Effects of olopatadine hydrochloride, an antihistamine drug, on skin inflammation induced by repeated topical application of oxazolone in mice

The Bladder Microbiome, Metabolome, Cytokines, and Phenotypes in Patients with Systemic Lupus Erythematosus

Emerging studies reveal unique bacterial communities in the human bladder, with alteration of composition associated to disease states. Systemic lupus erythematosus (SLE) is a complex autoimmune disease that is characterized by frequent impairment of the kidney. Here, we explored the bladder microbiome, metabolome, and cytokine profiles in SLE patients, as well as correlations between microbiome and metabolome, cytokines, and disease profiles. We recruited a group of 50 SLE patients and 50 individually matched asymptomatic controls. We used transurethral catheterization to collect urine samples, 16S rRNA gene sequencing to profile bladder microbiomes, and liquid chromatography-tandem mass spectrometry to perform untargeted metabolomic profiling. Compared to controls, SLE patients possessed unique bladder microbial communities and increased alpha diversity. These differences were accompanied by differences in urinary metabolomes, cytokines, and patients’ disease profiles. The SLE-enriched genera, including Bacteroides, were positively correlated with several SLE-enriched metabolites, including olopatadine. The SLE-depleted genera, such as Pseudomonas, were negatively correlated to SLE-depleted cytokines, including interleukin-8. Alteration of the bladder microbiome was associated with disease profile. For example, the genera Megamonas and Phocaeicola were negatively correlated with serum complement component 3, and Streptococcus was positively correlated with IgG. Our present study reveals associations between the bladder microbiome and the urinary metabolome, cytokines, and disease phenotypes. Our results could help identify biomarkers for SLE.

IMPORTANCE Contrary to dogma, the human urinary bladder possesses its own unique bacterial community with alteration of composition associated with disease states. Systemic lupus erythematosus (SLE) is a complex autoimmune disease often characterized by kidney impairment. Here, we explored the bladder microbiome, metabolome, and cytokine profiles in SLE patients, as well as correlations between the microbiome and metabolome, cytokines, and disease profiles. Compared to controls, SLE patients possessed a unique bladder microbial community and elevated alpha diversity. These differences were accompanied by differences in bladder metabolomes, cytokines, and patients’ disease profiles. SLE-enriched genera were positively correlated with several SLE-enriched metabolites. SLE-depleted genera were negatively correlated to SLE-depleted cytokines. Alteration of the bladder microbiome was associated with disease profile. Thus, our study reveals associations between the bladder microbiome and the bladder metabolome, cytokines, and disease phenotypes. These results could help identify biomarkers for SLE.

Pinaverium Bromide Attenuates Lipopolysaccharide-Induced Excessive Systemic Inflammation via Inhibiting Neutrophil Priming

Dominant infiltration of neutrophils is a hallmark of many inflammatory diseases, especially in septic shock. IL-1β as one of the most early released proinflammatory cytokine in neutrophil, plays a pivotal role in the progress of sepsis. In this study, we built a high-throughput-compatible drug screen assay platform based on our newly constructed reporter C57BL/6 mice, pIL1-DsRed, expressing the DsRed gene under the control of the IL-1β promoter. After screening 1200 U.S. Food and Drug Administration-approved compounds, we found that pinaverium bromide (PVB) significantly suppressed the DsRed expression of primed neutrophil and improved the survival rate of mice given LPS in an endotoxin challenge analogous to sepsis, regardless of whether PVB was administered before or after LPS. PVB also protected the liver and lung from LPS-induced damage and reduced organ-specific inflammatory responses. PVB decreased the production of IL-1β, IL-6, and CXCL1 mRNA in the lungs of LPS-treated mice and decreased the serum levels of liver transaminases (alanine aminotransferase and aspartate aminotransferase) at multiple time points and doses tested. PVB can significantly suppress primed neutrophil-specific respiratory bursts and migration as well. Lastly, PVB affected neutrophils' gene expression and phenotypic changes during neutrophil priming. PVB downregulated GM-CSF-induced expression of CD54 and dectin-2 (markers of fully primed neutrophils) at both mRNA and protein levels during late-phase neutrophil priming. In summary, we demonstrated that PVB can be used as a potential therapeutic agent for sepsis by inhibiting neutrophil priming.

Characterization and identification of charcoal of inedible Kerandang fish (Channa pleurophthalmus Blkr) body parts and potential antiallergenic properties

Background and Aim

The study about the antiallergenic properties of inedible fish body parts is still limited. Therefore, this study aimed to characterize the charcoal from the body parts of Kerandang fish (Channa pleurophthalmus Blkr) and identify its antiallergenic properties.

Materials and Methods

This study used some non-edible body parts extracted from the Kerandang fish (i.e., the scalp, scales, and dorsal, pectoral, ventral, anal, and caudal fins) using a maceration method with different solvents (ethanol, ethyl acetate, and chloroform). The identification of active compounds in the extract was carried out using liquid chromatography-high-resolution mass spectrometry (LC-HRMS) analysis, while the antihyaluronidase activity was determined using the antihyaluronidase test. The highest charcoal antihyaluronidase activity-extract was applied to ovalbumin-induced mice for 7 days with various doses (10, 15, and 20 mg/kg). The specific immunoglobulin E (IgE) was measured using enzyme-linked immunosorbent assay on day 8.

Results

Our LC-HRMS analysis showed that the active compound of charcoal in the caudal fins of Kerandang fish was hexadecanamide. The highest inhibition (IC₅₀) of hyaluronidase was found in the ethyl acetate extract of fish caudal fins at a concentration of 4 mg/mL. We found that 15 mg/kg body weight of charcoal of fish caudal fins suppressed IgE expression in male mice.

Conclusion

Our findings indicate that the charcoal of non-edible body parts of Kerandang and one of its constituent, hexadecanamide, may have strong antiallergic effects.

Inhibitory Effects of a Novel Chrysin-Derivative, CPD 6, on Acute and Chronic Skin Inflammation

The skin is an important physiological barrier against external stimuli, such as ultraviolet radiation (UV), xenobiotics, and bacteria. Dermal inflammatory reactions are associated with various skin disorders, including chemical-induced irritation and atopic dermatitis. Modulation of skin inflammatory response is a therapeutic strategy for skin diseases. Here, we synthesized chrysin-derivatives and identified the most potent derivative of Compound 6 (CPD 6). We evaluated its anti-inflammatory effects in vitro cells of macrophages and keratinocytes, and in vivo dermatitis mouse models. In murine macrophages stimulated by lipopolysaccharide (LPS), CPD 6 significantly attenuated the release of inflammatory mediators such as nitric oxide (NO) (IC₅₀ for NO inhibition: 3.613 μM) and other cytokines. In cultured human keratinocytes, CPD 6 significantly attenuated the release of inflammatory cytokines induced by the combination of IFN-γ and TNF-α, UV irradiation, or chemical irritant stimulation. CPD 6 inhibited NFκB and JAK2/STAT1 signaling pathways, and activated Nrf2/HO-1 signaling. In vivo relevancy of anti-inflammatory effects of CPD 6 was observed in acute and chronic skin inflammation models in mice. CPD 6 showed significant anti-inflammatory properties both in vitro cells and in vivo dermatitis animal models, mediated by the inhibition of the NFκB and JAK2-STAT1 pathways and activation of Nrf2/HO-1 signaling. We propose that the novel chrysin-derivative CPD 6 may be a potential therapeutic agent for skin inflammation.

Fexofenadine Suppresses Delayed-Type Hypersensitivity in the Murine Model of Palladium Allergy

Palladium is frequently used in dental materials, and sometimes causes metal allergy. It has been suggested that the immune response by palladium-specific T cells may be responsible for the pathogenesis of delayed-type hypersensitivity in study of palladium allergic model mice. In the clinical setting, glucocorticoids and antihistamine drugs are commonly used for treatment of contact dermatitis. However, the precise mechanism of immune suppression in palladium allergy remains unknown. We investigated inhibition of the immune response in palladium allergic mice by administration of prednisolone as a glucocorticoid and fexofenadine hydrochloride as an antihistamine. Compared with glucocorticoids, fexofenadine hydrochloride significantly suppressed the number of T cells by interfering with the development of antigen-presenting cells from the sensitization phase. Our results suggest that antihistamine has a beneficial effect on the treatment of palladium allergy compared to glucocorticoids.

A newly synthesized macakurzin C-derivative attenuates acute and chronic skin inflammation: The Nrf2/heme oxygenase signaling as a potential target

Impaired immune responses in skin play a pivotal role in the development and progression of chemical-associated inflammatory skin disorders. In this study, we synthesized new flavonoid derivatives from macakurzin C, and identified in vitro and in vivo efficacy of a potent anti-inflammatory flavonoid, Compound 14 (CPD 14), with its underlying mechanisms. In lipopolysaccharide (LPS)-stimulated murine macrophages and IFN-γ/TNF-α-stimulated human keratinocytes, CPD 14 significantly inhibited the release of inflammatory mediators including nitric oxide (NO), prostaglandins, and cytokines (IC50 for NO inhibition in macrophages: 4.61μM). Attenuated NF-κB signaling and activated Nrf2/HO-1 pathway were responsible for the anti-inflammatory effects of CPD 14. The in vivo relevance was examined in phorbol 12-myristate 13-acetate (TPA)-induced acute skin inflammation and oxazolone-induced atopic dermatitis models. Topically applied CPD 14 significantly protected both irritation- and sensitization-associated skin inflammation by suppressing the expression of inflammatory mediators. In summary, we demonstrated that a newly synthesized flavonoid, CPD 14, has potent inhibitory effects on skin inflammation, suggesting it is a potential therapeutic candidate to treat skin disorders associated with excessive inflammation.

Histamine suppresses regulatory T cells mediated by TGF-β in murine chronic allergic contact dermatitis

Regulatory T cells (Tregs) suppress effector T cells and ameliorate contact hypersensitivity (CH); however, the role of Tregs in chronic allergic contact dermatitis (CACD) has not been assessed. Repeated elicitation of CH has been used to produce CACD models in mice. We previously showed that the presence of histamine facilitates the creation of eczematous lesions in this model using histidine decarboxylase (HDC) (-/-) mice. Therefore, the effects of histamine on Tregs in the CACD model were investigated in this study. CACD was developed by repeated epicutaneous application of 2, 4, 6-trinitro-1-chlorobenzene (TNCB) on HDC (+/+) and HDC (-/-) murine skin to assess the effects of histamine in CACD. Histamine aggravated CACD in the murine model and suppressed the number of Tregs in the skin. Histamine also suppressed the level of TGF-β1 in this model. Recombinant TGF-β1 or anti-TGF-β1 antibody was injected into the dorsal dermis of HDC (+/+) mice daily just before TNCB challenge to determine the effects of histamine-regulated TGF-β on the Treg population in CACD. Recombinant TGF-β1 injection promoted the infiltration of Tregs in the skin and the production of IL-10; however, anti-TGF-β1 antibody injection suppressed the number of Tregs in the skin and the production of IL-10. Histamine suppresses the number of Tregs in CACD, and this effect is mediated by TGF-β.

Neutrophil priming occurs in a sequential manner and can be visualized in living animals by monitoring IL-1β promoter activation

Rapid enhancement of phagocyte functionality is a hallmark of neutrophil priming. GeneChip analyses unveiled elevated CD54, dectin-2, and IL-1β mRNA expression by neutrophils isolated from inflammatory sites. In fact, CD54 and dectin-2 protein expression was detected on neutrophils recovered from skin, peritoneal, and lung inflammation lesions but not on those in bone marrow or peripheral blood. Neutrophils increased CD54 and dectin-2 mRNA during migration in Boyden chambers and acquired CD54 and dectin-2 surface expression after subsequent exposure to GM-CSF. Neutrophils purified from IL-1β promoter-driven DsRed-transgenic mice acquired DsRed signals during cell migration or exposure to GM-CSF. CD54 and dectin-2 were expressed by DsRed(+) (but not DsRed(-)) neutrophils in GM-CSF-supplemented cultures, and neutrophils recovered from inflammatory sites exhibited strong DsRed signals. The dynamic process of neutrophil priming was studied in chemically induced inflammatory skin lesions by monitoring DsRed expression using confocal microscopy. A majority (>80%) of Ly6G(+) neutrophils expressed DsRed, and those DsRed(+)/Ly6G(+) cells exhibited crawling motion with a higher velocity compared with their DsRed(-)/Ly6G(+) counterparts. This report unveils motile behaviors of primed neutrophils in living animals. We propose that neutrophil priming occurs in a sequential manner with rapid enhancement of phagocyte functionality, followed by CD54 and dectin-2 mRNA and protein expression, IL-1β promoter activation, and accelerated motility. Not only do these findings provide a new conceptual framework for our understanding of the process of neutrophil priming, they also unveil new insights into the pathophysiology of many inflammatory disorders that are characterized by neutrophil infiltration.

A multicenter, double-blind, randomized, noninferiority comparison of 14 days' treatment with oral olopatadine 10 mg or cetirizine 10 mg in Chinese adults with cutaneous pruritus

OBJECTIVES

To assess whether olopatadine hydrochloride (OH) was noninferior to cetirizine in the treatment of cutaneous pruritus (CP).

PATIENTS AND METHODS

Patients with CP presenting at seven centers in China were randomly allocated to double-blind treatment with 5 mg of OH orally twice a day or cetirizine 10 mg orally once a day for 2 weeks. Patients were followed up on days 7 and 14. Noninferiority was predefined as a 20% maximum difference in the reduction of symptom score reducing indices (SSRI). Both intention-to-treat (ITT) and per-protocol populations were analyzed.

RESULTS

174 patients (86 receiving OH and 88 cetirizine) were included in the ITT population. In the ITT population, the mean reduction in SSRI was 0.640 ± 0.274 in the OH group and 0.603 ± 0.289 in the cetirizine group. The one-sided 97.5% CI (-0.047) met the criteria for noninferiority. Noninferiority was also demonstrated for SSRI in the per-protocol population, with reductions of 0.640 ± 0.271 with OH and 0.596 ± 0.287 with cetirizine (97.5% CI -0.043).The total effectiveness rate (TER) was similar in the OH (90.0%) and cetirizine (80.0%) groups. The corresponding one-sided 97.5% CI (-1.0%) also demonstrated noninferiority. The incidence of adverse events was 47.1% in the OH group and 41.4% in the cetirizine group (p = 0.453).

CONCLUSION

The efficacy of OH was noninferior to that of cetirizine in controlling itching indicating that it can be considered as a clinically relevant alternative therapy to cetirizine for the management of CP in adult Chinese patients.

The role of mitogen- and stress-activated protein kinase 1 and 2 in chronic skin inflammation in mice

Mitogen- and stress-activated protein kinase 1 and 2 (MSK1/2) are two kinases phosphorylated by both ERK1/2 and p38 MAPK. Recently, MSK1 and 2 have been reported to act as negative regulators of acute inflammation. In this study, we investigated the role of MSK1/2 in chronic skin inflammation using an oxazolone-induced allergic contact dermatitis model in MSK1/2 knockout mice and wild-type mice. MSK1/2 knockout mice were demonstrated to have significantly increased inflammation compared with wild-type mice. This was measured by an increased ear thickness, elevated infiltration of neutrophils in the skin and increased inflammatory histological changes. Furthermore, we found significantly elevated levels of the proinflammatory cytokines Tumor necrosis factor-α (TNF-α), IL-1β and IL-6 at both mRNA and protein levels in MSK1/2 knockout mice compared with wild-type mice after oxazolone treatment. In addition, the mRNA expression of the chemokine Thymus and activation regulated chemokine (TARC) was demonstrated to be significantly elevated in oxazolone-treated MSK1/2 knockout mice compared with wild-type mice. The increased expression of TARC was paralleled by increased infiltration of cells positive for the TARC receptor, CCR4, in the dermis of MSK1/2 knockout mice. Our results indicate that MSK1/2 are involved in the activation of feedback mechanisms that dampen oxazolone-induced skin inflammation.

A Role of Staphyococcus aureus, Interleukin-18, Nerve Growth Factor and Semaphorin 3A, an Axon Guidance Molecule, in Pathogenesis and Treatment of Atopic Dermatitis

Staphylococcus aureus (SA) is usually present not only in the skin lesions of atopic dermatitis (AD) but also in the atopic dry skin. SA discharges various toxins and enzymes that injure the skin, results in activation of epidermal keratinocytes, which produce and release IL-18. IL-18 that induces the super Th1 cells secreting IFN-γ and IL-13 is supposed to be involved in development of AD and its pathogenesis. Indeed, the number of SA colonies on the skin surface and the serum IL-18 levels in patients with AD significantly correlated with the skin scores of AD lesions. Also, there is strong positive correlation between the skin scores and serum IL-18 levels in DS-Nh mice (P<0.0001, r=0.64), which develop considerable AD-like legions when they are housed under conventional conditions, but develop skin legions with less severity and less frequency under specific pathogens free (SPF) conditions. Therefore, they are well-known as model mice of AD, in which SA is presumed to be critical factor for the development of AD lesions. Also, theses DS-Nh mice pretreated with Cy developed more remarkable AD-like lesions in comparison with non-treated ones. The levels of INF-r and IL-13 in the supernatants of the lymph node cell cultures stimulated with staphylococcal enterotoxin B (SEB) or ConA were increased in the Cy-treated mice, although the serum levels of total IgE were not. In this experiment, we revealed that Cy-treated mice, to which CD25 +CD4 + reguratory T cells taken from non-treated ones had been transferred, developed the AD-like legions with less severity and less number of SA colonies on the skin surface. Therefore, it is presumed that CD25 +CD4 + reguratory T cells might be involved in the suppression of super Th1 cells which are induced by IL-18 and are involved in the development of AD-like lesions rather than IgE production. The efficient induction of CD25 +CD4 + reguratory T cells is expected for the new type of treatment of AD. We also found that farnesol (F) and xylitol (X) synergistically inhibited biofilm formation by SA, and indeed the ratio of SA in total bacteria at sites to which the FX cream containing F and X had been applied was significantly decreased 1 week later, accompanied with improvement of AD, when compared with that before application and at placebo sites. Therefore, the FX cream is a useful skin-care agent for atopic dry skin colonized by SA. The nerve growth factor (NGF) in the horny layer (the horn NGF) of skin lesions on the cubital fossa was collected by tape stripping and measured using ELISA in AD patients before and after 2 and 4 weeks treatments. Simultaneously, the itch and eruptions on the whole body and on the lesions, in which the horn NGF was measured, were recorded, and also the peripheral blood eosinophil count, serum LDH level and serum total IgE level were examined. The level of NGF was significantly higher in AD patients than in healthy controls, correlated with the severity of itch, erythema, scale/xerosis, the eosinophil count and LDH level, and also significantly decreased after treatments with olopatadine and/or steroid ointment for 2 and 4 weeks. Therefore, the measurement of the NGF by this harmless method seems to be useful to assess the severity of AD and the therapeutic effects on AD. In AD patients, C-fiber in the epidermis increase and sprout, inducing hypersensitivity, which is considered to aggravate the disease. Semaphorin 3A (Sema3A), an axon guidance molecule, is a potent inhibitor of neurite outgrowth of sensory neurons. We administered recombinant Sema3A intracutaneously into the skin lesions of NC/Nga mice, an animal model of AD, and investigated the effect of Sema3A on the skin lesions and their itch. Sema3A dose-dependently improved skin lesions and attenuated the scratching behavior in NC/Nga mice. Histological examinations revealed a decrease in the epidermal thickness, the density of invasive nerve fibers in the epidermis, inflammatory infiltrate including mast cells and CD4 +T cells, and the production of IL-4 in the Sema3A-treated lesions. Because the interruption of the itch-scratch cycle likely contributes to the improvement of the AD-like lesions, Sema3A is expected to become a promising treatment of patients with refractory AD.

Toll-like receptor 2 is important for the T(H)1 response to cutaneous sensitization

BACKGROUND

Atopic dermatitis and allergic contact dermatitis are skin disorders triggered by epicutaneous sensitization with protein antigens and contact sensitization with haptens, respectively. Skin is colonized with bacteria, which are a source of Toll-like receptor (TLR) 2 ligands.

OBJECTIVE

We sought to examine the role of TLR2 in murine models of atopic dermatitis and allergic contact dermatitis.

METHODS

TLR2(-/-) mice and wild-type littermates were epicutaneously sensitized with ovalbumin (OVA) or contact sensitized with oxazolone (OX). Skin histology was assessed by means of hematoxylin and eosin staining and immunohistochemistry. Ear swelling was measured with a micrometer. Cytokine mRNA expression was examined by means of quantitative RT-PCR. Antibody levels and splenocyte secretion of cytokines in response to OVA stimulation were measured by means of ELISA. Dendritic cells were examined for their ability to polarize T-cell receptor/OVA transgenic naive T cells to T(H)1 and T(H)2.

RESULTS

In response to OVA sensitization, TLR2(-/-) mice experienced skin infiltration with eosinophils and CD4(+) cells, as well as upregulation of T(H)2 cytokine mRNAs that was comparable with that seen in wild-type littermates. In contrast, epidermal thickening, IFN-gamma expression in the skin, IFN-gamma production by splenocytes, and IgG2a anti-OVA antibody levels were impaired in TLR2(-/-) mice. After OX ear challenge, contact sensitized TLR2(-/-) mice exhibited defective ear swelling with impaired cellular infiltration, decreased epidermal thickening and local IFN-gamma expression, and impaired OX-specific IgG2a responses. Dendritic cells from TLR2(-/-) mice induced significantly lower production of IFN-gamma but normal IL-4 and IL-13 production in naive T cells.

CONCLUSIONS

These results indicate that TLR2 promotes the IFN-gamma response to cutaneously introduced antigens.

Effects of olopatadine in limited scleroderma with peripheral eosinophils

Scleroderma and eosinophilia often occur together, though the pathogenesis is unclear. We investigated the effect of olopatadine hydrochloride in a series of cases of limited scleroderma (LS). Ten patients with LS and positive eosinophil counts (LSE) were enrolled (average age, 85 years; six men and four women). Serum concentrations of the anti-Scl-70 antibody were positive. Olopatadine hydrochloride was prescribed at 10 mg/day for 3 weeks. Serum concentrations of the anti-Scl-70 antibody significantly decreased, but changes in eosinophil numbers and percentages in peripheral blood were not significant. Factor analysis suggested a correlation between serum concentrations of the anti-Scl-70 antibody and complement C4. Olopatadine could be effective in reducing anti-Scl-70 antibodies in the elderly with LSE.

Topically applied diterpenoids from Egletes viscosa (Asteraceae) attenuate the dermal inflammation in mouse ear induced by tetradecanoylphorbol 13-acetate- and oxazolone

The diterpene compounds, centipedic acid (CA) and 12-acetoxyhawtriwaic acid lactone (AHAL, tanabalin) isolated from the flower buds of Egletes viscosa LESS. (Asteraceae) were evaluated on acute and chronic models of mouse ear dermatitis. A single topical application of CA (0.125; 0.25 and 0.5 mg/ear) or AHAL (0.125, 0.25, 0.5 mg/ear) immediately before 12-O-tetradecanoylphorbol-13-acetate (TPA, 2.5 mug/ear) caused a dose-related significant inhibition of ear inflammatory edema and influx of polymorphonuclear cells, as evidenced by a decrease in ear thickness and reduced myeloperoxidase (MPO) activity and tumor necrosis factor-alpha (TNF-alpha) in ear tissue homogenates. The maximal obtained inhibition for both ear edema and neutrophil influx were almost similar to that of topically applied dexamethasone (0.05 mg/ear). The extent of inhibitions for the respective treatments of CA (0.5 mg/ear), AHAL (0.5 mg/ear), or dexamethasone (0.05 mg/ear) were in the order of 63%, 61% and 81% for the ear edema, and 90%, 95% and 95% for the neutrophil influx. Also, at similar doses, both diterpenes and dexamethasone effectively inhibited the delayed-type hypersensitivity reaction induced by repeated topical application of 1% oxazolone (OXA, 20 microl/ear), as evidenced by significant decreases in ear thickness and interferon-gamma (INF-gamma) levels in ear tissue. Histopathological analysis revealed a marked decrease in epidermal hyperplasia and neutrophil infiltration in animals pretreated with CA or AHAL, in a manner similar to dexamethasone. These data provide evidence for the anti-dermatitis effect of Egletes viscosa diterpenes, by mechanisms that involve a reduced neutrophil influx and decreased production of inflammatory cytokines, TNF-alpha and IFN-gamma.

Olopatadine hydrochloride accelerates the recovery of skin barrier function in mice

BACKGROUND

The skin barrier function in patients with atopic dermatitis is disrupted and prolonged topical steroid therapy produces epidermal barrier disturbance. Olopatadine hydrochloride (olopatadine; Allelock; Kyowa Hakko Kogyo Co., Ltd, Shizuoka, Japan) is an antiallergic drug with histamine H(1) receptor antagonistic action. This drug alleviates skin inflammation and decreases the number of scratching episodes in a murine model of chronic contact dermatitis.

OBJECTIVES

To investigate the effects of olopatadine and a steroid on the recovery of skin barrier function after barrier disruption in mice.

METHODS

The skin barrier of the ears of mice was disrupted by tape stripping. The recovery of skin barrier function was monitored by measurement of transepidermal water loss (TEWL) after barrier disruption. Epidermal hyperplasia was induced by repeated tape stripping for 7 days. Olopatadine was administered orally once daily from 3 days before the first barrier disruption. Betamethasone 17-valerate (betamethasone) was applied topically once daily from 3 days before barrier disruption.

RESULTS

Tape stripping led to a significant increase in TEWL. TEWL decreased with time after tape stripping and the skin barrier function recovered by over 60% within 9 h after tape stripping. The recovery of skin barrier in olopatadine-treated mice was significantly accelerated, compared with that in vehicle-treated mice. In contrast, the skin barrier recovery in mice treated with topical betamethasone was significantly delayed, compared with that in vehicle-treated mice. Combined treatment with olopatadine and betamethasone ameliorated the delay in barrier recovery induced by topical treatment with betamethasone. In addition, olopatadine significantly prevented the increase in epidermal thickness induced by prolonged barrier disruption.

CONCLUSIONS

These results suggest that systemic administration of olopatadine accelerates the recovery of skin barrier function and ameliorates the adverse effects of topical steroids on skin barrier recovery.

Olopatadine suppresses the migration of THP-1 monocytes induced by S100A12 protein

Olopatadine hydrochloride (olopatadine) is an antiallergic drug with histamine H(1) receptor antagonistic activity. Recently, olopatadine has been shown to bind to S100A12 which is a member of the S100 family of calcium-binding proteins, and exerts multiple proinflammatory activities including chemotaxis for monocytes and neutrophils. In this study, we examined the possibility that the interaction of olopatadine with S100A12 inhibits the proinflammatory effects of S100A12. Pretreatment of olopatadine with S100A12 reduced migration of THP-1, a monocyte cell line, induced by S100A12 alone, but did not affect recombinant human regulated upon activation, normal T cell expressed and secreted (RANTES)-induced migration. Amlexanox, which also binds to S100A12, inhibited the THP-1 migration induced by S100A12. However, ketotifen, another histamine H(1) receptor antagonist, had little effect on the activity of S100A12. These results suggest that olopatadine has a new mechanism of action, that is, suppression of the function of S100A12, in addition to histamine H(1) receptor antagonistic activity.

Neuronal conditions of spinal cord in dermatitis are improved by olopatadine

Intense pruritus and cutaneous reactivity represent cardinal features of eczema. The resulting scratching behaviors alter neuronal conditions of the spinal dorsal horn where the primary sensory afferent fibers transmit cutaneous stimulation and deteriorate eczematous skin lesions. We investigated the effects of olopatadine hydrochloride (olopatadine) on alteration of neuronal conditions of the spinal dorsal horn and eczematous skin lesions induced by contact dermatitis. Eczematous lesions were induced by repeated application of diphenylcyclopropenone (DCP) in BALB/c mice. Olopatadine suppressed scratching behavior caused by repeated application of DCP in mice. Increased expressions of c-Fos and substance P in the spinal dorsal horn following DCP application were improved by olopatadine. Furthermore, olopatadine diminished the number of infiltrating cells and levels of cytokines in eczematous skin lesions resulting from DCP application. Olopatadine improves neurological conditions in the spinal cord and eczematous skin lesions in a murine contact dermatitis model.

The effects of olopatadine hydrochloride on the number of scratching induced by repeated application of oxazolone in mice

It is suggested that atopic dermatitis is a skin disease associated with itching as subjective symptoms, and histamine H(1) receptor antagonists are used in order to prevent the itching, and the deterioration for scratch by itching. Histamine H(1) receptor selective anti-histamine olopatadine hydrochloride (olopatadine; Allelock shows consistent efficacy and safety in the treatment of allergic disorders. We investigated the possible efficacy of olopatadine on the number of scratching induced by repeated application of oxazolone in BALB/c mice. The repeated treatment of olopatadine significantly inhibited the ear swelling and the increased number of scratching. It significantly inhibited the increased production of interleukin (IL)-4, IL-1beta and granulocyte-macrophage colony-stimulating factor (GM-CSF) in the lesioned ear. Moreover, it significantly inhibited the increased production of nerve growth factor (NGF) and substance P. On the other hand, loratadine, bepotastine and chlorpheniramine did not inhibit the ear swelling and the increased number of scratching. These results indicate that olopatadine inhibited not only the increased production of cytokines but also NGF and substance P unlike other histamine H(1) receptor antagonists. It was suggested that olopatadine suppressed the increased number of scratching by the anti-inflammatory effects. Therefore, olopatadine appears to exert additional biological effects besides its blockade of a histamine H(1) receptor.

Effect of Olopatadine and Other Histamine H1 Receptor Antagonists on the Skin Inflammation Induced by Repeated Topical Application of Oxazolone in Mice

Histamine H1 receptor antagonists have long been prescribed for atopic dermatitis as an adjuvant therapy with topical therapy by local applied steroids. Olopatadine is one of the second-generation histamine H1 receptor antagonists that are treated for allergic disorders. We investigated that the effect of olopatadine on oxazolone-induced chronic contact hypersensitivity response in BALB/c mice compared with other histamine H1 receptor antagonists loratadine, cetirizine and fexofenadine. The chronic contact hypersensitivity induced by repeated application of oxazolone was treated with olopatadine and other histamine H1 receptor antagonists at the effective doses on histamine-induced paw edema in mice. The effects of these drugs in the oxazolone-induced model were quantified by measurements of ear swelling, and levels of cytokines in the lesioned ear. Olopatadine significantly inhibited the ear swelling and the increased production of IL-4, IL-1beta, IL-6, GM-CSF and NGF in the lesioned ear. On the other hand, the other histamine H1 receptor antagonists did not significantly suppress the increase in ear thickness. Moreover, they did not affect the production of cytokines in the lesioned ear. These results indicate that olopatadine appears to exert additional biological effects besides its blockade of the histamine H1 receptor.

Olopatadine hydrochloride suppresses the rebound phenomenon after discontinuation of treatment with a topical steroid in mice with chronic contact hypersensitivity

BACKGROUND

Olopatadine hydrochloride (olopatadine; Allelock) is one of the second-generation antihistamines that are treated for allergic disorders such as rhinitis, urticaria and eczema dermatitis. Olopatadine has recently been shown to have inhibitory effects on the chronic contact hypersensitivity induced by repeated application of oxazolone in mice. Although topical steroids have widely been prescribed for atopic dermatitis, a relapse often occurs within several days after discontinuation of their prolonged use.

OBJECTIVES

We investigated the possible efficacy of olopatadine against the relapse after discontinuation of prolonged use of topical prednisolone in the Balb/c mice with oxazolone-induced chronic contact hypersensitivity.

METHODS

Mice with the chronic contact hypersensitivity induced by repeated application of oxazolone were treated with olopatadine as a sequential therapeutic agent. The effects of olopatadine were quantified by measurements of ear-swelling, and levels of cytokines and histamine in the lesioned ear. Results Topical prednisolone (0.05 mg/ear/day) significantly inhibited the increases in ear swelling and production of IL-1beta, IL-4, IL-18, granulocyte-macrophage colony-stimulating factor (GM-CSF) and histamine. However, after discontinuation of the treatment with topical prednisolone, the inflammation relapsed and the IL-4 level exceeded the control one. The sequential treatment with olopatadine (10 mg/kg/day) after discontinuation of the treatment with topical prednisolone alone, or topical prednisolone with olopatadine, significantly inhibited the increases in ear swelling and levels of IL-1beta, IL-4, IL-18, GM-CSF, nerve growth factor and histamine.

CONCLUSIONS

These results indicate that olopatadine is an antihistamine agent having inhibitory activities against the rebound phenomenon following the discontinuation of topical steroid therapy. Olopatadine is thus expected to be a sequential therapeutic agent after discontinuation of the chronic treatment with a topical steroid.