Chlorogenic Acid Intravesical Therapy Changes Acute Voiding Behavior of Systemic Lipopolysaccharide Inflammation-Induced Cystitis Bladder in Mice

This study explores the potential efficacy of chlorogenic acid (CGA) in mitigating lipopolysaccharide (LPS)-induced cystitis in a mice model. C57BL/6J mice were divided into four groups: normal control (NC), LPS, LPS + low CGA, and LPS + high CGA. Evaluation methods included cystometrogram (CMG), histopathological, western blot, and immunohistological analysis. In the LPS group, CMG revealed abnormal voiding behavior with increased micturition pressure, voided volume (VV), and decreased voided frequency. Low CGA treatment in LPS mice demonstrated improved micturition pressure and inter-contraction intervals (ICI). However, high CGA treatment exhibited prolonged ICI and increased VV, suggesting potential adverse effects. Histological analysis of LPS-treated mice displayed bladder inflammation and interstitial edema. Low CGA treatment reduced interstitial edema and bladder inflammation, confirmed by Masson's trichrome staining. Western blotting revealed increased cytokeratin 20 (K20) expression in the low CGA group, indicating structural abnormalities in the bladder umbrella layer after LPS administration. In conclusion, low CGA treatment positively impacted voiding behavior and decreased bladder edema and inflammation in the LPS-induced cystitis mice model, suggesting its potential as a supplement for inflammation cystitis prevention. However, high CGA treatment exhibited adverse effects, emphasizing the importance of dosage considerations in therapeutic applications.

Coffee Chlorogenic Acids Incorporation for Bioactivity Enhancement of Foods: A Review

The demand of foods with high antioxidant capacity have increased and research on these foods continues to grow. This review is focused on chlorogenic acids (CGAs) from green coffee, which is the most abundant source. The main CGA in coffee is 5-O-caffeoylquinic acid (5-CQA). Coffee extracts are currently the most widely used source to enhance the antioxidant activity of foods. Due to the solubility of CGAs, their extraction is mainly performed with organic solvents. CGAs have been associated with health benefits, such as antioxidant, antiviral, antibacterial, anticancer, and anti-inflammatory activity, and others that reduce the risk of cardiovascular diseases, type 2 diabetes, and Alzheimer's disease. However, the biological activities depend on the stability of CGAs, which are sensitive to pH, temperature, and light. The anti-inflammatory activity of 5-CQA is attributed to reducing the proinflammatory activity of cytokines. 5-CQA can negatively affect colon microbiota. An increase in anthocyanins and antioxidant activity was observed when CGAs extracts were added to different food matrices such as dairy products, coffee drinks, chocolate, and bakery products. The fortification of foods with coffee CGAs has the potential to improve the functionality of foods.

Endothelium-Independent Relaxation of Vascular Smooth Muscle Induced by Persimmon-Derived Polyphenol Phytocomplex in Rats

The vasorelaxant effect of polyphenols is well known, and the mortality rate due to coronary artery disease is low in people who consume polyphenol-containing foods. We aimed to elucidate the mechanism by which polyphenols derived from persimmon juice (PJ) and persimmon leaves (PLs) induce vasorelaxation and suppress vasocontraction in the superior mesenteric arteries isolated from male Sprague Dawley rats. Vasocontraction was induced with 1 µM phenylephrine, and polyphenol-induced vasorelaxation was expressed as a percentage of the previous tone induced by phenylephrine. PJ powder (100 mg/L) induced higher levels of vasorelaxation (mean ± standard error of the mean, 88.6% ± 4.4%) than PLs powder (1 g/L; 72.0% ± 10.8%). Nitric oxide pathway inhibitors (NG-nitro-L-arginine methyl ester + carboxy-PTIO) did not affect persimmon-derived polyphenol-induced vasorelaxation, whereas potassium chloride, tetraethylammonium, and potassium-channel inhibitors did. Vasorelaxation was endothelium independent with both extracts. Phenylephrine-induced vasocontraction was suppressed by pretreatment with PJ and PLs powder, even when inositol triphosphate-mediated Ca²⁺ release and extracellular Ca²⁺ influx were inhibited. These results suggest that persimmon-derived polyphenol phytocomplex cause vasorelaxation and inhibit vasocontraction through hyperpolarization of smooth muscle cells. Persimmon-derived polyphenols may be able to prevent cardiovascular diseases caused by abnormal contraction of blood vessels.

Plant polyphenols Morin and Quercetin rescue nitric oxide production in diabetic mouse aorta through distinct pathways

Diabetic vascular complications are associated with endothelial dysfunction. Various plant-derived polyphenols benefit cardiovascular function by protecting endothelial nitric oxide (NO) production through as yet unclear mechanisms. This study compared the effects of two structurally similar polyphenols, Morin (MO) and Quercetin (QU), on endothelial function in isolated aorta from control and streptozotocin (STZ)-induced diabetic mice. Vascular function under treatment with MO, QU, and various signaling pathway modulators was measured by isometric tension in an organ bath system, NO production by chemical assay and HPLC, and changes in protein signaling factor expression or activity by western blotting (WB). Both polyphenols acted as potent vasodilators and this effect was associated with increased phosphorylation of Akt and endothelial NO synthase (eNOS). An Akt inhibitor blocked MO- and QU-induced vasorelaxation as well as Akt phosphorylation. However, inhibitors of phosphoinositide 3-kinase (PI3K) and AMP-activated protein kinase (AMPK) suppressed only QU-induced vasorelaxation, NO production, and AMPK phosphorylation. These results suggested that plant polyphenols MO and QU both promote eNOS-mediated NO production and vasodilation in diabetic aorta, MO via Akt pathway activation and QU via PI3K/Akt and AMPK pathway activation. Elucidation of these pathways may define effective therapeutic targets for diabetic vascular dysfunction.

Heme oxygenase-1 contributes to the protective effect of resveratrol against endothelial dysfunction in STZ-induced diabetes in rats

Endothelial dysfunction is a common complication of diabetes that mainly stems from increased reactive oxygen species, which makes antioxidants of great benefit. Resveratrol (RSV) is an antioxidant that shows protective effects in a variety of disease models where the ameliorative effect appears to be mediated, in part, via heme oxygenase-1 (HO-1) induction. However, the pathophysiological relevance of HO-1 in the ameliorative response of RSV in endothelial dysfunction is not clearly defined. The present study was conducted to investigate whether HO-1 plays a role in diabetes-induced vascular dysfunction. Streptozotocin-diabetic rats were treated with RSV (10 mg/kg) in presence or absence of an HO-1 blocker, Zinc protoporphyrin (ZnPP) to assess vascular function and indicators of disease status. We found that RSV treatment significantly abrogated diabetes induced vascular dysfunction. This improvement was associated with the ability of RSV to decrease oxidative stress markers alongside a reduction in the aortic TGF-β expression, elevation of NOS3 expression and aortic nitrite concentration as well as HO activity. These ameliorative effects were diminished when ZnPP was administered prior to RSV. Our results clearly demonstrate the protective effects of RSV in diabetes-associated endothelial dysfunction and verified a causal role of HO-1 in this setting.

Morin induces endothelium-dependent relaxation by activating TRPV4 channels in rat mesenteric arteries

Morin, a natural flavonol, has been reported to have beneficial pharmacological effects. Although its vascular protective effects have been studied, little is known about its effects on the mesenteric artery and the underlying mechanisms. Transient receptor potential vanilloid type 4 (TRPV4) channels are one of the most important Ca²⁺-permeable cation channels in vascular endothelial cells and play an important role in regulating rat mesenteric vascular tone. In the present study, the myogenic effects of morin were investigated using wire and pressure myography in the isolated mesenteric artery. Morin induced endothelium-dependent relaxation of isolated rat mesenteric arteries in a concentration-dependent manner. In addition, morin stimulated relaxation by activating TRPV4-mediated Ca²⁺ influx without affecting the nitric oxide (NO), hydrogen peroxide (H₂O₂), cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) pathways. In primary cultured rat mesenteric artery endothelial cells and over-expressing TRPV4 HEK 293 cells, the TRPV4 inhibitor HC067047 significantly reduced the morin-induced increase in intracellular Ca²⁺ concentration. Furthermore, in rats with hypertension induced by N^Ꞷ-nitro-L-arginine methyl ester (L-NAME), oral administration of morin (50 mg/kg/day) decreased systolic blood pressure. In L-NAME-induced hypertensive rats, morin significantly improved the relaxation response of the arteries to acetylcholine. Thus, we demonstrated that morin induces endothelium-dependent relaxation in the rat mesenteric artery by acting on TRPV4 channels to mediate Ca²⁺ influx and attenuate blood pressure in L-NAME-induced hypertension, thereby highlighting the potential of morin in the treatment of hypertension.

Impairment of amyloid precursor protein alpha-processing in cerebral microvessels of type 1 diabetic mice

The mechanisms underlying dysfunction of cerebral microvasculature induced by type 1 diabetes (T1D) are not fully understood. We hypothesized that in cerebral microvascular endothelium, α-processing of amyloid precursor protein (APP) is impaired by T1D. In cerebral microvessels derived from streptozotocin (STZ)-induced T1D mice protein levels of APP and its α-processing enzyme, a disintegrin and metalloprotease 10 (ADAM10) were significantly decreased, along with down-regulation of adenylate cyclase 3 (AC3) and enhanced production of thromboxane A₂ (TXA₂). In vitro studies in human brain microvascular endothelial cells (BMECs) revealed that knockdown of AC3 significantly suppressed ADAM10 protein levels, and that activation of TXA₂ receptor decreased APP expression. Furthermore, levels of soluble APPα (sAPPα, a product of α-processing of APP) were significantly reduced in hippocampus of T1D mice. In contrast, amyloidogenic processing of APP was not affected by T1D in both cerebral microvessels and hippocampus. Most notably, studies in endothelial specific APP knockout mice established that genetic inactivation of APP in endothelium was sufficient to significantly reduce sAPPα levels in the hippocampus. In aggregate, our findings suggest that T1D impairs non-amyloidogenic processing of APP in cerebral microvessels. This may exert detrimental effect on local concentration of neuroprotective molecule, sAPPα, in the hippocampus.

Augmented contractility of murine femoral arteries in a streptozotocin diabetes model is related to increased phosphorylation of MYPT1

Diabetes mellitus (DM) is a metabolic disorder with high prevalence, and a major risk factor for macro- and microvascular abnormalities. This study was undertaken to explore the mechanisms of hypercontractility of murine femoral arteries (FA) obtained from mice with streptozotocin (STZ)-induced diabetes and its relation to the phosphorylation profile of the myosin phosphatase target subunit 1, MYPT1. The immunoreactivity of MYPT1 toward phospho-MYPT1-T696, MYPT1-T853, or MYPT1-S695, used as a read out for MYPT1 phosphorylation, has been studied by Western Blotting. Contractile activity of FA from control and STZ mice has been studied by wire myography. At basal conditions (no treatment), the immunoreactivity of MYPT1-T696/T853 was ~2-fold higher in the STZ arteries compared with controls. No changes in MYPT1-T696/853 phosphorylation were observed after stimulation with the Thromboxan-A2 analog, U46619. Neither basal nor U46619-stimulated phosphorylation of MYPT1 at S695 was affected by STZ treatment. Mechanical distensibility and basal tone of FA obtained from STZ animals were similar to controls. Maximal force after treatment of FA with the contractile agonists phenylephrine (10 μmol/L) or U46619 (1 μmol/L) was augmented in the arteries of STZ mice by ~2- and ~1.5-fold, respectively. In summary, our study suggests that development of a hypercontractile phenotype in murine FA in STZ diabetes is at least partially related to an increase in phosphorylation of MLCP at MYPT1-T696/853. Interestingly, the phosphorylation at S695 site was not altered in STZ-induced diabetes, supporting the view that S695 may serve as a sensor for mechanical activity which is not directly involved in tone regulation.

Consumption of Chlorogenic Acids through Coffee and Health Implications

Chlorogenic acids (CGA) are the main antioxidant compounds in the Western diet, due to their high concentrations in coffee associated with the high consumption of the beverage. Until about 10 years ago, like many other phenolic compounds, CGA were thought to be poorly absorbed in the human digestive system. Along the years, large amounts of information on the absorption and metabolism of these compounds have been unveiled, and today, it is known that, on average, about one third of the consumed CGA from coffee is absorbed in the human gastrointestinal tract, although large inter-individual variation exists. Considering results from in vitro animal and human studies, it is possible to conclude that the antioxidant and anti-inflammatory effects of coffee CGA are responsible for, at least to a certain extent, the association between coffee consumption and lower incidence of various degenerative and non-degenerative diseases, in addition to higher longevity.

Polyphenols protect against age-associated apoptosis in female rat cochleae

Dietary antioxidants, polyphenols, have been found to be beneficial in protecting against the generation of oxidative stress in various diseases associated with aging. Age-related hearing loss (AHL) is the number one neurodegenerative disorder on our aged population. Sprague-Dawley rats divided into five groups according to their age (3, 6, 12, 18 and 24 months old) and treated with 100 mg/day/kg body weight of polyphenols were used. Then, cochleae were harvested to measure caspase activities (- 3, - 8 and - 9), caspase-3 gene expression, ATP levels, Bax, BcL-2 and p53 levels. 8-OHdG levels (marker of DNA oxidative damage) and annexin-V were also measured in cochleae. Increased levels of caspase-3 and 9 in cochlea were observed with age and this effect was attenuated by polyphenol treatment. In addition, ATP and Bcl-2 levels in older rats were recovered after administration of polyphenols, while Bax and p53 levels protein decreased. Oral supplementation with polyphenols also reduces DNA oxidative damage of cochlear cell. Treatment with polyphenols inhibits the activation of age-related apoptotic signaling by decreasing oxidative stress inside the rat cochlea.

The potential effects of chlorogenic acid, the main phenolic components in coffee, on health: a comprehensive review of the literature

Chlorogenic acid (CGA), an important biologically active dietary polyphenol, is produced by certain plant species and is a major component of coffee. Reduction in the risk of a variety of diseases following CGA consumption has been mentioned in recent basic and clinical research studies. This systematic review discusses in vivo animal and human studies of the physiological and biochemical effects of chlorogenic acids (CGAs) on biomarkers of chronic disease. We searched PubMed, Embase, Amed and Scopus using the following search terms: ("chlorogenic acid" OR "green coffee bean extract") AND (human OR animal) (last performed on April 1st, 2015) for relevant literature on the in vivo effects of CGAs in animal and human models, including clinical trials on cardiovascular, metabolic, cancerogenic, neurological and other functions. After exclusion of editorials and letters, uncontrolled observations, duplicate and not relevant publications the remaining 94 studies have been reviewed. The biological properties of CGA in addition to its antioxidant and anti-inflammatory effects have recently been reported. It is postulated that CGA is able to exert pivotal roles on glucose and lipid metabolism regulation and on the related disorders, e.g. diabetes, cardiovascular disease (CVD), obesity, cancer, and hepatic steatosis. The wide range of potential health benefits of CGA, including its anti-diabetic, anti-carcinogenic, anti-inflammatory and anti-obesity impacts, may provide a non-pharmacological and non-invasive approach for treatment or prevention of some chronic diseases. In this study, the effects of CGAs on different aspects of health by reviewing the related literatures have been discussed.

Isometric Stretch Alters Vascular Reactivity of Mouse Aortic Segments

Most vaso-reactive studies in mouse aortic segments are performed in isometric conditions and at an optimal preload, which is the preload corresponding to a maximal contraction by non-receptor or receptor-mediated stimulation. In general, this optimal preload ranges from about 1.2 to 8.0 mN/mm, which according to Laplace's law roughly correlates with transmural pressures of 10-65 mmHg. For physiologic transmural pressures around 100 mmHg, preloads of 15.0 mN/mm should be implemented. The present study aimed to compare vascular reactivity of 2 mm mouse (C57Bl6) aortic segments preloaded at optimal (8.0 mN/mm) vs. (patho) physiological (10.0-32.5 mN/mm) preload. Voltage-dependent contractions of aortic segments, induced by increasing extracellular K⁺, and contractions by α₁-adrenergic stimulation with phenylephrine (PE) were studied at these preloads in the absence and presence of L-NAME to inhibit basal release of NO from endothelial cells (EC). In the absence of basal NO release and with higher than optimal preload, contractions evoked by depolarization or PE were attenuated, whereas in the presence of basal release of NO PE-, but not depolarization-induced contractions were preload-independent. Phasic contractions by PE, as measured in the absence of external Ca²⁺, were decreased at higher than optimal preload suggestive for a lower contractile SR Ca²⁺ content at physiological preload. Further, in the presence of external Ca²⁺, contractions by Ca²⁺ influx via voltage-dependent Ca²⁺ channels were preload-independent, whereas non-selective cation channel-mediated contractions were increased. The latter contractions were very sensitive to the basal release of NO, which itself seemed to be preload-independent. Relaxation by endogenous NO (acetylcholine) of aortic segments pre-contracted with PE was preload-independent, whereas relaxation by exogenous NO (diethylamine NONOate) displayed higher sensitivity at high preload. Results indicated that stretching aortic segments to higher than optimal preload depolarizes the SMC and causes Ca²⁺ unloading of the contractile SR, making them extremely sensitive to small changes in the basal release of NO from EC as can occur in hypertension or arterial stiffening.

Phytobioactive compound-based nanodelivery systems for the treatment of type 2 diabetes mellitus - current status

Type 2 diabetes mellitus (T2DM) is a major chronic disease that is prevalent worldwide, and it is characterized by an increase in blood glucose, disturbances in the metabolism, and alteration in insulin secretion. Nowadays, food-based therapy has become an important treatment mode for type 2 diabetes, and phytobioactive compounds have gained an increasing amount of attention to this end because they have an effect on multiple biological functions, including the sustained secretion of insulin and regeneration of pancreatic islets cells. However, the poor solubility and lower permeability of these phyto products results in a loss of bioactivity during processing and oral delivery, leading to a significant reduction in the bioavailability of phytobioactive compounds to treat T2DM. Recently, nanotechnological systems have been developed for use as various types of carrier systems to improve the delivery of bioactive compounds and thus obtain a greater bioavailability. Furthermore, carrier systems in most nanodelivery systems are highly biocompatible, with nonimmunologic behavior, a high degree of biodegradability, and greater mucoadhesive strength. Therefore, this review focuses on the various types of nanodelivery systems that can be used for phytobioactive compounds in treating T2DM with greater antidiabetic effects. There is also additional focus on improving the effects of various phytobioactive compounds through nanotechnological delivery to ensure a highly efficient treatment of type 2 diabetes.

A Comparative Study of Vasorelaxant Effects of ATP, ADP, and Adenosine on the Superior Mesenteric Artery of SHR

We investigated superior mesenteric arteries from spontaneously hypertensive rats (SHR) to determine the relaxation responses induced by ATP, ADP, and adenosine and the relationship between the relaxant effects of these compounds and nitric oxide (NO) or cyclooxygenase (COX)-derived prostanoids. In rat superior mesenteric artery, relaxation induced by ATP and ADP but not by adenosine was completely eliminated by endothelial denudation. In the superior mesenteric arteries isolated from SHR [vs. age-matched control Wistar Kyoto rats (WKY)], a) ATP- and ADP-induced relaxations were weaker, whereas adenosine-induced relaxation was similar in both groups, b) ATP- and ADP-induced relaxations were substantially and partly reduced by N(G)-nitro-L-arginine [a NO synthase (NOS) inhibitor], respectively, c) indomethacin, an inhibitor of COX, increased ATP- and ADP-induced relaxations, d) ADP-induced relaxation was weaker under combined inhibition by NOS and COX, and e) adenosine-induced relaxation was not altered by treatment with these inhibitors. These data indicate that levels of responsiveness to these nucleotides/adenosine vary in the superior mesenteric arteries from SHR and WKY and are differentially modulated by NO and COX-derived prostanoids.

Effect of Long-Term Diabetes on Serotonin-Mediated Contraction in Carotid Arteries from Streptozotocin-Induced Diabetic Male and Female Rats

An accumulating body of evidence suggests that males and females differ in vascular function in arteries under pathophysiological states. In this study, we tested whether there was a sex difference associated with serotonin (5-hydroxytryptamine, 5-HT)-mediated contraction in the carotid arteries of long-term streptozotocin (STZ)-induced diabetic rats [viz. 23 or 24 weeks after STZ (65 mg/kg, intravenously (i.v.)) injection starting at 8 weeks old of rats]. In the control group, the 5-HT- and high-K⁺-induced contractions were greater in females than in males. In both sexes, treatment with STZ led to a decrease of 5-HT-induced contraction in carotid arteries compared to controls. In STZ-induced diabetic rats, the carotid arterial 5-HT-induced contraction was greater in female rats than in diabetic male rats. The high-K⁺-induced contraction was greater in diabetic female rats than in either age-matched female controls or diabetic male rats. Expression of the 5-HT_2A receptor, which is the main receptor for 5-HT-induced contraction in rat carotid arteries, was similar among the four groups. These results suggest that decreased 5-HT-induced carotid arterial contraction is seen in both sexes under long-term STZ-induced diabetic conditions. Further, this reduction seems to be weaker in females than in males. This alteration of 5-HT-induced contraction may be partly associated with increased voltage-dependent Ca²⁺ channel activity.

Sea fennel (Crithmum maritimum L.): phytochemical profile, antioxidative, cholinesterase inhibitory and vasodilatory activity

Sea fennel, a rediscovered star of the coastal cuisine, has been investigated for its phytochemical profile and biological potential. Sea fennel flowers, stems and leaves were analyzed for essential oils (EOs) isolated by hydrodistillation, as well as non-volatiles obtained by ethanolic extraction. Limonene were found to be a dominant compound in EOs and ethanolic extracts; ranging from 57.5-74.2 % and 0.7-8.1 mg/g dry plant material, respectively. In addition total phenolic content was determined for ethanolic extracts. All samples and their main phytochemicals were tested for various methods. EO and extract obtained from flowers were tested for vasodilatory activity on rat aortic rings. Antioxidant activity of EOs was extremely low in comparison to extracts, on the contrary to cholinesterase inhibition where EOs showed better activity than extracts. Flower extract and chlorogenic acid showed stronger vasodilators in comparison to EO and limonene. The obtained results point out the potential impact of the dominant compounds from EO and extract on the biological properties of the sea fennel.

Effects of the Nrf2 Protein Modulator Salvianolic Acid A Alone or Combined with Metformin on Diabetes-associated Macrovascular and Renal Injury

Nuclear factor E2-related factor 2 (Nrf2) is considered a promising target against diabetic complications such as cardiovascular diseases and diabetic nephropathy. Herein, we investigated the effects of a potential Nrf2 modulator, salvianolic acid A (SAA), which is a natural polyphenol, on diabetes-associated macrovascular and renal injuries in streptozotocin-induced diabetic mice. Given that lowering glucose is the first objective of diabetic patients, we also examined the effects of SAA combined with metformin (MET) on both complications. Our results showed that SAA significantly increased the macrovascular relaxation response to acetylcholine and sodium nitroprusside in diabetic mice. Interestingly, treatment with SAA alone only provided minor protection against renal injury, as reflected by minor improvements in impaired renal function and structure, despite significantly reduced oxidative stress observed in the diabetic kidney. We demonstrated that decreased oxidative stress and NF-κB p65 expression were associated with SAA-induced expression of Nrf2-responsive antioxidant enzymes heme oxygenase-1 (HO-1), NAD(P)H dehydrogenase (quinone) 1 (NQO-1), and glutathione peroxidase-1 (GPx-1) in vivo or in vitro, which suggested that SAA was a potential Nrf2 modulator. More significantly, compared with treatment with either SAA or MET alone, we found that their combination provided further protection against the macrovascular and renal injury, which was at least partly due to therapeutic activation of both MET-mediated AMP-activated protein kinase and SAA-mediated Nrf2/antioxidant-response element pathways. These findings suggested that polyphenol Nrf2 modulators, especially combined with drugs activating AMP-activated protein kinase, including hypoglycemic drugs, are worthy of further investigation to combat diabetic complications.

Chronic in vivo or acute in vitro resveratrol attenuates endothelium-dependent cyclooxygenase-mediated contractile signaling in hypertensive rat carotid artery

Exaggerated cyclooxygenase (COX) and thromboxane-prostanoid (TP) receptor-mediated endothelium-dependent contraction can contribute to endothelial dysfunction. This study examined the effect of resveratrol (RSV) on endothelium-dependent contraction and cell signaling in the common carotid artery (CCA) from spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY). Acetylcholine (Ach)-stimulated endothelium-dependent nitric oxide synthase (NOS)-mediated relaxation in precontracted SHR CCA was impaired (maximum 73 ± 6% vs. 87 ± 5% in WKY) (P < 0.05) by competitive COX-mediated contraction. Chronic (28-day) treatment in vivo (drinking water) with a ∼0.075 mg·kg(-1)·day(-1) RSV dose affected neither endothelium-dependent relaxation nor endothelium-dependent contraction and associated prostaglandin (PG) production evaluated in non-precontracted NOS-blocked CCA. In contrast, a chronic ∼7.5 mg·kg(-1)·day(-1) RSV dose improved endothelium-dependent relaxation (94 ± 6%) and attenuated endothelium-dependent contraction (58 ± 4% vs. 73 ± 5% in No-RSV) and PG production (183 ± 43 vs. 519 ± 93 pg/ml) in SHR CCA, while U46619-stimulated TP receptor-mediated contraction was unaffected. In separate acute in vitro experiments, 20-μM RSV preincubation attenuated endothelium-dependent contraction (6 ± 4% vs. 62 ± 2% in No Drug) and PG production (121 ± 15 vs. 491 ± 93 pg/ml) and attenuated U46619-stimulated contraction (134 ± 5% vs. 171 ± 4%) in non-precontracted NOS-blocked SHR CCA. Compound C, a known AMP-activated protein kinase (AMPK) inhibitor, did not prevent the RSV attenuating effect on Ach- and U46619-stimulated contraction but did prevent the RSV attenuating effect on PG production (414 ± 58 pg/ml). These data demonstrate that RSV can attenuate endothelium-dependent contraction both by suppressing arterial wall PG production, which may be partially mediated by AMPK, and by TP receptor hyporesponsiveness, which does not appear to be mediated by AMPK.

Constrictor prostanoids and uridine adenosine tetraphosphate: vascular mediators and therapeutic targets in hypertension and diabetes

Vascular dysfunction plays a pivotal role in the development of systemic complications associated with arterial hypertension and diabetes. The endothelium, or more specifically, various factors derived from endothelial cells tightly regulate vascular function, including vascular tone. In physiological conditions, there is a balance between endothelium-derived factors, that is, relaxing factors (endothelium-derived relaxing factors; EDRFs) and contracting factors (endothelium-derived contracting factors; EDCFs), which mediate vascular homeostasis. However, in disease states, such as diabetes and arterial hypertension, there is an imbalance between EDRF and EDCF, with a reduction of EDRF signalling and an increase of EDCF signalling. Among EDCFs, COX-derived vasoconstrictor prostanoids play an important role in the development of vascular dysfunction associated with hypertension and diabetes. Moreover, uridine adenosine tetraphosphate (Up4 A), identified as an EDCF in 2005, also modulates vascular function. However, the role of Up4 A in hypertension- and diabetes-associated vascular dysfunction is unclear. In the present review, we focused on experimental and clinical evidence that implicate these two EDCFs (vasoconstrictor prostanoids and Up4 A) in vascular dysfunction associated with hypertension and diabetes.

Effect of postnatal nutrition restriction on the oxidative status of neonates with intrauterine growth restriction in a pig model

OBJECTIVE

In offspring with intrauterine growth restriction (IUGR), where oxidative stress may play an important role in inducing metabolic syndrome, nutrition restriction has been shown to improve oxidative status. In this study, we aimed to investigate the effect of postnatal nutrition restriction on the oxidative status of IUGR neonates.

METHODS

A total of twelve pairs of piglets, of normal birth-weight (NBW) and with IUGR (7 days old), respectively, were randomly allocated to have adequate nutritional intake (ANI) and restricted nutritional intake (RNI) for a period of 21 days, respectively. This design produced 4 experimental groups: NBW-ANI, IUGR-ANI, NBW-RNI and IUGR-RNI (n = 6 per group). Serum, ileum and liver samples were analyzed for antioxidant parameters and the mRNA expression of genes with regard to oxidative status. The data were subjected to general linear model analysis and Duncan's test with a 5% significance level.

RESULTS

Irrespective of nutritional intake, the IUGR pigs had markedly lower activity of glutathione peroxidase (GPX), gene expressions of liver mitochondrial manganese superoxide dismutase (Mn-SOD) and ileum cytoplasmic copper/zinc (CuZn)-SOD and, accordingly, there was a markedly higher malondialdehyde concentration in the liver of these pigs compared to in the NBW pigs. Irrespective of body weight, pigs receiving ANI treatment had significantly lower activities of antioxidant enzymes in the serum (total antioxidative capability, CuZn-SOD and GPX) and liver (total SOD and glutathione reductase) and decreased gene expression of liver CuZn-SOD and Mn-SOD compared to the pigs receiving RNI. In addition, the IUGR pigs had a markedly lower concentration of liver reduced glutathione (GSH), ratio of GSH to oxidized glutathione, gene expression of ileum CuZn-SOD and extracellular SOD than the NBW pigs when receiving ANI, but not all of these differences were observed in those receiving RNI.

CONCLUSION

IUGR neonates may have poor antioxidant defense systems, and postnatal nutrition restriction has the potential to prevent oxidative stress.