Olmesartan protects against oxidative stress possibly through the Nrf2 signaling pathway and inhibits inflammation in daunorubicin-induced nephrotoxicity in rats

The emerging role of adaptor proteins in regulating innate immunity of sepsis

Sepsis is a life-threatening syndrome caused by a dysregulated immune response. A large number of adaptor proteins have been found to play a pivotal role in sepsis via protein-protein interactions, thus participating in inflammatory cascades, leading to the generation of numerous inflammatory cytokines, as well as oxidative stress and regulated cell death. Although available strategies for the diagnosis and management of sepsis have improved, effective and specific treatments are lacking. This review focuses on the emerging role of adaptor proteins in regulating the innate immunity of sepsis and evaluates the potential value of adaptor protein-associated therapeutic strategy for sepsis.

NRF2 Activation by Nitrogen Heterocycles: A Review

Several nitrogen heterocyclic analogues have been applied to clinical practice, and about 75% of drugs approved by the FDA contain at least a heterocyclic moiety. Thus, nitrogen heterocycles are beneficial scaffolds that occupy a central position in the development of new drugs. The fact that certain nitrogen heterocyclic compounds significantly activate the NRF2/ARE signaling pathway and upregulate the expression of NRF2-dependent genes, especially HO-1 and NQO1, underscores the need to study the roles and pharmacological effects of N-based heterocyclic moieties in NRF2 activation. Furthermore, nitrogen heterocycles exhibit significant antioxidant and anti-inflammatory activities. NRF2-activating molecules have been of tremendous research interest in recent times due to their therapeutic roles in neuroinflammation and oxidative stress-mediated diseases. A comprehensive review of the NRF2-inducing activities of N-based heterocycles and their derivatives will broaden their therapeutic prospects in a wide range of diseases. Thus, the present review, as the first of its kind, provides an overview of the roles and effects of nitrogen heterocyclic moieties in the activation of the NRF2 signaling pathway underpinning their antioxidant and anti-inflammatory actions in several diseases, their pharmacological properties and structural-activity relationship are also discussed with the aim of making new discoveries that will stimulate innovative research in this area.

Oxidative stress induced by sub-lethal exposure to copper as a mediator in development of bacterial resistance to antibiotics

Limited information exists on how bacterial resistance to antibiotics is acquired and altered in response to short-term metal stress, and what the prevailing pathways are. Here the precursor mechanisms of development of bacterial antibiotic resistance mediated by oxidative stress induce under sub-lethal Cu²⁺ exposure were explored. The results showed that the overall level of antibiotic resistance in wild-type Escherichia coli and antibiotic-resistant E. coli was enhanced under 4 and 20 mg/L Cu²⁺ exposure, as demonstrated by the 2- to 8-fold increase in minimum inhibitory concentration (MIC). The MIC correlated with the increase of the cellular ROS generation and the enhancement of the antioxidant enzyme activity (p < 0.05), suggesting that changes in antibiotic resistance under sub-lethal Cu²⁺ exposure could be associated with oxidative stress. Likewise, enhanced cell membrane permeability and an increase in the number of bacteria entering the viable but non culturable (VBNC) state contributed to bacterial resistance to antibiotics. Moreover, the variance partitioning analysis demonstrated that the alterations of the antibiotic resistance phenotype of wild-type E. coli was mainly caused by oxidative stress-mediated increase in cell membrane permeability and entry into the VBNC state. The development of antibiotic resistance in resistant E. coli was primarily attributed to changes in the abundance and horizontal transfer ability of its antibiotic resistance genes, both of which contributed up to 20 %. Taken together the results allowed to propose a conseptual scheme on developing bacterial antibiotic resistance mediated by oxidative stress under sub-lethal Cu²⁺ exposure. This result provided a strong basis for reduction of early bacterial resistance.

High throughput screen of small molecules as potential countermeasures to galactic cosmic radiation induced cellular dysfunction

Space travel increases galactic cosmic ray exposure to flight crews and this is significantly elevated once travel moves beyond low Earth orbit. This includes combinations of high energy protons and heavy ions such as ⁵⁶Fe or ¹⁶O. There are distinct differences in the biological response to low-energy transfer (x-rays) or high-energy transfer (High-LET). However, given the relatively low fluence rate of exposure during flight operations, it might be possible to manage these deleterious effects using small molecules currently available. Virtually all reports to date examining small molecule management of radiation exposure are based on low-LET challenges. To that end an FDA approved drug library (725 drugs) was used to perform a high throughput screen of cultured cells following exposure to galactic cosmic radiation. The H9c2 myoblasts, ES-D3 pluripotent cells, and Hy926 endothelial cell lines were exposed to a single exposure (75 cGy) using the 5-ion GCRsim protocol developed at the NASA Space Radiation Laboratory (NSRL). Following GCR exposure cells were maintained for up to two weeks. For each drug (@10µM), a hierarchical cumulative score was developed incorporating measures of mitochondrial and cellular function, oxidant stress and cell senescence. The top 160 scores were retested following a similar protocol using 1µM of each drug. Within the 160 drugs, 33 are considered to have an anti-inflammatory capacity, while others also indirectly suppressed pro-inflammatory pathways or had noted antioxidant capacity. Lead candidates came from different drug classes that included angiotensin converting enzyme inhibitors or AT1 antagonists, COX2 inhibitors, as well as drugs mediated by histamine receptors. Surprisingly, different classes of anti-diabetic medications were observed to be useful including sulfonylureas and metformin. Using a hierarchical decision structure, we have identified several lead candidates. That no one drug or even drug class was completely successful across all parameters tested suggests the complexity of managing the consequences of galactic cosmic radiation exposure.

Receptor for Advanced Glycation End Products (RAGE): A Pivotal Hub in Immune Diseases

As a critical molecule in the onset and sustainment of inflammatory response, the receptor for advanced glycation end products (RAGE) has a variety of ligands, such as advanced glycation end products (AGEs), S100/calcium granule protein, and high-mobility group protein 1 (HMGB1). Recently, an increasing number studies have shown that RAGE ligand binding can initiate the intracellular signal cascade, affect intracellular signal transduction, stimulate the release of cytokines, and play a vital role in the occurrence and development of immune-related diseases, such as systemic lupus erythematosus, rheumatoid arthritis, and Alzheimer’s disease. In addition, other RAGE signaling pathways can play crucial roles in life activities, such as inflammation, apoptosis, autophagy, and endoplasmic reticulum stress. Therefore, the strategy of targeted intervention in the RAGE signaling pathway may have significant therapeutic potential, attracting increasing attention. In this paper, through the systematic induction and analysis of RAGE-related signaling pathways and their regulatory mechanisms in immune-related diseases, we provide theoretical clues for the follow-up targeted intervention of RAGE-mediated diseases.

Olmesartan Ameliorates Organ Injury and Mortality in Rats With Peritonitis-Induced Sepsis

INTRODUCTION

Sepsis and related complications lead to high morbidity and mortality in humans and animals. Olmesartan medoxomil (OLM), a nonpeptide angiotensin II type 1 receptor blocker, has antiinflammatory and antioxidative effects in various experimental animal models. The present study aimed to investigate whether OLM protects against sepsis in a clinically relevant model of polymicrobial sepsis induced by cecal ligation and puncture (CLP).

METHODS

Sepsis was induced by CLP in anesthetized rats. OLM was administered intraperitoneally 3 h after CLP onset. Hemodynamic, biochemical, and inflammatory parameters were analyzed.

RESULTS

The administration of OLM in CLP rats significantly improved their survival rate. Moreover, OLM mitigated CLP-induced hypotension and organ injury (indicated by biochemical parameters), but not tachycardia. OLM significantly reduced the plasma levels of interleukin-6 and nitric oxide.

CONCLUSIONS

OLM markedly attenuated CLP-induced hypotension and organ injury, and hence improved survival by inhibiting the inflammatory response and nitrosative stress in this clinically relevant model of sepsis.

Nrf2 driven macrophage responses in diverse pathophysiological contexts: Disparate pieces from a shared molecular puzzle

The wide anatomical distribution of macrophages and their vast array of functions match various polarization states and their involvement in homeostasis and disease. The confluence of different cellular signaling networks, including direct involvement in inflammation, at the doorstep of the transcription factor Nuclear Factor- erythroid (NF-E2) p45-related factor 2 (Nrf2) activation raises the importance of deciphering the molecular circuitry at the background of multiple-discrete and antagonistic yet flexible and contextual pathways. While we primarily focus on wound healing and repair mechanisms that are affected in diabetic foot ulcers (DFUs), we strive to explore the striking similarities and differences in molecular events including inflammation, angiogenesis, and fibrosis during tissue injury and wound persistence that accumulates pro-inflammatory senescent macrophages, as a means to identify possible targets or cellular mediators to lessen DFU disease burden. In addition, the role of iron in the modulation of Nrf2 response in macrophages is crucial and reviewed here. Targeted approaches, unlike conventional treatments, in DFU management will require the review and re-assessment of mediators with relevance to other pathological conditions.

The role of the angiotensins in the pathogenesis of inflammatory joint disease

The significant humoral effect of the renin-angiotensin-aldosterone system on the regulation of the cardiovascular system and blood pressure has long been widely known. However, the identification and interpretation of new components of renin-angiotensin-aldosterone system in recent years can significantly expand the range of its potential effects on the body. The anti-inflammatory effect of drugs that block angiotensin II and its receptors, including in rheumatic diseases, can become practically significant for General therapists by their effect on reducing the concentration of inflammatory mediators and angiogenesis processes. The organoprotective and anti-inflammatory potentials of drugs that reduce the production of at demonstrated in vitro and in vivo experiments allow us to consider them as first-line angiotropic agents in patients with rheumatoid arthritis, especially in the presence of pathology of the cardiovascular system and kidneys.

Olmesartan Prevents Oligomerized Amyloid β (Aβ)-Induced Cellular Senescence in Neuronal Cells

Alzheimer's disease (AD) is a neurodegenerative disease with high morbidity. The deposition of oligomerized amyloid β (Aβ) is the pathological feature of AD. The Aβ-caused neuronal oxidative stress and cellular senescence play an important role in the development and progression of AD. Olmesartan is a novel angiotensin receptor blocker with promising antihypertensive properties and has recently been reported to exert anti-inflammatory and antioxidative stress effects. Blood pressure control using Angiotensin receptor blockers has shown multiple benefits in Alzheimer's disease models. In the present study, the effect of Olmesartan on oligomerized amyloid β (Aβ)-induced cellular senescence was investigated in cultured M17 neuronal cells. Our results show that Olmesartan treatment significantly ameliorates oligomerized Aβ-elevated ROS and MDA levels, as well as the induced senescent cells number. At the molecular level, Olmesartan inhibits the elevated expression of senescence biomarkers (p16 and p21). Furthermore, Olmesartan potently reversed the increased K382 acetylation of p53 and the downregulation of SIRT1. Moreover, we show that the effect of Olmesartan against cell senescence and deacetylation of p53 was abolished by inhibition of SIRT1, either by using nicotinamide or by transfection with SIRT1 siRNA. In conclusion, Olmesartan prevents oligomerized Aβ-induced cellular senescence in neuronal cells by downregulating p16 and p21 through a SIRT1 dependent deacetylation of p53; our finding indicates that Olmesartan has a protective effect in Aβ-induced neurotoxicity.

Kidney-accumulating olmesartan-loaded nanomicelles ameliorate the organ damage in a murine model of Alport syndrome

ACE inhibitors or angiotensin II receptor blockers (ACEi/ARBs) have been a cornerstone of the management in kidney disease, but their use is often limited by undesired systemic effects, such as symptomatic hypotension. To minimize the extra-renal effects of ACEi/ARBs, we formulated hydrophobically modified glycol chitosan (HGC) nanomicelles releasing olmesartan (HGC-Olm) that specifically accumulated in the kidney, and investigated whether kidney-specific delivery of olmesartan by HGC nanomicelles could ameliorate organ damage in Col4a3^-/- mouse, a murine model of progressive chronic kidney disease mimicking human Alport syndrome. Ex vivo tracing demonstrated that intravenously injected HGC-Olm nanomicelles were specifically delivered to the kidney, with sustained release of olmesartan for more than 48 h. Contrary to the conventional delivery of olmesartan via oral route, injection of HGC-Olm nanomicelles did not alter blood pressure in Col4a3^-/- mice. Immunohistochemistry revealed that HGC nanomicelles were diffusely distributed from the cortex and glomeruli to the outer medulla, sparing the inner medulla. Phenotypic analysis showed that the attenuation of kidney fibrosis in the kidney of Col4a3^-/- mice by HGC-Olm nanomicelles was comparable to that noted with conventionally delivered olmesartan. Therefore, our results suggest that HGC-Olm nanomicelles could be a safe and effective alternative drug delivery system for kidney diseases.

Protective effects of olmesartan and l-carnitine on doxorubicin-induced cardiotoxicity in rats

Doxorubicin (DOX), an anthracycline antibiotic, is an important antineoplastic agent due to its high antitumor efficacy in hematological as well as in solid malignancies. The clinical use of DOX is limited due to its cardiotoxic effects. The present study aimed to investigate the possible protective effect of olmesartan (Olm), l-carnitine (L-CA), and their combination in cardiotoxicity induced by DOX in rats. Male albino rats were randomly divided into seven experimental groups (n = 8): group I: normal control, group II: L-CA, group III: Olm, group IV: DOX. The other three groups were treated with Olm (10 mg/kg), L-CA (300 mg/kg), and their combination for 2 weeks after induction of cardiotoxicity by a single dose of DOX (20 mg/kg). In the results, DOX showed a significant elevation in serum troponin I, creatine kinase-MB (CK-MB), and lactate dehydrogenase (LDH) together with increased inflammation manifested by the rise of tumor necrosis factor-alpha (TNF-α), intercellular adhesion molecules-1 (ICAM-1), interleukin IL-1β (IL-1β), myeloperoxidase (MPO), nuclear factor-kappa B (NF-κB), and transforming growth factor beta (TGF-β) in cardiac tissues as well as DOX-induced oxidative stress by increasing in malondialdehyde (MDA) and decreasing in superoxide dismutase (SOD) and glutathione (GSH) in heart tissues. In addition, caspase-3 activity was boosted as indication of increased apoptosis. On the other hand, administration of L-CA and Olm attenuated the DOX-evoked disturbances in the abovementioned parameters. In addition, DOX exhibited echocardiographic changes and severe histopathological changes, which were significantly reversed by L-CA and Olm treatment. In conclusion, the present study data confirm the protective role of L-CA and Olm in DOX-induced cardiotoxicity, which may be related to its antioxidant, antiinflammatory, and antiapoptotic agents.

Olmesartan Medoxomil, An Angiotensin II-Receptor Blocker, Ameliorates Renal Injury In db/db Mice

Background

Diabetic nephropathy (DN) is a common complication of diabetes mellitus (DM) and also a major cause of end-stage renal disease (ESRD). Olmesartan medoxomil (OM) is an angiotensin II receptor blocker (ARB) and has been shown to exhibit renoprotective effects on a streptozotocin (STZ)-induced diabetic rat model. Yet, whether OM affects DN progression and renal injury in db/db mice, a type 2 diabetic murine model, has not been established.

Methods

Wild-type (n = 15) and db/db mice (n = 15) were treated with control saline or OM via oral gavage. The physiological and biochemical parameters were evaluated and histological examinations of kidney specimens were performed.

Results

Compared with saline-treated db/db mice, db/db mice administered with OM showed ameliorated diabetic physiological and biochemical parameters. In addition, OM decreased urinary albumin excretion and plasma creatinine level in db/db mice. Moreover, histologically, OM reduced glomerular hypertrophy and injury, and also ameliorated tubular injury, thus suggesting that OM improves renal function and minimizes renal pathological deterioration in db/db mice.

Conclusion

Our study reveals a beneficial role of OM in ameliorating DN in db/db mice, which is associated with its renoprotective function.

Angiotensins and rheumatoid arthritis

At present, the role of the renin-angiotensin system (RAS) in regulating the cardiovascular system and maintaining water and electrolyte homeostasis has been well studied. However, over the past decades, new components of the RAS have been identified, suggesting a wider range of its potential effects on the body. It is of fundamentally importance for rheumatologists to affect inflammation, including rheumatoid inflammation, through blockade of angiotensin (AT) II formation via the effects of AT 1–7 and angiotensin-converting enzyme inhibitors, as well as through suppression of angiogenesis, primarily by reducing the production of endothelial growth factor. The organ-protective and antiinflammatory potential of drugs that reduce the production of AT, which has been proven in in vitro and in vivo experiments, allows us to consider them as first-line angiotropic agents in patients with rheumatoid arthritis, especially in the presence of concomitant hypertension and/or nephropathy.

Angiotensin II induces oxidative stress and upregulates neuroprotective signaling from the NRF2 and KLF9 pathway in dopaminergic cells

Nuclear factor-E2-related factor 2 (NRF2) is a transcription factor that activates the antioxidant cellular defense in response to oxidative stress, leading to neuroprotective effects in Parkinson's disease (PD) models. We have previously shown that Angiotensin II (AngII) induces an increase in reactive oxygen species (ROS) via AngII receptor type 1 and NADPH oxidase (NOX), which may activate the NRF2 pathway. However, controversial data suggest that AngII induces a decrease in NRF2 signaling leading to an increase in oxidative stress. We analyzed the effect of AngII and the dopaminergic neurotoxin 6-hydroxydopamine (6-OHDA) in culture and in vivo, and examined the effects on the expression of NRF2-related genes. Treatment of neuronal cell lines Mes23.5, N27 and SH-SY5Y with AngII, 6-OHDA or a combination of both increased ROS production and reduced cell viability. Simultaneously, these treatments induced an increase in expression in the NRF2-regulated genes heme oxygenase 1 (Hmox1), NAD(P)H quinone dehydrogenase 1 (Nqo1) and Kruppel like factor 9 (Klf9). Moreover, overexpression of KLF9 transcription factor caused a reduction in the production of ROS induced by treatment with AngII or 6-OHDA and improved the survival of these neuronal cells. Rats treated with AngII, 6-OHDA or a combination of both also showed an increased expression of NRF2 related genes and KLF9. In conclusion, our data indicate that AngII induces a damaging effect in neuronal cells, but also acts as a signaling molecule to activate NRF2 and KLF9 neuroprotective pathways in cellular and animal models of PD.

Management of arterial hypertension with angiotensin receptor blockers: Current evidence and the role of olmesartan

Elevated blood pressure (BP) is a major determinant of morbidity and mortality burden related to cardio‐metabolic risk. Current guidelines indicate that controlling and lowering BP promotes cardiovascular (CV) risk reduction. Among antihypertensive agents, angiotensin receptor blockers (ARBs) are characterized by an efficacy profile equivalent to other antihypertensive agents and are provided with excellent tolerability and low discontinuation rates during chronic treatments. Moreover, CV outcomes are reduced by ARBs. Olmesartan is a long‐lasting ARB which proved to achieve a comparable or more effective action in lowering BP when compared to other ARBs. Olmesartan, in fact, displayed a larger and more sustained antihypertensive effect over the 24 hours, with a buffering effect on short‐term BP variability. These are important features which differentiate olmesartan from the other principles of the same class and that may help to control the increased CV risk in the presence of high BP variability. Olmesartan shows similar benefits as other ARBs in terms of all‐cause and CV mortality, and a favorable tolerability profile. Combination of olmesartan with long‐lasting calcium‐channel blockers and thiazide diuretics represents a rational and effective therapy. Thus, ARBs, including olmesartan, represent one of the most effective and safe treatments for patients with arterial hypertension.

Usefulness of the Whole Blood Passage Time as a Predictor of Primary Cardiovascular Events in Patients With Traditional Cardiovascular Risk Factors

BACKGROUND

Recent clinical studies have reported that impaired hemorheology is a significant cardiovascular risk factor, but there has been no prospective study of its relationship with cardiovascular events. The aim of this prospective study was to assess the efficacy of whole blood passage time (WBPT), measured by a microchannel array flow analyzer (MC-FAN), as a predictor of primary cardiovascular events in patients with traditional cardiovascular risk factors.

METHODS

The study enrolled 1,134 outpatients with traditional cardiovascular risk factors but no history of cardiovascular events (438 men and 696 women; mean ± standard deviation age, 67 ± 11 years). Based on the value of WBPT, the patients were assigned to one of three groups: L (low, WBPT < 50 s; n = 499), M (medium, WBPT 50 - 70 s; n = 295), or H (high, WBPT > 70 s; n = 340). The utility of the WBPT as a predictor of primary cardiovascular events was evaluated.

RESULTS

During the follow-up period (median 81.9 months), major adverse cardiovascular events (MACE) occurred in 95 cases (L, 21 cases (4.2%); M, 24 cases (8.1%); H, 50 cases (14.7%); P < 0.001, log-rank test). In multivariate Cox regression analyses, the risk for MACE was significantly higher in group H than in group L (hazard ratio, 2.32; 95% confidence interval, 1.31 - 3.20; P < 0.01). A WBPT cut-off of 72.4 s yielded the largest area under the curve of 0.705 (95% confidence interval: 0.678 - 0.732), with a sensitivity of 51.7% and specificity of 85.4% for discriminating between those who did and did not experience MACE during the follow-up period.

CONCLUSION

This study showed that WBPT evaluated by a MC-FAN was a predictor of primary cardiovascular events in patients with traditional cardiovascular risk factors.

Small molecule disruption of G protein βγ subunit signaling reprograms human macrophage phenotype and prevents autoimmune myocarditis in rats

The purpose of this study was to determine whether blocking of G protein βγ (Gβγ) signaling halts heart failure (HF) progression by macrophage phenotype manipulation. Cardiac Gβγ signaling plays a crucial role in HF pathogenesis. Previous data suggested that inhibiting Gβγ signaling reprograms T helper cell 1 (Th1) and Th2 cytokines, suggesting that Gβγ might be a useful drug target for treating HF. We investigated the efficacy of a small molecule Gβγ inhibitor, gallein, in a clinically relevant, experimental autoimmune myocarditis (EAM) model of HF as well as in human macrophage phenotypes in vitro. In the myocardium of HF patients, we observed that G protein coupled receptor kinase (GRK)2 levels were down-regulated compared with healthy controls. In rat EAM, treatment with gallein effectively improved survival and cardiac function, suppressed cardiac remodeling, and further attenuated myocardial protein expression of GRK2 as well as high mobility group box (HMGB)1 and its cascade signaling proteins. Furthermore, gallein effectively inhibited M1 polarization and promoted M2 polarization in vivo in the EAM heart and in vitro in human monocyte-derived macrophages. Taken together, these data suggest that the small molecule Gβγ inhibitor, gallein, could be an important pharmacologic therapy for HF as it can switch the phenotypic reprogramming from M1 to M2 phenotype in a rat model of EAM heart and in human macrophages.

Collaborative Power of Nrf2 and PPARγ Activators against Metabolic and Drug-Induced Oxidative Injury

Mammalian cells have evolved a unique strategy to protect themselves against oxidative damage induced by reactive oxygen species (ROS). Especially, two transcription factors, nuclear factor erythroid 2p45-related factor 2 (Nrf2) and peroxisome proliferator-activated receptor γ (PPARγ), have been shown to play key roles in establishing this cellular antioxidative defense system. Recently, several researchers reported ameliorating effects of pharmacological activators for these Nrf2 and PPARγ pathways on the progression of various metabolic disorders and drug-induced organ injuries by oxidative stress. In this review, general features of Nrf2 and PPARγ pathways in the context of oxidative protection will be summarized first. Then, a number of successful applications of natural and synthetic Nrf2 and PPARγ activators to the alleviation of pathological and drug-related oxidative damage will be discussed later.

Olmesartan Prevented Intra-articular Inflammation Induced by Zymosan in Rats

The objective of this study was to study the effect of olmesartan medoxomil (OLM), an antihypertensive drug, on intra-articular inflammation induced by zymosan (Zy) in Wistar rats. Intra-articular inflammation was induced in the right knees of rats by 1 mg Zy dissolved in saline. The animals were divided into the following groups: saline only (oral saline and intra-articular saline); Zy only (intra-articular Zy and oral saline), and intra-articular Zy and oral OLM (5, 15, or 30 mg/kg) or diclofenac sodium (SD; 100 mg/kg). Twenty-four hours after Zy injection, synovial fluid was collected for total leukocyte counts, blood was collected for biochemical measurements, and synovial tissue was collected for histopathology, immunohistochemistry, immunofluorescence and myeloperoxidase (MPO), malonaldehyde (MDA), and non-protein sulphydryl (NPSH) assays. OLM doses of 15 and 30 mg/kg had protective effects, as evidenced by improved histopathological parameters of synovium, reduced total leukocyte counts, reduced MPO and MDA levels, and increased NPSH group levels compared with the Zy group. OLM reduced immunostaining for cyclooxygenase 2, tumour necrosis factor and interleukin 17 and increased immunostaining for superoxide dismutase and glutathione peroxidase. SD produced similar results. The drugs studied caused no change in biochemical parameters of the animals. OLM showed protective effects in this model of Zy-induced intra-articular inflammation.

Modulation of Macrophage Polarization and HMGB1-TLR2/TLR4 Cascade Plays a Crucial Role for Cardiac Remodeling in Senescence-Accelerated Prone Mice

The aim of this study was to investigate the role of macrophage polarization in aging heart. Macrophage differentiation is pathogenically linked to many inflammatory and immune disorders. It is often preceded by myocardial inflammation, which is characterized by increased cardiac damage and pro-inflammatory cytokine levels. Therefore, we investigated the hypothesis that senescence accelerated-prone (SAMP8) mice cardiac tissue would develop macrophage polarization compared with senescence-resistant control (SAMR1) mice. Both SAMP8 and SAMR1 mice were sacrificed when they became six month old. We evaluated, histo-pathological changes and modifications in protein expression by Western blotting and immuno-histochemical staining for M1 and M2 macrophage markers, high mobility group protein (HMG)B1 and its cascade proteins, pro-inflammatory factors and inflammatory cytokines in cardiac tissue. We observed significant upregulation of HMGB1, toll-like receptor (TLR)2, TLR4, nuclear factor (NF)κB p65, tumor necrosis factor (TNF)α, cyclooxygenase (COX)2, interferon (IFN)γ, interleukin (IL)-1β, IL-6 and M1 like macrophage specific marker cluster of differentiation (CD)68 expressions in SAMP8 heart. In contrast, M2 macrophage specific marker CD36, and IL-10 expressions were down-regulated in SAMP8 mice. The results from the study demonstrated that, HMGB1-TLR2/TLR4 signaling cascade and induction of phenotypic switching to M1 macrophage polarization in SAMP8 mice heart would be one of the possible reasons behind the cardiac dysfunction and thus it could become an important therapeutic target to improve the age related cardiac dysfunction.

Olmesartan Combined With Amlodipine on Oxidative Stress Parameters in Type 2 Diabetics, Compared With Single Therapies: A Randomized, Controlled, Clinical Trial

To evaluate the effects of a fixed combination of olmesartan/amlodipine compared with olmesartan or amlodipine alone on some parameters of endothelial damage in diabetic, hypertensive patients.We enrolled 221 patients; 74 were randomized to olmesartan 20 mg, 72 to amlodipine 10 mg, and 75 to olmesartan/amlodipine fixed combination 20/5 mg for 12 months. We assessed blood pressure monthly; in addition, we also assessed at baseline, and after 6 and 12 months, the following parameters: lipoprotein (a), myeloperoxidase (MPO), isoprostanes, and paraoxonase-1 (PON-1). Blood pressure values obtained with fixed olmesartan/amlodipine combination were significantly lower than those reached with single monotherapies. There was a reduction of lipoprotein (a), and isoprostanes levels with olmesartan/amlodipine fixed combination, both compared with baseline, and with single monotherapies. On the other hand, there was an increase of PON-1 with fixed olmesartan/amlodipine combination, both compared with baseline, and with single drugs. All treatments reduced MPO compared with baseline; however, in group-to-group comparison, MPO reduction was greater with olmesartan/amlodipine fixed combination. Fixed combination of olmesartan/amlodipine was more effective than single monotherapies in reducing oxidative stress, especially in increasing PON-1, and reducing isoprostanes levels in diabetic and hypertensive patients.

Pyrrolidine Dithiocarbamate Inhibits NF-KappaB Activation and Upregulates the Expression of Gpx1, Gpx4, Occludin, and ZO-1 in DSS-Induced Colitis

Inflammatory bowel disease (IBD) correlates with oxidative stress, inflammation, and alteration in several signal pathways, including nuclear transcription factor-kappaB (NF-κB). Pyrrolidine dithiocarbamate (PDTC), an inhibitor of NF-κB, has been widely demonstrated to exhibit an antioxidant and anti-inflammatory function. This study aimed to test the hypothesis that NF-κB inhibitor PDTC confers a beneficial role in a colitis model induced by dextran sodium sulfate (DSS) in mouse. The results showed that DSS decreased daily weight gain, induced colonic inflammation, suppressed the expression of antioxidant enzymes and tight junctions, and activated NF-κB and nuclear factor erythroid 2-related factor 2/Kelch-like ECH-associated protein 1 (Nrf2/Keap1) signaling pathways. PDTC significantly upregulated (P < 0.05) Gpx1, Gpx4, occludin, and ZO-1 expressions in the DSS-induced colitis model. Meanwhile, PDTC reversed (P < 0.05) the activation of NF-κB signal pathway caused by DSS treatment. In conclusion, PDTC could serve as an adjuvant therapy for the patient with IBD.

The protective effect of Trillin LPS-induced acute lung injury by the regulations of inflammation and oxidative state

Inflammation response and oxidative stress have been reported to be involved in the pathogenesis of acute lung injury (ALI). Accordingly, anti-inflammatory treatment is proposed to be a possible efficient therapeutic strategy for ALI. The purpose of our present study was to evaluate the anti-inflammatory efficacy of trillin (Tr) on ALI induced by lipopolysaccharide (LPS) in mice and explore the underlying mechanism. BALB/c mice received Tr (50, 100 mg/kg) intraperitoneally 1 h prior to the intratracheal instillation of lipopolysaccharide (LPS) challenge. Pretreatment with Tr at the dose of 50, 100 mg/kg markedly ameliorated lung wet-to-dry weight (W/D) ratio, myeloperoxidase (MPO) activity and pulmonary histopathological conditions. In addition, the protective efficacy of Tr might be attributed to the down-regulations of neutrophil infiltration, malondialdehyde (MDA), inflammatory cytokines and the up-regulations of super-oxide dismutase (SOD), catalase(CAT), glutathione(GSH), Glutathione Peroxidase(GSH-Px) in bronchoalveolar lavage fluid (BALF). Meanwhile, our study revealed some correlations between (NF-E2-related factor 2) Nrf2/heme oxygenase (HO)-1/nuclear factor-kappa B (NF-κB) pathways and the beneficial effect of Tr, as evidenced by the significant up-regulations of HO-1 and Nrf2 protein expressions as well as the down-regulations of p-NF-κB and p-inhibitor of NF-κB (IκB) in lung tissues. Taken together, our results indicated that Tr exhibited protective effect on LPS-induced ALI by the regulations of related inflammatory events via the activations of Nrf2, HO-1 and NF-κB pathway. The current study indicated that Tr could be a potentially effective candidate medicine for the treatment of ALI.

Naringenin ameliorates daunorubicin induced nephrotoxicity by mitigating AT1R, ERK1/2-NFκB p65 mediated inflammation

Inflammation and oxidative stress play important roles in the progression of renal damage. The natural polyphenol naringenin is known to exert potent antioxidant and anti-inflammatory effects. In this study, we have investigated the effect of naringenin on kidney dysfunction, fibrosis, endoplasmic reticulum (ER) stress, angiotensin II type I receptor (AT1R) expression and inflammation in daunorubicin (DNR) induced nephrotoxicity model. Nephrotoxicity was induced in rats by intravenous injection of DNR at a cumulative dose of 9 mg/kg. After 1 week, naringenin (20mg/kg/day. p.o) was administered daily for 6 weeks. Biochemical studies were performed to evaluate renal function. Western blotting was performed to measure the protein levels of AT1R, endothelin (ET)1, ET receptor type A (ETAR), extracellular signal-regulated kinase (ERK)1/2, nuclear factor (NF)κB p65, peroxisome proliferator activated receptor (PPAR)γ, oxidative/ER stress, apoptosis, and inflammatory markers in the kidney of DNR treated rats. Histopathological analysis was done using hemotoxylin eosin and Masson trichrome stained renal sections to investigate the structural abnormalities and fibrosis. DNR treated rats suffered from nephrotoxicity as evidenced by worsened renal function, increased blood urea nitrogen, serum creatinine levels in renal tissues and histopathogical abnormalities. Treatment with naringenin mitigated these changes. Furthermore, naringenin up regulated PPARγ and down regulated AT1R, ET1, ETAR, p-ERK1/2, p-NFκB p65, ER stress, apoptosis, and inflammatory markers. Our results suggest that naringenin has an ability to improve renal function and attenuates AT1R, ERK1/2-NFκB p65 signaling pathway in DNR induced nephrotoxicity in rats.

Modulation of HMGB1 translocation and RAGE/NFκB cascade by quercetin treatment mitigates atopic dermatitis in NC/Nga transgenic mice

Quercetin, glycosylated form of flavonoid compound, has potent antioxidant and anti-inflammatory properties. In this study, we have investigated the effects of quercetin on skin lesion, high-mobility group box (HMGB)1 cascade signalling and inflammation in atopic dermatitis (AD) mouse model. AD-like lesion was induced by the application of house dust mite extract to the dorsal skin of NC/Nga transgenic mouse. After AD induction, quercetin (50 mg/kg, p.o) was administered daily for 2 weeks. We evaluated dermatitis severity, histopathological changes and changes in protein expression by Western blotting for HMGB1, receptor for advanced glycation end products (RAGE), toll-like receptor (TLR)4, nuclear factor (NF)κB, nuclear factor erythroid-2-related factor (Nrf)2, kelch-like ECH-associated protein (Keap)1, extracellular signal-regulated kinase (ERK)1/2, cyclooxygenase (COX)2, tumor necrosis factor (TNF)α, interleukin (IL)-1β, IL-2Rα and other inflammatory markers in the skin of AD mice. In addition, serum levels of T helper (Th) cytokines (interferon (IFN)γ, IL-4) were measured by enzyme-linked immunosorbent assay. Quercetin treatment attenuated the development of AD-like skin lesions. Histological analysis showed that quercetin inhibited hyperkeratosis, parakeratosis, acanthosis, mast cells and infiltration of inflammatory cells. Furthermore, quercetin treatment downregulated cytoplasmic HMGB1, RAGE, nuclear p-NFκB, p-ERK1/2, COX2, TNFα, IL-1β, IL-2Rα, IFNγ and IL-4 and upregulated nuclear Nrf2. Our data demonstrated that the HMGB1/RAGE/NFκB signalling might play an important role in skin inflammation, and quercetin treatment could be a promising agent for AD by modulating the HMGB1/RAGE/NFκB signalling and induction of Nrf2 protein.

Lycopene attenuates colistin-induced nephrotoxicity in mice via activation of the Nrf2/HO-1 pathway

Nephrotoxicity is the major dose-limiting factor for the clinical use of colistin against multidrug-resistant (MDR) Gram-negative bacteria. This study aimed to investigate the protective effect of lycopene on colistin-induced nephrotoxicity in a mouse model. Fifty mice were randomly divided into 5 groups: the control group (saline solution), the lycopene group (20 mg/kg of body weight/day administered orally), the colistin group (15 mg/kg/day administered intravenously), the colistin (15 mg/kg/day) plus lycopene (5 mg/kg/day) group, and the colistin (15 mg/kg/day) plus lycopene (20 mg/kg/day) group; all mice were treated for 7 days. At 12 h after the last dose, blood was collected for measurements of blood urea nitrogen (BUN) and serum creatinine levels. The kidney tissue samples were obtained for examination of biomarkers of oxidative stress and apoptosis, histopathological assessment, and quantitative reverse transcription-PCR (qRT-PCR) analysis. Colistin treatment significantly increased concentrations of BUN and serum creatinine, tubular apoptosis/necrosis, lipid peroxidation, and heme oxygenase 1 (HO-1) activity, while the treatment decreased the levels of endogenous antioxidant biomarkers glutathione (GSH), catalase (CAT), and superoxide dismutase (SOD). Notably, the changes in the levels of all biomarkers were attenuated in the kidneys of mice treated with colistin by lycopene (5 or 20 mg/kg). Lycopene treatment, especially in the colistin plus lycopene (20 mg/kg) group, significantly downregulated the expression of NF-κB mRNA (P < 0.01) but upregulated the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and HO-1 mRNA (both P < 0.01) in the kidney compared with the results seen with the colistin group. Our data demonstrated that coadministration of 20 mg/kg/day lycopene can protect against colistin-induced nephrotoxicity in mice. This effect may be attributed to the antioxidative property of lycopene and its ability to activate the Nrf2/HO-1 pathway.

Curcumin prevents maleate-induced nephrotoxicity: relation to hemodynamic alterations, oxidative stress, mitochondrial oxygen consumption and activity of respiratory complex I

The potential protective effect of the dietary antioxidant curcumin (120 mg/Kg/day for 6 days) against the renal injury induced by maleate was evaluated. Tubular proteinuria and oxidative stress were induced by a single injection of maleate (400 mg/kg) in rats. Maleate-induced renal injury included increase in renal vascular resistance and in the urinary excretion of total protein, glucose, sodium, neutrophil gelatinase-associated lipocalin (NGAL) and N-acetyl β-D-glucosaminidase (NAG), upregulation of kidney injury molecule (KIM)-1, decrease in renal blood flow and claudin-2 expression besides of necrosis and apoptosis of tubular cells on 24 h. Oxidative stress was determined by measuring the oxidation of lipids and proteins and diminution in renal Nrf2 levels. Studies were also conducted in renal epithelial LLC-PK1 cells and in mitochondria isolated from kidneys of all the experimental groups. Maleate induced cell damage and reactive oxygen species (ROS) production in LLC-PK1 cells in culture. In addition, maleate treatment reduced oxygen consumption in ADP-stimulated mitochondria and diminished respiratory control index when using malate/glutamate as substrate. The activities of both complex I and aconitase were also diminished. All the above-described alterations were prevented by curcumin. It is concluded that curcumin is able to attenuate in vivo maleate-induced nephropathy and in vitro cell damage. The in vivo protection was associated to the prevention of oxidative stress and preservation of mitochondrial oxygen consumption and activity of respiratory complex I, and the in vitro protection was associated to the prevention of ROS production.

Peritoneal air exposure elicits an intestinal inflammation resulting in postoperative ileus

BACKGROUND

The pathogenesis of postoperative ileus (POI) is complex. The present study was designed to investigate the effects of peritoneal air exposure on the POI intestinal inflammation and the underlying mechanism.

METHODS

Sprague-Dawley rats were randomized into five groups (6/group): the control group, the sham group, and three exposure groups with peritoneal air exposure for 1, 2, or 3 h. At 24 h after surgery, we analyzed the gastrointestinal transit, the serum levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-10, the myeloperoxidase activity, and the levels of TNF-α, IL-1β, IL-6, and IL-10 in the ileum and colon. The oxidant and antioxidant levels in the ileum and colon were analyzed by measuring malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and total antioxidant capacity (T-AOC).

RESULTS

Peritoneal air exposure caused an air-exposure-time-dependent decrease in the gastrointestinal transit. The length of peritoneal air exposure is correlated with the severity of both systemic and intestinal inflammations and the increases in the levels of MDA, SOD, GSH-Px, and T-AOC.

CONCLUSIONS

The length of peritoneal air exposure is proportional to the degree of intestinal paralysis and the severity of intestinal inflammation, which is linked to the oxidative stress response.