Chondroitin Sulfate Safety and Quality

Abstract

The industrial production of chondroitin sulfate (CS) uses animal tissue sources as raw material derived from different terrestrial or marine species of animals. CS possesses a heterogeneous structure and physical-chemical profile in different species and tissues, responsible for the various and more specialized functions of these macromolecules. Moreover, mixes of different animal tissues and sources are possible, producing a CS final product having varied characteristics and not well identified profile, influencing oral absorption and activity. Finally, different extraction and purification processes may introduce further modifications of the CS structural characteristics and properties and may lead to extracts having a variable grade of purity, limited biological effects, presence of contaminants causing problems of safety and reproducibility along with not surely identified origin. These aspects pose a serious problem for the final consumers of the pharmaceutical or nutraceutical products mainly related to the traceability of CS and to the declaration of the real origin of the active ingredient and its content. In this review, specific, sensitive and validated analytical quality controls such as electrophoresis, eHPLC (enzymatic HPLC) and HPSEC (high-performance size-exclusion chromatography) able to assure CS quality and origin are illustrated and discussed.

Keywords: chondroitin sulfate; food supplements; glycosaminoglycans; nutraceuticals; osteoarthritis.

Figure 1

Structure of the disaccharides present in chondroitin sulfate backbone constituted of d-glucuronic acid and N-acetyl-d-galactosamine linked by β(1→3) bonds. The various disaccharides are linked each other by β(1→4) linkages. Minor percentages of very rare disaccharides may also have a sulfate group in position C3 of the glucuronic acid. Ac, acetyl group.

Figure 2

Natural contaminations eventually present in chondroitin sulfate preparations and responsible for reduced title and possible side-effects.

Figure 3

Natural polysaccharides eventually present in chondroitin sulfate preparations and the consequences on the chondroitin quality and title.

Figure 4

Acetate cellulose electrophoresis able to detect the presence of (A) keratan sulfate (KS) or (B) dermatan sulfate (DS) and/or heparan sulfate (HS) in chondroitin sulfate (CS) preparations (material owned by the same author).

Figure 5

Natural biomolecules possibly present in chondroitin sulfate preparations and their related problems.

Figure 6

Common possible pathogen contamination and transmissible infective agents in chondroitin sulfate preparations and their effects.

Figure 7

Artificially adulterated chondroitin sulfate by identified substances and their consequences.

Figure 8

Specific analytical procedures able to distinguish between chondroitin sulfate produced from different origin and to assess CS quality and real quantity.