/kg) restored hemodynamic variables and lipid peroxidation and attenuated the vasoconstrictor responses induced by NE in the thoracic aorta. In addition, NaHS treatment increased relative adrenal gland weight and the GSH 2 :GSSG ratio. Taken together, our results demonstrate that NaHS alleviates CRS-induced hypertension by reducing oxidative stress and restoring vascular function in the thoracic aorta.

The antihypertensive action of C-phycocyanin is related to the prevention of angiotensin II-caused vascular dysfunction in chronic kidney disease.

C-phycocyanin (CPC) is a photosynthetic protein found in Arthrospira maxima with a nephroprotective and antihypertensive activity that can prevent the development of hemodynamic alterations caused by chronic kidney disease (CKD). However, the complete nutraceutical activities are still unknown. This study aims to determine if the antihypertensive effect of CPC is associated with preventing the impairment of hemodynamic variables through delaying vascular dysfunction. Twenty-four normotensive male Wistar rats were divided into four groups: (1) sham + 4 mL/kg/d vehicle (100 mM of phosphate buffer, PBS) administered by oral gavage (og), (2) sham + 100 mg/kg/d og of CPC, (3) CKD induced by 5/6 nephrectomy (CKD) + vehicle, (4) CKD + CPC. One week after surgery, the CPC treatment began and was administrated daily for four weeks. At the end treatment, animals were euthanized, and their thoracic aorta was used to determine the vascular function and expression of AT1, AT2, and Mas receptors. CKD-induced systemic arterial hypertension (SAH) and vascular dysfunction by reducing the vasorelaxant response of angiotensin 1-7 and increasing the contractile response to angiotensin II. Also, CKD increased the expression of the AT1 and AT2 receptors and reduced the Mas receptor expression. Remarkably, the treatment with CPC prevented SAH, renal function impairment, and vascular dysfunction in the angiotensin system. In conclusion, the antihypertensive activity of CPC is associated with avoiding changes in the expression of AT1, AT2, and Mas receptors, preventing vascular dysfunction development and SAH in rats with CKD.

Controlled Release of Phycocyanin in Simulated Gastrointestinal Conditions Using Alginate-Agavins-Polysaccharide Beads.

C-phycocyanin (CPC) is an antioxidant protein that, when purified, is photosensitive and can be affected by environmental and gastrointestinal conditions. This can impact its biological activity, requiring an increase in the effective amount to achieve a therapeutic effect. Therefore, the aim of this study was to develop a microencapsulate of a complex matrix, as a strategy to protect and establish a matrix for the controlled release of CPC based on polysaccharides such as agavins (AGV) using ionic gelation. Four matrices were formulated: M1 (alginate: ALG), M2 (ALG and AGV), M3 (ALG, AGV, and κ-carrageenan: CGN), and M4 (ALG, AGV, CGN, and carboxymethylcellulose: CMC) with increasing concentrations of CPC. The retention and diffusion capacities of C-phycocyanin provided by each matrix were evaluated, as well as their stability under simulated gastrointestinal conditions. The results showed that the encapsulation efficiency of the matrix-type encapsulates with complex composites increased as more components were added to the mixtures. CMC increased the retention due to the hydrophobicity that it provides by being in the polysaccharide matrix; CGN enabled the controlled diffusive release; and AGV provided protection of the CPC beads under simulated gastrointestinal conditions. Therefore, matrix M4 exhibited an encapsulation efficiency for CPC of 98% and a bioaccessibility of 10.65 ± 0.65% after the passage of encapsulates through in vitro digestion.

C-Phycocyanin prevents acute myocardial infarction-induced oxidative stress, inflammation and cardiac damage.

CONTEXT: C-Phycocyanin is a protein with anti-scavenger, antioxidant and anti-inflammatory actions against agents that cause cellular damage. The cardioprotective action of C-phycocyanin against acute myocardial infarction (AMI) has not been studied in animal models. OBJECTIVE: To investigate C-phycocyanin's effect on oxidative stress, inflammation and cardiac damage in a model of isoproterenol-induced AMI. MATERIALS AND METHODS: Wistar rats were divided into four groups: (1) sham + vehicle (0.9% saline solution by oral gavage, OG); (2) sham + C-phycocyanin (50 mg/kg/d, OG); (3) AMI + vehicle, and (4) AMI + C-phycocyanin. AMI was induced by administering isoproterenol (20, 10, 5 and 3 mg/kg each dose per day), and serum cardiac enzymes were quantified. After five days, the animals were euthanized; the heart was dissected to determine oxidative stress, redox environment, inflammation and cardiac damage markers. RESULTS: We observed that C-phycocyanin reduced AMI-increased cardiac enzymes (CK by about 53%, CKMB by about 60%, AST by about 16% and ALT by about 21%), lipid peroxidation (57%), reactive oxygen species (50%), nitrites (46%), oxidized glutathione (41%), IL1ß (3%), INFγ (5%), TNFα 3%), Bcl2 (37%), Bax (43%), COX2 (21%) and caspase 9 (61%). Finally, C-phycocyanin reduced AMI-induced aberrant histological changes related to myonecrosis, interstitial oedema and inflammatory infiltration in the heart muscle. CONCLUSIONS: C-Phycocyanin prevents AMI-induced oxidative stress, inflammation and heart damage. This study is the first report that employed C-phycocyanin in an animal model of AMI and supports the potential use of C-phycocyanin in the management of AMI.

The Nutraceutical Antihypertensive Action of C-Phycocyanin in Chronic Kidney Disease Is Related to the Prevention of Endothelial Dysfunction.

C-phycocyanin (CPC) is an antihypertensive that is not still wholly pharmacologically described. The aim of this study was to evaluate whether CPC counteracts endothelial dysfunction as an antihypertensive mechanism in rats with 5/6 nephrectomy (NFx) as a chronic kidney disease (CKD) model. Twenty-four male Wistar rats were divided into four groups: sham control, sham-treated with CPC (100 mg/Kg/d), NFx, and NFx treated with CPC. Blood pressure was measured each week, and renal function evaluated at the end of the treatment. Afterward, animals were euthanized, and their thoracic aortas were analyzed for endothelium functional test, oxidative stress, and NO production. 5/6 Nephrectomy caused hypertension increasing lipid peroxidation and ROS production, overexpression of inducible nitric oxide synthase (iNOS), reduction in the first-line antioxidant enzymes activities, and reduced-glutathione (GSH) with a down-expression of eNOS. The vasomotor response reduced endothelium-dependent vasodilation in aorta segments exposed to acetylcholine and sodium nitroprusside. However, the treatment with CPC prevented hypertension by reducing oxidative stress, NO system disturbance, and endothelial dysfunction. The CPC treatment did not prevent CKD-caused disturbance in the antioxidant enzymes activities. Therefore, CPC exhibited an antihypertensive activity while avoiding endothelial dysfunction.

The joint effect of congenital hypothyroidism and hypercaloric diet consumption as triggers of type 2 diabetes mellitus.

Introduction: Congenital hypothyroidism affects metabolic and thyroid programming, having a deleterious effect on bodyweight regulation promoting metabolic diseases. This work aimed to demonstrate the development of type 2 diabetes mellitus (T2D) in animals with congenital hypothyroidism, only by the consumption of a mild hypercaloric diet in the extrauterine stage. Methods: Two groups of female Wistar rats (n = 9): euthyroid and hypothyroid were used. Hypothyroidism was induced by a thyroidectomy with parathyroid reimplantation. Male offsprings post-weaning were divided into four groups (n = 10): euthyroid, hypothyroid, euthyroid + hypercaloric diet, and hypothyroid + hypercaloric diet. The hypercaloric diet consisted of ground commercial feed plus 20% lard and was administered until postnatal week 40. Bodyweight and energy intake were monitored weekly. Also, metabolic and hormonal markers related to cardiovascular risk, insulin resistance, and glucose tolerance were analyzed at week 40. Then, animals were sacrificed to perform the morphometric analysis of the pancreas and adipose tissue. Results: T2D was developed in animals fed a hypercaloric diet denoted by the presence of central obesity, hyperphagia, hyperglycemia, dyslipidemia, glucose tolerance, insulin resistance and hypertension, as well as changes in the cytoarchitecture of the pancreas and adipose tissue related to T2D. The results show that congenital hypothyroid animals had an increase in metabolic markers and an elevated cardiovascular risk. Conclusions: Congenital hypothyroid animals develop T2D, having the highest metabolic disturbances and a worsened clinical prognosis than euthyroid animals.

C-phycoerythrin from Phormidium persicinum Prevents Acute Kidney Injury by Attenuating Oxidative and Endoplasmic Reticulum Stress.

C-phycoerythrin (C-PE) is a phycobiliprotein that prevents oxidative stress and cell damage. The aim of this study was to evaluate whether C-PE also counteracts endoplasmic reticulum (ER) stress as a mechanism contributing to its nephroprotective activity. After C-PE was purified from Phormidium persicinum by using size exclusion chromatography, it was characterized by spectrometry and fluorometry. A mouse model of HgCl2-induced acute kidney injury (AKI) was used to assess the effect of C-PE treatment (at 25, 50, or 100 mg/kg of body weight) on oxidative stress, the redox environment, and renal damage. ER stress was examined with the same model and C-PE treatment at 100 mg/kg. C-PE diminished oxidative stress and cell damage in a dose-dependent manner by impeding the decrease in expression of nephrin and podocin normally caused by mercury intoxication. It reduced ER stress by preventing the activation of the inositol-requiring enzyme-1α (IRE1α) pathway and avoiding caspase-mediated cell death, while leaving the expression of protein kinase RNA-like ER kinase (PERK) and activating transcription factor 6α (ATF6α) pathways unmodified. Hence, C-PE exhibited a nephroprotective effect on HgCl2-induced AKI by reducing oxidative stress and ER stress.