Development and Evaluation of Virola oleifera Formulation for Cutaneous Wound Healing.

In regions adjacent to the Brazilian Atlantic Forest, Virola oleifera (VO) resin extract has been popularly used for decades as a skin and mucosal healing agent. However, this antioxidant-rich resin has not yet been investigated in wound healing, whose physiological process might also be aggravated by oxidative stress-related diseases (e.g., hypertension/diabetes). Our aim, therefore, was to investigate whether VO resin presents healing effects through an innovative cream for topical applications. For this, adult male Wistar rats were divided into four groups. Then, four 15 mm excisions were performed on the shaved skin. All treatments were applied topically to the wound area daily. At the end of experiments (0, 3rd, and 10th days) macroscopic analysis of wound tissue contraction and histological analysis of inflammatory cell parameters were performed. The group treated with VO cream showed the best wound contraction (15%, p < 0.05) and reduced levels of lipid peroxidation and protein oxidation (118% and 110%, p < 0.05, respectively) compared to the control group. Our results demonstrated the healing capacity of a new formulation prepared with VO, which could be, at least in part, justified by antioxidant mechanisms that contribute to re-epithelialization, becoming a promising dermo-cosmetic for the treatment of wound healing.

The Gut Microbiota-Brain Axis: A New Frontier on Neuropsychiatric Disorders.

Alzheimer's disease (AD) is a progressive and incurable neurodegenerative disorder of integrative areas of the brain, characterized by cognitive decline and disability resulting in negative impacts on the family of the patients and the health care services worldwide. AD involves oxidative stress, neuroinflammation and accelerated apoptosis, accompanied by deposition of amyloid-ß peptide plaques and tau protein-based neurofibrillary tangles in the central nervous system. Among the multiple factors that contribute to the onset and evolution of this disease, aging stands out. That is why the prevalence of this disease has increased due to the constant increase in life expectancy. In the hope of finding new, more effective methods to slow the progression of this disease, over the last two decades, researchers have promoted "omics"-based approaches that include the gut microbiota and their reciprocal interactions with different targets in the body. This scientific advance has also led to a better understanding of brain compartments and the mechanisms that affect the integrity of the blood-brain barrier. This review aims to discuss recent advances related to the gut-brain-microbiota axis in AD. Furthermore, considering that AD involves psychiatric symptoms, this review also focuses on the psychiatric factors that interact with this axis (an issue that has not yet been sufficiently addressed in the literature).

Optimal Parameters of Laser Therapy to Improve Critical Calvarial Defects.

Body bones play diverse pivotal roles, including the protection of vital organs. For instance, the integrative functions of the brain controlling diverse peripheral actions can be affected by a traumatic injury on the calvaria and the reparative process of a large defect is a challenge in the integrative physiology. Therefore, the development of biomaterials and approaches to improve such defects still requires substantial advances. In this regard, the most attractive approaches have been covering the cavity with inorganic bovine bone (IBB) and, more recently, also using low-level laser therapy (LT), but this issue has opened many questions. Here, it was determined the number of LT sessions required to speed up and to intensify the recovery process of two 5-mm-diameter defects promoted in the calvaria of each subgroup of six adult Wistar rats. The quantitative data showed that 30 days post-surgery, the recovery process by using blood clot-filling was not significantly influenced by the number of LT sessions. However, in the IBB-filled defects, the number of LT sessions markedly contributed to the improvement of the reparative process. Compared to the Control group (non-irradiated), the percentage of mineralization (formation of new bone into the cavities) gradually increased 25, 49, and 52% with, respectively, 4, 7, and 11 sessions of LT. In summary, combining the use of IBB with seven sessions of LT seems to be an optimal approach to greatly improve the recovery of calvarial defects. This translational research opens new avenues targeting better conditions of life for those suffering from large bone traumas and in the present field could contribute to preserve the integrative functions of the brain.

Benefits of multi-day supplementation with probiotic kefir in Rasmussen encephalitis: the first case report.

INTRODUCTION: Rasmussen encephalitis (RE) is a rare inflammatory disease, characterized by unilateral hemispheric atrophy, focal intractable seizures, progressive hemiparesis, and neurological deficits. CASE REPORT: The patient is a young man under pharmacotherapy for epilepsy, exhibiting classical abnormal movements, which are consider typical hallmarks of RE. During clinical care sessions, he presented many episodes of tonic-clonic seizures involving sudden loss of consciousness followed by a post-ictal phase with weakness and interaction difficulty. During the kefir supplementation, the patient presented only short-term absence seizures, quickly returning to activities. Additionally, he presented cognitive and language improvement, being more responsive to commands. The daily diary control of patient's mother and caregiver at school reported an impressive reduction in number and severity of seizures, becoming less aggressive and more involved in school activities. The serum biochemical markers showed that kefir administration caused a significant decrease of pro-inflammatory and a simultaneous increase of anti-inflammatory cytokine levels. In parallel, after treatment, this probiotic reduced reactive oxygen species levels, increased NO bioavailability, revealing antiapoptotic and antigenotoxic effects. Regarding the microbiological analysis, kefir increased Lactobacillus and Bifidobacterium species. CONCLUSION: To our knowledge, this is the first case reporting remarkable beneficial effects of the probiotic kefir in RE. This case report strongly suggests kefir supplementation as a potential and safe-effective adjuvant therapeutic strategy in the control and treatment of RE.

Extreme blood lactate rising after very short efforts in top-level track and field male sprinters.

Two top-level (10"04 and 10"13 in 100-m dash) and 2 sub-elite (10"97 and 11"44 in 100-m dash) male sprinters completed, after a standardised warm-up, various jump, sprint and weightlifting exercises in two consecutive days at the start of pre-season. Before and 30 s after the tests, the [La-] were measured with a portable lactate analyser. The top-level sprinters exhibited much larger [La-] than the sub-elite sprinters (< 5 mmol·L-1) after all the exercise tests. The maximum values recorded were 20.4 mmol·L-1 after the 20-m sprint tests for Athlete 1, and 22.4 mmol·L-1 after CMJ testing for Athlete 2. The greater Δ% were recorded after CMJ testing for Athlete 1 (from 1.9 to 13.6 mmol·L-1), and after the power clean test for Athlete 2 (from 1.4 to 17.6 mmol·L-1). These results suggest a different metabolic response to very short efforts (≤3 s) in top-level track and field sprinters. These findings reinforce the need to include lactate assessments, during training and evaluation sessions, to better understand the acute and chronic adaptations to training of sprinters of different levels.

The Emerging Scenario of the Gut-Brain Axis: The Therapeutic Actions of the New Actor Kefir against Neurodegenerative Diseases.

The fact that millions of people worldwide suffer from Alzheimer's disease (AD) or Parkinson's disease (PD), the two most prevalent neurodegenerative diseases (NDs), has been a permanent challenge to science. New tools were developed over the past two decades and were immediately incorporated into routines in many laboratories, but the most valuable scientific contribution was the "waking up" of the gut microbiota. Disturbances in the gut microbiota, such as an imbalance in the beneficial/pathogenic effects and a decrease in diversity, can result in the passage of undesired chemicals and cells to the systemic circulation. Recently, the potential effect of probiotics on restoring/preserving the microbiota was also evaluated regarding important metabolite and vitamin production, pathogen exclusion, immune system maturation, and intestinal mucosal barrier integrity. Therefore, the focus of the present review is to discuss the available data and conclude what has been accomplished over the past two decades. This perspective fosters program development of the next steps that are necessary to obtain confirmation through clinical trials on the magnitude of the effects of kefir in large samples.

An Update to Calcium Binding Proteins.

Ca2+ binding proteins (CBP) are of key importance for calcium to play its role as a pivotal second messenger. CBP bind Ca2+ in specific domains, contributing to the regulation of its concentration at the cytosol and intracellular stores. They also participate in numerous cellular functions by acting as Ca2+ transporters across cell membranes or as Ca2+-modulated sensors, i.e. decoding Ca2+ signals. Since CBP are integral to normal physiological processes, possible roles for them in a variety of diseases has attracted growing interest in recent years. In addition, research on CBP has been reinforced with advances in the structural characterization of new CBP family members. In this chapter we have updated a previous review on CBP, covering in more depth potential participation in physiopathological processes and candidacy for pharmacological targets in many diseases. We review intracellular CBP that contain the structural EF-hand domain: parvalbumin, calmodulin, S100 proteins, calcineurin and neuronal Ca2+ sensor proteins (NCS). We also address intracellular CBP lacking the EF-hand domain: annexins, CBP within intracellular Ca2+ stores (paying special attention to calreticulin and calsequestrin), proteins that contain a C2 domain (such as protein kinase C (PKC) or synaptotagmin) and other proteins of interest, such as regucalcin or proprotein convertase subtisilin kexins (PCSK). Finally, we summarise the latest findings on extracellular CBP, classified according to their Ca2+ binding structures: (i) EF-hand domains; (ii) EGF-like domains; (iii) ɣ-carboxyl glutamic acid (GLA)-rich domains; (iv) cadherin domains; (v) Ca2+-dependent (C)-type lectin-like domains; (vi) Ca2+-binding pockets of family C G-protein-coupled receptors.

Sildenafil reduces aortic endothelial dysfunction and structural damage in spontaneously hypertensive rats: Role of NO, NADPH and COX-1 pathways.

Arterial hypertension is a condition associated with endothelial dysfunction, accompanied by an imbalance in the production of reactive oxygen species (ROS) and NO. The aim of this study was to investigate and elucidate the possible mechanisms of sildenafil, a selective phosphodiesterase-5 inhibitor, actions on endothelial function in aortas from spontaneously hypertensive rats (SHR). SHR treated with sildenafil (40 mg/kg/day, p.o., 3 weeks) were compared to untreated SHR and Wistar-Kyoto (WKY) rats. Systolic blood pressure (SBP) was measured by tail-cuff plethysmography and vascular reactivity was determined in isolated rat aortic rings. Circulating endothelial progenitor cells and systemic ROS were measured by flow cytometry. Plasmatic total antioxidant capacity, NO production and aorta lipid peroxidation were determined by spectrophotometry. Scanning electron microscopy was used for structural analysis of the endothelial surface. Sildenafil reduced high SBP and partially restored the vasodilator response to acetylcholine and sodium nitroprusside in SHR aortic rings. Using selective inhibitors, our experiments revealed an augmented participation of NO, with a simultaneous decrease of oxidative stress and of cyclooxygenase-1 (COX-1)-derived prostanoids contribution in the endothelium-dependent vasodilation in sildenafil-treated SHR compared to non-treated SHR. Also, the relaxant responses to sildenafil and 8-Br-cGMP were normalized in sildenafil-treated SHR and sildenafil restored the pro-oxidant/antioxidant balance and the endothelial architecture. In conclusion, sildenafil reverses endothelial dysfunction in SHR by improving vascular relaxation to acetylcholine with increased NO bioavailability, reducing the oxidative stress and COX-1 prostanoids, and improving cGMP/PKG signaling. Also, sildenafil reduces structural endothelial damage. Thus, sildenafil is a promising novel pharmacologic strategy to treat endothelial dysfunction in hypertensive states reinforcing its potential role as adjuvant in the pharmacotherapy of cardiovascular diseases.

Probiotics as Beneficial Dietary Supplements to Prevent and Treat Cardiovascular Diseases: Uncovering Their Impact on Oxidative Stress.

The gut microbiota, the ecosystem formed by a wide symbiotic community of nonpathogenic microorganisms that are present in the distal part of the human gut, plays a prominent role in the normal physiology of the organism. The gut microbiota's imbalance, gut dysbiosis, is directly related to the origin of various processes of acute or chronic dysfunction in the host. Therefore, the ability to intervene in the gut microbiota is now emerging as a possible tactic for therapeutic intervention in various diseases. From this perspective, evidence is growing that a functional dietary intervention with probiotics, which maintain or restore beneficial bacteria of the digestive tract, represents a promising therapeutic strategy for interventions in cardiovascular diseases and also reduces the risk of their occurrence. In the present work, we review the importance of maintaining the balance of the intestinal microbiota to prevent or combat such processes as arterial hypertension or endothelial dysfunction, which underlie many cardiovascular disorders. We also review how the consumption of probiotics can improve autonomic control of cardiovascular function and provide beneficial effects in patients with heart failure. Among the known effects of probiotics is their ability to decrease the generation of reactive oxygen species and, therefore, reduce oxidative stress. Therefore, in this review, we specifically focus on this antioxidant capacity and its relationship with the beneficial cardiovascular effects described for probiotics.

Beneficial Morphofunctional Changes Promoted by Sildenafil in Resistance Vessels in the Angiotensin II-Induced Hypertension Model.

BACKGROUND: By acting on multiple targets and promoting diverse actions, angiotensin II (Ang II) plays a pivotal role in vascular function. Recent studies suggested that phosphodiesterase-5 (PDE-5) inhibitors exhibit therapeutic effects in cardiovascular diseases. Here, the effects of sildenafil on vascular disturbances were analyzed in a mouse model of Ang II-induced hypertension. METHODS AND RESULTS: Male C57BL/6 mice were used as untreated animals (control) or infused with Ang II (1000 ηg/kg/min) for 28 days and treated with sildenafil (40 mg/kg/min) or vehicle (Ang II) during the last two weeks. After 4 weeks, the Ang II animals exhibited a high systolic blood pressure (186±3 mmHg vs. 127±3 mmHg for control mice), which was attenuated by sildenafil (163±7 mmHg). The mesenteric vessels from the Ang II animals revealed damage to the endothelial layer, an increase in the cross-section area (1.9-fold) and vascular cell production of peroxynitrite (512±13 a.u.), which was ameliorated in the Ang II-Sil group (1.2-fold and 400±17 a.u.). Analysis of the vascular responsiveness showed an increased contractility response to norepinephrine in Ang II animals (Rmax: 70%), which was abolished by sildenafil through increased nitric oxide (NO) bioavailability and decreased reactive oxygen species (ROS) and vasoconstrictor prostanoids. CONCLUSION: Sildenafil attenuates the morphofunctional deleterious effects of Ang II on resistance vessels. The benefits of sildenafil seem to occur through restoring the balance of ROS/NO/eicosanoids. Therefore, this study opened new avenues for further clinical targeting of the treatment of cardiovascular diseases related to activation of the renin-angiotensin system.

Sildenafil (Viagra®) Prevents Cox-1/ TXA2 Pathway-Mediated Vascular Hypercontractility in ApoE-/- Mice.

BACKGROUND/AIMS: The atherosclerotic apolipoprotein E-deficient (apoE-/-) mouse exhibits impaired vasodilation and enhanced vasoconstriction responsiveness. The objectives of this study were: a) to determine the relative contribution of cyclooxygenases (Cox-1 and Cox-2), thromboxane A2 (TXA2) and endothelin-1 (ET-1) to enhancing vascular hyperresponsiveness in this model of atherosclerosis and b) to investigate the beneficial effects of the phosphodiesterase 5 inhibitor sildenafil on this endothelial dysfunction. METHODS: Adult male apoE-/- mice were treated with sildenafil (40 mg/kg/day, for 3 weeks) and compared with non-treated ApoE-/- and wild-type mice. The beneficial effects of sildenafil on vascular contractile response to phenylephrine (PE) in aortic rings were evaluated before and after incubation with Cox-1 (SC-560) or Cox-2 (NS-398) inhibitors or the TP antagonist SQ-29548, and on contractile responsiveness to ET-1. RESULTS: ApoE-/- mice exhibited enhanced vasoconstriction to PE (Rmax ∼35%, p<0.01), which was prevented by treatment with sildenafil. The enhanced PE-induced contractions were abolished by both Cox-1 inhibition and TP antagonist, but were not modified by Cox-2 inhibition. Aortic rings from ApoE-/- mice also exhibited enhanced contractions to ET-1 (Rmax ∼30%, p<0.01), which were attenuated in sildenafil-treated ApoE-/- mice. In addition, we observed augmented levels of vascular proinflammatory cytokines in ApoE-/- mice, which were partially corrected by treatment with sildenafil (IL-6, IL-10/IL-6 ratio and MCP-1). CONCLUSION: The present data show that the Cox-1/TXA2 pathway prevails over the Cox-2 isoform in the mediation of vascular hypercontractility observed in apoE-/-mice. The results also show a beneficial effect of sildenafil on this endothelial dysfunction and on the proinflammatory cytokines in atherosclerotic animals, opening new perspectives for the treatment of other endothelium-related cardiovascular abnormalities.

Ultrasound-assisted extraction of Achyrocline satureioides prevents contrast-induced nephropathy in mice.

Achyrocline satureioides or Macela, has been largely used in traditional folk medicine in Brazil as an anti-inflammatory agent and to treat various digestive disorders. The aim of the present study was to evaluate the preventive action of the extracts of A. satureioides obtained by maceration and ultrasound-assisted extraction, quercetin and N-acetylcysteine against contrast-induced nephropathy in mice. The antioxidant activity, cytotoxicity and inhibition of nitric oxide (NO) production in macrophages were evaluated. Also, chemical analyses of phenolic compounds, total flavonoids, and quercetin by LC-MS/MS present in various extracts of A. satureioides were performed. Thirty six mice were divided into six groups: control group (C), Contrast-Induced Nephropathy group (CIN), Group N-acetylcysteine 200mg/kg (NAC); Group quercetin 10mg/kg (Q), Group Macela 10mg/kg (M10), and Group Macela 50mg/kg (M50). The serum levels of urea and creatinine, advanced oxidation protein products (AOPP) and renal ultrastructure were evaluated by electron microscopy scanning. Ultrasound-assisted extraction improved the quality of extract (with 100% ethanol), since did not show toxicity to fibroblasts, and showed potent antioxidant activity and a high content of phenolic compounds, flavonoids, and quercetin, in addition to being able to reduce the production of NO in dose-dependent effect in macrophages. Results showed that animals treated with Macela extracts maintained normal levels of urea, creatinine, and AOPP, while preserving ultrastructure of the renal cells. The obtained results were more promising than NAC and Q groups in protecting against renal failure caused by CIN, showing that the plant can be a promising drug for preventing this disease.

Chronic administration of the soluble, nonbacterial fraction of kefir attenuates lipid deposition in LDLr-/- mice.

OBJECTIVES: Kefir is obtained by the action of acidic bacteria and yeasts that exist in symbiotic association in kefir grains. Recently, this fermented milk drink has been recommended for the treatment of several clinical conditions, such as inflammatory, gastrointestinal, or cardiovascular-related diseases, or a combination of these diseases. However, its effects on atherosclerosis are not yet clear. The aim of this study was to prove that chronic treatment with a soluble, nonbacterial fraction of kefir could reduce the progression of atherosclerosis in low-density lipoprotein receptor-deficient (LDLr-/-) mice. METHODS: LDLr-/- mice were divided into four groups as follows: RESULTS: The soluble, nonbacterial fraction of kefir reduced lipid deposition (P < 0.05) independent of hypercholesterolemia. Moreover, kefir was capable of diminishing the circulating proinflammatory intereukin (IL)-6 level and the ratio of tumor necrosis factor-α to IL-10 (50% and 42%, P < 0.05, respectively) and augmenting the antiinflammatory IL-10 level by approximately 74% (P < 0.05). CONCLUSIONS: Chronic treatment with a soluble nonbacterial fraction of kefir was able to decrease the lipid deposition in LDLr-/- hypercholesteremic mice, at least in part through modifying the circulating cytokine profile. The beneficial effects of kefir provide new perspectives for its use as an adjuvant in the prevention of atherosclerosis.

Effects of Kefir on the Cardiac Autonomic Tones and Baroreflex Sensitivity in Spontaneously Hypertensive Rats.

AIMS: It has been previously shown that the probiotic kefir (a symbiotic matrix containing acid bacteria and yeasts) attenuated the hypertension and the endothelial dysfunction in spontaneously hypertensive rats (SHR). In the present study, the effect of chronic administration of kefir on the cardiac autonomic control of heart rate (HR) and baroreflex sensitivity (BRS) in SHR was evaluated. METHODS: SHR were treated with kefir (0.3 mL/100 g body weight) for 60 days and compared with non-treated SHR and with normotensive Wistar-Kyoto rats. Cardiac autonomic vagal (VT) and sympathetic (ST) tones were estimated through the blockade of the cardiac muscarinic receptors (methylatropine) and the blockade of ß1-adrenoceptor (atenolol). The BRS was evaluated by the tachycardia and bradycardia responses to vasoactive drug-induced decreases and increases in arterial blood pressure (BP), respectively. Additionally, spontaneous BRS was estimated by autoregressive spectral analysis. RESULTS: Kefir-treated SHR exhibited significant attenuation of basal BP, HR, and cardiac hypertrophy compared to non-treated SHR (12, 13, and 21%, respectively). Cardiac VT and ST were significantly altered in the SHR (~40 and ~90 bpm) compared with Wistar rats (~120 and ~30 bpm) and were partially recovered in SHR-kefir (~90 and ~25 bpm). SHR exhibited an impaired bradycardic BRS (~50%) compared with Wistar rats, which was reduced to ~40% in the kefir-treated SHR and abolished by methylatropine in all groups. SHR also exhibited a significant impairment of the tachycardic BRS (~23%) compared with Wistar rats and this difference was reduced to 8% in the SHR-kefir. Under the action of atenolol the residual reflex tachycardia was smaller in SHR than in Wistar rats and kefir attenuated this abnormality. Spectral analysis revealed increased low frequency components of BP (~3.5-fold) and pulse interval (~2-fold) compared with Wistar rats and these differences were reduced by kefir-treatment to ~1.6- and ~1.5-fold, respectively. Spectral analysis also showed an impairment of spontaneous BRS in SHR, but kefir-treatment caused only a tendency to reverse this result. CONCLUSIONS: The novelty of this study is that daily chronic consumption of a low dose of kefir reduced the impairment of the cardiac autonomic control of HR and of the impaired BRS in SHR.

Predictive value of cystatin C for the identification of illness severity in adult patients in a mixed intensive care unit.

OBJECTIVES: This study compared serum cystatin C (CysC) with conventional biomarkers of renal function in terms of their ability to predict illness severity in patients in a mixed intensive care unit (ICU). The present study also tested the hypothesis that increased CysC could predict illness severity in different clinical conditions in adult patients admitted to the ICU. DESIGN AND METHODS: The performance of serum creatinine, urea and CysC, as well as the Glomerular Filtration Rate (GFR) estimates (Cockcroft-Gault/MDRD/Larsson and CKD-EPI Equations) in predicting illness severity was compared in 60 critically ill patients. Adult patients admitted to the hospital were screened for eligibility in this prospective and observational study. The mean patient age was 52±19years. The average APACHE II score was 9.5±6 for the entire sample. The patients were assigned to two different degrees of severity, and the internally derived cut off value was an APACHE II score<10 or ≥10. RESULTS: Both serum CysC and urea showed significant correlations with APACHE II, even after controlling for age. Urea and CysC levels, as well as the GFR estimated by the method of Larsson and Cockcroft-Gault, remained significantly increased in patients in the APACHEII ≥10 group. The ROC curve analyses indicated that both urea and CysC levels have high sensitivity and specificity in the prediction of illness severity using the APACHE II as a gold standard prognostic stratification system. Furthermore, CysC was more accurate than the Larsson, CKD-EPI CysC, CKD-EPI Cr-CysC, Cockcroft-Gault and CKD-EPI Cr CFR estimation methods compared with the MDRD method. Additionally, CysC was a good predictor in both young and old patients, whereas urea was not predictive of illness severity. CONCLUSIONS: Our findings suggest that CysC and GFR estimates (Larsson or CKD-EPI CysC methods) are good predictors of illness severity in adult patients hospitalized in a mixed ICU.

The protective effects of oral low-dose quercetin on diabetic nephropathy in hypercholesterolemic mice.

AIMS: Diabetic nephropathy (DN) is one of the most important causes of chronic renal disease, and the incidence of DN is increasing worldwide. Considering our previous report (Gomes et al., 2014) indicating that chronic treatment with oral low-dose quercetin (10 mg/Kg) demonstrated anti-oxidative, anti-apoptotic and renoprotective effects in the C57BL/6J model of DN, we investigated whether this flavonoid could also have beneficial effects in concurrent DN and spontaneous atherosclerosis using the apolipoprotein E-deficient mouse (apoE(-/-)). METHODS: Streptozotocin was used to induce diabetes (100 mg/kg/day, 3 days) in male apoE(-/-) mice (8 week-old). After 6 weeks, the mice were randomly separated into DQ: diabetic apoE(-/-) mice treated with quercetin (10 mg/kg/day, 4 weeks, n = 8), DV: diabetic ApoE(-/-) mice treated with vehicle (n = 8) and ND: non-treated non-diabetic mice (n = 8). RESULTS: Quercetin treatment diminished polyuria (~30%; p < 0.05), glycemia (~25%, p < 0.05), normalized the hypertriglyceridemia. Moreover, this bioflavonoid diminished creatininemia (~30%, p < 0.01) and reduced proteinuria but not to normal levels. We also observed protective effects on the renal structural changes, including normalization of the index of glomerulosclerosis and kidney weight/body weight. CONCLUSIONS: Our data revealed that quercetin treatment significantly reduced DN in hypercholesterolemic mice by inducing biochemical changes (decrease in glucose and triglycerides serum levels) and reduction of glomerulosclerosis. Thus, this study highlights the relevance of quercetin as an alternative therapeutic option for DN, including in diabetes associated with dyslipidemia.

Sildenafil Improves Vascular Endothelial Structure and Function in Renovascular Hypertension.

In translational medicine, the discovery of new drugs or new potential uses for currently available drugs is crucial for treating the resistant hypertension associated with renal artery stenosis. The phosphodiesterase 5 inhibitor sildenafil has been shown to reduce blood pressure and to improve the endothelium-dependent relaxation in the two kidney, one clip (2K1C) mouse model of renovascular hypertension. In the present study, we evaluated the effects of sildenafil (40 mg/kg/day for two weeks) on the endothelial structure and contractile function in mesenteric resistance arteries 28 days after clipping the renal artery. The data showed an enhanced vascular contractile response to norepinephrine in 2K1C hypertensive mice (56%) when compared with Sham mice, which was associated with increased oxidative stress and with a thinning of endothelial cells. Sildenafil treatment caused a significant amelioration in the enhanced contractile responsiveness (18%), which was associated to the recovery of the endothelial surface and abolishment of the oxidative stress. These data suggest that sildenafil could be considered a promising therapeutic option to manage endothelial dysfunction and hypertension in resistant patients.

Mechanisms of enhanced vasoconstriction in the mouse model of atherosclerosis: the beneficial effects of sildenafil.

Sildenafil ameliorates aortic relaxations in apolipoprotein E knockout (apoE) mice. Now, we tested the hypothesis that endothelial dysfunction (ED) in this model is characterized by contractile hyperresponsiveness to phenylephrine (PE) and that this abnormality may be repaired using sildenafil. The aortic rings were evaluated in apoE mice treated with sildenafil (apoE-sil, 40 mg/kg/day) and compared with apoE and wild-type (WT) mice administered with vehicle (veh). The apoE-veh mice exhibited an imbalance of nitric oxide and reactive oxygen species (NO/ROS) levels and an increased maximum response (Rmax, 20%) and sensitivity (7%) to PE, which were not modified by endothelial removal. Under the prostanoids blockade, vasocontraction was decreased more in apoE-veh (-37%) than in WT (-27%) and apoE-sil (-30%) mice. NADPH-oxidase blockade abolished the enhanced contractile responsiveness in apoE-veh (-33%), without effects in WT and apoE-sil groups. The atherosclerotic lesions and the imbalance of NO/ROS were reduced (40%) in apoE-sil mice. In conclusion, ED in apoE mice was characterized by decreased NO-bioavailability and contractile hyperresponsiveness, due to thromboxane and oxidative stress, and was normalized by sildenafil. The beneficial effects of this phosphodiesterase-5 inhibitor on ED and lipid deposition provide new insights for its use as adjuvant in the treatment of atherosclerosis.

Renoprotective, anti-oxidative and anti-apoptotic effects of oral low-dose quercetin in the C57BL/6J model of diabetic nephropathy.

BACKGROUND: Diabetic nephropathy (DN) is one of the major causes of end-stage renal disease in diabetic patients. Increasing evidence from studies in the rodents has suggested that this disease is associated with increased oxidative stress due to hyperglycemia. In the present study, we evaluated the renoprotective, anti-oxidative and anti-apoptotic effects of the flavonoid quercetin in C57BL/6J model of DN. METHODS: DN was induced by streptozotocin (STZ, 100 mg/kg/day, for 3 days) in adult C57BL/6J mice. Six weeks later, mice were divided into the following groups: diabetic mice treated with quercetin (DQ, 10 mg/kg/day, 4 weeks), diabetic mice treated with vehicle (DV) or non-treated non-diabetic (ND) mice. RESULTS: Quercetin treatment caused a reduction in polyuria (~45%) and glycemia (~35%), abolished the hypertriglyceridemia and had significant effects on renal function including, decreased proteinuria and high plasma levels of uric acid, urea and creatinine, which were accompanied by beneficial effects on the structural changes of the kidney including glomerulosclerosis. Flow cytometry showed a decrease in oxidative stress and apoptosis in DN mice. CONCLUSION: Taken together, these data show that quercetin effectively attenuated STZ-induced cytotoxicity in renal tissue. This study provides convincing experimental evidence and perspectives on the renoprotective effects of quercetin in diabetic mice and outlines a novel therapeutic strategy for this flavonoid in the treatment of DN.