Disodium Chromoglycate Research Articles

Production of giant unilamellar vesicles and encapsulation of lyotropic nematic liquid crystals

We describe a modified microfluidic method for making Giant Unilamellar Vesicles (GUVs) via water/octanol-lipid/water double emulsion droplets. At a high enough lipid concentration we show that the de-wetting of the octanol from these droplets occurs spontaneously (off-chip) without the need to use shear to aid the de-wetting process. The resultant mixture of octanol droplets and GUVs can be separated by making use of the buoyancy of the octanol. A simpler microfluidic device and pump system can be employed and, because of the higher flow-rates and much higher rate of formation of the double emulsion droplets (∼1500 s-1 compared to up to ∼75 s-1), it is easier to make larger numbers of GUVs and larger volumes of solution. Because of the potential for using GUVs that incorporate lyotropic nematic liquid crystals in biosensors we have used this method to make GUVs that incorporate the nematic phases of sunset yellow and disodium chromoglycate. However, the phase behaviour of these lyotropic liquid crystals is quite sensitive to concentration and we found that there is an unexpected spread in the concentration of the contents of the GUVs obtained.

Amyotrophic Lateral Sclerosis, Neuroinflammation, and Cromolyn

Amyotrophic lateral sclerosis (ALS) is an upper motor neuron disease with an unknown pathogenesis and no effective treatment. A recent study found that treatment of a mouse model of ALS (TgSOD1 mice) intraperitoneally with the mast-cell blocker disodium chromoglycate (cromolyn) had a small but significant effect on disease onset, improvement of neurologic symptoms, and decrease in the expression of proinflammatory cytokines and chemokines in the spinal cord and plasma of the TgSOD1 mice. Treatment with cromolyn also reduced degranulation of mast cells in the tibialis anterior muscle. There was no effect on survival. These findings are important in their support of the involvement of mast cells in the pathogenesis of ALS but are limited by the small effect of cromolyn, which was given intraperitoneally and is poorly absorbed after oral administration. Instead, use of the structurally related flavonoid tetramethoxyluteolin, which is a more potent inhibitor of proinflammatory cytokine release from mast cells and also inhibits activated microglia, may offer significant advantages over cromolyn. Development of mast cell inhibitors could benefit not only allergic disorders but also inflammatory and neurodegenerative disorders.

Dietary cholesterol is essential to mast cell activation and associated obesity and diabetes in mice

Mast cell (MC) deficiency in KitW-sh/W-sh mice and inhibition with disodium chromoglycate (DSCG) or ketotifen reduced obesity and diabetes in mice on a high-cholesterol (1.25%) Western diet. Yet, Kit-independent MC-deficient mice and mice treated with DSCG disproved MC function in obesity and diabetes when mice are fed a high-fat diet (HFD) that contains no cholesterol. This study reproduced the obesity and diabetes inhibitory activities of DSCG and ketotifen from mice on a Western diet. Yet, such inhibitory effects were diminished in mice on the HFD. DSCG and ketotifen MC inhibitory activities were recovered from mice on the HFD supplemented with the same amount of cholesterol (1.25%) as that in the Western diet. DSCG and ketotifen effectively blunted the high-cholesterol diet-induced elevations of blood histamine and adipose tissue MC degranulation. Pearson's correlation test demonstrated significant and positive correlations between plasma histamine and total cholesterol or low-density lipoprotein-cholesterol (LDL). In cultured bone marrow-derived MCs, plasma from mice following a Western diet or a cholesterol-supplemented HFD, but not those from HFD-fed mice, induced MC degranulation and the release of β-hexosaminidase, histamine, and serotonin. IgE, LDL, very low-density lipoprotein, and high-density lipoprotein also induced MC activation, which can be inhibited by DSCG and ketotifen depending on the doses and types of MC inhibitors and cholesterol, and also the MC granule molecules of interest. DSCG or ketotifen lost their activities in inhibiting LDL-induced activation of MCs from LDL receptor-deficient mice. These results indicate that dietary cholesterol critically influences the function of mouse MCs.

Brownian Dynamics of Particles "Dressed" by Chiral Director Configurations in Lyotropic Chromonic Liquid Crystals.

We study Brownian dynamics of colloidal spheres, with planar anchoring conditions, suspended in the nematic phase of the lyotropic chromonic liquid crystal disodium chromoglycate (DSCG). Unlike typical liquid crystals, the unusually small twist elastic modulus of DSCG permits two energetically distinct helical distortions (twisted tails) of the nematic director to "dress" the suspended spheres. Video microscopy is used to characterize the helical distortions versus particle size and to measure particle mean-square displacements. Diffusion coefficients parallel and perpendicular to the far-field director, and their anisotropy ratio, are different for the two twisted tail configurations. Moreover, the crossover from subdiffusive to diffusive behavior is anomalously slow for motion perpendicular to the director (>100 s). Simple arguments using Miesowicz viscosities and ideas about twist relaxation are suggested to understand the mean-square displacement observations.

Arrangement of chromonic liquid crystals near hydrophobic and hydrophillic surfaces

The possibility of utilizing the lyotropic Chromonic Liquid Crystal (LCLC) in the detection of the biological cells, such as bacteria, virus etc. and biological macromolecules like protein, DNA etc. have attracted a number of researchers in recent time. The organization of the LCLC near surfaces is important to explore these applications. We have explored the time-dependent effects of surface re-arrangements of LCLCs (disodium chromo glycate (DSCG) and Sunset Yellow (SSY)) using the polarized microscope. It is found that the initial arrangement of DSCG and SSY depends on the hydrophobicity of the surface. A strong hydrophobic surface leads to the homeotropic arrangements of DSCG and SSY. However, the moderately hydrophobic surface cannot give the homeotropic arrangements of LCLCs. With the passage of time, the evolved texture of the LCLCs is independent of surface hydrophobicity. The effect of surfaces on DSCG is more pronounced compared to that on SSY.

Imaging of bacteria using chromonic liquid crystals

ABSTRACTWe explored adsorption isotherms of Escherichia coli (E.coli) and Salmonella over the poly-L-lysine (PLL) coated glass surface. The detection of the adsorbed bacteria was explored using 14 wt% di-sodium-chromo-glycate (DSCG) solution in water and 5CB. The textures of the optical cells made up of LCs and the adsorbed bacteria over PLL-coated glass substrate were obtained by using a polarized microscope in the transmission mode under crossed polars. We found that DSCG solution exhibits a dark spot on the adsorbed E.coli and Salmonella. In contrast to DSCG solution, 5CB did not show any dark spot.

Anti-anaphylactic effects of Trichilia monadelpha (Thonn.) J. J. De Wilde extracts on rodent models of anaphylaxis.

Effects of petroleum ether and ethanolic extracts of Trichilia monadelpha stem bark (PEE and EAE) on compound 48/80-induced systemic and passive anaphylaxis were determined. Survival rate, extravasation, degranulation of mast cells, and secretion of tumour necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were measured after pre-treatment with extracts (10-100 mg/kg) and disodium chromoglycate (2.5-250 μg/kg) and induction of anaphylaxis in C57BL/6 mice or Sprague-Dawley rats with compound 48/80. Histopathological assessments were made from skin biopsies of rats. Data was analyzed by Kaplan-Meier Survival Log-Rank Analysis, or One-way ANOVA and Holm-Sidak’s post hoc test. PEE and EAE inhibited (P ≤ 0.0001) tremors in systemic anaphylaxis passive cutaneous anaphylactic reactions and extravasation, stabilized or prevented (P ≤ 0.001-0.0001) mast cell degranulation, and inhibited (P ≤ 0.001-0.0001) TNF-α and IL-6 secretion. Per the findings, PEE and EAE of T. monadelpha have exhibited substantial anti-anaphylactic and anti-inflammatory property (with PEE performing better) which substantiates its use traditionally in management of allergies and other inflammatory disorders.

Exploitation of orientation of liquid crystals 5CB and DSCG near surfaces to detect low protein concentration

We report the alignment of 4-cyano-4-pentylbiphenyl (5CB), a thermotropic liquid crystal (LC), and disodium chromo glycate (DSCG), a lyotropic LC, on the hydrophobic head group containing dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride (DMOAP) and hydrophilic amine head group. Based on the texture observed using a polarised microscope for modified surfaces, we propose the alignment of the LCs on the modified surfaces. It is further supported by Fourier transform infra-red spectroscopy (FTIR) data of the corresponding system. Next, the texture under a polarised microscope for the LCs on protein bovine serum albumin adsorbed over the amine and DMOAP surfaces was observed. The difference in texture of LCs over the proteins depends on its concentration in solution. The difference is due to the amount of adsorbed proteins present on the surface. Above a critical amount of protein at the surface, the LCs show homeotropic arrangement.

Effect of conjugated linoleic acid on compound 48/80-induced pruritus in mice

Pruritus is one of the most important symptoms of allergic inflammatory skin disease. Conjugated linoleic acid (CLA) has been reported to have preventive effects against allergic inflammation. The objective of this study was to determine whether or not oral administration of CLA suppresses pruritus induced by compound 48/80 (composed of N-methyl-p-methoxy phenethylamine with formaldehyde) in mice, and if so, whether or not this effect is associated with serum histamine and prostaglandin (PG) E2 levels. Liquid CLA mixture (36.25% 9c-11t CLA, 36.95% 10t-12c CLA, 1.12% 9c-11c, and 1.94% t9-t11 CLA) was emulsified in 0.5% carboxymethyl cellulose (CMC) sodium salt and orally administered to mice at doses of 200 mg/kg once per day for 3 days. Similarly, disodium chromoglycate (DSCG), an antipruritic substance, was administered orally at the same concentrations as the negative control. Compound 48/80, a pruritus-inducing reagent, was subcutaneously injected 30 minutes after final administration of CLA. Scratching behavior of mice was counted just after compound 48/80 injection. Serum histamine and PGE2 concentrations were evaluated individually. Mice administered with CLA showed reduced frequency of scratching behavior compared to those without CLA. Antipruritic activities in CLA-treated and DSCG-treated groups were 48.5% and 26.8%, respectively. CLA and DSCG also diminished serum concentrations of histamine and PGE2 compared to compound 48/80 alone, respectively. This result suggests that dietary CLA has an antipruritic effect by down-regulating serum histamine and PGE2 levels for relief of compound 48/80-induced scratching behavior in mice, which will be useful in allergic pruritus as a preventive medicine.

Mast cell activation and degranulation promotes renal fibrosis in experimental unilateral ureteric obstruction

Progressive renal fibrosis is the final common pathway leading to renal failure irrespective of the initiating cause. Clinical studies of renal fibrosis found that prominent mast cell accumulation correlated with worse outcomes. Mast cells are pluripotent innate immune cells that synthesize and secrete profibrotic mediators. Here we use mast cell-deficient (Kit(W-sh/W-sh)) mice to define a functional pathogenic role for these cells in the development of renal fibrosis. Intrarenal collagen deposition was significantly decreased in mast cell-deficient compared to wild-type mice 7 and 14 days after unilateral ureteric obstruction. The intrarenal expression of mRNAs for transforming growth factor-β, α-smooth muscle actin, chemokines, and renal macrophages and CD4(+) T cells were also decreased in mast cell-deficient mice. Reconstitution of the mast cell population in mast cell-deficient mice with wild-type bone marrow-derived mast cells restored the pattern and intensity of renal fibrosis to levels seen in wild-type mice following ureteric ligation. Interestingly, the mast cells were recruited, activated, and degranulated within 6 h of ureteric ligation. A mast cell stabilizer that impairs degranulation, disodium chromoglycate, significantly attenuated renal fibrosis following ureteric ligation in wild-type mice. Thus, mast cells promote renal fibrosis and their targeting may offer therapeutic potential in the treatment of renal fibrosis.

Drugs Acting on Mast Cells Functions: A Cell Biological Perspective

Mast cells are bone marrow derived cells capable of secreting many active molecules: mediators stored in specific granules, such as histamine and heparin; small molecules produced immediately upon stimulation, such as lipid derivatives and nitric oxide; and many constitutively secreted, pleiotropic cytokines. Thanks to these secretion products and perhaps direct cell-cell interactions, mast cells play roles in inflammation and tissue repair, angiogenesis and fibrosis. Mast cells themselves respond to many mediators of their own, giving rise to autocrine loops. Successful anti-allergic therapies have typically targeted the receptors for mast cell secretory products, particularly those for histamine. Among agents directly affecting mast cells, disodium chromoglycate and glucocorticoids are known since some time, while new pharmacological approaches may stem from the recognition of an interference with mast cell growth and differentiation by cyclosporine A, monoclonal antibodies, interferons, and JAK3 inhibitors. The action of agents that affect mast cell differentiation and function is considered here from a cell and tissue biological perspective as a premise to the application of these agents to the clinics, therefore special attention has been paid to references pertaining to humans.

Role of Mast Cells in Acupuncture Effect: A Pilot Study

To better understand the therapeutic effectiveness of acupuncture, questions about the underlying mechanisms need to be addressed. Here we describe the impact of manual stimulation by an acupuncture needle of zusanli (stomach 36 [ST36]) on analgesia in rats. The analgesic effect was more pronounced after stimulation of ST36 than after stimulation of a sham point near the acupuncture point. At the same time, we determined in tissue slices the density of mast cells in the acupuncture points and nearby points, as well as the degree of degranulation before and after stimulation. We found that the density of mast cells from the ST36 of rats was higher than that from a nearby sham point. In addition, acupuncture resulted in a remarkable increase in degranulation of the mast cells. Pretreatment of the acupuncture point with disodium chromoglycate not only counteracted the phenomenon of degranulation but also reduced analgesic effect of acupuncture. Our experiments on inhibition of degranulation of mast cells in tissue from acupuncture points demonstrates the possible role of mast cells in acupuncture effects.

Comparative evaluation of successive extracts of leaf and stem bark of Albizzia lebbeck for mast cell stabilization activity

Successive chloroform, methanol and water extracts of bark and leaves of Albizzia lebbeck were tested for its in vitro mast cell stabilizing effect against compound 48/80. Methanolic extract of leaf and methanolic and water extracts of bark have shown maximum activity comparable to that of disodium chromoglycate.

Optical characterization of the nematic lyotropic chromonic liquid crystals: Light absorption, birefringence, and scalar order parameter

We report on the optical properties of the nematic (N) phase formed by lyotropic chromonic liquid crystals (LCLCs) in well aligned planar samples. LCLCs belong to a broad class of materials formed by one-dimensional molecular self-assembly and are similar to other systems such as "living polymers" and "wormlike micelles." We study three water soluble LCLC forming materials: disodium chromoglycate, a derivative of indanthrone called Blue 27, and a derivative of perylene called Violet 20. The individual molecules have a planklike shape and assemble into rodlike aggregates that form the phase once the concentration exceeds about 0.1 M. The uniform surface alignment of the N phase is achieved by buffed polyimide layers. According to the light absorption anisotropy data, the molecular planes are on average perpendicular to the aggregate axes and thus to the nematic director. We determined the birefringence of these materials in the N and biphasic N-isotropic (I) regions and found it to be negative and significantly lower in the absolute value as compared to the birefringence of typical thermotropic low-molecular-weight nematic materials. In the absorbing materials Blue 27 and Violet 20, the wavelength dependence of birefringence is nonmonotonic because of the effect of anomalous dispersion near the absorption bands. We describe positive and negative tactoids formed as the nuclei of the new phase in the biphasic N-I region (which is wide in all three materials studied). Finally, we determined the scalar order parameter of the phase of Blue 27 and found it to be relatively high, in the range 0.72-0.79, which puts the finding into the domain of general validity of the Onsager model. However, the observed temperature dependence of the scalar order parameter points to the importance of factors not accounted for in the athermal Onsager model, such as interaggregate interactions and the temperature dependence of the aggregate length.

Salt Effects on the Phase Behavior, Structure, and Rheology of Chromonic Liquid Crystals

Chromonic liquid crystals are formed by the addition of aromatic molecules such as disodium chromoglycate (cromolyn) to water. In this study, we investigate the addition of salts to the lyotropic nematic phase of cromolyn aqueous solutions. The addition of sodium and potassium salts shifts the isotropic-nematic phase boundary upward by more than 10 degrees C, so that samples that were isotropic at room temperature are transformed into nematic phases. Salt effects are predominantly dictated by the cation, not the anion, and appear to differ based on cation size. In contrast to small, hydrated cations like sodium, large, weakly hydrated cations such as tetraethylammonium and tetrabutylammonium shift the phase boundary downward, thus stabilizing the isotropic phase at the expense of the nematic one. The phase behavior results are highly correlated with viscosity measurements, with an upward shift in the phase boundary correlating with an increase in solution viscosity and vice versa. We also probe the microstructure in cromolyn-salt solutions, both indirectly by small-angle neutron scattering (SANS) and directly by cryo-transmission electron microscopy (cryo-TEM). The cryo-TEM images show the presence of rodlike aggregates that possibly undergo a higher order aggregation into bundles in the presence of salt.

An evaluation of the acidogenic potential of asthma inhalers

Aim: The aims of the present study were firstly to investigate the inherent pH and titratable acidity of commercially available paediatric asthma inhalers in the United Kingdom and secondly to assess their in vivo acidogenic potential (saliva pH and plaque pH (PpH) tests) in a group of healthy adult volunteers. Materials and methods: Manually actuated metered dose inhaler (MDI) and dry powder inhaler (DPI) formulations of all available preventor (glucocorticoids, disodium chromoglycate), reliever (β 2 agonists) and combination asthma medication were investigated. The inherent pH and titratable acidity of 18 inhalers were determined and analysed using t-tests, ANOVA and post hoc Tukey’s tests. Following this the oral pH responses after inhaler use were assessed in 14 healthy adult volunteers (complying with the FNDH criteria, 1985) who participated in a random blind study to determine both the salivary pH (SpH) and plaque pH following inhaler use. Non-parametric tests of significance (Mann-Whitney and Wilcoxon Signed-Ranked Tests) were used to analyse pH responses according to vehicle of delivery (MDI/DPI), lactose content and generic drug. Results: The inherent pH of the DPIs ( n=8, mean pH=5.06) was significantly lower ( P<0.005) than that of the MDIs ( n=10, mean pH=6.45) and the titratable acidity of the lactose-based DPIs was twice that of the non-lactose-based DPIs ( P<0.000). Lactose-based DPIs produced significantly lower salivary pH and plaque pH readings, greater maximum pH drops from baseline pH and larger areas below baseline pH in comparison with that of all other inhalers tested ( P<0.05). All inhalers, however, failed to depress plaque pH below pH 6. Conclusions: Although none of the inhalers were able to demonstrate an acidogenic response below the “critical” pH, the substantial pH drops observed with the lactose-based DPIs may be an important consideration for enamel demineralisation.

Surface-assisted photoalignment control of lyotropic liquid crystals. Part 2. Photopatterning of aqueous solutions of a water-soluble anti-asthmatic drug as lyotropic liquid crystalsFor Part 1, see ref. 4.

The photocontrol of the alignment of aqueous solutions of an anti-asthmatic drug, disodium chromoglycate (DSCG), as a lyotropic liquid crystal (LLC), was performed by irradiation of a thin film of (4-phenylazophenyl methacrylate) with linearly polarised light. The addition of a non-ionic surfactant to the LLC is a necessary condition to performing the alignment photocontrol because of the generation of nematic phase. The orientational direction of molecules of the drug was perpendicular to the electric vector of the actinic light, suggesting that columnar supramolecular aggregates composed of stacked DSCG molecules align in parallel with the long molecular axis of photooriented azobenzene chromophores, which lies in an orthogonal position with respect to the electric vector of the light. A general guideline for the photoalignment control of LLC is discussed on the basis of the results for DSCG and for a water-soluble dye, C. I. Direct blue 67, reported in Part 1 of the series.

Studies on immunomodulatory activity of Withania somnifera (Ashwagandha) extracts in experimental immune inflammation

The immunomodulatory activities of an Indian Ayurvedic medicinal preparation, i.e. extracts from Ashwagandha, Withania somnifera (L.) Dunal (Solanaceae), namely WST and WS2, were studied in mice for immune inflammation: active paw anaphylaxis and delayed type hypersensitivity (DTH). Immunomodulatory effect was assessed in If IgE-mediated anaphylaxis as reduction of ovalbumin-induced paw edema, in animals treated with WS2 at doses of 150 and 300 mg/kg, and the results were compared with the standard drug disodium chromoglycate. In the DTH model, the modulatory effect was assessed as potentiation or suppression of the reaction, revealing an increase or decrease in mean foot pad thickness, respectively. Potentiation of the DTH reaction was observed in animals treated with cyclophosphamide at a dose of 20 mg/kg, WST at a dose of 1000 mg/kg and WS2 at a dose of 300 mg/kg. On the other hand, cyclophosphamide-induced potentiation of DTH reaction was suppressed in animals treated with WST and WS2. A significant increase in white blood cell counts and platelet counts was observed in animals treated with WST. A protective effect in cyclophosphamide-induced myelosuppression was observed in animals treated with WST and WS2, revealing a significant increase in white blood cell counts and platelet counts. Cyclophosphamide-induced immunosuppression was counteracted by treatment with WS2, revealing significant increase in hemagglutinating antibody responses and hemolytic antibody responses towards sheep red blood cells.

Oxatomide in Food Allergies. Comparative Study versus Disodium Chromoglycate

A randomized, controlled, single blind study was carried out to compare the efficacy and safety of oxatomide and disodium chromoglycate in the treatment of adverse reactions to food. Twenty-three patients (16F and 7M) with urticaria (16 patients), respiratory (5 patients), intestinal (15 patients) and/or neurological symptoms (3 patients) were treated for 60 days: 14 (9F and 5M; mean ± SD age 36.3 ± 13.8 years) with oxatomide, 60 mg every evening and 9 (7F and 2M; 31.5 ± 15.1 years) with disodium chromoglycate, 500 mg three times a day. Both therapies lasted two months. On admission and after 15,30 and 60 days skin (wheals, itching, vesicular blisters, scratching lesions), respiratory (rhinorrhea, sneezing, coughing, wheezing), intestinal (constipation, diarrhea, bloating, abdominal pain and/or cramps) and neurological (headache, irritability) symptoms were assessed. Wheals decreased in number and size in both groups (p&lt;0.005). Itching became less severe in the two groups (p&lt;0.05), although the improvement in the oxatomide group was faster. Vesicular blisters, present in one patient in the oxatomide group at baseline, disappeared by days 15 and 30, reappearing in a mild form at the end of the study. The frequency of scratching lesions decreased. Sneezing and wheezing disappeared in both groups. Digestive system symptoms also improved. Both treatments were effective as regards cutaneous, intestinal and respiratory symptoms, with a significant reduction of itching, wheals and vesicular blisters and the complete relies of intestinal disorders. The drugs were well tolerated.

Activity of leukocyte elastase in patients' plasma is a significant indicator of atopic diseases

It is commonly known that activation of plasma kallikrein-kinin system is of great importance in the pathogenesis of atopic diseases. Plasma kallikrein most likely activates other arginine-esterases in human plasma. Diagnostic and prognostic values of the total arginine-esterase activity and the activity of leukocyte elastase (LE) in plasma of patients with allergic rhinitis (AR), atopic bronchial asthma (ABA) and atopic dermatitis (AD) were examined in this study. Our results demonstrate that the level of arginine-esterase activity was slightly elevated only in plasma of patients with ABA (424 ± 24; N-360 ± 20 mU/ml), but not with AR and AD. Elastase-like activity in human plasma proved to be a far more informative indicator of the atopic states than arginine-esterase activity. In plasma of patients with AR, ABA and AD the activity of LE exceeded the normal level in 1.7, 1.8, and 2.4 times, respectively. Treatment of these atopic states with Ditec (Boehringer Ingelheim) led to some improvements of the patient' states. The main component of this drug (disodium chromoglycate) inhibited the activity of leukocyte elastase in experiments in vitro.