Chondroitin Sulfate Derivatives Research Articles

Catalase and chondroitin sulfate derivatives against thrombotic effect induced by reactive oxygen species in a rat artery

Antithrombotic activity of catalase (CAT) and chondroitin sulfate (CHS) preparations was studied in a rat model of arterial injury induced by ferrous chloride. Equal doses (according to catalytically active CAT) were used to examine the effect of native CAT, CAT–CHS covalent conjugate and mixture of native CAT and free CHS in a ratio corresponding to their contents in the conjugate. The antithrombotic activity of the derivatives was determined by the time during which arterial occlusion developed (occlusion time) and by the mass of the formed thrombus. The antithrombotic activities of the conjugate and mixture were similar and markedly higher than that of native CAT. The conjugate was more effective with respect to deceleration and prevention of arterial occlusion. Small doses of the preparations altered the structure of the formed thrombus, promoting sustained blood flow. Further investigations of the antithrombotic activity of CAT, superoxide dismutase and CHS derivatives have been outlined.

Oral bioavailability of chondroitin sulfate (Condrosulf ®) and its constituents in healthy male volunteers

Objective Drug treatment of osteoarthritis (OA) includes symptomatic slow-acting drugs (SYSADOA). This class of compounds have a slow onset of action and improve OA symptoms. Among the SYSADOA, Condrosulf ® (manufactured by IBSA), whose active ingredient is chondroitin sulfate, has proven to be a valuable therapeutic tool for the symptomatic treatment of OA after oral administration. The aim of this study was to assess the bioavailability of chondroitin sulfate and its constituents after oral administration of Condrosulf ® to 20 healthy male volunteers. Pharmacokinetic parameters and the structure and properties of plasma chondroitin sulfate were determined after administration of Condrosulf ®. The possible physiological regulation of plasma levels of endogenous chondroitin sulfate during the day was also assessed. Design Condrosulf ® (composed of bovine origin chondroitin sulfate, 4 g) was orally administered to 20 healthy human volunteers, and chondroitin sulfate derivatives were extracted and purified from plasma over a 48 h period. Polysaccharide fractions absorbed by oral route were characterized and quantified by agarose-gel electrophoretic technique, and densitometric scanning. In addition, the percentage of constituent disaccharides and charge density were measured in an effort to physico-chemically characterize chondroitin sulfate fractions absorbed per os. Results Plasma levels of endogenous chondroitin sulfate were detectable in all subjects, and the mean values calculated on six subjects varied during the day from 0.3 to 5.3 μg/ml. After administration of Condrosulf ®, chondroitin sulfate plasma levels increased (more than 200%) in all subjects with a peak concentration after 2 h, with the increase reaching significance from 2 to 6 h. Absorption of exogenous chondroitin sulfate was also proved by the change in the composition of disaccharides in plasma after drug administration with respect to baseline. A significant decrease in the relative amount of non-sulfated disaccharide was measured (reaching the minimum relative percentage of 22.96±11.68% at 4 h). At the same time 4-sulfated disaccharide increased to a maximum of 60.50±10.45% after 4 h and 6-sulfated disaccharide appeared in blood, reaching a maximum concentration of 17.33±6.52% after 2 h. Concomitantly the mean charge density increased from 0.40±0.09 at pre-dose to a maximum of 0.78±0.11 4 h after Condrosulf ® administration. As for safety, the treatment was well tolerated and did not determine any relevant change in vital signs nor ECG. Conclusions From this study and literature data, it appears that exogenous chondroitin sulfate (Condrosulf ®) is absorbed as a high molecular mass polysaccharide together with derivatives resulting from a partial depolymerization and/or desulfation. Copyright 2002 OsteoArthritis Research Society International. Published by Elsevier Science Ltd. All rights reserved.

Influence of charge density, sulfate group position and molecular mass on adsorption of chondroitin sulfate onto coral

The adsorption of chondroitin sulfate onto granules of natural coral of specific diameter, between 100 and 500 μm, having high calcium content (>98%) and a homogeneous surface was investigated. Several chondroitin sulfate samples desulfated to various extents, with a sulfate to disaccharide ratio (charge density) of 0.98–0.07 and non-sulfated polysaccharide possessing a chondroitin sulfate backbone structure were tested for their ability to adsorb onto coral. Adsorption of chondroitin sulfate onto coral depends on its charge density, as the removal of sulfate groups totally abolishes this capacity. Various chondroitin sulfates of molecular mass from 26,950 to 1140 were also tested. No appreciable effect depending on the molecular mass was evident. Also, chondroitin sulfate fractions with molecular mass of about 3530 (formed by about 6 disaccharide units) and 1140 (formed by about 2 disaccharide units) retain their full capacity to adsorb onto coral. Furthermore, the position of sulfate groups inside the polysaccharide chains does not influence the ability of chondroitin sulfate to adsorb onto coral. In fact, chondroitin sulfate derivatives almost completely sulfated (>90%) in position 4 of galactosamine and chondroitin almost completely (>90%) sulfated in position 6 show a full adsorbtion onto coral. Thus, large amounts of chondroitin sulfate are adsorbed onto coral, and sulfate groups are of paramount importance in the adsorption process. On the other hand, the capacity of chondroitin sulfate to adsorb onto coral is quite aspecific. In fact, it does not depend on the presence of sulfate groups esterified in a specific position or sulfated sequences arranged in blocks but rather on the presence of sulfate groups, and this ability increases with increasing charge density, as indicated by the values of the Langmuir constant, the adsorption capacity, that decreases with decreasing chondroitin sulfate charge density reaching very low values for the totally desulfated polymer.

Glycosaminoglycan polysulfate-induced stimulation of hyaluronic acid synthesis in rabbit knee synovial membrane: Involvement of binding protein and calcium ion

We have previously reported that naturally occurring sulfated glycosaminoglycans having a chondroitin-type structure and glycosaminoglycan polysulfate (GAGPS, a persulfated derivative of chondroitin sulfate) caused a specific stimulation of hyaluronic acid synthesis in rabbit knee synovial membranes [H. Nishikawa et al. (1985) Arch. Biochem. Biophys. 240, 146–153]. In the present study, the interaction of [ 3H]GAGPS and the surface of the rabbit knee synovial membranes and the relationship between this interaction and the stimulatory effect of GAGPS on the hyaluronic acid synthesis were examined in order to define the stimulatory mechanism of hyaluronic acid synthesis by GAGPS. A part of the [ 3H]GAGPS taken up by the synovial membranes was released from the membranes by trypsin treatment. The interaction of [ 3H]GAGPS and the surface of the isolated synovial membranes was diminished by pretreatment of the membranes with proteases or chelating reagents. Pretreatment of synovial membranes with trypsin or ethylene glycol bis(β-aminoethyl ether) N,N′-tetraacetic acid had little effect on the basal hyaluronic acid synthesis but caused the loss of GAGPS-induced stimulation of hyaluronic acid synthesis accompanied by significant decrease (20% P < 0.05- P < 0.01) in the interaction between GAGPS and the surface of the synovial membranes. Dermatan sulfate having a chondroitin-type structure also stimulated hyaluronic acid synthesis but this effect was not additive to the stimulation of hyaluronic acid synthesis by GAGPS. Heparin had no effect on either the basal hyaluronic acid synthesis or the GAGPS-induced stimulation of hyaluronic acid synthesis. These results indicate that binding of GAGPS to certain distinct protein components on the surface of synovial membranes is involved in the stimulatory mechanism of hyaluronic acid synthesis by GAGPS, and that the binding may be mediated by Ca 2+ ion. The binding was also found to be specific for sulfated glycosaminoglycans having a chondroitin-type structure.

Influences of sulfated glycosaminoglycans on biosynthesis of hyaluronic acid in rabbit knee synovial membrane

The effect of various sulfated glycosaminoglycans on glycoconjugates syntheses in synovial membranes of rabbit knee joints in culture was investigated by two different approaches. In the first approach, synovial membranes isolated from rabbit knee joints were cultured in the presence of sulfated glycosaminoglycans and [ 14C]glucosamine. In the second approach, solutions of sulfated glycosaminoglycans were injected into rabbit knee joints and synovial membranes isolated from the joints were cultured in the presence of [ 14C]glucosamine. The major part of [ 14C]glucosamine-labeled glycoconjugates associated with the synovial membranes and secreted into culture medium was hyaluronic acid. Of the natural glycosaminoglycans tested, dermatan sulfate gave the maximum stimulation of hyaluronic acid synthesis followed by chondroitin 4- and 6-sulfate. Heparin, heparan sulfate, keratan sulfate, keratan polysulfate, and hyaluronic acid had no significant effect. Of the chemically polysulfated glycosaminoglycans, GAGPS (a persulfated derivative of chondroitin sulfate) gave high stimulation but N-acetylchitosan 3,6-disulfate had no effect. The effect of sulfated glycosaminoglycans on hyaluronic acid synthesis was the same in both experimental approaches. The increase in the amount of secreted hyaluronic acid in culture medium paralleled that in synovial membranes. The results indicate that the galactosamine-containing sulfated glycosaminoglycans have a specific stimulatory effect on hyaluronic acid synthesis. A high degree of sulfation of the molecules appeared to potentiate the stimulatory effect.