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Nebivolol is a third generation beta blocker with endothelial nitric oxide synthase (eNOS) agonist properties. Considering the role of reactive oxygen species (ROS) in the uncoupling of eNOS, we hypothesized that the preadministration of an antioxidant as tempol, could improve the hypotensive response of nebivolol in normotensive animals increasing the nitric oxide (NO) bioavailability by a reduction of superoxide (O2•−) basal level production in the vascular tissue. Male Sprague Dawley rats were given tap water to drink (control group) or tempol (an antioxidant scavenger of superoxide) for 1 week. After 1 week, Nebivolol, at a dose of 3 mg/kg, was injected intravenously to the control group or to the tempol-treated group. Mean arterial pressure, heart rate, and blood pressure variability were evaluated in the control, tempol, nebivolol, and tempol nebivolol groups, as well as, the effect of different inhibitor as Nβ-nitro-l-arginine methyl ester (L-NAME, a Nitric oxide synthase blocker) or glybenclamide, a KATP channel inhibitor. Also, the expression of α,β soluble guanylate cyclase (sGC), phospho-eNOS, and phospho-vasodilator-stimulated phosphoprotein (P-VASP) were evaluated by Western Blot and cyclic guanosine monophosphate (cGMP) levels by an enzyme-linked immunosorbent assay (ELISA) commercial kit assay. We showed that pretreatment with tempol in normotensive rats produces a hypotensive response after nebivolol administration through an increase in the NO bioavailability and sGC, improving the NO/cGMP/protein kinase G (PKG) pathway compared to that of the nebivolol group. We demonstrated that tempol preadministration beneficiates the response of a third-generation beta blocker with eNOS stimulation properties, decreasing the basal uncoupling of eNOS, and improving NO bioavailability. Our results clearly open a possible new strategy therapeutic for treating hypertension. [ABSTRACT FROM AUTHOR]

Cardiovascular diseases remain a leading cause of morbidity and mortality worldwide, requiring innovative therapeutic strategies. This project explores a nano-pharmaceutical approach to enhance the efficacy of cardiovascular drugs, focusing on carvedilol and curcumin. These agents, known for their potential cardiovascular benefits, are encapsulated within Soluplus® micelles to form a novel drug delivery system. The novelty of this formulation lies in its ability to significantly improve the solubility of both carvedilol and curcumin, which have traditionally been limited by their hydrophobic nature. By utilizing Soluplus® micelles, we have developed a unique delivery system that optimizes the therapeutic potential of both drugs. The nanomicelles were meticulously characterized for drug loading, size distribution, and morphological features. The carvedilol and curcumin release patterns were investigated, revealing sustained and controlled release profiles. Additionally, the antioxidant capacity of the micellar formulation was evaluated, demonstrating the preservation of curcumin's antioxidative properties. In vivo studies using spontaneously hypertensive male rats explored the pharmacokinetics and hemodynamic effects of the nanomicellar system. These results indicated successful encapsulation of both drugs without altering their plasma profiles. Furthermore, the administration of carvedilol and curcumin micelles exhibited a more significant reduction in mean arterial pressure compared to individual drug administration, suggesting a potential synergistic effect. In conclusion, this nano-pharmaceutical approach offers a promising avenue for cardiovascular therapy, providing a platform for combined drug delivery and potential synergistic effects. The optimized formulation could lead to improved patient outcomes and enhanced cardiovascular health., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Environmental hexachlorobenzene (HCB) increases blood pressure (BP) in female rats, causing alterations in arterial structure and function. Here we study the role of Angiotensin II receptor type 1 (AT1) in HCB-induced hypertension through the use of AT1 antagonist losartan. HCB-treated male rats showed a 22.7% increase in BP which was prevented by losartan. Losartan blocked HCB-induced changes in arterial morphology (decreased aorta cell number and increased wall thickness). Losartan also prevented HCB-induced alterations in artery relaxation by acetylcholine and nitroprusside but not the reduction in the maximum contraction by phenylephrine. Losartan rescued arterial molecular alterations caused by HCB (i.e. an increase in TGF-β1 and AT1 expression and a decrease in eNOS expression and nitrite levels) and reduced hydrogen sulfide plasma concentration. In conclusion: in this work we demonstrate that AT1 activity is involved in HCB effects on the vascular system leading to hypertension., Competing Interests: The authors declare no conflict of interest., (© 2021 Published by Elsevier B.V.)

Ethnopharmacological Relevance: Minthostachys verticillata (Griseb.) Epling (Lamiaceae), known as Peperina is a medicinal native plant, with a traditional use as a digestive, antispasmodic and antidiarrheic., Aim of the Study: Despite its folkloric use, no scientific evaluation of this plant related to the gastrointestinal inflammatory process has been carried out to date. The present study aims to assess the effects of M. verticillata on gastrointestinal system in experimental models., Materials and Methods: M. verticillata (250 and 500 mg/kg) was orally tested in a colitis model induced by acetic acid. Colon weight/length ratio, oxidative stress (oxidized and reduced glutathione), histological changes using Alcian blue and hematoxylin & eosin staining and expression of IL1β, TNFα, iNOS, COX-2 were evaluated. The effect of the extract in three additional in vivo models were studied: intestinal motility and diarrhea induced by ricin oil, and visceral pain induced by intracolonic administration of capsaicin. Finally, the activity on concentration response curves of acetylcholine, calcium chloride, potassium and serotonin were achieved in isolated rat jejunum., Results: In the colitis model, M. verticillata induced a significant reduction in the colon weight/length ratio, oxidative stress and expression levels of IL-1β, iNOS and COX-2. Also, the extract diminished the severity of microscopic tissue damage and showed protective effect on goblet cells. Intestinal motility, diarrhea, visceral pain-related behaviors and referred hyperalgesia were significantly reduced when the animals were treated with the extract. Furthermore, in isolated jejunum, M. verticillata significantly reduced the contraction induced by serotonin and acetylcholine. Likewise, the extract non-competitively inhibited the response-concentration induced by CaCl 2 and inhibited both low and high K + -induced contractions., Conclusions: This is the first study to validate traditional use of M. verticillata for digestive disorders and demonstrated that its aqueous extract could represent a promising strategy in targeting the multifactorial pathophysiology of inflammatory bowel disease., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Methyl gallate is a gallotannin widely distributed in nature. Previous studies have demonstrated its antioxidant, anti-inflammatory, antimicrobial and anti-tumor activities. In the present study, the activity of methyl gallate on experimental models of inflammatory bowel disease has been investigated. Experimental colitis was induced in Sprague-Dawley rats through the intracolonic instillation of an acetic acid solution (2 mL, 4% v/v). Methyl gallate (100 and 300 mg/kg, p.o.) and the reference drug mesalazine (100 mg/kg, p.o.) were tested. Methyl gallate induced a significant reduction in the colon weight/length ratio and macroscopic lesion score. Besides, the malondialdehyde content and the GSSG/GSH ratio were remarkably decreased. Furthermore, the administration of methyl gallate reduced the expression of COX 2 , IL-6, TNFα and the severity of microscopic tissue damage induced by acetic acid, while the mean goblet cell density was significantly higher in both the group treated with methyl gallate and the one treated with mesalazine, in comparison with untreated animals. The Na + K + ATPase pump activity was recovered in treated groups (control: 827.2 ± 59.6, colitis: 311.6 ± 54.8, methyl gallate 100 mg/kg: 642.2 ± 175.0, methyl gallate 300 mg/kg: 809.7 ± 100.6, mesalazine: 525.3 ± 81.7). Methyl gallate was also found to induce a significant reduction in the castor oil-induced intestinal motility in Swiss mice, decreasing the peristalsis by 74.5 and 58.82% at 100 and 300 mg/kg p.o., respectively. This compound also antagonized the jejunum contractions induced by Ach and CaCl 2 . This study demonstrates that methyl gallate exerts beneficial effects in a preclinical model of intestinal disorders.

Aim: To determine the effect of tempol in normal rats fed high salt on arterial pressure and the balance between antagonist components of the renal renin-angiotensin system., Methods: Sprague-Dawley rats were fed with 8% NaCl high-salt (HS) or 0.4% NaCl (normal-salt, NS) diet for 3 wk, with or without tempol (T) (1 mmol/L, administered in drinking water). Mean arterial pressure (MAP), glomerular filtration rate (GFR), and urinary sodium excretion (UVNa) were measured. We evaluated angiotensin II (Ang II), angiotensin 1-7 (Ang 1-7), angiotensin converting enzyme 2 (ACE2), mas receptor (MasR), angiotensin type 1 receptor (AT1R) and angiotensin type 2 receptor (AT2R) in renal tissues by immunohistochemistry., Results: The intake of high sodium produced a slight but significant increase in MAP and differentially regulated components of the renal renin-angiotensin system (RAS). This included an increase in Ang II and AT1R, and decrease in ACE-2 staining intensity using immunohistochemistry. Antioxidant supplementation with tempol increased natriuresis and GFR, prevented changes in blood pressure and reversed the imbalance of renal RAS components. This includes a decrease in Ang II and AT1R, as increase in AT2, ACE2, Ang (1-7) and MasR staining intensity using immunohistochemistry. In addition, the natriuretic effects of tempol were observed in NS-T group, which showed an increased staining intensity of AT2, ACE2, Ang (1-7) and MasR., Conclusion: These findings suggest that a high salt diet leads to changes in the homeostasis and balance between opposing components of the renal RAS in hypertension to favour an increase in Ang II. Chronic antioxidant supplementation can modulate the balance between the natriuretic and antinatriuretic components of the renal RAS., Competing Interests: Conflict-of-interest statement: The authors have no conflicts of interest to disclose.

Unlabelled: Our aim was to analyze the effect of circulating triglyceride rich lipoprotein (TRL) on endothelial function in metabolic syndrome (MetS)., Methods: We studied 40 patients with MetS (ATPIII), divided into those presenting normal endothelial function (n=19) and those with endothelial dysfunction (n=21) by means of the evaluation of pulse wave velocity, before and after brachial artery ischemia. In fasting serum we measured lipid and lipoprotein profile, insulin and glucose (HOMA-IR). Moreover, isolated TRL (d<1006g/l) were chemically characterized. In parallel, using randomly selected TRL from MetS patients with endothelial dysfunction (n=6) and MetS patients with normal endothelial function (n=6), the ability of TRL to inhibit ACh-induced vasorelaxation (10(-9)-10(-5)mM) on aortic rings previously pre-contracted by noradrenaline (10(-8)mM) was evaluated., Results: Interestingly, TRL isolated from MetS patients presenting endothelial dysfunction showed triglyceride over-enrichment (59.1±4.8 vs. 54.1±4.7%; p=0.04), even after adjusting by potential confounders (p=0.05). In addition, while TRL resulting from both MetS groups significantly inhibited endothelium dependent vasorelaxation (p<0.001), TRL from MetS patients with endothelial dysfunction showed a strong tendency to a greater inhibition of vasorelaxation (p=0.06). Moreover, TRL-triglyceride (%) showed a strong tendency to correlate with the grade of vasorelaxation inhibition exerted by TRL (r=0.60; p=0.05)., Conclusion: These results, taken together, would allow inferring for the first time that the predominance of triglyceride over-enriched TRL in circulation in MetS would induce endothelial dysfunction, contributing to the inherent cardiovascular risk of MetS., (Copyright © 2016 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.)

The aim of this study was to demonstrate the effects of atrial natriuretic peptide (ANP) on organic cation transporters (OCTs) expression and activity, and its consequences on dopamine urinary levels, Na+, K+-ATPase activity and renal function. Male Sprague Dawley rats were infused with isotonic saline solution during 120 minutes and randomized in nine different groups: control, pargyline plus tolcapone (P+T), ANP, dopamine (DA), D-22, DA+D-22, ANP+D-22, ANP+DA and ANP+DA+D-22. Renal functional parameters were determined and urinary dopamine concentration was quantified by HPLC. Expression of OCTs and D1-receptor in membrane preparations from renal cortex tissues were determined by western blot and Na+, K+-ATPase activity was determined using in vitro enzyme assay. 3H-DA renal uptake was determined in vitro. Compared to P+T group, ANP and dopamine infusion increased diuresis, urinary sodium and dopamine excretion significantly. These effects were more pronounced in ANP+DA group and reversed by OCTs blockade by D-22, demonstrating that OCTs are implied in ANP stimulated-DA uptake and transport in renal tissues. The activity of Na+, K+-ATPase exhibited a similar fashion when it was measured in the same experimental groups. Although OCTs and D1-receptor protein expression were not modified by ANP, OCTs-dependent-dopamine tubular uptake was increased by ANP through activation of NPR-A receptor and protein kinase G as signaling pathway. This effect was reflected by an increase in urinary dopamine excretion, natriuresis, diuresis and decreased Na+, K+-ATPase activity. OCTs represent a novel target that links the activity of ANP and dopamine together in a common mechanism to enhance their natriuretic and diuretic effects.

Background: Endothelial nitric oxide synthase (eNOS) is known to be expressed in endothelium and smooth muscle cells of arteries. The aim of this study was to investigate the expression of eNOS in intimal and medial layer of aorta from rats fed with a high salt diet and its modulation by losartan and tempol., Methods: Rats were fed during three weeks with: normal salt diet (NS, 0.4% NaCl); high salt diet (HS, 8% NaCl); NS plus tempol 1 mM (NS-T); HS plus tempol (HS-T); NS plus losartan 40mg.kg-1 (NS-L) and HS plus losartan (HS-L). Systolic blood pressure was recorded by the tail cuff method. Rats were then anaesthetized and the thoracic aorta and small arteries (bronchial branches of aorta) were processed to evaluate the expression of eNOS and aquaporin-1 (AQP-1) by immunohistochemistry., Results: HS group showed increased systolic blood pressure, increased eNOS and AQP-1 immunoexpression in the aorta intimal layer, and decreased eNOS immunoexpression in the aorta medial layer, respect to NS group. Losartan and tempol prevented hypertension and changes in the expression of eNOS and AQP-1 of the intimal layer. However, only tempol increased the expression of eNOS elicited by sodium overload in the medial layer of the aorta and small arteries respect to HS group., Conclusions: A high salt diet decreases eNOS expression in vascular smooth muscle layers of aorta and small arteries, which is reversed by tempol. These results suggest an adverse effect of oxidative stress on vascular eNOS in rats fed a high salt diet independently of hypertension.

Vanillic acid is found at high concentrations in many plants used in traditional medicine. It has been associated with a variety of pharmacologic activities such as carcinogenesis inhibition, apoptosis and inflammation; however, it has become most popular for its pleasant creamy odor. Since there are few reports concerning the antinociceptive activity of this phenolic compound, the aim of this work was to study this activity in in vivo animal models. Vanillic acid was administered by the intraperitoneal route producing a dose-dependent inhibition of the acetic acid-induced writhing response (ED 50 : 9.3mg/kg). The antinociceptive activity was inhibited by the pretreatment with ondansetron and yohimbine, indicating that the serotoninergic and adrenergic systems could participate in the mechanism underlying the analgesic activity of vanillic acid. This compound was also demonstrated to interact with ASICs (Acid-sensing Ion Channels) as well as with TPRV1, TRPA1, and TRPM8 receptors in vivo. Furthermore, vanillic acid did not interfere with the locomotor function or motor coordination. The plasmatic phenolic content, analyzed by HPLC, showed that its t 1/2 and AUC were 0.123h and 1.38μg·h/mL; respectively. In conclusion, vanillic acid might represent a potential therapeutic option for the treatment of pain., (Copyright © 2015 Elsevier Inc. All rights reserved.)

The aim of this study was to assess whether endogenous Ang II and oxidative stress produced by acute hypertonic sodium overload may regulate the expression of aquaporin-1 (AQP-1) and aquaporin-2 (AQP-2) in the kidney. Groups of anesthetized male Sprague-Dawley rats were infused with isotonic saline solution (control) or with hypertonic saline solution (Na group, 1 M NaCl), either alone or with losartan (10 mg kg(-1)) or tempol (0.5 mg min(-1) kg(-1)) during 2 h. Renal function parameters were measured. Groups of unanesthetized animals were injected intraperitoneally with hypertonic saline solution, with or without free access to water intake, Na+W, and Na-W, respectively. The expression of AQP-1, AQP-2, Ang II, eNOS, and NF-kB were evaluated in the kidney by Western blot and immunohistochemistry. AQP-2 distribution was assessed by immunofluorescence. Na group showed increased natriuresis and diuresis, and Ang II and NF-kB expression, but decreased eNOS expression. Losartan or tempol enhanced further the diuresis, and AQP-2 and eNOS expression, as well as decreased Ang II and NF-kB expression. Confocal immunofluorescence imaging revealed labeling of AQP-2 in the apical plasma membrane with less labeling in the intracellular vesicles than the apical membrane in kidney medullary collecting duct principal cells both in C and Na groups. Importantly, our data also show that losartan and tempol induces a predominantly accumulation of AQP-2 in intracellular vesicles. In unanesthetized rats, Na+W group presented increased diuresis, natriuresis, and AQP-2 expression (112 ± 25 vs 64 ± 16; *p < 0.05). Water deprivation increased plasma sodium and diuresis but decreased AQP-2 (46 ± 22 vs 112 ± 25; §p < 0.05) and eNOS expression in the kidney. This study is a novel demonstration that renal endogenous Ang II-oxidative stress, induced in vivo in hypernatremic rats by an acute sodium overload, regulates AQP-2 expression.

In the kidney, a high salt intake favors oxidative stress and hypoxia and causes the development of fibrosis. Both atrial natriuretic peptide (ANP) and hypoxia inducible factor (HIF-1α) exert cytoprotective effects. We tested the hypothesis that renal expression of ANP and HIF-1α is involved in a mechanism responding to the oxidative stress produced in the kidneys of rats chronically fed a high sodium diet. Sprague-Dawley rats were fed with a normal salt (0.4% NaCl) (NS) or a high salt (8% NaCl) (HS) diet for 3 weeks, with or without the administration of tempol (T), an inhibitor of oxidative stress, in the drinking water. We measured the mean arterial pressure (MAP), glomerular filtration rate (GFR), and urinary sodium excretion (UVNa). We evaluated the expression of ANP, HIF-1α, and transforming growth factor (TGF-β1) in renal tissues by western blot and immunohistochemistry. The animals fed a high salt diet showed increased MAP and UVNa levels and enhanced renal immunostaining of ANP, HIF-1α, and TGF-β1. The administration of tempol together with the sodium overload increased the natriuresis further and prevented the elevation of blood pressure and the increased expression of ANP, TGF-β1, and HIF-1α compared to their control. These findings suggest that HIF-1α and ANP, synthesized by the kidney, are involved in an adaptive mechanism in response to a sodium overload to prevent or attenuate the deleterious effects of the oxidative stress and the hypoxia on the development of fibrosis.

Context: The genus Urtica has been known since ancient times. It has known to be useful for the treatment of different human ailments., Objective: The present work evaluated the neuropharmacological effects of a hydroalcoholic extract of Urtica circularis (Hicken) Sorarú (Urticaceae). materials and method: The effect on central nervous system of U. circularis hydroalcoholic extract (from leaves and stems) administered by the intraperitoneal route in mice was evaluated by several tests: Pentobarbital- and midazolam-induced hypnosis, open field, hole board, elevated plus-maze and forced swimming. Phytochemical analysis was performed by high-performance liquid chromatography., Results: A total of 300 mg/kg i.p. of the extract produced a significant prolongation of pentobarbital- (40 mg/kg i.p.; 60.1 min versus 25.4 min) and midazolam- (50 mg/kg i.v.; 53.4 min versus 25.1 min) induced sleeping time. The extract's administration caused a marked reduction of the head-dipping response (DE50: 373 mg/kg i.p.) in the hole-board test. Urtica circularis extract (DE50: 46 mg/kg i.p.) reduced the spontaneous locomotor activity in the open field test. Flumazenil and atropine significantly antagonized the extract's effect on the locomotor activity. No motor coordination disturbance was observed in the rota rod test at any doses. In the forced swimming test, the extract did not produce any change in the immobility time and it had no significant effects in elevated plus maze test. The phytochemical analysis revealed the presence of chlorogenic acid, vanillic acid, caffeic acid, vicenin-2, p-cumaric acid, ferulic acid, vitexin and isovitexin., Conclusion: This study revealed that U. circularis hydroalcoholic extract possesses sedative activity, facilitating GABAergic and cholinergic transmission.

Objective: It has been reported that LDL inhibits endothelium-dependent relaxation (EDR) and that HDL can neutralize this effect. However, the atherogenic properties of VLDL have been so far difficult to demonstrate. Studies on VLDL are controversial, and nothing is known about the role of HDL on potential VLDL vascular actions. We examined the effect of human VLDLs on EDR, and the role of HDL in this system., Methods: VLDL (n=14) and LDL (n=6) were isolated from volunteer subjects. Normal HDL was obtained from one healthy donor. VLDL ability to inhibit ACh-induced vasorelaxation (10(-9)-10(-5)mM) on aortic rings previously precontracted by noradrenaline (10(-8)mM) was measured in the presence and absence of HDL., Results: ACh-induced maximal relaxation (R%) was mildly, but not significantly attenuated in the presence of VLDL (72±7%), while LDL caused a significant inhibition (60±10%, p<0.05) when compared to incubation in the absence of lipoproteins. VLDLs were subdivided into 2 groups depending on their cholesterol/triglyceride ratio: 0.18-0.22 (n=8) was considered typical and 0.10-0.15, rich in triglycerides (VLDLRT, n=6). Typical VLDL had no effect on EDR (p=0.38), however R% from VLDLRT was lower (54±7%, p<0.01) similar to the one obtained with LDL (p=0.32). HDL showed favorable effects on EDR inhibition induced by the presence of VLDLRT (p<0.05.)., Conclusion: Although typical VLDL did not cause endothelial dysfunction, triglyceride-enriched VLDL had inhibitory effect on EDR. It is proposed that alterations in VLDL composition would increase its atherogenic capacity. Moreover HDL appears to protect endothelium from VLDL action., (Copyright © 2013 Elsevier Inc. All rights reserved.)

The self-assembly process is a valuable tool for constructing nano and microstructures. Microtubes (MTs) self-assembled from amphiphiles are novel promising nanomaterials as they have easy self-assembly in aqueous solutions, reproducibility and biocompatibility. The incorporation of amphotericin B (AmB) into lipid microtubes formed from 12-hydroxystearic acid (12HSA) when mixed with ethanolamine in aqueous media was investigated. MTs of several concentrations of lipid material and AmB were prepared. The structure was characterized by phase-contrast microscopy, TEM and SEM. The type of interaction was analyzed by FTIR and DSC. Stability studies were carried out at room temperature and at 4 °C. Loading efficiency of the system was found to be much higher than the drug solubility in water. MTs with 1% of 12HSA and 1 mg/ml of AmB showed to be the most stable formulation. In vitro skin penetration assay showed a flux of 18.20±3.35 μg/cm(2). Amb-loaded MTs in vitro antifungal activity was evaluated and formulation showed similar results to that of AmB deoxycholate showing that AmB retained its antifungal activity in the MTs formulation., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Ethnopharmacological Relevance: Artemisia copa Phil. (Asteraceae) is a medicinal plant commonly used in traditional medicine in Argentina., Aim of the Study: The vasorelaxant and hypotensive activities of the aqueous extract of Artemisia copa have been investigated., Materials and Methods: The in vitro effect of the extract and isolated compounds from Artemisia copa was investigated using isolated rat aortic rings. The acute effect caused by the intravenous (i.v.) infusion (0.1-300mg/kg) on blood pressure and heart rate was evaluated in spontaneous hypertensive rats. In addition, a phytochemical analysis of the extract was performed by HPLC., Results: Artemisia copa had a relaxant effect in endothelium-intact aortic rings that had been pre-contracted with 10(-7)M phenylephrine (Emax=96.7±1.3%, EC50=1.1mg/ml), 10(-5)M 5-hydroxytriptamine (Emax=96.7±3.5%, EC50=1.5mg/ml) and 80mM KCl (Emax=97.9± 4.4%, EC50=1.6mg/ml). In denuded aortic rings contracted by phenylephrine, a similar pattern was observed (Emax=92.7±6.5%, EC50=1.8mg/ml). l-NAME, indomethacin, tetraethylammonium and glibenclamide were not able to block the relaxation induced by the extract. Nevertheless, the pre-treatment with Artemisia copa attenuated the CaCl2-induced contraction in a concentration-dependent manner (Emax: 86% of inhibition for 3mg/ml and 52% de-inhibition for 1mg/ml). This pre-treatment also induced a significant attenuation of the norepinephrine-induced contraction in a concentration-dependent manner (Emax: 72.7% of inhibition for 3mg/ml and 27% de inhibition for 1mg/ml) in a Ca(2+) free medium. Upon analyzing the composition of the extract, the presence of p-coumaric acid, isovitexin, luteolin and chrysoeriol were found. Luteolin (CE50: 1.5μg/ml), chrysoeriol (CE50: 13.2μg/ml) and p-coumaric acid (CE50: 95.2μg/ml), isolated from the aqueous extract, caused dilatation of thoracic aortic rings pre-contracted with phenylephrine. Artemisia copa administered i.v. also induced a decrease in the mean arterial pressure but did not affect the heart rate in hypertensive rats., Conclusions: The aqueous extract of Artemisia copa proved to have vasorelaxing and hypotensive effects through the inhibition of Ca(2+) influx via membranous calcium channels and intracellular stores. The presence of luteolin, chrysoeriol and p-coumaric acid found in this plant could be involved in this effect., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

Artemisia copa Phil. (Compositae) is used in popular medicine as a digestive and for gastric pains. The effects of A. copa aqueous extract and its isolated compounds were evaluated on isolated rat jejunum. The extract inhibited non-competitively the cumulative concentration-response curves induced by acetylcholine and CaCl2. The tonic jejunum contractions induced by 80 mM KCl were inhibited by A. copa. Relaxant effects of A. copa on the tonic contraction induced by 25 mM KCl, [EC50: 0.94 mg mL(-1) (0.64-1.39)], was not inhibited by glibenclamide, TEA, l-NAME or methylene blue. Chrysoeriol, spinacetin and luteolin (30 µg mL(-1)), produced an antagonism on the CaCl2 concentration-response curve, showing an inhibition of the maximum contractions (70.0% ± 5.0%, 49.1% ± 4.5% and 77.0% ± 3.5% of E max, respectively), whereas tricin did not inhibit when the same concentration was used. A. copa exerts spasmolytic activity by blocking calcium channels and three isolated compounds could be, at least partly, responsible for the effect.

Ethnopharmacological Relevance: Lithrea molleoides (Vell.) Engl. (Anacardiaceae) is a medicinal plant commonly used in traditional medicine in South America., Aim of the Study: In the present study, the in vivo antinociceptive effect of L. molleoides' aqueous extract and its isolated compounds has been investigated., Materials and Methods: Antinociceptive activity was evaluated through writhing, formalin and hot plate tests in mice. The phytochemical analysis was performed., Results: The extract produced significant inhibition on nociception induced by acetic acid (ED50: 8.7 mg/kg, i.p.) and formalin (ED50: 7.7 mg/kg, i.p.) administered intraperitoneally and also orally. Yohimbine diminished the activity of the extract in the acetic acid test meanwhile haloperidol enhanced its effect. Two majority compounds, shikimic and vanillic acid were active in chemical nociceptive models used in this work, producing the highest inhibition of the writhing response at a dose of 30 mg/kg i.p. (55.4% and 57.1%, respectively) meanwhile at 100 mg/kg p.o. produced a slight response (23.3% and 23.9%, respectively)., Conclusions: These results suggest that L. molleoides' aqueous extract produced antinociception possibly related to the presence of shikimic and vanillic acid. The adrenergic and dopaminergic systems seem to be involved in the mechanism of antinociception of the extract., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

Vicenin-2 (1), a flavonoid glycoside, was isolated and identified from an ethanol extract of the aerial parts of Urtica circularis. This crude extract was found to possess significant anti-inflammatory activity in a carrageenan-induced rat hind paw edema model (41.5% inhibition at a dose of 300 mg/kg; ip). The effects of 1 on several inflammatory mediators were investigated. In cultured murine macrophages, this compound modified LPS-induced total nitrite and TNF-α production, in addition to the LPS-induced translocation of the nuclear factor NF-κB.

Background: Studies carried out in vitro have recently shown that salt loading induces an increasing mechanical stretch and a flow-induced superoxide production in the thick ascending limb of Henle's loop. In this regard, we hypothesized that the oxidative stress induced by salt overload could stimulate inflammatory and fibrogenic signaling pathways in normal rats., Methods: Sprague Dawley rats were fed with an 8% NaCl high- (HS) or 0.4% NaCl normal-salt (NS) diet for 3 weeks, with or without Tempol (T) administration (1 mM, administered in drinking water). Mean arterial pressure (MAP), glomerular filtration rate (GFR) and urinary sodium excretion (UVNa) were measured. NAD(P)H oxidase p47phox, angiotensin II (Ang II), transforming growth factor ß1 (TGF-ß1), a-smooth muscle actin (a-SMA) and nuclear factor-kappa B (NF-kB) expression were evaluated in renal tissues by immunohistochemistry., Results: A high NaCl diet produced a slight but significant increase in MAP and enhanced UVNa and oxidative stress. Administration of a high NaCl diet induced the overexpression of TGF-ß1, a-SMA and NF-?B in cortex and medulla, while Ang II increased in proximal convoluted tubules, and decreased in cortical collecting ducts. Tempol administration prevented these changes and simultaneously normalized MAP accompanied by an enhancement in GFR and UVNa., Conclusion: The results showed that a high NaCl diet is able to produce a renal profibrotic response also in normal rats, which could be associated with oxidative stress rather than intrarenal Ang II expression.

The antinociceptive and antiinflammatory activities of the ethanol extract of the aerial part of Urtica urens were determined by experimental animal models. U. urens extract was found to possess significant antinociceptive activity in chemically induced mouse pain models (ED₅₀ 39.3 mg/kg: 17.2-74.5 mg/kg) in the writhing test and 62.8% inhibition of the licking time in the late phase of the formalin test at a dose of 500 mg/kg p.o. and antiinflammatory activity on carrageenan-induced rat hind paw edema (41.5% inhibition at a dose of 300 mg/kg i.p.). The extract displayed activity neither in the thermal model of pain nor in the topical inflammation model. The major component of the extract was determined as chlorogenic acid (670 mg/1000 g dry weight) and could be partly responsible for this activity., (Copyright © 2010 John Wiley & Sons, Ltd.)

The aim of this work was to study the role of local intrarenal angiotensin II (Ang II) and the oxidative stress in the up-regulation of pro-inflammatory cytokines expression observed in rats submitted to an acute sodium overload. Sprague-Dawley rats were infused for 2 h with isotonic saline solution (Control group) and with hypertonic saline solution alone (Na group), plus the AT1 receptor antagonist losartan (10 mg kg(-1) in bolus) (Na-Los group), or plus the superoxide dismutase mimetic tempol (0.5 mg min(-1) kg(-1)) (Na-Temp group). Mean arterial pressure, glomerular filtration rate, and fractional sodium excretion (FE(Na)) were measured. Ang II, NF-kappaB, hypoxia inducible factor-1 alpha (HIF-1 alpha), transforming growth factor beta1 (TGF-beta1), smooth muscle actin (alpha-SMA), endothelial nitric oxide synthase (eNOS), and RANTES renal expression was evaluated by immunohistochemistry. Ang II, NF-kappaB, and TGF-beta1 and RANTES early inflammatory markers were overexpressed in Na group, accompanied by enhanced HIF-1 alpha immunostaining, lower eNOS expression, and unmodified alpha-SMA. Losartan and tempol increased FE(Na) in sodium overload group. Although losartan reduced Ang II and NF-kappaB staining and increased eNOS expression, it did not restore HIF-1 alpha expression and did not prevent inflammation. Conversely, tempol increased eNOS and natriuresis, restored HIF-1 alpha expression, and prevented inflammation. Early inflammatory markers observed in rats with acute sodium overload is associated with the imbalance between HIF-1 alpha and eNOS expression. While both losartan and tempol increased natriuresis and eNOS expression, only tempol was effective in restoring HIF-1 alpha expression and down-regulating TGF-beta1 and RANTES expression. The protective role of tempol, but not of losartan, in the inflammatory response may be associated with its greater antioxidant effects., ((c) 2010 Wiley-Liss, Inc.)

Background/aims: The present study was designed to evaluate the effects of a salt load combined with exogenous low nonhypertensive angiotensin II (Ang II) doses on Ang II intrarenal regulation., Methods: Sprague-Dawley rats were infused with Ang II nonhypertensive doses (0.1 microg.kg(-1).h(-1) and 5 microg.kg(-1).h(-1)) and saline overload (Na 0.5 M, Na 1.0 M and Na 1.5 M) for 2 h (0.04 ml.min(-1)). Sodium tubular reabsorption, sodium urinary excretion and mean arterial pressure (MAP) were measured. Ang II was evaluated in the kidneys by immunohistochemistry., Results: Ang II levels in glomeruli and vessels were exacerbated when sodium load and Ang II were given simultaneously, independently of MAP elevation. In tubules, Ang II staining in the presence of sodium overload was greater in the Ang 0.1 groups than in the Ang 5 groups. Compared with the controls, sodium tubular reabsorption rose in the Ang 0.1-Na 0.5 and Ang 0.1-Na 1 groups and sodium urinary excretion decreased in the Ang 5-Na 0.5 and Ang 5-Na 1 groups. MAP increased in the Ang 5-Na 1 and Ang 5-Na 1.5 groups., Conclusion: We conclude that local renal Ang II levels were upregulated when acute sodium overload and nonhypertensive Ang II doses were administered simultaneously in normal rats, independently from blood pressure and glomerular function changes., (Copyright 2009 S. Karger AG, Basel.)

Angiotensin II (Ang II) promotes sodium-retention, cell growth and fibrosis in addition to its classical effects on blood pressure and fluid homeostasis. In this study we examined whether low and non-hypertensive doses of exogenous Ang II could enhance the intrarenal expression of transforming growth factor-beta1 (TGF-beta1) observed in rats submitted to sodium overload. Sprague-Dawley-rats were infused for 2 h with 0.1 and 5 microg kg(-1) h(-1) Ang II (Ang 0.1 and Ang 5, respectively) together with saline solution at four different concentrations (isotonic and Na 0.5 mol L(-1), Na 1.0 mol L(-1) and Na 1.5 mol L(-1)). Renal function and mean arterial blood pressure (BP) were measured. The renal distributions of TGF-beta1, alpha-smooth-muscle-actin (alpha-SMA) and nuclear factor-kappaB (NF-kappaB) were evaluated by immunohistochemistry. While the Ang 0.1 groups were normotensive, the Ang 5 groups developed arterial hypertension progressively, and the highest blood pressure values were observed when rats were simultaneously infused with Na 1.5 mol L(-1). Glomerular function was not altered in any group. In cortical tubules, all groups infused with Ang II (0.1 and 5) and hypertonic saline solution (HSS) showed an increase in TGF-beta1 immunostaining compared to those infused with HSS alone. In medullary tubules, only the Ang 5-Na 0.5 group showed a significant increase in TGF-beta 1 immunostaining compared to the Na 0.5 group. Peritubular positive staining for alpha-SMA was present in groups receiving Ang alone or Ang-Na, in a sodium concentration-dependent manner. In cortical-tubules, NF-kappaB immunostaining was significantly increased in the Ang groups in comparison with the control and in Ang-Na 0.5 and Ang-Na 1.0 groups in comparison with the Na 0.5 mol L(-1) and Na 1.5 mol L(-1) groups, respectively, except in the case of the Ang 0.1-Na 1.5 mol L(-1) and Ang 5-Na 1.5 mol L(-1) groups. Moreover, Ang II and sodium overload induced additional changes in TGF-beta1, alpha-SMA and NF-kappaB immunostanding in glomeruli, medullary tubules and renal vessels. In conclusion, the interaction of Ang II with acute-sodium overload exacerbated intrarenal TGF-beta1, alpha-SMA and NF-kappaB expression, independently from changes in blood pressure levels, in normal rats.

The aim of this study was to provide new insights into the role of angiotensin II and arterial pressure in the regulation of antioxidant enzyme activities in a renovascular model of cardiac hypertrophy. For this purpose, aortic coarcted rats were treated with losartan or minoxidil for 7 days. Angiotensin II induced cardiac hypertrophy and oxidative stress via Nox4, p22(phox) and p47(phox), which are components of the NAD(P)H oxidase. Antioxidant enzymes were regulated by arterial pressure and were not implicated in cardiac hypertrophy. Heme oxygenase-1, the rate-limiting enzyme in heme catabolism, behaved as a catalase and glutathione peroxidase, and is regulated by arterial pressure. In summary, the present report indicates that cardiac hypertrophy, induced by renovascular hypertension, depends on angiotensin II through reactive oxygen species and is not prevented by the action of antioxidant enzymes.