species comprises both kappa and lambda types although it has been shown that these do Europe and Asia and yield kappa and lambda carrageenans. Expert food author, Jill Frank, explains the three main structures of carrageenan, kappa, iota and lambda, and their contribution to the gelling. Adicionalmente, las salmueras que contenían carragenina kappa, carragenina These produce primarily iota, kappa and lambda carrageenans, respectively.
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Carrageenan closely resembles the endogenous galactose or N-acetylgalactosamine-containing glycosaminoglycans GAGschondroitin lambca CSdermatan sulfate DSand keratan sulfate.
However, these GAGs have beta-1,3 and beta-1,4 glycosidic bonds, in contrast to the unusual alpha-1,3 glycosidic bond in carrageenan.
Since sulfatase activity is inhibited by sulfate, and carrageenan is so highly sulfated, we tested the effect of carrageenan exposure on sulfatase activity in human intestinal and mammary epithelial cell lines and found that carrageenan exposure significantly reduced the activity of sulfatases, including N-acetylgalactosaminesulfatase, galactosesulfatase, iduronate sulfatase, steroid sulfatase, arylsulfatase A, SULF-1,2, and heparan sulfamidase.
Consistent with the inhibition of sulfatase activity, following exposure to carrageenan, GAG content increased significantly and showed marked differences in disaccharide composition. Specific changes in heparin-heparan sulfate disaccharides included increases in 6S disaccharides, as well as increases in NS and 2S6S carragennia.
Study results suggest that carrageenan inhibition of sulfatase activity leads to re-distribution of the cellular GAG composition with increase in di-sulfated CS and with potential consequences for cell structure and function. The common food additive, carrageenan, is consumed in the average diet in sufficient quantities to have biological effects.
In contrast to the glycoside digoxin, which is generally prescribed in doses of 0. Individuals who consume several carrageenan-containing foods may ingest several grams of carrageenan per day [ 34 ]. Carrageenan is found in a wide range of processed foods, including ice cream, whipped cream, infant formula, deli meats, sour cream, puddings, soymilk, yogurt, and dietary supplements.
Carrageenan is also used in pharmaceuticals as an excipient, and in cqrragenina air fresheners, cosmetics, and darragenina foods, due to its ability to improve the texture and solubility of ingredients. The Joint Expert Committee Food and Agriculture Organization of the UN and the WHO on Food Additives has recommended that carrageenan be excluded from infant formula and that current intake of carrageenan in the diet be re-evaluated [ 5 ].
Three major types of carrageenan are used in food products. In thousands of experiments, carrageenans have been used to induce inflammation, since inflammation is a predictable effect of exposure to carrageenan in animal and cell-based models.
For the most part, these experiments were designed to test the effectiveness of anti-inflammatory agents or to study the mediators of inflammation [ 8 ]. In recent experiments, we have identified specific mechanisms by which carrageenan causes inflammation, and have demonstrated activation of an innate immune pathway of inflammation and a reactive-oxygen species ROS -mediated pathway [ 9 — 12 ].
In the current careagenina, we assess the effect of carrageenan exposure on sulfatase activity of human epithelial cells in culture and determine changes in GAG content and disaccharide composition and present these findings to better understand how lanbda exposure impacts upon the endogenous GAGs.
Mammary cell lines included: The methods for culture of these cells were reported previously and were those that were recommended [ 1617 ]. Cell homogenates were prepared and assays were performed using at least triplicate biological samples with technical replicates of each measurement.
Substrates for determinations of activity of galactosesulfatase GALNS and iduronatesulfatase IDS were obtained Moscerdam Substrates, Rotterdam, The Netherlandsand the assays were performed in accord with previously published protocols [ 1819 ].
Fluorescence readings were taken at llambda and nm. Pre-chilled reagents were used, and cells were homogenized in ddH 2 O by sonication. The optical density of the clear supernatant was measured at nm in a Beckman spectrophotometer. The substrate was 0. Activity at 48 h was determined by the procedures described above and were within the standard deviation carragebina the activity at 4 days that is reported in Table 1 for these enzymes. Antibodies used for detection were ARSB rabbit polyclonal antibody 1: Rabbit or mouse IgG was used for control experiments.
The formaldehyde was removed and cells were washed with wash buffer 0. The linearity of the determinations was confirmed by comparisons of the intensity at three different cell concentrations.
Total RNA was extracted using carrageninna RNeasy minikit Qiagen from replicate biological samples of carrageenan-treated and control samples. Each chip contained 11 probeset pairs carragnina probes total for each gene with 54, transcripts present on the chip.
Pair-wise comparisons of control vs. All other chemicals were of regent grade. The molecular weights MW of the CS disaccharides are: The MW of the HS disaccharides are: The molecular weights of the carrageenan disaccharides are different than those of the GAGs disaccharides. The carrageenan-derived disaccharides consist of 3,6-anhydro-galactose A-Unit and galactose G-Unit or two galactose G-unit. The MW of the carrageenan-derived disaccharides are: Particulates were removed from the ,ambda solutions by passing each carrageninz a syringe filter containing a 0.
The GAGs were freeze-dried for future use. The isolated glycosaminoglycans GAGs were subjected to carbazole assay to quantify the amount of GAGs in each sample using heparan sulfate as standard. The amount of GAGs was determined in samples of 10 7 cells treated with carrageenan for 4 days.
The cationic dye 1,9-dimethylmethylene blue reacts with the sulfated GAG, producing an insoluble dye-GAG complex, and the sGAG content is determined by the amount of dye recovered from the test sample following exposure to Blyscan Dissociation Reagent. Absorbance maximum of 1,9-dimethylmethylene blue is nm.
C4S was determined by this assay following immunoprecipitation of cell lysates from treated and control cells carrwgenina the C4S 4D1 antibody Abnova to detect native C4S, as previously described [ 27 ].
Wilmington, DE equipped with an ion trap, binary pump followed by microflow, and a UV detector.
The electrospray interface was set in positive ionization mode with the skimmer potential czrragenina All of the activity measurements declined following carrageenan exposure. Similarly, expression of sulfatases was not carrzgenina modified in a cDNA microarray to be significantly changed.
The GAGs detected by carbazole assay are the uronic acid containing disaccharides and glycosaminoglycans, including hyaluronan HAa nonsulfated GAG, but excluding keratan carrwgenina, a sulfated GAG not containing an uronic acid residue. NCM cells exposed to kappa, iota or lambda-carrageenan for 4 days and unexposed cell control were isolated by a three-step procedure lamba protease digestion, strong anion-exchange chromatography on a spin column, followed by salt release.
Under the conditions used in the strong anion-exchange spin column step, unsulfated HA is poorly recovered. The carbazole assay detects uronic acid containing glycosaminoglycans and oligosaccharides, including hyaluronan, chondroitinsulfate, chondroitinsulfate, dermatan sulfate, heparin, heparan sulfate, and disaccharides, but not keratan sulfate or carrageenan. The 1,9-dimethylmethylene blue assay detects sulfated GAG, but does not detect disaccharides, carrageenan, hyaluronan, or other unsulfated oligosaccharides.
The total sulfated GAG and the C4S content, determined by 1,9-dimethylmethylene blue assay, also demonstrated significant increases following carrageenan exposure Table 3B. In the zoom in figure Fig.
Carrageenan – Wikipedia
In contrast, these lamdba were not present in the unexposed control cell sample. Zoom in figure of samples identified above. Carargenina method is particularly useful in the analysis of small amounts of biological samples or samples having very low amounts of GAG.
The disaccharide composition Table 5 again demonstrates a remarkable similarity in disaccharide composition upon carrageenan exposure and a major difference from the control untreated cells. The commonly used food additive carrageenan resembles the naturally occurring sulfated GAGs, since it is composed of repeating sulfated disaccharide units. Since carrageenan is so highly sulfated and resembles the endogenous GAG, the studies in this report were performed to determine the impact of carrageenan on activity of several sulfatase enzymes and the impact on cellular GAG composition.
The assays were performed using standard methods caeragenina involve exogenous substrates and non-physiological conditions, and assays compared activity following carrageenan exposure vs.
The assays have been developed to be sulfatase-specific and employ different temperature, pH, substrates, buffers, and inhibitors.
kappa carrageenan gels: Topics by
Measurements consistently demonstrated that exposure of human colonic epithelial cells and mammary cells to carrageenan reduced the sulfatase activity.
In contrast, cDNA microarray and cell-based ELISA did not demonstrate significant differences in sulfatase expression following carrageenan, suggesting a direct effect on enzyme function or on enzyme activation. The precise mechanism by which carrageenan inhibits enzyme activity is not yet determined, but may be attributable to an increase in sulfate, since sulfate is reported to inhibit the activity of the sulfatases [ 3132 ].
Carrageenans may interfere with the endogenous substrate—enzyme reaction and product dissociation, and thereby inhibit the measurable enzyme activity in the sulfatase assays that utilize the exogenous substrates. Since degradation of chondroitinsulfate requires removal of the carrxgenina at the non-reducing end carragejina ARSB N-acetylgalactos-aminesulfatasesilencing ARSB activity by siRNA increased the abundance of cellular GAGs, in experiments reported in bronchial, mammary, renal, and colonic epithelial cells [ 162733 — 35 ].
In association with the reduced ARSB activity, cellular sulfated GAG and C4S were increased, secretion of vital molecules, including IL-8 and bradykinin, was reduced, and cellular sequestration of IL-8 and kininogen was increased, indicating the impact of sulfatase activity and GAG sulfation upon vital cell functions [ 3335 ]. Also, since chondroitinsulfation is critical for plasmodial attachment, carrageenan, by effects on ARSB, and, thereby, on chondroitin sulfation, may have an impact on malarial infectivity [ 34 ].
In addition to the inhibitory effects on activity of sulfatase enzymes, and consistent with these effects, carrageenan exposure leads to marked increase in total cellular sulfated GAG content. This effect is attributable in part to impaired degradation of the GAGs when hydrolysis of sulfate groups is inhibited. Consistent with the inhibition of sulfatase enzyme activity and the overall increase in the GAG abundance, disaccharide analysis confirmed that the carrageenan exposure provokes profound changes in the composition of these cellular GAGs.
Galectin-3, -7, and -9 binding to sulfated GAGs has been linked to the extent of sulfation, suggesting that the effects of carrageenan on sulfatase activity may impact upon galectin binding [ 36 ].
Since galectins are linked to multiple critical cellular events, the carrageenan-induced changes in GAGs may lead to cwrragenina changes laambda cell functions and cell regulation through transcriptional effects, as well as altered GAG interactions [ 37 — 39 ]. Further analysis of the ccarragenina of carrageenan exposure may provide new insights into how GAG sulfation and sulfatases influence cell fate.
The implications for human disease may be profound, since carrageenan is consumed in significant quantity in the human diet. Exposure to the common food additive significantly reduced the activity of multiple sulfatase enzymes in human colonic and mammary epithelial cells. These changes in sulfatase activity were accompanied by marked increase in cellular GAGs. Disaccharide analysis demonstrated that CSD- and CSE-derived disaccharides were present following carrageenan exposure, but not in the untreated control.
These determinations indicate that exposure to the common food additive carrageenan has profound effects on sulfatase activity and GAG abundance and composition that may affect vital cell processes.
The authors acknowledge the contributions of Dr. National Center for Biotechnology InformationU. Author manuscript; available in Lqmbda Nov Author information Copyright and License information Disclaimer. The publisher’s final edited version of this article is available at Biochimie.
See other articles in PMC that cite the published article. Introduction The common food additive, carrageenan, is consumed in the average diet in sufficient quantities to have biological effects. Open in a separate window. Methods and materials 2. Quantification of glycosaminoglycans The isolated glycosaminoglycans GAGs were subjected to carbazole assay to quantify the amount of GAGs in each sample using heparan sulfate as standard.
Table 3 GAGs following exposure to different types of carrageenan. Disaccharide composition analysis 3. Discussion The commonly used food additive carrageenan resembles the naturally occurring sulfated GAGs, since it is composed of repeating sulfated disaccharide units.
Conclusions Exposure to the common food additive significantly reduced the activity of multiple sulfatase enzymes in human colonic and mammary epithelial cells.
Acknowledgment The carragenia acknowledge the contributions of Dr. West J, Miller KA.