Histamine H1-receptor antagonists inhibit nuclear factor-kappaB and activator protein-1 activities via H1-receptor-dependent and -independent mechanisms

Intranasal corticosteroids reduced acute rhinosinusitis in children with allergic rhinitis: A nested case-control study

BACKGROUND

Children with allergic rhinitis (AR) have substantially more acute rhinosinusitis than children without AR. We evaluated whether intranasal corticosteroids (INCS), second-generation antihistamines (SGH), and/or intranasal antihistamines (INH) for AR affect acute rhinosinusitis in children with AR aged 2-18 years.

METHODS

By using the National Health Research Institutes Database 2005 of Taiwan, a cohort of patients with AR aged 2-18 years treated with AR medications between 2002 and 2018 was made, within which a nested case-control study was performed. Risk settings for acute rhinosinusitis cases matched controls for age, sex, and comorbidities. Current users of INCS, INH, and/or SGH were compared with remote and recent users of any AR medications and current users of INCS with and without SGH were compared with current users of SGH.

RESULTS

Current users of SGH and/or INCS had a higher risk of acute rhinosinusitis than remote users of AR drugs, and current users of SGH had a higher risk of acute rhinosinusitis than recent users; however, no difference in the risk of acute rhinosinusitis was found between current users of INCS and recent users of AR drugs. Current users of INCS with and without SGH had a lower risk of acute rhinosinusitis than current users of SGH alone.

CONCLUSIONS

Treatment of INCS with and without SGH diminished the risk of acute rhinosinusitis compared with treatment using SGH alone. Adequate INCS treatment for patients with AR is important to reduce the incidence of acute rhinosinusitis.

Pharmacological Characterization of the Zebrafish (Danio Rerio) Histamine H1 Receptor Reveals the Involvement of the Second Extracellular Loop in the Binding of Histamine

The zebrafish (Danio rerio) histamine H1 receptor gene (zfH1R) was cloned in 2007 and reported to be involved in fish locomotion. Yet, no detailed characterization of its pharmacology and signaling properties have so far been reported. In this study, we pharmacologically characterized the zfH1R expressed in HEK-293T cells by means of [3H]-mepyramine binding and G protein-signaling assays. The zfH1R [dissociation constant (KD), 0.7 nM] displayed similar affinity for the antagonist [3H]-mepyramine as the human histamine H1 receptor (hH1R) (KD, 1.5 nM), whereas the affinity for histamine is 100-fold higher than for the human H1R. The zfH1R couples to Gαq/11 proteins and activates several reporter genes, i.e., NFAT, NFϰB, CRE, VEGF, COX-2, SRE, and AP-1, and zfH1R-mediated signaling is prevented by the Gαq/11 inhibitor YM-254890 and the antagonist mepyramine. Molecular modeling of the zfH1R and human H1R shows that the binding pockets are identical, implying that variations along the ligand binding pathway could underly the differences in histamine affinity instead. Targeting differentially charged residues in extracellular loop 2 (ECL2) using site-directed mutagenesis revealed that Arg21045x55 is most likely involved in the binding process of histamine in zfH1R. This study aids the understanding of the pharmacological differences between H1R orthologs and the role of ECL2 in histamine binding and provides fundamental information for the understanding of the histaminergic system in the zebrafish. SIGNIFICANCE STATEMENT: The use of the zebrafish as in vivo models in neuroscience is growing exponentially, which asks for detailed characterization of the aminergic neurotransmitter systems in this model. This study is the first to pharmacologically characterize the zebrafish histamine H1 receptor after expression in HEK-293T cells. The results show a high pharmacological and functional resemblance with the human ortholog but also reveal interesting structural differences and unveils an important role of the second extracellular loop in histamine binding.

Molecular mechanism of antihistamines recognition and regulation of the histamine H1 receptor

Histamine receptors are a group of G protein-coupled receptors (GPCRs) that play important roles in various physiological and pathophysiological conditions. Antihistamines that target the histamine H1 receptor (H1R) have been widely used to relieve the symptoms of allergy and inflammation. Here, to uncover the details of the regulation of H1R by the known second-generation antihistamines, thereby providing clues for the rational design of newer antihistamines, we determine the cryo-EM structure of H1R in the apo form and bound to different antihistamines. In addition to the deep hydrophobic cavity, we identify a secondary ligand-binding site in H1R, which potentially may support the introduction of new derivative groups to generate newer antihistamines. Furthermore, these structures show that antihistamines exert inverse regulation by utilizing a shared phenyl group that inserts into the deep cavity and block the movement of the toggle switch residue W4286.48. Together, these results enrich our understanding of GPCR modulation and facilitate the structure-based design of novel antihistamines.

Chlorpheniramine, an Old Drug with New Potential Clinical Applications: A Comprehensive Review of the Literature

Chlorpheniramine Maleate (CPM), also known as chlorphenamine, is a potent alkylamine first-generation H1 antihistamine that has been used since the 1950s. CPM is a widely popular drug commonly used to treat allergic conditions, given its antihistamine properties. Although mainly used in over-the-counter treatment for cough and colds, various studies discuss a wide range of CPM's clinical uses, such as treating asthma, plasma cell gingivitis, chronic urticaria, and depression, among others. This antihistamine is usually taken orally; however, intravenous, intramuscular, and subcutaneous routes have been documented. Intranasal routes of this drug have recently been explored, especially due to its antiviral properties against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Accordingly, given CPM's extensive medical and safety profile, the present review explores this versatile drug's current and potential clinical applications. Although it is widely used mainly for treating common colds and aforementioned allergic conditions, CPM can be used for other clinical indications. The repurposing of CPM for other clinical indications, such as COVID-19, needs to be further explored through more extensive studies.

Ameliorative effect of desloratadine against cisplatin-induced renal and testicular toxicity in rats: Attention to TLR4/NLRP3 inflammasome signaling pathway

Cisplatin (CIS) is a potent anticancer drug that is used in the treatment of different types of cancer. Owing to its serious side effects, its clinical use is considerably limited.

AIMS

This study was mapped to investigate the potential effects of desloratadine (DES) against CIS-induced nephrotoxicity and testicular injury.

MAIN METHODS

DES (5 and 10 mg/kg) was orally administered for 10 days, and CIS was injected once (10 mg/kg, i.p.) in adult male rats on day 9 to induce both renal and testicular toxicity.

KEY FINDINGS

DES significantly attenuated CIS-induced alterations in histopathology and biomarkers. DES resulted in a significant reduction in serum levels of creatinine (Cr), urea, and blood urea nitrogen (BUN), in addition to a marked decrease in urinary levels of albumin and total protein. Additionally, DES efficiently reinstated the oxidative balance by preventing the elevation of malondialdehyde (MDA) and enhancing superoxide dismutase (SOD) activity, and increasing glutathione (GSH) levels. Moreover, DES produced a profound decrease in renal and testicular levels of nucleotide-binding domain-(NOD) like receptor 3 (NLRP3), interleukin (IL)-1β, and caspase-1 when compared to the CIS group. Furthermore, DES significantly decreased CIS-induced elevation in toll-like receptor 4 (TLR4), tumor necrosis factor-alpha (TNF-α), and nuclear factor-kappa B (NF-κB) levels in both renal and testicular tissues.

SIGNIFICANCE

DES can be used as adjuvant therapy with CIS in cancerous cases, pending further clinical studies.

Anti-Inflammatory Activities of an Anti-Histamine Drug, Loratadine, by Suppressing TAK1 in AP-1 Pathway

Loratadine is an anti-histamine routinely used for treating allergies. However, recent findings have shown that Loratadine may also have anti-inflammatory functions, while their exact mechanisms have not yet been fully uncovered. In this paper, we investigated whether Loratadine can be utilized as an anti-inflammatory drug through a series of in vitro and in vivo experiments using a murine macrophage cell line and an acute gastritis mouse model. Loratadine was found to dramatically reduce the expression of pro-inflammatory genes, including MMP1, MMP3, and MMP9, and inhibit AP-1 transcriptional activation, as demonstrated by the luciferase assay. Therefore, we decided to further explore its role in the AP-1 signaling pathway. The expression of c-Jun and c-Fos, AP-1 subunits, was repressed by Loratadine and, correspondingly, the expression of p-JNK, p-MKK7, and p-TAK1 was also inhibited. In addition, Loratadine was able to reduce gastric bleeding in acute gastritis-induced mice; Western blotting using the stomach samples showed reduced p-c-Fos protein levels. Loratadine was shown to effectively suppress inflammation by specifically targeting TAK1 and suppressing consequent AP-1 signaling pathway activation and inflammatory cytokine production.

Levocetirizine and montelukast in the COVID-19 treatment paradigm

Levocetirizine, a third-generation antihistamine, and montelukast, a leukotriene receptor antagonist, exhibit remarkable synergistic anti-inflammatory activity across a spectrum of signaling proteins, cell adhesion molecules, and leukocytes. By targeting cellular protein activity, they are uniquely positioned to treat the symptoms of COVID-19. Clinical data to date with an associated six-month follow-up, suggests the combination therapy may prevent the progression of the disease from mild to moderate to severe, as well as prevent/treat many of the aspects of ‘Long COVID,’ thereby cost effectively reducing both morbidity and mortality. To investigate patient outcomes, 53 consecutive COVID-19 test (+) cases (ages 3–90) from a well-established, single-center practice in Boston, Massachusetts, between March – November 2020, were treated with levocetirizine and montelukast in addition to then existing protocols [2]. The data set was retrospectively reviewed. Thirty-four cases were considered mild (64%), 17 moderate (32%), and 2 (4%) severe. Several patients presented with significant comorbidities (obesity: n = 22, 41%; diabetes: n = 10, 19%; hypertension: n = 24, 45%). Among the cohort there were no exclusions, no intubations, and no deaths. The pilot study in Massachusetts encompassed the first COVID-19 wave which peaked on April 23, 2020 as well as the ascending portion of the second wave in the fall. During this period the average weekly COVID-19 case mortality rate (confirmed deaths/confirmed cases) varied considerably between 1 and 7.5% [37]. FDA has approved a multicenter, randomized, placebo-controlled, Phase 2 clinical trial design, replete with electronic diaries and laboratory metrics to explore scientific questions not addressed herein.

Could Histamine H1 Receptor Antagonists Be Used for Treating COVID-19?

COVID-19 has rapidly become a pandemic worldwide, causing extensive and long-term health issues. There is an urgent need to identify therapies that limit SARS-CoV-2 infection and improve the outcome of COVID-19 patients. Unbalanced lung inflammation is a common feature in severe COVID-19 patients; therefore, reducing lung inflammation can undoubtedly benefit the clinical manifestations. Histamine H1 receptor (H1 receptor) antagonists are widely prescribed medications to treat allergic diseases, while recently it has emerged that they show significant promise as anti-SARS-CoV-2 agents. Here, we briefly summarize the novel use of H1 receptor antagonists in combating SARS-CoV-2 infection. We also describe the potential antiviral mechanisms of H1 receptor antagonists on SARS-CoV-2. Finally, the opportunities and challenges of the use of H1 receptor antagonists in managing COVID-19 are discussed.

The effect of desloratadine on ischemia reperfusion induced oxidative and inflammatory renal injury in rats

Purpose: To examine the effect of desloratadine on kidney ischemia-reperfusion (I/R) injury in albino Wistar male rats using biochemical and histopathological methods.Methods: The treated with ischemia-reperfusion + 5 mg/kg desloratadine (IRD) group (n-6) was given 5 mg/kg desloratadine by gavage orally, and applied renal ischemia-reperfusion (BIR) group (n-6) and control (SG) group undergoing Sham operation (n-6) rats were given distilled water as solvent one hour before ketamine anesthesia. During the anesthesia period, ischemia was induced for 2 h unilaterally in the left kidney of all rats followed by reperfusion for 6 h. The kidneys of the SG group had sham operation without any intervention.Results: Our biochemical test results showed that malondialdehyde (MDA), nuclear factor kappa (NF-κB), tumor necrosis factor alpha (TNF-α), interleukin one beta (IL-1β), creatinine, and blood urea nitrogen (BUN) levels were significantly increased in the BIR group compared to the healthy control and IRD groups treated with desloratadine. Histopathological results were revealed tubular dilatation, tubular necrosis, loss of brushy margins, cast formation, and apoptotic bodies in tubular epithelial cells in the BIR group. There were no histopathological findings except for the swelling of tubule epithelial cells and the accumulation of proteinous material in some tubule lumens in renal tissue of desloratadine-treated rats.Conclusions: Experimental results suggested that desloratadine may be useful in the treatment of renal I/R injury.

FDA-drug screening identifies deptropine inhibiting hepatitis E virus involving the NF-κB-RIPK1-caspase axis

Hepatitis E virus (HEV) infection is the leading cause of acute hepatitis worldwide and can develop into chronic infection in immunocompromised patients, promoting the development of effective antiviral therapies. In this study, we performed a screening of a library containing over 1000 FDA-approved drugs. We have identified deptropine, a classical histamine H1 receptor antagonist used to treat asthmatic symptoms, as a potent inhibitor of HEV replication. The anti-HEV activity of deptropine appears dispensable of the histamine pathway, but requires the inhibition on nuclear factor-κB (NF-κB) activity. This further activates caspase mediated by receptor-interacting protein kinase 1 (RIPK1) to restrict HEV replication. Given deptropine being widely used in the clinic, our results warrant further evaluation of its anti-HEV efficacy in future clinical studies. Importantly, the discovery that NF-κB-RIPK1-caspase pathway interferes with HEV infection reveals new insight of HEV-host interactions.

Multifunctional chitosan-coated poly(lactic-co-glycolic acid) nanoparticles for spatiotemporally controlled codelivery of ceramide and C-phycocyanin to treat atopic dermatitis

Atopic dermatitis is an inflammatory disease associated with defective skin barrier. The co-administration of a lipid-enhancing skin barrier composed of ceramide with an anti-inflammatory agent is required to effectively treat atopic dermatitis. As atopic dermatitis treatment is affected by the dosage and frequency of medication, the development of nanoparticles that have long-term efficacy with a single dose would be advantageous. In this study, skin-sensitive chitosan nanoparticles codelivering ceramide and C-phycocyanin were developed to provide anti-inflammatory effects with no cytotoxicity, and their effect on stratum corneum formation in a rat atopic dermatitis model was examined. Analysis of the messenger RNA expression of keratinization factors demonstrated that the stratum corneum–formation effect of poly(lactic-co-glycolic acid) nanoparticles containing ceramide was similar to or higher than that of ceramide alone. Compared to the nanoparticles without C-phycocyanin, nanoparticles coated with C-phycocyanin and chitosan attenuated histamine release. In addition, despite frequent washing, the nanoparticles were well fixed to the epidermis after their administration. The results suggest that a single treatment with the combination of lipid therapy/anti-inflammatory nanoparticles is a convenient and high-efficiency means to increase stratum corneum formation in atopic dermatitis patients.

Levocetirizine Pretreatment Mitigates Lipopolysaccharide-Induced Lung Inflammation in Rats

This research was conducted to investigate possible protective influences of levocetirizine, a nonsedating H₁ antihistamine, against lipopolysaccharide (LPS)-induced lung injury in rats. Male Sprague Dawley rats received either levocetirizine (1 mg/kg/day, orally) or the vehicle of the drug (2 ml/kg/day, orally) for 1 week before a single IP injection of LPS (7.5 mg/kg). A group of normal rats served as control. The experiments were terminated 18 h after the LPS challenge. Serum C-reactive protein levels were determined. Moreover, total cell count, lactate dehydrogenase (LDH) activity, protein levels, and total NOx were evaluated in bronchoalveolar lavage fluid (BALF). Pulmonary edema was evaluated as the wet/dry lung weight ratio. Lung tissue homogenate was assessed for antioxidant/pro-oxidant status. BALF and lung tissue levels of tumor necrosis factor-α (TNF-α) were assessed. Lungs were examined for histological alterations. LPS-mediated lung injury was manifested by pulmonary edema, leukocyte infiltration, oxidative stress, and inflammation. Levocetirizine attenuated lung edema and mitigated the increases in BALF protein levels, LDH activity, and lung leukocyte recruitment in LPS-challenged rats. Additionally, TNF-α protein levels in BALF and lung tissue were diminished by levocetirizine administration. Levocetirizine also exhibited a potent antioxidant activity as indicated by a decrease in lung tissue levels of malondialdehyde and an enhancement of superoxide dismutase activity. Histological examination of lung tissues confirmed the beneficial effect of levocetirizine against LPS-induced histopathological alterations. In conclusion, levocetirizine may offer protection against lung tissue damage and inflammation in LPS-challenged rats.

Relaxant effect of Lippia origanoides essential oil in guinea-pig trachea smooth muscle involves potassium channels and soluble guanylyl cyclase

ETHNOPHARMACOLOGICAL RELEVANCE

Lippia origanoides H.B.K. is an aromatic species used in folk medicine to treat respiratory diseases, including asthma.

AIM OF THE STUDY

The aim of this work was to evaluate the relaxing potential and mechanism of action of the L. origanoides (LOO) essential oil in isolated guinea-pig trachea.

MATERIALS AND METHODS

Leaves from L. origanoides were collected at experimental fields under organic cultivation, at the Forest Garden of Universidade Estadual de Feira de Santana. Essential oil was extracted by hydrodistillation, analyzed by GC/FID and GC/MS and the volatile constituents were identified. Spasmolytic activity and relaxant mechanism of LOO were assayed in isolated guinea-pig trachea contracted with histamine, carbachol or hyperpolarizing KCl.

RESULTS

Chemical analysis revealed the presence of carvacrol (53.89%) as major constituent. LOO relaxed isolated guinea-pig trachea pre-contracted with KCl 60 mM [EC₅₀ = 30.02 μg/mL], histamine 1 µM [EC₅₀ = 9.28 μg/mL] or carbachol 1 µM [EC₅₀ = 51.80 μg/mL]. The pre-incubation of glibenclamide, CsCl, propranolol, indomethacin, hexamethonium, aminophylline or L-NAME in histamine-induced contractions did not alter significantly the relaxant effect of LOO. However, the presence of 4-aminopyridine, tetraethylammonium or methylene blue reduced LOO effect, while the presence of dexamethasone or atropine potentialized the LOO relaxant effect. LOO pre-incubation inhibited carbachol-evoked contractions, with this effect potentialized in the presence of sodium nitroprusside and blocked in the presence of ODQ.

CONCLUSIONS

The relaxant mechanism of LOO on the tracheal smooth muscle possibly involves stimulating of soluble guanylyl cyclase with consequent activation of the voltage-gated and Ca²⁺-activated K⁺ channels.

Time-dependent effects of olanzapine treatment on the expression of histidine decarboxylase, H1 and H3 receptor in the rat brain: The roles in olanzapine-induced obesity

Antipsychotic treatment, particularly olanzapine and clozapine, induces severe obesity. The Histamine H1 receptor is considered to be an important contributor to olanzapine-induced obesity, however how olanzapine modulates the histaminergic system is not sufficiently understood. This study examined the effect of olanzapine on key molecules of the histaminergic system, including histidine decarboxylase (HDC), H1 receptor (H1R) and H3 receptor (H3R), in the brain at different stages of olanzapine-induced obesity. During short-term treatment (8-day), olanzapine increased hypothalamic HDC mRNA expression and H1R binding in the arcuate nucleus (Arc) and ventromedial hypothalamus (VMH), without changing H3R binding density. HDC mRNA and Arc H1R binding were positively correlated with increased food intake, feeding efficiency and weight gain. When the treatment was extended to 16 and 36 days, H1R binding was increased not only in the hypothalamic Arc and VMH but also in the brainstem dorsal vagal complex (DVC). The H1R bindings in the Arc, VMH and DVC were positively correlated with weight gain induced by olanzapine treatment. However, the expression of HDC and H3R mRNA was not increased. These results suggest that olanzapine time-dependently modulates histamine neurotransmission, which suggested the different neuronal mechanisms underlying different stages of weight gain development. Treatment targeting the H1R may be effective for both short- and long-term olanzapine-induced weight gain.

Chlorpheniramine attenuates histamine-mediated aquaporin 5 downregulation in human nasal epithelial cells via suppression of NF-κB activation

Background: Aquaporin 5 (AQP5) is most likely the primary water channel in the human nasal mucosa and acts as a key tight junction protein. The signaling cascades responsible for AQP5 regulation are still works in progress. Objective: This study sought to determine the effects of histamine and chlorpheniramine on AQP5 expression in human nasal epithelial cells (HNEpC) and to detect the signaling cascades responsible for these effects. Methods: HNEpC were cultured with four concentrations of histamine or chlorpheniramine in vitro. The sub-cellular distribution of AQP5 was explored using immunocytochemistry. The pharmacologic effects of histamine and chlorpheniramine on the expression of the phosphorylation of cyclic adenosine monophosphate-responsive element binding protein (p-CREB), the AQP5 and the NF-κB protein were examined using Western blotting. Results: AQP5 was found to be located in cell membrane and cytoplasm and present in every group without significant difference. Histamine inhibits the expression of AQP5 and p-CREB in HNEpC, while chlorpheniramine dose-dependently increases these protein levels with statistical significance. HNEpC treated with histamine and chlorpheniramine in turn showed the same trends as those intervened separately with these two drugs. Moreover, chlorpheniramine had the ability to reverse the inhibitory effect of histamine. Western blotting analysis revealed that after incubation with 10-4 M histamine, NF-κB protein was significantly heightened by 165% compared with the untreated control group. Again, such increase can be significantly reversed after chlorpheniramine treatment. Conclusions: The current study demonstrated that histamine inhibits CREB phosphorylation in HNEpC, which results in decreased AQP5 expression via activation of NF-κB pathway. Chlorpheniramine attenuates the inhibitory effect of histamine in p-CREB/AQP5 expression via suppression of NF-κB signal cascades. This observation could provide additional insight into the anti-inflammatory effects of H1-antihistamines that contribute to maintain airway surface liquid and mucosal defense.

Discovery of new muscarinic acetylcholine receptor antagonists from Scopolia tangutica

Scopolia tangutica (S. tangutica) is a traditional Chinese medicinal plant used for antispasmodics, anesthesia, analgesia and sedation. Its pharmacological activities are mostly associated with the antagonistic activity at muscarinic acetylcholine receptors (mAchRs) of several known alkaloids such as atropine and scopolamine. With our recent identification of four hydroxycinnamic acid amides from S. tangutica, we hypothesized that this plant may contain previously unidentified alkaloids that may also contribute to its in vivo effect. Herein, we used a bioassay-guided multi-dimension separation strategy to discover novel mAchR antagonists from S. tangutica. The core of this approach is to use label-free cell phenotypic assay to first identify active fractions, and then to guide purification of active ligands. Besides four tropanes and six cinnamic acid amides that have been previously isolated from S. tangutica, we recently identified two new tropanes, one new cinnamic acid amide, and nine other compounds. Six tropane compounds purified from S. tangutica for the first time were confirmed to be competitive antagonists of muscarinic receptor 3 (M3), including the two new ones 8 and 12 with IC₅₀ values of 1.97 μM and 4.47 μM, respectively. Furthermore, the cinnamic acid amide 17 displayed 15-fold selectivity for M1 over M3 receptors. These findings will be useful in designing lead compounds for mAchRs and elucidating mechanisms of action of S. tangutica.

Comparison of the effects of levocetirizine and losartan on diabetic nephropathy and vascular dysfunction in streptozotocin-induced diabetic rats

This work was designed to investigate the effects of levocetirizine, a histamine H1 receptor antagonist, on diabetes-induced nephropathy and vascular disorder, in comparison to an angiotensin II receptor antagonist, losartan. Diabetes was induced in male Sprague Dawley rats by a single intraperitoneal injection of streptozotocin (50mg/kg). Diabetic rats were divided into three groups; diabetic, diabetic-levocetirizine (0.5mg/kg/day) and diabetic-losartan (25mg/kg/day). Treatments were started two weeks following diabetes induction and continued for additional eight weeks. At the end of the experiment, urine was collected and serum was separated for biochemical measurements. Tissue homogenates of kidney and aorta were prepared for measuring oxidative stress, nitric oxide (NO), transforming growth factor-β1 (TGF-β1) and tumor necrosis factor-α (TNF-α). Moreover, histological analyses were conducted and aortic vascular reactivity was investigated. Levocetirizine improved renal function in diabetic rats (evidenced by mitigation of diabetes-induced changes in kidney to body weight ratio, serum albumin, urinary proteins and creatinine clearance). Moreover, levocetirizine attenuated the elevated renal levels of TNF-α and TGF-β1, ameliorated renal oxidative stress and restored NO bioavailability in diabetic kidney. These effects were comparable to or surpassed those produced by losartan. Moreover, levocetirizine, similar to losartan, reduced the enhanced responsiveness of diabetic aorta to phenylephrine. Histological evaluation of renal and aortic tissues further confirmed the beneficial effects of levocetirizine on diabetic nephropathy and revealed a greater attenuation of diabetes-induced vascular hypertrophy by levocetirizine than by losartan. In conclusion, levocetirizine may offer comparable renoprotective effect to, and possibly superior vasculoprotective effects than, losartan in streptozotocin-diabetic rats.

Desloratadine citrate disodium injection, a potent histamine H(1) receptor antagonist, inhibits chemokine production in ovalbumin-induced allergic rhinitis guinea pig model and histamine-induced human nasal epithelial cells via inhibiting the ERK1/2 and NF-kappa B signal cascades

Chemokines have chemotactic properties on leukocyte subsets whose modulation plays a pivotal role in allergic inflammatory processes. Our present study was designed to investigate the anti-allergic and anti-inflammatory properties of desloratadine citrate disodium injection (DLC) and elucidate the molecular mechanisms of its anti-inflammatory properties. The anti-allergic effects of DLC were evaluated based on allergic symptoms, serological marker production and histological changes of the nasal mucosa in guinea pigs model of allergic rhinitis. The anti-inflammatory properties and molecular mechanisms of DLC were explored by studying the regulation of a set of chemokines and extracellular signal-regulated kinase (ERK)1/2 and nuclear factor-kappa B (NF-κB) pathways, after DLC treatment in guinea pigs model of allergic rhinitis in vivo and histamine-activated human nasal epithelial cells (HNECs) in vitro. In vivo model in guinea pigs, DLC alleviated the rhinitis symptoms, inhibited inflammatory cells infiltration in nasal lavage fluid (NLF) and histamine, monocyte chemotactic protein (MCP)-1, regulated on activation normal T cell expressed, and presumably secreted (RANTEs) and interleukin (IL)-8 release in sera and P-ERK1/2 and NF-κB activation in nasal mucosa. In vitro, DLC markedly inhibited histamine-induced production of MCP-1, RANTEs and IL-8 and suppressed c-Raf, mitogen-activated protein/extracellular signal-regulated kinase kinase (MEK) and ERK1/2 activation in HNECs. These results provide evidence that DLC possesses potent anti-allergic and anti-inflammatory properties. The mechanism of action underlying DLC in allergic inflammation appears to be inhibition of the phosphorylation of ERK1/2, in addition to blocking of the NF-κB pathway.

The H1-receptor antagonist cetirizine ameliorates high-fat diet-induced glucose intolerance in male C57BL/6 mice, but not diabetes outcome in female non-obese diabetic (NOD) mice

BACKGROUND

It has been proposed that the histamine 1-receptor (H1-receptor) not only promotes allergic reactions, but also modulates innate immunity and autoimmune reactions. In line with this, we have recently reported that the H1-receptor antagonist cetirizine partially counteracts cytokine-induced beta-cell signaling and destruction. Therefore, the aim of this study was to determine whether cetirizine affects diabetes in NOD mice, a model for human type 1 diabetes, and glucose intolerance in high-fat diet C57BL/6 mice, a model for human glucose intolerance.

METHODS

Female NOD mice were treated with cetirizine in the drinking water (25 mg/kg body weight) from 9 until 30 weeks of age during which precipitation of diabetes was followed. Male C57BL/6 mice were given a high-fat diet from 5 weeks of age. When the mice were 12 weeks of age cetirizine was given for 2 weeks in the drinking water. The effects of cetirizine were analyzed by blood glucose determinations, glucose tolerance tests, and insulin sensitivity tests.

RESULTS

Cetirizine did not affect diabetes development in NOD mice. On the other hand, cetirizine treatment for 1 week protected against high-fat diet-induced hyperglycemia. The glucose tolerance after 2 weeks of cetirizine treatment was improved in high-fat diet mice. We observed no effect of cetirizine on the insulin sensitivity of high-fat diet mice.

CONCLUSION

Our results suggest a protective effect of cetirizine against high-fat diet-induced beta-cell dysfunction, but not against autoimmune beta-cell destruction.

Fexofenadine regulates nuclear factor-κB signaling and endoplasmic reticulum stress in intestinal epithelial cells and ameliorates acute and chronic colitis in mice

The aim of this study was to evaluate the effect of fexofenadine on intestinal inflammation. HCT116 and COLO205 cells were pretreated with fexofenadine and then stimulated with tumor necrosis factor (TNF)-α. Interleukin (IL)-8 expression was determined by real-time reverse-transcription polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay. DNA-binding activity of nuclear factor-κB was assessed by electrophoretic mobility shift assay. The molecular markers of endoplasmic reticulum (ER) stress were evaluated by Western blot analysis and PCR. In the acute colitis model, mice were given 4% dextran sulfate sodium (DSS) for 5 days with or without fexofenadine. IL-10(-/-) mice were used to evaluate the effect of fexofenadine on chronic colitis. Fexofenadine significantly inhibited the upregulated expression of IL-8 in HCT116 and COLO205 cells stimulated with TNF-α. Fexofenadine suppressed nuclear factor-κB DNA-binding activity. C/EBP homologous protein mRNA expression was enhanced in the presence of TNF-α, and it was dampened by pretreatment of fexofenadine. In addition, the induction of ER stress markers caspase-12 and p-eukaryotic initiation factor 2 (eIF2)-α was significantly suppressed by the pretreatment of fexofenadine. Administration of fexofenadine significantly reduced the severity of DSS-induced murine colitis, as assessed by the disease activity index, colon length, and histology. In addition, the DSS-induced phospho-IκB kinase activation was significantly decreased in fexofenadine-pretreated mice. Finally, fexofenadine significantly reduced the severity of colitis and the immunoreactivity of caspase-12 and p-eIF2-α in IL-10(-/-) mice as compared with controls. These results suggest that fexofenadine is a potential therapeutic agent for the treatment of inflammatory bowel disease.

The H1-receptor antagonist cetirizine protects partially against cytokine- and hydrogen peroxide-induced β-TC6 cell death in vitro

OBJECTIVE

It has been proposed that the histamine 1 (H(1)) receptor not only promotes allergic reactions but also modulates autoimmune diseases, such as type 1 diabetes. In line with this, it has recently been reported that the H(1)-receptor antagonist cetirizine can counteract the activation of signals/factors pertinent to the pathogenesis of type 1 diabetes and cytokine-induced β-cell destruction. Therefore, the overall aim of this study was to determine whether H(1)-receptor antagonists affect cytokine-induced β-cell death and signaling in vitro.

METHODS

The insulin-producing cell line β-TC6 was exposed to the proinflammatory cytokines interleukin 1β(+) interferon γ, or hydrogen peroxide. The H(1)-receptor antagonists desloratadine and cetirizine were added to the cell cultures and cell viability; macrophage inhibitory factor levels, c-Jun N-terminal kinase phosphorylation, c-Jun expression, and β-catenin levels were analyzed by flow cytometry, real-time polymerase chain reaction, and immunoblotting.

RESULTS

Cetirizine protected partially against both cytokine- and hydrogen peroxide-induced cell death. This effect was paralleled by an inhibition of cytokine-induced c-Jun N-terminal kinase phosphorylation, c-Jun induction, and a restoration of macrophage inhibitory factor contents. Cetirizine also increased the β-TC6 cell contents of β-catenin at basal conditions.

CONCLUSIONS

Our results indicate a protective effect of a specific H(1)-receptor antagonist.

A METHOD FOR THE DETECTION OF MEANINGFUL AND REPRODUCIBLE GROUP SIGNATURES FROM GENE EXPRESSION PROFILES

Gene expression microarrays are commonly used to detect the biological signature of a disease or to gain a better understanding of the underlying mechanism of how a group of drugs treat a specific disease. The outcome of such experiments, e.g. the signature, is a list of differentially expressed genes. Reproducibility across independent experiments remains a challenge. We are interested in creating a method that can detect the shared signature of a group of expression profiles, e.g. a group of samples from individuals with the same disease or a group of drugs that treat the same therapeutic indication. We have developed a novel Weighted Influence — Rank of Ranks (WIMRR) method, and we demonstrate its ability to produce both meaningful and reproducible group signatures.

Aryl hydrocarbon receptor negatively regulates LPS-induced IL-6 production through suppression of histamine production in macrophages

Macrophages play a pivotal role in innate immune responses to pathogens via toll-like receptors. We previously demonstrated that aryl hydrocarbon receptor (Ahr) in combination with signal transducer and activator of transcription 1 (Stat1) negatively regulates pro-inflammatory cytokine production by inhibiting nuclear factor-κB activation in macrophages after LPS stimulation. Here, we show that Ahr also negatively regulates production of the pro-inflammatory cytokine IL-6 by suppressing histamine production in macrophages stimulated by LPS. We found that Ahr-Sp1 complex, independent of Stat1, represses histidine decarboxylase expression by inhibiting LPS-induced Sp1 phosphorylation on Ser residues in macrophages; this leads to suppression of histamine production. Moreover, we found that loratadine and chlorpromazine, histamine 1 receptor (H1R) antagonists, more effectively impair the production of LPS-induced IL-6 than that of other inflammatory cytokines in Ahr(-/-) macrophages. Collectively, these results demonstrate that Ahr negatively regulates IL-6 production via H1R signaling through the suppression of histamine production in macrophages following LPS stimulation.

Combination treatment of mice with CRx-153 (nortriptyline and desloratadine) decreases the severity of experimental autoimmune encephalomyelitis

Pro-inflammatory CD4(+) T cell-mediated autoimmune diseases, such as multiple sclerosis, are hypothesized to be initiated and maintained by self-reactive interferon-gamma (IFN-γ) and interleukin-17 (IL-17) producing CD4(+) T cells. Previous studies have shown moderate to significant alterations in inflammatory T cell responses and potentially treatment of autoimmune disease by administration of antihistamine or tricyclic antidepressants alone. The goal of the present study was to determine if treatment of PLP(139-151)-induced relapsing-remitting experimental autoimmune encephalomyelitis (R-EAE) in SJL/J mice with a combination of two FDA approved drugs for other indications could decrease R-EAE disease. The findings show that combination treatment with desloratadine and nortriptyline decreases the mean clinical score, disease relapse frequency, and number of CD4(+) T cells infiltrating into the CNS. In addition, combination treatment of PLP(139-151) primed mice decreases the level of IFN-γ and IL-17 secreted via a decrease in both the number of cells secreting and the amount of cytokine secreted per cell following PLP(139-151) reactivation ex vivo. This is in contrast to an increase in the level of IL-4 produced and the number of IL-4 secreting cells. The data also show that combination treatment with desloratadine and nortriptyline inhibits the production of IFN-γ and IL-17 produced by naive CD4(+) T cells activated in the presence of Th1 cell- and Th17 cell-promoting conditions, while increasing the level of IL-4 produced by naive CD4(+) T cells activated in the presence of Th2 cell-promoting conditions. The present findings suggest a novel method for the development of a putative autoimmune therapy.

Transcriptional microarray analysis reveals suppression of histamine signaling by Kujin alleviates allergic symptoms through down-regulation of FAT10 expression

Previously, we have shown that hot water extract from Kujin, the dried roots of Sophora flavescens alleviates allergic symptoms by suppressing histamine signaling at the transcription level in toluene 2,4-diisocyanate (TDI)-sensitized rats. To know more insights into the mechanism of the anti-allergic action of Kujin, we carried out the microarray analysis to explore genes that were up-regulated by treatment with TDI and also were suppressed these up-regulated gene expression by Kujin. Microarray analysis revealed the substantial up-regulation of FAT10 (also called UbD) mRNA due to TDI sensitization and Kujin extract significantly suppressed this up-regulation. FAT10 is an ubiquitin like protein having an active role in the immune system and is induced by proinflammatory cytokines. Activation of NF-κB by FAT10 also has been reported. However, the role of FAT10 in allergic pathogenesis remains unknown. Here we investigated the correlation of FAT10-NF-κB signaling with histamine signaling in TDI-sensitized rats. Real time RT-PCR analysis confirmed that treatment with TDI up-regulated FAT10 mRNA expression in the nasal mucosa of TDI-sensitized rats and Kujin extract suppressed this elevation. Treatment with H(1)-antihistamines suppressed the TDI-induced up-regulation of FAT10 mRNA expression in TDI-sensitized rats. Direct administration of histamine into the nasal cavity of non-TDI-treated normal rats up-regulated the expression of FAT10 mRNA. Our data suggest that Kujin might alleviate allergic symptoms by inhibition of NF-κB activation through suppression of histamine-induced up-regulation of FAT10 mRNA expression.

Lipopolysaccharide induces H1 receptor expression and enhances histamine responsiveness in human coronary artery endothelial cells

Summary Histamine is a well-recognized modulator of vascular inflammation. We have shown that histamine, acting via H1 receptors (H1R), synergizes lipopolysaccharide (LPS)-induced production of prostaglandin I(2) (PGI(2)), PGE(2) and interleukin-6 (IL-6) by endothelial cells. The synergy between histamine and LPS was partly attributed to histamine -induced expression of Toll-like receptor 4 (TLR4). In this study, we examined whether LPS stimulates the H1R expression in human coronary artery endothelial cells (HCAEC) with resultant enhancement of histamine responsiveness. Incubation of HCAEC with LPS (10-1000 ng/ml) resulted in two-fold to fourfold increases in H1R mRNA expression in a time-dependent and concentration-dependent fashion. In contrast, LPS treatment did not affect H2R mRNA expression. The LPS-induced H1R mRNA expression peaked by 4 hr after LPS treatment and remained elevated above the basal level for 20-24 hr. Flow cytometric and Western blot analyses revealed increased expression of H1R protein in LPS-treated cells. The specific binding of [(3)H]pyrilamine to H1R in membrane proteins from LPS-treated HCAEC was threefold higher than the untreated cells. The LPS-induced H1R expression was mediated through TLR4 as gene silencing by TLR4-siRNA and treatment with a TLR4 antagonist inhibited the LPS effect. When HCAEC were pre-treated with LPS for 24 hr, washed and challenged with histamine, 17-, 10- and 15-fold increases in PGI(2), PGE(2) and IL-6 production, respectively, were noted. Histamine-induced enhancement of the synthesis of PGI(2), PGE(2) and IL-6 by LPS-primed HCAEC was completely blocked by an H1R antagonist. The results demonstrate that LPS, through TLR4 activation, up-regulates the expression and function of H1R and amplifies histamine-induced inflammatory responses in HCAEC.

Ebastine in the light of CONGA recommendations for the development of third-generation antihistamines

In 2003 a consensus group on new-generation antihistamines (CONGA) defined the characteristics required for a third-generation H(1) antihistamine as there had been much controversy about this issue since the early 1990s. One of the antihistamines that had been claimed to belong to such a group is the second-generation antihistamine, ebastine. The objective of this review is to analyze the pharmacology of ebastine, in light of the CONGA recommendations for the development of new-generation antihistamines: (1) anti-inflammatory properties, (2) potency, efficacy and effectiveness, (3) lack of cardiotoxicity, (4) lack of drug interactions, (5) lack of CNS effects, and (6) pharmacological approach. Ebastine seems to have anti-inflammatory properties that help to ameliorate nasal congestion, though this has not yet been conclusively demonstrated. Its pharmacological-therapeutic profile does not differ greatly from that of other second-generation antihistamines. Its cardiac safety has been widely assessed and no cardiac toxicity has been found at therapeutic doses despite initial concerns. The risk of potentially relevant drug interactions has been investigated and ruled out. Ebastine does not produce sedation at therapeutic doses and drug interaction studies with classical CNS depressants have not demonstrated a synergistic effect. Pharmacologically, ebastine is an H(1) inverse agonist. Perhaps the answer to the quest for new-generation antihistamines lies not only in H(1) but in a combined approach with other histamine receptors.