Anti-inflammatory and antinociceptive effects of salbutamol on acute and chronic models of inflammation in rats: involvement of an antioxidant mechanism

Influence of the ERK/CHGB pathway in breast cancer progression under chronic stress

BACKGROUND

Breast cancer is one of the most common malignancies among women, and its development involves a variety of complex molecular mechanisms. Extracellular signal-regulated kinase (ERK) and Chromogranin B (CHGB) are known to play key roles in various cancers. This study aims to explore the impact of the ERK/CHGB pathway in a chronic stress environment simulated by salbutamol on the development of breast cancer.

METHODS

This study utilized female BALB/c mice to establish a breast cancer model, dividing them into control, salbutamol-treated, and salbutamol-inhibitor-treated groups. Cell culture, immunohistochemistry, Western Blot, real-time fluorescent quantitative PCR, and Transwell migration assays were employed to assess the effects of salbutamol and the ERK/CHGB pathway.

RESULTS

Salbutamol treatment significantly enhanced the proliferation, migration, and invasiveness of breast cancer cells, associated with the activation of the ERK pathway and the inhibition of CHGB. The salbutamol-inhibitor-treated group exhibited a marked suppression of these effects. Additionally, the interaction of the ERK/CHGB pathway in an extracellular stress environment provided advantages for the survival and proliferation of breast cancer cells.

CONCLUSION

This study demonstrates that a chronic stress environment simulated by salbutamol can promote malignant behaviors in breast cancer cells through the ERK/CHGB pathway. These findings offer new molecular targets for breast cancer treatment and highlight the potential importance of managing chronic stress and blocking specific molecular pathways in cancer therapy.

Salbutamol ameliorates skeletal muscle wasting and inflammatory markers in streptozotocin (STZ)-induced diabetic rats

Diabetes accelerates muscle atrophy, leading to the deterioration of skeletal muscles. This study aimed to assess the potential of the β2-adrenoceptor agonist, salbutamol (SLB), to alleviate muscle atrophy in streptozotocin (STZ)-induced diabetic rats. Male Sprague Dawley rats were randomized into four groups (n=6): control, SLB, STZ (55 mg/kg, single i.p.), and STZ + SLB (6 mg/kg, orally for 4 weeks). After the final SLB dose, animals underwent tests to evaluate muscle strength and coordination, including forelimb grip strength, wire-hanging, actophotometer, rotarod, and footprint assessments. Rats were then sacrificed, and serum and gastrocnemius (GN) muscles were collected for further analysis. Serum evaluations included proinflammatory markers (tumor necrosis factor α, interleukin-1β, interleukin-6), muscle markers (creatine kinase, myostatin), testosterone, and lipidemic markers. Muscle oxidative stress (malonaldehyde, protein carbonyl), antioxidants (glutathione, catalase, superoxide dismutase), and histology were also performed. Additionally, 1H nuclear magnetic resonance serum profiling was conducted. SLB notably enhanced muscle grip strength, coordination, and antioxidant levels, while reduced proinflammatory markers and oxidative stress in STZ-induced diabetic rats. Reduced serum muscle biomarkers, increased testosterone, restored lipidemic levels, and improved muscle cellular architecture indicated SLB's positive effect on muscle condition in diabetic rats. Metabolomics profiling revealed that the STZ group significantly increased the phenylalanine-to-tyrosine ratio (PTR), lactate-to-pyruvate ratio (LPR), acetate, succinate, isobutyrate, and histidine. SLB administration restored these perturbed serum metabolites in the STZ-induced diabetic group. In conclusion, salbutamol significantly protected against skeletal muscle wasting in STZ-induced diabetic rats.

Salbutamol Attenuates Diabetic Skeletal Muscle Atrophy by Reducing Oxidative Stress, Myostatin/GDF-8, and Pro-Inflammatory Cytokines in Rats

Type 2 diabetes is a metabolic disorder that leads to accelerated skeletal muscle atrophy. In this study, we aimed to evaluate the effect of salbutamol (SLB) on skeletal muscle atrophy in high-fat diet (HFD)/streptozotocin (STZ)-induced diabetic rats. Male Sprague Dawley rats were divided into four groups (n = 6): control, SLB, HFD/STZ, and HFD/STZ + SLB (6 mg/kg orally for four weeks). After the last dose of SLB, rats were assessed for muscle grip strength and muscle coordination (wire-hanging, rotarod, footprint, and actophotometer tests). Body composition was analyzed in live rats. After that, animals were sacrificed, and serum and gastrocnemius (GN) muscles were collected. Endpoints include myofibrillar protein content, muscle oxidative stress and antioxidants, serum pro-inflammatory cytokines (interleukin-1β, interleukin-2, and interleukin-6), serum muscle markers (myostatin, creatine kinase, and testosterone), histopathology, and muscle 1H NMR metabolomics. Findings showed that SLB treatment significantly improved muscle strength and muscle coordination, as well as increased lean muscle mass in diabetic rats. Increased pro-inflammatory cytokines and muscle markers (myostatin, creatine kinase) indicate muscle deterioration in diabetic rats, while SLB intervention restored the same. Also, Feret's diameter and cross-sectional area of GN muscle were increased by SLB treatment, indicating the amelioration in diabetic rat muscle. Results of muscle metabolomics exhibit that SLB treatment resulted in the restoration of perturbed metabolites, including histidine-to-tyrosine, phenylalanine-to-tyrosine, and glutamate-to-glutamine ratios and succinate, sarcosine, and 3-hydroxybutyrate (3HB) in diabetic rats. These metabolites showed a pertinent role in muscle inflammation and oxidative stress in diabetic rats. In conclusion, findings showed that salbutamol could be explored as an intervention in diabetic-associated skeletal muscle atrophy.

Activation of β2-Adrenergic Receptors in Microglia Alleviates Neuropathic Hypersensitivity in Mice

Drugs enhancing the availability of noradrenaline are gaining prominence in the therapy of chronic neuropathic pain. However, underlying mechanisms are not well understood, and research has thus far focused on α2-adrenergic receptors and neuronal excitability. Adrenergic receptors are also expressed on glial cells, but their roles toward antinociception are not well deciphered. This study addresses the contribution of β2-adrenergic receptors (β2-ARs) to the therapeutic modulation of neuropathic pain in mice. We report that selective activation of β2-ARs with Formoterol inhibits pro-inflammatory signaling in microglia ex vivo and nerve injury-induced structural remodeling and functional activation of microglia in vivo. Systemic delivery of Formoterol inhibits behaviors related to neuropathic pain, such as mechanical hypersensitivity, cold allodynia as well as the aversive component of pain, and reverses chronically established neuropathic pain. Using conditional gene targeting for microglia-specific deletion of β2-ARs, we demonstrate that the anti-allodynic effects of Formoterol are primarily mediated by microglia. Although Formoterol also reduces astrogliosis at late stages of neuropathic pain, these functions are unrelated to β2-AR signaling in microglia. Our results underline the value of developing microglial β2-AR agonists for relief from neuropathic pain and clarify mechanistic underpinnings.

Targeting the Beta-2-Adrenergic Receptor and the Risk of Developing Alzheimer's Disease: A Retrospective Inception Cohort Study

Background:

Animal studies suggested that β2-Adrenergic receptors (β2AR) may be a potential target for the treatment of Alzheimer’s disease (AD).

Objective:

This retrospective inception cohort study aimed to assess the association between antagonists and agonists of the β2AR and the risk of starting treatment for AD in older adults.

Methods:

A retrospective inception cohort study was conducted among older adults who initiated either non-selective βAR antagonists or selective β2AR agonists using the University Groningen IADB.nl prescription database (study period 1994–2019). For each exposed cohort, two reference cohorts (A and B) were matched on age at index date. The main outcome was defined as at least two prescriptions for cholinesterase inhibitors (rivastigmine, galantamine, and donepezil) and/or memantine. Cox proportional hazard regression models were used to estimate hazard ratios (HR).

Results:

The risk of developing AD was elevated among patients exposed to non-selective βAR antagonists (A: aHR 3.303, 95% CI 1.230–8.869, B: aHR 1.569, 95% CI 0.560–4.394) and reduced among patients exposed to selective β2AR agonists (A: aHR 0.049, 95% CI 0.003–0.795, B: aHR 0.834, 95% CI 0.075–9.273) compared to reference patients.

Conclusion:

These findings suggest that exposure to non-selective βAR antagonists is associated with an increased risk for developing AD whereas there may be a decreased risk for developing AD after exposure to selective β2AR agonists.

Systems Biology–Derived Genetic Signatures of Mastitis in Dairy Cattle: A New Avenue for Drug Repurposing

Simple Summary

Therapeutic success of bovine mastitis depends mainly on accurately diagnosing the type of pathogen involved. Despite the development prospects for bovine mastitis diagnosis, including new biomarker discovery to target specific pathogens with high sensitivity and specificity, treatment studies have shown controversial results, and the most efficient, safe, and economical treatments for mastitis are still topics of scientific debate. The goal of this research is the integration of different levels of systems biology data to predict candidate drugs for the control and management of E. coli mastitis. We propose that the novel drugs could be used by pharmaceutical scientists or veterinarians to find commercially efficacious medicines.

Abstract

Mastitis, a disease with high incidence worldwide, is the most prevalent and costly disease in the dairy industry. Gram-negative bacteria such as Escherichia coli (E. coli) are assumed to be among the leading agents causing acute severe infection with clinical signs. E. Coli, environmental mastitis pathogens, are the primary etiological agents of bovine mastitis in well-managed dairy farms. Response to E. Coli infection has a complex pattern affected by genetic and environmental parameters. On the other hand, the efficacy of antibiotics and/or anti-inflammatory treatment in E. coli mastitis is still a topic of scientific debate, and studies on the treatment of clinical cases show conflicting results. Unraveling the bio-signature of mastitis in dairy cattle can open new avenues for drug repurposing. In the current research, a novel, semi-supervised heterogeneous label propagation algorithm named Heter-LP, which applies both local and global network features for data integration, was used to potentially identify novel therapeutic avenues for the treatment of E. coli mastitis. Online data repositories relevant to known diseases, drugs, and gene targets, along with other specialized biological information for E. coli mastitis, including critical genes with robust bio-signatures, drugs, and related disorders, were used as input data for analysis with the Heter-LP algorithm. Our research identified novel drugs such as Glibenclamide, Ipratropium, Salbutamol, and Carbidopa as possible therapeutics that could be used against E. coli mastitis. Predicted relationships can be used by pharmaceutical scientists or veterinarians to find commercially efficacious medicines or a combination of two or more active compounds to treat this infectious disease.

Standardized study of atorvastatin possible osteoarthritis disease-modifying effect in a rat model of osteoarthritis

We studied the osteoarthritis (OA)-modifying effects of atorvastatin in an experimental OA rat model and possible underlining mechanisms. We used 62 adult male Sprague-Dawley rats (250-300 g): 32 rats were used to assess the effects of atorvastatin on surgically induced OA in the knee, and 30 rats were used to assess the potential inflammatory effects of carrageenan-induced paw edema. In the OA model, joint stiffness was assessed by measuring the knee extension angle, and pathological changes in the OA knee joint were determined by histological examination and the measurement of serum biochemical markers, including interleukin-1β (IL-1β), matrix metalloproteinase-13 (MMP-13), and reduced glutathione (GSH). In the carrageenan-induced paw edema model, both paw thickness and pain threshold were assessed in different groups. Atorvastatin significantly improved joint stiffness, pathological changes, a significant mitigation of the higher MMP-13 and IL-1β, and a significant increase of reduced GSH in OA rats. Additionally, atorvastatin significantly improved both paw thickness and pain threshold in animals. Atorvastatin is a potential OA-modifying drug that warrants further clinical investigation.

Systemic administration of a β2-adrenergic receptor agonist reduces mechanical allodynia and suppresses the immune response to surgery in a rat model of persistent post-incisional hypersensitivity

Beta 2 adrenergic receptor (β2 AR) activation in the central and peripheral nervous system has been implicated in nociceptive processing in acute and chronic pain settings with anti-inflammatory and anti-allodynic effects of β2-AR mimetics reported in several pain states. In the current study, we examined the therapeutic efficacy of the β2-AR agonist clenbuterol in a rat model of persistent postsurgical hypersensitivity induced by disruption of descending noradrenergic signaling in rats with plantar incision. We used growth curve modeling of ipsilateral mechanical paw withdrawal thresholds following incision to examine effects of treatment on postoperative trajectories. Depletion of spinal noradrenergic neurons delayed recovery of hypersensitivity following incision evident as a flattened slope compared to non-depleted rats (-1.8 g/day with 95% CI -2.4 to -1.085, p < 0.0001). Chronic administration of clenbuterol reduced mechanical hypersensitivity evident as a greater initial intercept in noradrenergic depleted (6.2 g with 95% CI 1.6 to 10.8, p = 0.013) and non-depleted rats (5.4 g with 95% CI 1.2 to 9.6, p = 0.018) with plantar incision compared to vehicle treated rats. Despite a persistent reduction in mechanical hypersensitivity, clenbuterol did not alter the slope of recovery when modeled over several days (p = 0.053) or five weeks in depleted rats (p = 0.64). Systemic clenbuterol suppressed the enhanced microglial activation in depleted rats and reduced the density of macrophage at the site of incision. Direct spinal infusion of clenbuterol failed to reduce mechanical hypersensitivity in depleted rats with incision suggesting that beneficial effects of β2-AR stimulation in this model are largely peripherally mediated. Lastly, we examined β2-AR distribution in the spinal cord and skin using in-situ hybridization and IHC. These data add to our understanding of the role of β2-ARs in the nervous system on hypersensitivity after surgical incision and extend previously observed anti-inflammatory actions of β2-AR agonists to models of surgical injury.

Circular Dichroism Spectroscopy Identifies the β-Adrenoceptor Agonist Salbutamol As a Direct Inhibitor of Tau Filament Formation in Vitro

Potential drug treatments for Alzheimer's disease (AD) may be found by identifying compounds that block the assembly of the microtubule-associated protein tau into neurofibrillar tangles associated with neuron destabilization and cell death. Here, a small library of structurally diverse compounds was screened in vitro for the ability to inhibit tau aggregation, using high-throughput synchrotron radiation circular dichroism as a novel tool to monitor the structural changes in the protein as it assembles into filaments. The catecholamine epinephrine was found to be the most effective tau aggregation inhibitor of all 88 screened compounds. Subsequently, we tested chemically similar phenolamine drugs from the β-adrenergic receptor agonist class, using conventional circular dichroism spectroscopy, thioflavin T fluorescence, and transmission electron microscopy. Two compounds, salbutamol and dobutamine, used widely in the treatment of respiratory and cardiovascular disease, impede the aggregation of tau in vitro. Dobutamine reduces both the rate and yield of tau filament formation over 24 h; however, it has little effect on the structural transition of tau into β-sheet structures over 24 h. Salbutamol also reduces the yield and rate of filament formation and additionally inhibits tau's structural change into β-sheet-rich aggregates. Salbutamol has a good safety profile and a half-life that facilitates permeation through the blood-brain barrier and could represent an expediated approach to developing AD therapeutics. These results provide the motivation for the in vivo evaluation of pre-existing β-adrenergic receptor agonists as a potential therapy for AD through the reduction of tau deposition.

Impairment of endothelial progenitor cells function in patient with mustard gas intoxication

Background: Sulfur mustard (SM), also known as mustard gas, was first widely used in the Iraq-Iran. After SM exposure, the most prominent clinical signs are the development of extensive non-healing skin wounds and pulmonary signs, persisting over long time. Since the most frequent complications in SM-intoxicated patients are respiratory and dermatologic lesions, and with respect to the important role of endothelial progenitor cells (EPCs) in the pathophysiology of these lesion, we conducted this study to recognize the potential effects of SM on biological features of EPCs in patients exposed with this gas.Methods: In this study, 30 patients with the history of SM exposure during the Iran-Iraq war (1984-1988), 27 patients with pulmonary signs with no history of SM exposure and 20 healthy participants were included. Cell population and function of EPCs were assessed 4 years post-exposure. For this purpose, circulating EPCs (cEPCs) were harvested and cultivated, then the biological features of these cells, including migratory, proliferative, and tubulogenic activities were analyzed. We also measured serum antioxidants levels and mRNA levels of some proangiogenic factors in EPCs from SM-intoxicated patients.Results: Our results showed lesser number of cEPCs in patients exposed with SM, which was associated with decreased proliferative, migratory, and tubulogenic activity of these cells. Also, we found the lesser serum activity of SOD, GPX and MDA in the SM group than in the healthy control group.Conclusions: SM exposure resulted in decreased proliferation and migration of EPCs, which was associated with decreased tubule formation and angiogenic factors.

(R)-Salbutamol Improves Imiquimod-Induced Psoriasis-Like Skin Dermatitis by Regulating the Th17/Tregs Balance and Glycerophospholipid Metabolism

Psoriasis is a skin disease that is characterized by a high degree of inflammation caused by immune dysfunction. (R)-salbutamol is a bronchodilator for asthma and was reported to alleviate immune system reactions in several diseases. In this study, using imiquimod (IMQ)-induced mouse psoriasis-like dermatitis model, we evaluated the therapeutic effects of (R)-salbutamol in psoriasis in vivo, and explored the metabolic pathway involved. The results showed that, compared with IMQ group, (R)-salbutamol treatment significantly ameliorated psoriasis, reversed the suppressive effects of IMQ on differentiation, extreme keratinocyte proliferation, and infiltration of inflammatory cells. Enzyme-linked immunosorbent assays (ELISA) showed that (R)-salbutamol markedly reduced the plasma levels of IL-17. Cell analysis using flow cytometry showed that (R)-salbutamol decreased the proportion of CD4+ Th17+ T cells (Th17), whereas it increased the percentage of CD25+ Foxp3+ regulatory T cells (Tregs) in the spleens. (R)-salbutamol also decreased the weight ratio of spleen to body. Furthermore, untargeted metabolomics showed that (R)-salbutamol affected three metabolic pathways, including (i) arachidonic acid metabolism, (ii) sphingolipid metabolism, and (iii) glycerophospholipid metabolism. These results demonstrated that (R)-salbutamol can alleviate IMQ-induced psoriasis through regulating Th17/Tregs cell response and glycerophospholipid metabolism. It may provide a new use of (R)-salbutamol in the management of psoriasis.

Effect of (R)-salbutamol on the switch of phenotype and metabolic pattern in LPS-induced macrophage cells

Evidence demonstrates that M1 macrophage polarization promotes inflammatory disease. Here, we discovered that (R)‐salbutamol, a β₂ receptor agonist, inhibits and reprograms the cellular metabolism of RAW264.7 macrophages. (R)‐salbutamol significantly inhibited LPS‐induced M1 macrophage polarization and downregulated expressions of typical M1 macrophage cytokines, including monocyte chemotactic protein‐1 (MCP‐1), interleukin‐1β (IL‐1β) and tumour necrosis factor α (TNF‐α). Also, (R)‐salbutamol significantly decreased the production of inducible nitric oxide synthase (iNOS), nitric oxide (NO) and reactive oxygen species (ROS), while increasing the reduced glutathione (GSH)/oxidized glutathione (GSSG) ratio. In contrast, (S)‐salbutamol increased the production of NO and ROS. Bioenergetic profiles showed that (R)‐salbutamol significantly reduced aerobic glycolysis and enhanced mitochondrial respiration. Untargeted metabolomics analysis demonstrated that (R)‐salbutamol modulated metabolic pathways, of which three metabolic pathways, namely, (a) phenylalanine metabolism, (b) the pentose phosphate pathway and (c) glycerophospholipid metabolism were the most noticeably impacted pathways. The effects of (R)‐salbutamol on M1 polarization were inhibited by a specific β₂ receptor antagonist, ICI‐118551. These findings demonstrated that (R)‐salbutamol inhibits the M1 phenotype by downregulating aerobic glycolysis and glycerophospholipid metabolism, which may propose (R)‐salbutamol as the major pharmacologically active component of racemic salbutamol for the treatment of inflammatory diseases and highlight the medicinal value of (R)‐salbutamol.

Anti-inflammatory and antioxidant properties of jervine, a sterodial alkaloid from rhizomes of Veratrum album

BACKGROUND

Veratrum, hellebore is an important plant species of the Liliaceae family and jervine is the characteristic steroidal alkaloid constituent of Veratrum album.

PURPOSE

In the current study, anti-inflammatory and antioxidant effects of jervine isolated from NH₄OH-benzene extract of V. album rhizomes were investigated on CAR induced paw edema in rats.

METHODS/STUDY DESIGN

In inflammatory study, 50, 100, 200 and 400  mg/kg doses of jervine, 25  mg/kg doses of DIC and IND were orally administered, and the volume of the foots were measured up to their knee arthrosis by plethismometer. After one hour of the oral administration of the all treatments, 0.1 ml of CAR solution (1%) was injected into the foot of the all rat groups and the volume of the foots were measured during 5 h after CAR injection. GPx, SOD, GR, MPO, CAT enzymes activities and GSH, LPO levels of the supernatants of paw homogenates and inflammation biomarkers such as TNF-α and IL-1β in the rats serums were also estimated.

RESULTS

According to the present results, jervine exerted 50.4-73.5% anti-inflammatory effects in carrageenan induced paw edema. Inflammation biomarkers such as TNF-α, IL-1β and MPO that increased by CAR injection were suppressed by the administrations of all doses of jervine, IND and DIC. In all paw tissues, LPO levels as indicator of oxidative tissue damage were found to be high in CAR-treated group and it was found to be decreased in all doses of jervine.

CONCLUSION

Jervine, DIC and IND reduced the negative effects of CAR due to increasing effects on the SOD, CAT, GSH, GPx and GR antioxidants.

Formoterol treatment prevents the effects of endotoxin on muscle TNF/NF-kB, Akt/mTOR, and proteolytic pathways in a rat model. Role of IGF-I and miRNA 29b

Inflammatory diseases are associated with muscle wasting as a result of an increase in proteolysis. The purpose of this study was to elucidate whether administration of a β2 adrenergic agonist, formoterol, was able to prevent the acute effects of sepsis induced by liposaccharide (LPS) injection on rat gastrocnemius muscle and to evaluate the possible roles of corticosterone, IGF-I, miR-23a, and miR-29b. For this purpose, male Wistar rats were injected with LPS and/or formoterol. Formoterol treatment decreased LPS-induced increase in serum corticosterone, TNFα upregulation, and NF-κB(p65) and Forkhead box protein O1 activation in the gastrocnemius. Atrogin-1, muscle RING-finger protein-1, microtubule-associated protein-1 light chain 3b (LC3b), and the lipidation of LC3b-I to LC3b-II were increased by LPS, and formoterol blocked these effects. Serum IGF-I and its mRNA levels in the gastrocnemius were decreased, whereas mecano growth factor and IGF binding protein 3 mRNA levels were increased in the rats injected with LPS but not in the rats that received LPS and formoterol. Similarly, LPS decreased Akt and mammalian target of rapamycin phosphorylation, and formoterol blocked these decreases. Finally, miR-29b expression in the gastrocnemius was upregulated by endotoxin injection, whereas miR-23a was not significantly different. Formoterol treatment did not significantly modify LPS-induced increase in muscle miR-29b. Furthermore, in control rats formoterol increased the expression of this miRNA. We conclude that formoterol decreases endotoxin-induced inflammation and proteolysis in rat skeletal muscle. Those responses can be a direct effect of β2 adrenergic receptor stimulation or/and of blocking the effects of LPS on corticosterone and IGF-I. Muscle miR-23a and -29b do not seem to play an important role in those responses.

The exogenous administration of CB2 specific agonist, GW405833, inhibits inflammation by reducing cytokine production and oxidative stress

The present study aimed to investigate the role of cannabinoid 2 (CB2) receptors in a rat model of acute inflammation. Therefore, the potential of anti-inflammatory effects of CB2 receptor agonist (GW405833), CB2 receptor antagonist (AM630), and diclofenac, were investigated in carrageenan induced paw oedema in rats: as were assessed by measuring paw oedema; myeloperoxidase (MPO) activity in paw tissue; malondialdehyde (MDA) concentration; glutathione (GSH) level in paw tissue for oxidant/antioxidant balance; cytokine (interleukin-1β, IL-1β; tumour necrosis factor-α, TNF-α) levels in serum; histopathology of paw tissue for inflammatory cell accumulations. The results showed that GW405833 or diclofenac significantly reduced carrageenan-induced paw oedema. GW405833 also inhibited the increase of MPO activity, the recruitment of total leukocytes and neutrophils, and MDA concentration during carrageenan-induced acute inflammation, along with reversed nearly to the normal levels the increased of TNF-α, and IL-1β in serum. AM630 did not affect inflammation alone however clearly reversed the effects of agonist when co-administered. The mechanism of GW405833's suppression of inflammation is supported by these results, which are achieved by the inhibition of neutrophil migration, which regulates the reduction of oxidative stress, TNF-α and IL-1β levels. Finally, the activation of CB2 receptor, by selective agonist, has a major role in peripheral inflammation, and in the near future, targeting the peripheral cannabinoid system as a promising alternative to treat inflammation diseases may be considered a novel pharmacologic approach.

Chemical Profile and Anti-inflammatory Activity of Total Flavonoids from Glycyrrhiza Uralensis Fisch

Glycyrrhiza uralensis Fisch. (G. uralensis) is one of the most widely used herbal medicines. This study was designed to enrich total flavonoids (TFF) from G. uralensis. The chemical profile of TFF was identified by HPLC and colorimetric assay. The TFF mainly contained liquiritin apioside, liquiritin, isoliquiritin apioside, liquiritigenin and isoliquiritigenin without glycyrrhizic acid. To study the anti-inflammatory activity of TFF, the DMB-induced ear vasodilatation assay and carrageenan-induced rat paw edema model have been utilized. Treatment with TFF showed significant anti-inflammatory activities in the two models. The two in-vivo edema assays demonstrated that the TFF possesses significant dose-dependent anti-inflammatory activity, similar to that of indomethacin at a dose of 500 mg/kg. In rat paws with carrageenan, treatment with TFF (500 and 250 mg/kg) markedly inhibited the expression of IL-1β and iNOS. TFF at all doses noticeably decreased levels of NO and MDA at the site of inflammation, while only i.g. TFF at a dose of 500 mg/kg significantly decreased TNF-α levels in the carrageenan-injected paws. In addition, an increase in SOD activity was induced by TFF at all doses. These results revealed that TFF exhibited significant anti-inflammatory activity in acute inflammatory models.

Mast cells and pro-inflammatory cytokines roles in assessment of grape seeds extract anti-inflammatory activity in rat model of carrageenan-induced paw edema

OBJECTIVES

Reactive oxygen species (ROS)-produced oxidative disorders were involved at the pathophysiology of many inflammatory processes via the generation of pro-inflammatory cytokines and antioxidant defense system suppression. Although herbal antioxidants as mono-therapy relief many inflammatory diseases including, autoimmunity rheumatoid arthritis, but as combination therapy with other proven anti-inflammatory drugs in order to decreasing their toxic impacts has not yet been studied clearly, especially against chemical substances that's induced local inflammation with characteristic edema.

MATERIALS AND METHODS

Grape seeds extract (GSE) at a concentration of 40 mg/kg B. wt alone or in combination with indomethacin (Indo.) at a dose of 5 mg/Kg B. wt orally given for 10 days prior (gps VI, VII, VIII) or as a single dose after edema induction (gps IX, X, XI) in rat's left hind paw by sub-planter single injection of 0.1 carrageenan: saline solution (1%) (gp. V) to assess the prophylactic and therapeutic anti-inflammatory activities of both through the estimation of selective inflammatory mediators and oxidative damage-related biomarkers as well as tissue mast cell scoring. Furthermore, both substances were given alone (gps II, III, IV) for their blood, liver and kidney safety evaluation comparing with negative control rats (gp. I) which kept without medication.

RESULTS

A marked reduction on the inflammatory mediators, edema volume and oxidative byproducts in edema bearing rats' prophylactic and treated with grape seeds extract and indomethacin was observed. Indomethacin found to induce some toxicological impacts which minimized when administered together with GSE.

CONCLUSION

GSE is a safe antioxidant agent with anti-inflammatory property.

β2-receptor agonists salbutamol and terbutaline attenuated cytokine production by suppressing ERK pathway through cAMP in macrophages

β₂-receptor agonists are used in the treatment of inflammatory obstructive lung diseases asthma and COPD as a symptomatic remedy, but they have been suggested to possess anti-inflammatory properties, also. β₂-receptor activation is considered to lead to the activation of ERK pathway through G-protein- and cAMP-independent mechanisms. In this study, we investigated the effects of β₂-receptor agonists salbutamol and terbutaline on the production of inflammatory factors in macrophages. We found that β₂-receptor agonists inhibited LPS-induced ERK phosphorylation and the production of MCP-1. A chemical cAMP analog 8-Br-cAMP also inhibited ERK phosphorylation and TNF and MCP-1 release. As expected, MAPK/ERK kinase (MEK)1/2 inhibitor PD0325901 inhibited ERK phosphorylation and suppressed both TNF and MCP-1 production. In conclusion, we suggest that β₂-receptor agonists salbutamol and terbutaline inhibit inflammatory gene expression partly by a mechanism dependent on cAMP leading to the inhibition of ERK signaling in macrophages. Observed anti-inflammatory effects of β₂-receptor agonists may contribute to the clinical effects of these drugs.

Effects of salbutamol on the inflammatory parameters and angiogenesis in the rat air pouch model of inflammation

In the present study, effects of salbutamol on the inflammatory parameters, angiogenesis, interleukin-1 beta (IL-1β) and vascular endothelial growth factor (VEGF) levels were investigated in an air pouch model of inflammation. Inflammation was induced by intrapouch administration of 1% solution of sterile carrageenan in male Wistar rats. Salbutamol (125, 250 and 500 µg/rat) and salbutamol (500 µg/rat) plus propranolol (100 μg/rat) were injected intrapouch. After 6 and 72 h, fluid inside the pouches was collected to measure volume of exudates, leukocytes number and IL-1β levels. To determine angiogenesis, the granulation tissues were dissected out and weighed 3 days after carrageenan injection, then hemoglobin concentration was assessed using a hemoglobin assay kit. In addition, amount of VEGF in the exudates was measured 72 h after induction of inflammation. Leukocyte accumulation and the volume of exudates were significantly inhibited by salbutamol administration. In addition, salbutamol decreased the production of VEGF and IL-1β. Moreover, all used doses of salbutamol significantly inhibited angiogenesis. Interestingly, effects of salbutamol on the attenuation of angiogenesis and inflammatory parameters was similar to diclofenac sodium. Co-administration of propranolol with salbutamol clearly reversed anti-inflammatory effects of salbutamol. Salbutamol can decrease acute and chronic inflammation by β₂-adrenergic receptors activation. The observed IL-1β and VEGF inhibitory properties of salbutamol may be responsible for anti-inflammatory and anti-angiogenic effect of the agent.

Blocking of urotensin receptors as new target for treatment of carrageenan induced inflammation in rats

This study investigated possible role of U-II and its receptor expression in inflammation by using UTR agonist and antagonist in carrageenan induced acute inflammation. Rats were divided into 5 groups as (1) Healthy control, (2) Carrageenan control, (3) Carrageenan +Indomethacin 20mg/kg, orally, (4) Carrageenan +AC7954 (U-II receptor agonist, intraperitoneally) 30mg/kg and (5) Carrageenan +SB657510 (UTR antagonist, intraperitoneally) 30mg/kg. 1h after drug administration, carrageenan was injected. At the 3rd hour after carrageenan injection, agonist produced no effect while antagonist 63% anti-inflammatory effect respectively. UTR and UT-II expression increased in carrageenan induced paw tissue. Antagonist administration prevented the decrease in an antioxidant system and also capable to decrease TNF-α and IL-6 mRNA expressions. This study showed the role of urotensin II receptors in the physiopathogenesis of acute inflammatory response that underlying many diseases accompanied by inflammation.

Microemulsion-Based Topical Hydrogels of Tenoxicam for Treatment of Arthritis

Tenoxicam (TNX) is a non-steroidal anti-inflammatory drug (NSAID) used for the treatment of rheumatoid arthritis, osteoarthritis, ankylosing spondylitis, backache and pain. However, prolonged oral use of this drug is associated with gastrointestinal adverse events like peptic ulceration, thus necessitating its development as topical formulation that could obviate the adverse effects and improve patient compliance. The present study was aimed at development of microemulsion-based formulations of TNX for topical delivery at the affected site. The pseudoternary phase diagrams were developed and microemulsion formulations were prepared using Captex 300/oleic acid as oil, Tween 80 as surfactant and n-butanol/ethanol as co-surfactant. Optimized microemulsions were characterized for drug content, droplet size, viscosity, pH and zeta potential. The ex vivo permeation studies through Laca mice skin were performed using Franz diffusion cell assembly, and the permeation profile of the microemulsion formulation was compared with aqueous suspension of drug and drug incorporated in conventional cream. Microemulsion formulations of TNX showed significantly higher (p < 0.001) mean cumulative percent permeation values in comparison to conventional cream and suspension of drug. In vivo anti-arthritic and anti-inflammatory activity of the developed TNX formulations was evaluated using various inflammatory models such as air pouch model, xylene-induced ear edema, cotton pellet granuloma and carrageenan-induced inflammation. Microemulsion formulations were found to be superior in controlling inflammation as compared to conventional topical dosage forms and showed efficacy equivalent to oral formulation. Results suggest that the developed microemulsion formulations may be used for effective topical delivery of TNX to treat various inflammatory conditions.

Formoterol decreases muscle wasting as well as inflammation in the rat model of rheumatoid arthritis

Adjuvant-induced arthritis is an experimental model of rheumatoid arthritis that is associated with body weight loss and muscle wasting. β2-adrenergic receptor agonists are powerful anabolic agents that trigger skeletal muscle hypertrophy and have been proposed as a promising treatment for muscle wasting in human patients. The aim of this work was to determine whether formoterol, a selective β2-adrenoreceptor agonist, is able to ameliorate muscle wasting in arthritic rats. Arthritis was induced in male Wistar rats by intradermal injection of Freund's adjuvant. Control and arthritic rats were injected daily with 50 μg/kg sc formoterol or saline for 12 days. Body weight change, food intake, and arthritis index were analyzed. After euthanasia, in the gastrocnemius mRNA was analyzed by PCR, and proteins were analyzed by Western blotting. Arthritis decreased gastrocnemius weight, cross-sectional area, and myofiber size, whereas formoterol increased those variables in both arthritic and control rats. Formoterol decreased the external signs of arthritis as well as NF-κB(p65) activation, TNFα, and COX-2 levels in the gastrocnemius of arthritic and control rats. Those effects of formoterol were associated with a decreased expression of myostatin, atrogin-1, and MuRF1 and in LC3b lipidation. Arthritis increased the expression of MyoD, myogenin, IGF-I, and IGFBP-3 and -5 in the gastrocnemius. In control and in arthritic rats, treatment with formoterol increased Akt phosphorylation and myogenin levels, whereas it decreased IGFBP-3 expression in the gastrocnemius. These data suggest that formoterol has an anti-inflammatory effect and decreases muscle wasting in arthritic rats through increasing Akt activity and myogenin and decreasing myostatin, the p-NF-κB(p65)/TNF pathway, and IGFBP-3.

An association between neuropeptide Y levels and leukocyte subsets in stress-exacerbated asthmatic mice

Neuropeptide Y (NPY) was recently proposed to be associated with stress and airway inflammation; however, this has rarely been studied in animal models of asthma. Twenty-four C57BL/6 mice were randomly divided into 3 groups of 8 each: naive control group, asthma group (with an established asthma model), and stressed asthma group (with established asthma and stress models). Bronchoalveolar lavage (BAL) fluid was collected for total cell counts using a hemocytometer and for cytological examinations by Wright stain. Differential inflammatory cell counts were performed to identify eosinophils, macrophages, neutrophils, and lymphocytes. NPY and corticosterone serum levels were determined with enzyme immunoassay kits. Stress was associated with increased airway inflammatory response, which was manifested by the accumulation of total leukocytes and eosinophils in the BAL fluid in comparison with the asthma and the control groups. The levels of NPY (p<0.05) and corticosterone (p<0.01) were elevated in the stressed asthma group in comparison with the control and asthma groups. The concentration of NPY and corticosterone positively correlated with the total leukocyte count (r=0.892, p<0.05 and r=0.937, p<0.01 respectively) and eosinophil numbers (r=0.806, p=0.053 and r=0.885, p<0.01 respectively). Stress may be associated with elevated peripheral NPY level, which was observed to be associated with exacerbated airway inflammation in asthmatic mice.

Anti-Inflammatory Effects of β2-Receptor Agonists Salbutamol and Terbutaline Are Mediated by MKP-1

Mitogen-activated protein kinase phosphatase 1 (MKP-1) expression is induced by inflammatory factors, and it is an endogenous suppressor of inflammatory response. MKP-1 expression is increased by PDE4 inhibitor rolipram suggesting that it is regulated by cAMP-enhancing compounds. Therefore, we investigated the effect of β₂-receptor agonists on MKP-1 expression and inflammatory response. We found that β₂-receptor agonists salbutamol and terbutaline, as well as 8-Br-cAMP, increased MKP-1 expression. Salbutamol and terbutaline also inhibited p38 MAPK phosphorylation and TNF production in J774 mouse macrophages. Interestingly, salbutamol suppressed carrageenan-induced paw inflammation in wild-type mice, but the effect was attenuated in MKP-1(-/-) mice. In conclusion, these data show that β₂-receptor agonists increase MKP-1 expression, which seems to mediate, at least partly, the observed anti-inflammatory effects of β₂-receptor agonists.

In vivo and in vitro anti-inflammatory activity of Cryptostegia grandiflora Roxb. ex R. Br. leaves

Background

Despite Cryptostegia grandiflora Roxb. ex R. Br. (Apocynaceae) leaves are widely used in folk Caribbean Colombian medicine for their anti-inflammatory effects, there are no studies that support this traditional use. Therefore, this work aimed to evaluate the effect of the total extract and primary fractions obtained from Cryptostegia grandiflora leaves, using in vivo and in vitro models of inflammation, and further get new insights on the mechanisms involved in this activity.

Results

Ethanolic extract of Cryptostegia grandiflora leaves, and its corresponding ether and dichloromethane fractions, significantly reduced inflammation and myeloperoxidase activity (MPO) in ear tissue of mice treated with 12-O-tetradecanoyl-phorbol-13-acetate (TPA). Histological analysis revealed a reduction of edema and leukocyte infiltration. Complementarily, we demonstrated that extract and fractions reduced nitric oxide (NO•) and prostaglandin E2 (PGE2) production in LPS-stimulated RAW 264.7 macrophages, as well as scavenging activity on DPPH and ABTS radicals.

Conclusions

Our results demonstrated for the first time the anti-inflammatory activity of Cryptostegia grandiflora leaves, supporting its traditional use. This activity was related to inhibition of MPO activity, and PGE2 and NO• production. These mechanisms and its antioxidant activity could contribute, at least in part, to the anti-inflammatory effect showed by this plant.

Assessment of different energy delivery settings in laser and LED phototherapies in the inflammatory process of rat's TMJ induced by carrageenan

Temporomandibular disorders (TMDs) are mostly inflammatory conditions widespread in the population. Previous studies have shown positive effects of either laser or light-emitting diode (LED) phototherapies on treating TMDs, but their action and mechanism in the inflammatory infiltrate of the temporomandibular joint are still poorly understood. The aim of this study was to assess, through histological analysis, the effectiveness of using laser light (λ 780 nm, 70 mW, continous wave (CW), 10 J) and LED (λ 850 ± 10 nm, 100 mW, CW, 10 J) on the inflammation of the temporomandibular joint of rats induced by carrageenan. Forty-five animals were divided into three groups with five animals each according to the experimental times of 2, 3, and 7 days: inflammation, inflammation+laser phototherapy, and inflammation+LED phototherapy. The first irradiation was performed 24 h after induction with an interval of 48 h between sessions. After animal death, specimens were processed and stained with hematoxylin-eosin (HE) and picrosirius. Then, the samples were examined histologically. Data were statistically analyzed. The inflammation group showed mild to moderate chronic inflammatory infiltrate between bone trabecules of the condyle. Over the time course of the study in the laser group, the region of the condyle presented mild chronic inflammation and intense vascularization. In the LED group, the condyle showed aspects of normality and absence of inflammation in some specimens. In all the time points, the laser-irradiated groups showed greater amount of collagen deposition in the condyle (p = 0.04) and in the disc (p = 0.03) when compared to the inflammation and LED groups, respectively. Laser- and LED-treated groups demonstrate a smaller number of layers of the synovial membrane when compared to the non-irradiated groups. It was concluded that, in general, laser and LED phototherapies resulted in a reduction of inflammatory infiltrate in the temporomandibular joint of rat.

Structure-bias relationships for fenoterol stereoisomers in six molecular and cellular assays at the β2-adrenoceptor

Functional selectivity is well established as an underlying concept of ligand-specific signaling via G protein-coupled receptors (GPCRs). Functionally, selective drugs could show greater therapeutic efficacy and fewer adverse effects. Dual coupling of the β2-adrenoceptor (β2AR) triggers a signal transduction via Gsα and Giα proteins. Here, we examined 12 fenoterol stereoisomers in six molecular and cellular assays. Using β2AR-Gsα and β2AR-Giα fusion proteins, (R,S')- and (S,S')-isomers of 4'-methoxy-1-naphthyl-fenoterol were identified as biased ligands with preference for Gs. G protein-independent signaling via β-arrestin-2 was disfavored by these ligands. Isolated human neutrophils constituted an ex vivo model of β2AR signaling and demonstrated functional selectivity through the dissociation of cAMP accumulation and the inhibition of formyl peptide-stimulated production of reactive oxygen species. Ligand bias was calculated using an operational model of agonism and revealed that the fenoterol scaffold constitutes a promising lead structure for the development of Gs-biased β2AR agonists.

Targeting α- and β-Adrenergic Receptors Differentially Shifts Th1, Th2, and Inflammatory Cytokine Profiles in Immune Organs to Attenuate Adjuvant Arthritis

The sympathetic nervous system (SNS) regulates host defense responses and restores homeostasis. SNS-immune regulation is altered in rheumatoid arthritis (RA) and rodent models of RA, characterized by nerve remodeling in immune organs and defective adrenergic receptor (AR) signaling to immune cell targets. The SNS typically promotes or suppresses inflammation via α- and β₂-AR activation, respectively, and indirectly drives humoral immunity by blocking Th1 cytokine secretion. Here, we investigate how β₂-AR stimulation and/or α-AR blockade at disease onset affects disease pathology and cytokine profiles in relevant immune organs from male Lewis rats with adjuvant-induced arthritis (AA). Rats challenged to induce AA were treated with terbutaline (TERB), a β₂-AR agonist (600 μg/kg/day) and/or phentolamine (PHEN), an α-AR antagonist (5.0 mg/kg/day) or vehicle from disease onset through severe disease. We report that in spleen, mesenteric (MLN) and draining lymph node (DLN) cells, TERB reduces proliferation, an effect independent of IL-2. TERB also fails to shift T helper (Th) cytokines from a Th1 to Th2 profile in spleen and MLN (no effect on IFN-γ) and DLN (greater IFN-γ) cells. In splenocytes, TERB, PHEN, and co-treatment (PT) promotes an anti-inflammatory profile (greater IL-10) and lowers TNF-α (PT only). In DLN cells, drug treatments do not affect inflammatory profiles, except PT, which raised IL-10. In MLN cells, TERB or PHEN lowers MLN cell secretion of TNF-α or IL-10, respectively. Collectively, our findings indicate disrupted β₂-AR, but not α-AR signaling in AA. Aberrant β₂-AR signaling consequently derails the sympathetic regulation of lymphocyte expansion, Th cell differentiation, and inflammation in the spleen, DLNs and MLs that is required for immune system homeostasis. Importantly, this study provides potential mechanisms through which reestablished balance between α- and β₂-AR function in the immune system ameliorates inflammation and joint destruction in AA.

Mustard Gas Inhalation Injury

Mustard gas (sulfur mustard [SM], bis-[2-chloroethyl] sulfide) is a vesicating chemical warfare agent and a potential chemical terrorism agent. Exposure of SM causes debilitating skin blisters (vesication) and injury to the eyes and the respiratory tract; of these, the respiratory injury, if severe, may even be fatal. Therefore, developing an effective therapeutic strategy to protect against SM-induced respiratory injury is an urgent priority of not only the US military but also the civilian antiterrorism agencies, for example, the Homeland Security. Toward developing a respiratory medical countermeasure for SM, four different classes of therapeutic compounds have been evaluated in the past: anti-inflammatory compounds, antioxidants, protease inhibitors and antiapoptotic compounds. This review examines all of these different options; however, it suggests that preventing cell death by inhibiting apoptosis seems to be a compelling strategy but possibly dependent on adjunct therapies using the other drugs, that is, anti-inflammatory, antioxidant, and protease inhibitor compounds.

Evaluation of coagulation activation after rhinovirus infection in patients with asthma and healthy control subjects: an observational study

Background

Asthma exacerbations are frequently triggered by rhinovirus infections. Both asthma and respiratory tract infection can activate haemostasis. Therefore we hypothesized that experimental rhinovirus-16 infection and asthmatic airway inflammation act in synergy on the haemostatic balance.

Methods

28 patients (14 patients with mild allergic asthma and 14 healthy non-allergic controls) were infected with low-dose rhinovirus type 16. Venous plasma and bronchoalveolar lavage fluid (BAL fluid) were obtained before and 6 days after infection to evaluate markers of coagulation activation, thrombin-antithrombin complexes, von Willebrand factor, plasmin-antiplasmin complexes, plasminogen activator inhibitor type-1, endogenous thrombin potential and tissue factor-exposing microparticles by fibrin generation test, in plasma and/or BAL fluid. Data were analysed by nonparametric tests (Wilcoxon, Mann Whitney and Spearman correlation).

Results

13 patients with mild asthma (6 females, 19-29 y) and 11 healthy controls (10 females, 19-31 y) had a documented Rhinovirus-16 infection. Rhinovirus-16 challenge resulted in a shortening of the fibrin generation test in BAL fluid of asthma patients (t = -1: 706 s vs. t = 6: 498 s; p = 0.02), but not of controls (t = -1: 693 s vs. t = 6: 636 s; p = 0.65). The fold change in tissue factor-exposing microparticles in BAL fluid inversely correlated with the fold changes in eosinophil cationic protein and myeloperoxidase in BAL fluid after virus infection (r = -0.517 and -0.528 resp., both p = 0.01).

Rhinovirus-16 challenge led to increased plasminogen activator inhibitor type-1 levels in plasma in patients with asthma (26.0 ng/mL vs. 11.5 ng/mL in healthy controls, p = 0.04). Rhinovirus-16 load in BAL showed a linear correlation with the fold change in endogenous thrombin potential, plasmin-antiplasmin complexes and plasminogen activator inhibitor type-1.

Conclusions

Experimental rhinovirus infection induces procoagulant changes in the airways of patients with asthma through increased activity of tissue factor-exposing microparticles. These microparticle-associated procoagulant changes are associated with both neutrophilic and eosinophilic inflammation. Systemic activation of haemostasis increases with Rhinoviral load.

Trial registration

This trial was registered at the Dutch trial registry (http://www.trialregister.nl): NTR1677.

Phytol, a diterpene alcohol, inhibits the inflammatory response by reducing cytokine production and oxidative stress

Studies have shown that diterpenes have anti-inflammatory and redox-protective pharmacological activities. The present study aimed to investigate the anti-inflammatory properties of phytol, a diterpene alcohol, in a mouse model of acute inflammation, and phytol effect on leukocyte recruitment, cytokines levels, and oxidative stress. The anti-inflammatory activities of phytol were assessed by measuring paw edema induced by different inflammatory agents (e.g., λ-carrageenan, compound 48/80, histamine, serotonin, bradykinin, and prostaglandin E2 [PGE2 ]), myeloperoxidase (MPO) activity, peritonitis model and cytokine levels. Further, oxidative stress was evaluated by determining glutathione (GSH) levels and malondialdehyde (MDA) concentration. The results showed that phytol (7.5, 25, 50, and 75 mg/kg) significantly reduced carrageenan-induced paw edema, in a dose-dependent manner. In addition, phytol (75 mg/kg) inhibited compound 48/80-, histamine-, serotonin-, bradykinin- and PGE2 -induced paw edema. It also inhibited the recruitment of total leukocytes and neutrophils; decreased MPO activity, tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) levels, and MDA concentration; and increased GSH levels during carrageenan-induced acute inflammation. These results suggest that phytol attenuates the inflammatory response by inhibiting neutrophil migration that is partly caused by reduction in IL-1β and TNF-α levels and oxidative stress.

Dissociations in the effects of β2-adrenergic receptor agonists on cAMP formation and superoxide production in human neutrophils: support for the concept of functional selectivity

In neutrophils, activation of the β2-adrenergic receptor (β2AR), a Gs-coupled receptor, inhibits inflammatory responses, which could be therapeutically exploited. The aim of this study was to evaluate the effects of various β2AR ligands on adenosine-3',5'-cyclic monophosphate (cAMP) accumulation and N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP)-induced superoxide anion (O2(•-)) production in human neutrophils and to probe the concept of ligand-specific receptor conformations (also referred to as functional selectivity or biased signaling) in a native cell system. This is an important question because so far, evidence for functional selectivity has been predominantly obtained with recombinant systems, due to the inherent difficulties to genetically manipulate human native cells. cAMP concentration was determined by HPLC/tandem mass spectrometry, and O2(•-) formation was assessed by superoxide dismutase-inhibitable reduction of ferricytochrome c. β2AR agonists were generally more potent in inhibiting fMLP-induced O2(•-) production than in stimulating cAMP accumulation. (-)-Ephedrine and dichloroisoproterenol were devoid of any agonistic activity in the cAMP assay, but partially inhibited fMLP-induced O2(•-) production. Moreover, (-)-adrenaline was equi-efficacious in both assays whereas the efficacy of salbutamol was more than two-fold higher in the O2(•-) assay. Functional selectivity was visualized by deviations of ligand potencies and efficacies from linear correlations for various parameters. We obtained no evidence for involvement of protein kinase A in the inhibition of fMLP-induced O2(•-) production after β2AR-stimulation although cAMP-increasing substances inhibited O2(•-) production. Taken together, our data corroborate the concept of ligand-specific receptor conformations with unique signaling capabilities in native human cells and suggest that the β2AR inhibits O2(•-) production in a cAMP-independent manner.

Anti-inflammatory effects and acute toxicity of hydroethanolic extract of Jacaranda decurrens roots in adult male rats

ETHNOPHARMACOLOGICAL RELEVANCE

Jacaranda decurrens subsp. symmetrifoliolata Farias and Proença (Bignoniaceae) is a species traditionally used for the treatment of inflammatory diseases. However, until this moment, there is no scientific evidence of these effects.

AIM OF STUDY

To evaluate the anti-inflammatory effects of hydroethanolic root extract of Jacaranda decurrens in rats and to determine the safe of this plant after acute exposure.

MATERIALS AND METHODS

The acute toxicity of Jacaranda decurrens root extract (EJD) was evaluated by oral administration to male rats as single doses of 0; 500; 1000 or 2000 mg/kg body weight. General behavior and toxic symptoms were observed for 14 days. The anti-inflammatory activity was evaluated in carrageenan-induced inflammatory paw edema and myeloperoxidase activity in male rats.

RESULTS

No signs of acute toxicity were observed, indicating that the LD(50) is greater than 2000 mg/kg. EJD (100 and 300 mg/kg) significantly reduced edema formation and at higher dose, the reduction was similar to dexamethasone. A significant decrease in myeloperoxidase activity was also observed.

CONCLUSIONS

The present study shows that Jacaranda decurrens extract has anti-inflammatory properties in rats without causing acute toxicity. These properties observed may be due to the presence of bioactive constituents such as ursolic acid.