A Review on Gum Tragacanth and Its Biomedical Applications

Gum Tragacanth (GT) is a heterogeneous highly branched polysaccharide obtained from Asiatic species of Astragalus. Iran is the world’s largest producer of GT. This gum has been vastly used in food, pharmaceutical, cosmetic, ceramic and textile industries. In recent decades, the world market for GT has severely decreased due to a number of reasons such as the war between Iran and Iraq and the approval of xanthan gum for the food industry with the advantage of low price and constant quality. In recent years, owing to desirable properties and advantage of the use of GT in medicine, research on biomedical applications of this gum continues to grow significantly. In this study, along with a report on the properties of GT, the research on the new applications of this gum in biomedical fields are reviewed. Overall, tragacanth has excellent water adsorption capacity, biodegradability and biocompatibility, and a great potential for chemical and physical modifications. In addition, the presence of fucose and galactose in the branches of GT has improved its potential for application in tissue engineering and gene/drug delivery. So, it can be used as a promising candidate for biomedical applications in near future. To meet this expectation, further study on gum characterization and modification is necessary. However, it should be noted that the gum exudate from various species of Astragalus had different soluble/swellable ratio, chemical composition, methoxyl content and acetylation degree, so exhibit different rheological properties, ability to reduce surface tension, ability to increase viscosity, chemistry, physical and chemical interaction and other behaviors. Consequently, any try for development of biomedical applications of tragacanth without respect to the plant species will lead to misleading results.