Rat Aorta Research Articles

ELECTRON MICROSCOPY SIGNS OF NORMAL AND DYSFUNCTIONAL RAT AORTIC ENDOTHELIUM

HighlightsA fundamental distinguishing feature of normal endothelial cell morphotypes from pathological ones is their preserved orientation along the direction of blood flow in the absence of cytoplasmic or membrane defects.The main characteristics of dysfunctional endothelial cells include a spherical shape (indicating a loss of cellular orientation along the direction of blood flow), the presence of large vacuoles within the cell, cytoplasmic vacuolization, impaired plasma membrane integrity, reduced contrast between the nucleus and cytoplasm, and partial detachment of the endothelial cell from the basement membrane.The condition of organelles (mitochondria, Golgi complex, and endoplasmic reticulum) and impaired basement membrane integrity are not sensitive or specific markers of dysfunctional endothelium compared to the aforementioned features Aim. To analyze the electron microscopic features of normal and dysfunctional endothelium using the descending aorta of rats (characterized by laminar blood flow).Methods. The study was conducted on 5 male Wistar rats (age ≈ 6 months, body weight ≈ 500 g). The extracted aortas were chemically fixed in 2.5% glutaraldehyde, post-fixed in 1% osmium tetroxide solution with 1.5% potassium ferrocyanide, incubated with 1% thiocarbohydrazide, stained in 2% aqueous osmium tetroxide solution, contrasted in 1% phosphotungstic acid, stained with 2% gadolinium triacetate, dehydrated in ascending concentrations of ethanol, isopropanol, and acetone, embedded in a mixture of acetone and epoxy resin, and then in pure Araldite 502 epoxy resin, followed by its polymerization. After grinding and polishing, the aorta samples were contrasted with lead citrate, coated with carbon, and visualized using backscattered scanning electron microscopy.Results. Electron microscopic analysis identified three main morphotypes of normal endothelial cells: 1) elongated shape along the direction of blood flow and an elongated nucleus; semicircular shape with an oval, round, kidney-shaped, or polymorphic nucleus with a less pronounced but clearly visible orientation along the direction of blood flow; 3) large nucleus with an even less pronounced but visible orientation along the direction of blood flow. The basement membrane of normal endothelial cells often contained various defects. Dysfunctional endothelium also exhibited several morphotypes, characterized by different combinations of the following features: spherical shape and loss of cell orientation along the direction of blood flow, presence of large vacuoles within the cell, cytoplasmic vacuolization, disruption of plasma membrane integrity, reduced contrast between the nucleus and cytoplasm, and partial detachment of the endothelial cell from the basement membrane. However, pronounced changes in the structure of organelles or the adjacent basement membrane were often not observed in dysfunctional endothelial cells.Conclusion. The preservation of orientation along the direction of blood flow indicates a normal phenotype of endothelial cells in the absence of other signs of dysfunctional endothelium (vacuoles within the cytoplasm, cytoplasmic vacuolization, disruption of plasma membrane integrity, reduced contrast between the nucleus and cytoplasm, and partial detachment of the endothelial cell from the basement membrane).

Novel Tryptophyllin Peptides from Physalaemus centralis Inhibit Oxidative Stress-Induced Endothelial Dysfunction in Rat Aorta Preparation.

Amphibian skin is a rich source of molecules with biotechnological potential, including the tryptophyllin family of peptides. Here, we report the identification and characterization of two tryptophyllin peptides, FPPEWISR and FPWLLS-NH2, from the skin of the Central Dwarf Frog, Physalaemus centralis. These peptides were identified through cDNA cloning and sequence comparison. FPWLLS-NH2 shares its primary structure with a previously identified peptide from the skin of Pelophylax perezi, named PpT-2. Another peptide, FPPEWISR, is novel and was named PcT-1. After solid-phase peptide synthesis, both peptides exhibited significant antioxidant activity, with PcT-1 and PpT-2 demonstrating ABTS radical scavenging capacities of 0.305 and 0.269 mg Trolox equivalents/mg peptide, respectively, and ORAC values of 0.319 and 0.248 mg Trolox equivalents/mg peptide. Additionally, PcT-1 and PpT-2 inhibited AAPH-induced hemolysis in human red blood cells, achieving a protection level comparable to Trolox at 0.2 mg/mL. In rat aorta preparations, both peptides partially restored acetylcholine-induced vasorelaxation following pyrogallol-induced oxidative stress, with a greater protective effect of PpT-2. Hemolytic activity assay indicated no cytotoxicity in human red blood cells, and tests on Galleria mellonella larvae confirmed their low toxicity in vivo. These findings highlight the biotechnological potential of PcT-1 and PpT-2 as antioxidant agents, paving the way for new therapeutic applications in combating oxidative stress-related diseases.

Anti-angiogenic and anti-oxidant effects of 2-NTI indole derivative vs. suramin in ex vivo, in vivo, and in vitro studies.

Angiogenesis is an intricate pathway that involves the formation of new blood capillaries from old, functioning ones. Improper angiogenesis is a feature of numerous maladies, including malignancy and autoimmune disorders. Indole-related derivatives are believed to interfere with the mitotic spindle, inhibiting the multiplication, and invasion of cancerous human cells. 5-bromo-2-(5-(4-nitrophenyl)-4H-1,2,4-triazol-3-yl)-1H-indole (2-NTI) is one of such compounds with outstanding anti-angiogenic, and anti-proliferative properties. To evaluate 2-NTI's antiangiogenic and anti-oxidant activities and potential mechanisms of action in comparison with the standard agent, suramin. The rat aortic ring (RAR) and Chick chorioallantois membrane (CAM) assays were employed to determine antiangiogenic efficacy and dose response, while the DPPH assay estimated free radical scavenging activity. Besides, an MTT test was performed to evaluate antiproliferative activity in HUVECs; however, RT-PCR assessed the gene expression level of VEGF in HCT116 cells. 2-NTI displayed a significant and dose-dependent suppression of angiogenesis (83.04%) at 100μg/mL concentration versus the negative controls in the RAR assay. 2-NTI also showed no toxicity in the HUVEC cell line, with an IC50 of 876.6μg/mL, but it significantly reduced the formation of free radicals (IC50 of 135.2µg/mL) and VEGF gene expression (at doses of 200 and 400µg/mL) versus the negative controls and suramin. In CAM model, 2-NTI generated considerable blood vessel regression as compared to the negative control. 2-NTI possesses potent anti-angiogenic actions, which might be explained by its profound anti-proliferative and free radical detoxifying activities.

The Influence of Cell Isolation and Culturing on Natriuretic Peptide Receptors in Aortic Vascular Smooth Muscle Cells.

Vascular smooth muscle cell (SMC) relaxation by guanylyl cyclases (GCs) and cGMP is mediated by NO and its receptor soluble GC (sGC) or natriuretic peptides (NPs) ANP/BNP and CNP with the receptors GC-A and GC-B, respectively. It is commonly accepted that cultured SMCs differ from those in intact vessels. Nevertheless, cell culture often remains the first step for signaling investigations and drug testing. Previously, we showed that even popular reference genes changed dramatically after SMC isolation from aorta. Regarding NP receptors, a substantial amount of data relies on cell culture. We hypothesize that the NP/cGMP system in intact aortic tunica media differs from isolated and cultured aortic SMCs. Therefore, we studied isolation and culturing effects on the expression of NP receptors GC-A, GC-B, and NP clearance receptor (NPRC) compared to sGC. We investigated intact tunica media and primary SMCs from the longitudinal halves of the same rat aorta. GC activity was monitored by cyclic guanosine monophosphate (cGMP). In addition, we hypothesize that there are sex-dependent differences in the NP/cGMP cascade in both intact tissue and cultured cells. We, therefore, analyzed a male and female cohort. Expression was quantified by RT-qPCR comparing aortic media and SMCs with our recently validated reference gene (RG) small nuclear ribonucleoprotein 2 (U2). Only GC-A was stably expressed. In intact media, GC-A exceeded GC-B and NPRC. However, GC-B, NPRC, and sGC were dramatically upregulated in cultured SMCs of the same aortae different from the stable GC-A. The expression was mirrored by NP-induced GC activity. In cultured cells, changes in GC activity were delayed compared to receptor expression. Minor differences between both sexes could also be revealed. Thus, isolation and culture fundamentally alter the cGMP system in vascular SMCs with potential impact on drug testing and scRNAseq. Especially, the dramatic increase in the clearance receptor NPRC in culture might distort all physiological ANP, BNP, and CNP effects.

The effect of CGRP antagonist and exercise training on mitochondrial dynamics in the aorta of male rats

The effect of CGRP antagonist and exercise training on mitochondrial dynamics in the aorta of male rats

Effects of a Rosmarinus officinalis L. Extract and Rosmarinic Acid in Improving Streptozotocin-Induced Aortic Tissue Damages in Rats.

Rosmarinus officinalis L. (R. officinalis) is an aromatic medicinal species with important nutraceutical potential, having rosmarinic acid (RA) as one of its main metabolites. The present study aims to evaluate the effects of an extract obtained from the leaves of this species and of its main metabolite in improving the streptozotocin-induced damage of hearts and aorta of diabetic rats. The leaves of the species were used to obtain a hydroethanolic extract, which was analyzed using the LC/MS method. Diabetes mellitus was induced by intraperitoneal streptozotocin administration in rats. After two weeks, oxidative stress parameters were evaluated from the heart and aorta homogenates. NOS3, AMPK, and adiponectin levels were quantified using ELISA tests, and thoracic aorta rings were isolated for contractility evaluation in the organ bath. Phospho-NF-κB, NRF2, HIF1 alfa, iNOS, and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) quantification were performed using the Western blot technique. Carnosic acid, together with rosmarinic acid, were proven to be the main metabolites identified in the composition of the tested extract. Administration of the extract and of RA improved the relaxation response to acetylcholine and the redox status, with the reduction in malondialdehyde (MDA), nitric oxide synthase 3 (NOS 3), AMP-activated protein kinase (AMPK), adiponectin, reduced (GSH) and oxidized glutathione (GSSG) levels, and superoxide dismutase (SOD) activity. RA significantly enhanced the expression of HIF 1α, NRF2, and pNFkB in the heart. Administration of the R. officinalis extract and of RA-alleviated oxidative stress, proving vascular and cardiac antioxidant properties in the hearts and aorta of diabetic rats.

Comparison of Histomorphometric Characteristics of Heart and Aorta in Young Adult and Aged Rats

Aim: The aim of this study was to compare the histomorphometric and immunohistochemical properties of the heart and aorta in young adult and aged rats. Material and Methods: Sixteen female Wistar albino rats, eight young adult (6 months old, female, 233.25±13.85 g) and rats were used in the study. The rats were sacrificed under high dose anaesthesia and heart and aortic tissues were collected. Ventricular and septum interventiculare thicknesses were measured on the heart tissues, tunica media, tunica intima thickness and aortic diameter were measured histomorphometrically on the aortic tissues. In addition, Inducible Nitric Oxide Synthase (iNOS) in the smooth muscle cells of the tunica media of the aorta and occludin protein levels in the aorta and heart endothelium were examined by immunohistochemical method and histological scoring was performed. Results: As a result of statistical analysis, body weight, heart weight, heart weight/body weight ratio, tunica media and intima thicknesses, and aortic diameters were found to be statistically significantly higher in aged rats compared to young adult rats (p

Relaxant Effect of Rosuvastatin in Isolated Rat Aorta with Perivascular Adipose Tissue

Objective: Rosuvastatin displays favorable pleiotropic effects on vascular system to reduce the risk of cardiovascular events besides providing an intensive reduction in LDL-C levels. The role of perivascular adipose tissue (PVAT) in modulating the vasorelaxant effect of rosuvastatin is not evaluated so far. The present study aimed to investigate the vascular relaxant effect of rosuvastatin in rat aortic rings with intact PVAT, as well as to evaluate the possible mechanisms underlying this effect in relation to nitric oxide (NO) and prostaglandin pathways. Methods: Thoracic aorta rings with intact PVAT, isolated from male Wistar rats (n=5), were mounted on an isolated organ bath system. Endothelium-dependent responses to acetylcholine (Ach,10-6-10-4M) were obtained in aortic rings precontracted submaximally with phenylephrine (Phe,10-6-3x105M). The concentration-dependent relaxant effect of rosuvastatin (10-7-10-4M) was examined in the absence and presence of NO inhibitor, L-NOARG (10-4M, 30min.) and cyclooxygenase inhibitor, indomethacin (10-5M, 30min.). Vascular relaxation capacity of aortic rings was checked by the nitrovasodilator, sodium nitroprusside (SNP,10-6 M) at the end of the experiments. Results: Rosuvastatin (10-7-10-4M) produced concentration-dependent relaxations in Phe-precontracted rat aortic rings with intact PVAT. Pretreatment with L-NOARG significantly attenuated the relaxant responses to rosuvastatin in isolated rat aortic rings with intact PVAT. However, pretreatment with indomethacin did not modify the relaxations to rosuvastatin. In the aortic rings, maximal relaxation responses to Ach and SNP were determined to be 75.87±2.68% and 102.54±2.92%, respectively. Conclusions: This study will provide a basis for investigating the interaction between PVAT and statins in vascular homeostasis.

Features of molecular phenotype and ultrastructure of smooth muscle cells in ascending aorta in premature born rats

Preterm birth can contribute to the development of diseases of circulatory system in adulthood due to the incompleteness of the morphogenesis of the blood vessels wall. Smooth muscle cells are the leading cell population in the middle shell of the aortic wall and are plastic in nature, i. e. they are able to change their phenotype depending on the conditions of their environment. The presence of synthetically active smooth muscle cells in the aortic wall of an adult individual is a predictor of the formation of a wide range of cardiovascular diseases. The aim of our study is to identify the morphofunctional features of molecular phenotype and ultrastructure of smooth muscle cells of ascending aorta wall in rats born 12 and 24 hours prematurely. The paper presents the results of immunohistochemical and morphometric, as well as ultrastructural analysis of ascending aorta wall in Wistar rats born 12 and 24 hours prematurely. It has been shown that preterm birth leads to a later change in the phenotype of smooth muscle cells from synthetic to contractile, which can negatively affect the morphofunctional state of the cardiovascular system.

PM2.5 Induces the Instability of Atherosclerotic Plaques by Activating the Notch Signaling Pathway InVivo and InVitro.

Fine particulate matter (PM2.5) can exacerbate the instability of atherosclerotic plaques although the exact chemical process driving atherosclerosis remains unknown. In order to create atherosclerotic models, a high-fat diet and vitamin D3 injections were given to 56 Wistar rats in this investigation. The atherosclerotic rats were split into four groups at random and given different doses of PM2.5 (0, 1.5, 7.5, and 37.5 mg/kg) for 4 weeks. To investigate the mechanism, foam cells were exposed to PM2.5 (0, 25, 50, and 100 μg/mL) for 24 h. The results showed that PM2.5 exposure caused collagen fibers thinner and muscle fibers were disorganized. PM2.5 exposure significantly affected the expression of MMP2, MMP9, TIMP2, and vimentin in aortas of atherosclerotic rats. Moreover, PM2.5 exposure increased the expression of the Notch signaling pathways which was correlated with the expression of atherosclerotic plaque stability-related genes. PM2.5 exposure also increased the apoptosis rate of foam cells. The expression of MMP2, MMP9, and vimentin was increased and TIMP2 was decreased with the increasing PM2.5 dose in foam cells. The inhibition of the Notch signaling pathway can alleviate the alteration of atherosclerotic plaque stability-related genes. The findings demonstrated that PM2.5 exposure can cause atherosclerotic plaques to become unstable, aggravating the progression of atherosclerosis, a process in which the Notch signaling pathway is crucial.

The New Nitric Oxide Donor, FOR 911B, Induces Relaxation in Isolated Rat Aorta Involving the NO/sGC/cGMP Pathway and K+ Channels

Background: Nitric oxide (NO) is a gaseous molecule considered to be a protagonist in the dilation of blood vessels, and its property and/or bioavailability are reduced in pathophysiological conditions such as cardiovascular diseases. Therefore, its exogenous administration becomes attractive, and new classes of compounds able to induce NO release have emerged to minimize the adverse effects found by existing NO donor drugs. Objective: Our aim was to investigate the vasorelaxant effect and mechanism of action induced by the ruthenium complex, which contains nitric oxide in its structure, [Ru(phen)2(TU)NO](PF6)3 (FOR 911B), in isolated rat aorta. Methods: The animals were euthanized, and the aorta artery was identified, removed, and immediately placed in modified Krebs–Henseleit solution. To verify tissue viability, a contraction was obtained with phenylephrine (Phe) (0.1 μM), and to assess endothelial integrity, acetylcholine (ACh) (1 μM) was added. Results: In the present study, we demonstrated, for the first time, that FOR 911B promotes vasorelaxation in a concentration-dependent manner in isolated rat aortic artery rings. After the removal of the vascular endothelium, the potency and efficacy of the relaxation were not altered. With pre-incubation with hydroxocobalamin, the relaxing response was abolished, and with the use of ODQ, the main NO receptor blocker, the vasorelaxant effect was attenuated with a shift of the curve to the right. To investigate the participation of K+ channels, the solution concentration was changed to KCl (20 and 60 mM), and it was pre-incubated with the non-selective K+ channels blocker (TEA). Under these conditions, relaxation was altered, demonstrating that K+ channels are activated by FOR 911B. By selectively blocking the different subtypes of K+ channels with specific blockers, we demonstrated that the subtypes KV, KIR, SKCa, and BKCa are involved in the vasodilator effect induced by FOR 911B. Conclusions: The results obtained demonstrated that FOR 911B promotes vascular relaxation in aortic artery rings in a concentration-dependent manner and independent of the vascular endothelium through the participation of the NO/sGC/cGMP pathway, as well as with the involvement of different K+ channels.

Greater TIMP-1 protein levels and neointimal formation represent sex-dependent cellular events limiting aortic vessel expansion in female rats.

Fragmentation/loss of the structural protein elastin represents the precipitating event translating to aortic expansion and subsequent aneurysm formation. The present study tested the hypothesis that greater protein expression of tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) and neointimal growth secondary to a reduction of medial elastin content represent sex-dependent events limiting aortic vessel expansion in females. TIMP-1 protein levels were higher in the ascending aorta of female versus male patients diagnosed with a bicuspid aortic valve (BAV). The latter paradigm was recapitulated in the aorta of adult male and female rats complemented by greater TIMP-2 expression in females. CaCl2 (0.5 M) treatment of the infrarenal aorta of adult male and female rats increased the in situ vessel diameter and expansion was significantly smaller in females despite a comparable reduction of medial elastin content. The preferential appearance of a neointimal region of the CaCl2-treated infrarenal aorta of female rats may explain in part the smaller in situ expansion and neointimal growth correlated positively with the % change of the in situ diameter. Neointimal formation was secondary to a significant increase in the density of medial/neointimal vascular smooth muscle cells (VSMCs) that re-entered the G2-M phase whereas VSMC cell cycle re-entry was attenuated in the CaCl2-treated infrarenal aorta of male rats. Thus, greater TIMP-1 expression in the aorta of female BAV patients may prevent excessive elastin fragmentation and preferential neointimal growth following CaCl2-treatment of the infrarenal aorta of female rats represents a sex-dependent biological event limiting vessel expansion secondary to a significant loss of the structural protein.

Enhancing small diameter tissue engineered vascular grafts with heparin and hepatocyte growth factor: A promising approach.

Currently, there is often a lack of suitable small-caliber graft vessels for treating cardiovascular diseases because of thrombosis and intimal hyperplasia. Tissue engineered vascular grafts (TEVGs) promise a potential solution to this issue. Acellular vascular matrix with good mechanical properties and biocompatibility is commonly used as a tissue engineered scaffold. In this study, acellular rat aortas were preloaded with heparin and hepatocyte growth factor (HGF) to fabricate small diameter TEVGs. In terms of the biomechanical properties, this scaffold was similar to native rat aortas. We implanted this scaffold into a rat abdominal aorta, and the acellular aorta with heparin only was used as control. The patency at 6 months of the two groups was 100%. At 1 month, a complete layer of endothelial cells could be seen on the surface of the vascular lumen of the scaffold with heparin and HGF. The results also showed that the intimal thickness was significantly reduced in the grafts coated with HGF compared to the control grafts. In conclusion, the small-diameter TEVGs constructed by acellular vascular scaffolds coated with heparin and HGF have a promising clinical application prospect.

Serum pharmacochemistry of Panacis Japonici Rhizoma extract based on UPLC-Q-Exactive Orbitrap-MS

In this study, the chemical components of Panacis Japonici Rhizoma extract and absorbed components in rats were identified by ultra-high performance liquid chromatography-quadrupole exactive orbitrap mass spectrometry(UPLC-Q-Exactive Orbitrap-MS). The separation was performed by gradient elution on Waters UPLC BEH C_(18) column(2.1 mm×100 mm, 1.7 μm) with the mobile phase of water and acetonitrile containing 0.1% formic acid. High resolution multistage mass spectrometry data were collected by electrospray ionization in positive and negative ion modes. The chemical components of Panacis Japonici Rhizoma extract were identified by comparing with the retention time, high resolution precise molecular weight, and secondary fragment ions of reference substances and related literature. After intragastric administration of Panacis Japonici Rhizoma extract, blood was collected from the abdominal aorta of rats for separation of the serum, and the absorbed components were scanned and identified. The results showed that 43 chemical components were detected in the Panacis Japonici Rhizoma extract, including 22 saponins, 9 amino acids, 5 polysaccharides, 2 volatile oils, and 5 nucleosides. In the serum, 18 components were detected, including 10 prototype components, 6 metabolites, and 2 unknown components. This study analyzed the chemical components and absorbed components of Panacis Japonici Rhizoma extract, providing clues for clarifying the pharmacological basis of Panacis Japonici Rhizoma.

Mathurameha ameliorates cardiovascular complications in high-fat diet/low-dose streptozotocin-induced type 2 diabetic rats: insights from histological and proteomic analysis.

Type 2 diabetes mellitus (T2DM) is a global health concern with increasing prevalence. Mathurameha, a Thai herbal formula, has shown promising glucose-lowering effects and positive impacts on biochemical profiles in diabetic rats. The present study investigated the protective effects of Mathurameha on cardiovascular complications in high-fat diet/streptozotocin (HFD/STZ)-induced type 2 diabetic rats using histological and proteomic analyses. Thirty-five male Sprague-Dawley rats were divided into seven groups: normal diet (ND), ND with aqueous extract (ND + AE450), ND with ethanolic extract (ND + EE200), diabetes (DM), DM with AE (DM + AE450), DM with EE (DM + EE200), and DM with metformin (DM + Met). Mathurameha, especially at 200mg/kg EE, significantly reduced adipocyte size, cardiac and vascular abnormalities, collagen deposition, and arterial wall thickness in DM rats. Proteomic analysis of rat aortas revealed 30 significantly altered proteins among the ND, DM, and DM + EE200 groups. These altered proteins are involved in various biological processes related to diabetes. Biochemical assays showed that Mathurameha reduced lipid peroxidation (MDA), increased antioxidant levels (GSH), and decreased the expression of inflammatory markers (ICAM1, TNF-α). In conclusion, Mathurameha exhibited significant protective effects against cardiovascular complications in HFD/STZ-induced type 2 diabetic rats through its antioxidant and anti-inflammatory properties.

Rosmarinic acid alleviates the cardiac abnormalities in high fat diet induced hypercholesterolemic rats

Hyperlipidemia is a well-known risk factor for atherosclerosis and subsequent atherosclerotic cardiovascular diseases that are associated with high morbidity and mortality in obese and diabetic patients worldwide. The current study looked on rosmarinic acid's cadioprotective effects in rats fed a high-fat diet as there was no study on this aspect. The rats were given a high-fat diet comprising of 84.3 % conventional laboratory rat chow, 5 % lard, 10 % egg yolk powder, 0.2 % cholesterol, and 0.5 % bile salt to produce hypercholesterolemia. Over a span of eight weeks. The plasma lipid profile, cardiac marker enzymes, membrane bound ATPases, lysosomal enzymes, CRP, fibrinogen, proinflammatory cytokines (IL-1β, IL-6,TNF-α, NF-κB),anti-inflammatory cytokine(IL-10) lipid peroxidation markers, enzymatic and non-enzymatic antioxidant enzymes activity were examined. The thoracic aorta's histopathology was also analyzed. It was discovered that the rats fed a high-fat diet had hypercholesterolemia and showed aberrant values in the aforementioned parameters. However, rats given rosmarinic acid (100 mg/kg b.w.) had these anomalies reversed to near-normal levels. The biochemical investigation was corroborated by enhanced histological examination of the thoracic aorta in rats suffering from hypercholestolemia. The effects of rosmarinic acid on a number of measures were similar to those of the prescription medication simvastatin. These findings revealed that rosmarinic acid is an important component in the cardiovascular system's defence against a high-fat diet induced hypercholesterolemia

The Effect of Thermal Processes on the Organoleptic and Nutraceutical Quality of Tomato Fruit (Solanum lycopersicum L.).

The present study investigated the changes in the organoleptic characteristics, nutraceuticals, and antioxidant activity of tomato fruits subjected to different thermal processes: tomato sauce (80 °C for 30 min), blanching treatment (100 °C for 10 s), and the superheated steam method (SHS; 100 °C for 7 min) compared with fresh tomato fruit. Even though SHS negatively modified the color of the product (L* -7% than fresh tomatoes), it was the only technology able to increase the antioxidant activity compared with fresh tomatoes (e.g., +40.3% in ABTS assay), whilst lycopene and ascorbic acid contents reported similar values to fresh tomatoes. Regarding lycopene, only 5Z-lycopene (with a higher bioavailability than (all-E)-isomers) was found in all samples, and SHS maintained the same level observed in fresh tomato fruit. Furthermore, SHS technology preserved the antioxidant effects of fresh tomato extract even in human endothelial cells. This result confirmed those obtained in previous "cell-free" assays and demonstrated that SHS treatment significantly maintains the biological properties of tomato fruit in preventing oxidative stress. However, heat-treated tomato extracts did not show the same effects as fresh tomato extract against noradrenaline-induced vasoconstriction in isolated rat aortic rings. This study demonstrates that the use of SHS technology can be considered an innovative and sustainable thermal process (in terms of maintaining the nutraceutical quality) for tomato fruits, thus paving the way for future investigations on the effects of fresh and heat-treated tomatoes after intestinal absorption in vitro and in vivo.

Biphasic effect of limonene on contraction of isolated rat aorta

Limonene, a monoterpene found in essential oils, has various activities, such as antifungal, antioxidant, neuroprotective, gastroprotective and vasorelaxant. However, the observation of limonene's biphasic effect in preclinical studies provides crucial information about its dose-dependent actions. Understanding this behavior is essential for optimizing therapeutic doses and anticipating possible side effects prior to clinical trials. The objective of this study is to provide a more detailed characterization and investigation of the mechanisms of action of limonene on the contractile tonus of isolated aorta.The experiments were carried out on aortic rings isolated from rats, subjected to isometric recording of contractions in their circular smooth muscle and exposed to different concentrations of limonene. It was found that limonene blocked the contraction induced by KCl (60 mM), but had a biphasic effect on the contraction induced by phenylephrine (0.1 μM). At lower concentrations, limonene was able to amplify the contraction induced by phenylephrine, while at higher concentrations, it inhibited it. The nitric oxide synthase blockers L-NAME and ruthenium red, a TRP ion channel blocker, did not significantly interfere with the biphasic character of limonene. However, indomethacin, a blocker of arachidonic acid derivatives, completely blocked the amplification of contraction induced by phenylephrine. In addition, limonene promoted relaxation in contractions induced by BAY-K 8644, a calcium channel agonist and by Ba2+. Limonene has complex effects on aortic tone, amplifying or inhibiting contractions, suggesting that the therapeutic window should be carefully studied to optimize clinical results.

Persicaria minor (Huds.) Opiz Exhibits Antihypertensive Effects by Inhibiting the Angiotensin-Converting Enzyme/Angiotensin II Type 1 Receptor Pathway in Human Endothelial Cells.

Overactivation of the angiotensin-converting enzyme (ACE)/angiotensin II type 1 receptor (AT1R) pathway leads to vasoconstriction and elevated blood pressure. Persicaria minor (Huds.) Opiz is an herbal plant known for its antioxidant, anti-hyperlipidemic, and anti-atherosclerotic properties, with bioactive compounds that exhibit antihypertensive effects. Therefore, this study aimed to evaluate the antihypertensive effects of the standardized aqueous extract of P. minor leaf (AEPM) through the ACE/AT1R pathway in human umbilical vein endothelial cells (HUVECs) induced with phorbol 12-myristate 13-acetate (PMA). HUVECs were stimulated with PMA to induce ACE, with or without AEPM or captopril treatment, for 24 h. Subsequently, ACE mRNA expression, ACE protein levels, ACE activity, angiotensin II levels, and AT1R expression were measured. The results demonstrated that AEPM treatment significantly reduced ACE mRNA expression, ACE protein levels, ACE activity, angiotensin II levels, and AT1R expression in PMA-induced HUVECs. The modulatory effects of AEPM on the ACE/AT1R pathway were comparable to those of captopril. Ex vivo experiments further confirmed that AEPM reduced the contraction responses of rat aortic rings to PMA. In conclusion, P. minor effectively inhibits the ACE/AT1R pathway in PMA-induced HUVECs, suggesting its potential as a natural antihypertensive agent.

Dehydroepiandrosterone (DHEA), a circulating steroid hormone precursor produced potent vasorelaxation in rat aorta and mesenteric arteries through blockade of L-type voltage-dependent calcium channels

Dehydroepiandrosterone (DHEA) is known for potent cardioprotective properties and diminished DHEA level in plasma is often associated with hypertension and age-related anomalies. However, putative ex-vivo vasorelaxation potential of DHEA in systemic resistance vessels like mesenteric arteries and conduit arteries like aorta are still to be worked out. The study aimed to explore vasorelaxation potential of DHEA in superior and resistance mesenteric arteries and aorta in rats and to determine the contribution L-type Voltage dependent calcium channel (L-VDCC) in the relaxation response in these arterial tissues. Ex-vivo vasorelaxation potential of DHEA in isolated arterial tissues were evaluated and the mechanism of vasorelaxation induced by DHEA was characterized by contraction experiment in isolated arterial tissue and in-vitro calcium imaging assay using Fluo-4 in primary vascular smooth muscle cells derived from aorta. In the current study, DHEA was found to exhibit potent concentration dependent, endothelium and potassium channel independent vasorelaxation response in conduit and resistance arteries. The block of L-type VDCCs was evident from the findings that DHEA in a concentration-dependent manner inhibited both BAY K-8644 and CaCl2-induced contractions. The results of the contraction experiment were further substantiated by Fluo-4 mediated calcium imaging assay in primary rat vascular smooth muscle wherein DHEA concentration dependently blocked noradrenaline and BAY K-8644-induced rise in intracellular calcium fluorescence. The present study showed potent endothelium and potassium channel independent vasorelaxation properties of DHEA in aorta, superior and resistance mesenteric artery mediated predominantly through blockade of L-VDCC.