In vitro antisickling activity of cromolyn sodium

Abstract

Summary.The improvement in sickle cell disease (SCD) children receiving cromolyn sodium therapy prompted us to investigate its antisickling activity in vitro. The number of sickle cells was determined in deoxygenated blood samples from 15 children with severe SCD. At the eight concentrations tested, cromolyn sodium exhibited a significantly higher activity than pentoxifylline, the standard compound.Therefore cromolyn sodium would appear to be an interesting candidate for SCD therapy and deserves further in vivo investigations.Keywords: cromolyn sodium, antisickling activity, corpuscular indices.New approaches have been recently proposed for the treatment of SCD such as bone marrow transplantation or HbF synthesis modulation . Ancillary treatments aimed at the correction of secondary erythrocytic or rheological abnormalities also deserve renewed interest.At our centre, allergy had been previously diagnosed in 43% of SCD children. Treatment by allergen eviction and anti-allergic drugs such as cromolyn sodium was followed by a dramatic reduction of vaso-occlusive crises and of recurrent airway infections in some children (Toppet et al, 1993). Therefore we initiated an in vitro study of the possible effect of cromolyn sodium on sickling using as standard pentoxifylline whose antisickling activity, mediated by calcium L channels blockade, is well established (Ellory et al, 1994). MATERIALS AND METHODSBlood collection. Samples from 15 African children with severe SCD were collected. All the patients except two had a previous history of multiple recurrent vaso-occlusive crises. Seven of them were on hydroxyurea therapy at time of the study.The Hospital Ethics Committee approved the study protocol. Oral informed consent was obtained from patients and their legal guardians. Erythrocytes preparation. 5 ml of venous blood drawn in EDTA-rinsed tubes were processed within 2 h of collection. The red cells were washed three times in a phosphatebuffered saline (PBS, pH 7·40) and suspended in twice their volume of PBS.Drugs and control solutions. Stock-solutions of pentoxifylline (3,7-dihydro-3,7-dimethyl-1-(5-oxohexyl)-1H-purine-2,6-dione, Hoechst Roussel, Bruxelles, Belgium) and of cromolyn sodium (5,5 0 -[(hydroxy-1,3-propanediyl)bis-(oxy)[bis] 4-oxo-4H-1-benzopyran-2-carboxylic acid, disodium salt], Sigma Chemie, Bornem, Belgium) were prepared in PBS and kept at 4ЊC. PBS was used as control.Deoxygenating device. The apparatus included a gas tank, a 250 ml glass flask half-filled with water, a 10 ml glass tube, a flexible duct and a water bath maintained at 37ЊC. All the containers were stoppered with their upper part allowing inlet and outlet of the gas (5% CO 2 in N 2 ) which was prehumidified by bubbling in the flask. After incubation for 60 min, 150 ml of the erythrocytes suspension to which had been added 150 ml of the tested drug solution, were transferred into the tube and the humidified gas was bubbled in the preparation for 30 min at a constant flow rate of 3 ml/ min. The lower part of the flask and the tube were im...

In vitro Inhibitory Effects of Disodium Cromoglycate on Ionic Transports Involved in Sickle Cell Dehydration

“…In the 1990s, that action was underscored by clinicians of the Hôpital des Enfants Reine Fabiola (Brussels) who observed a clinical improvement and a diminishing importance of vaso-occlusive crises among asthmatic patients with SCD [15] . The action was confirmed by an in vitro study which showed a decrease in the number of SS cells when red cells from SCD patients were deoxygenated in the presence of DSCG [16] . In 2000 and 2006, ex vivo studies demonstrated that the number of SS cells was significantly decreased after DSCG treatment [17,18] , and a clinical study on 17 patients with SCD treated with DSCG showed a significantly decreasing SS crisis [18] .…”

“…The antisickling activity of DSCG has well been demonstrated [16][17][18] . The inhibition of the Gardos channel was suggested as a possible mechanism of this effect, but no experiment confirmed this hypothesis.…”

“…Nine volumes of this RBC suspension were also diluted with 1 volume of DSCG solution 10 m M in HBS (DSCG+ sample), getting a final DSCG concentration of 1 m M . These suspensions were then incubated for 60 min at 37 ° C. The deoxygenating device was described by Fall et al [16] . Deoxygenation was performed at 37 ° C under a flow of nitrogen during up to 24 h, the gas flow being set to 3 ml/min for obtaining an efficient sickling [19][20][21] .…”

Clinical response of patients with sickle cell anemia to cromolyn sodium nasal spray

“…Antisickling activity of cromolyn sodium was also investigated in vitro by Fall et al [5]. Cromolyn sodium was found much more active than Pentoxifylline at each concentration and time [5,10]. We scheduled our trial over a long duration of time to prove that the new medications were truly effective in controlling pain in sickle cell patients.…”

Inflammatory targets of therapy in sickle cell disease

“…Both agents inhibited release of SP and CGRP from the skin and dorsal root ganglion preparations of transgenic SCD mice (128). It has previously been established that cromolyn sodium exerts anti-sickling and possibly membrane stabilizing effect on sickle erythrocytes in vitro (138). Inhalation and intranasal administration of cromolyn sodium ( cromoglicate ) markedly reduced the number of sickle erythrocytes in patients (139).…”