Common Trade Names
None known; usually sold as tragacanth or gum tragacanth.
Available as a gel, gum, powder, tablets, and viscous solution.
Tragacanth is obtained by drying the gummy substance that exudes from the cut tap root and branches of Astracantha gummifer or other Astracantha species, low thorny shrubs that belong to the legume family. The plants are native to the Middle East.
Tragacanth gum consists of two major fractions, tragacanthin and bassorin, with trace amounts of starch, a cellulose-like substance, amino acids, and amino acid derivatives. Tragacanthin is water-soluble and consists of an arabinogalactan and tragacanthic acid; bassorin is a complex of methoxylated acids that swells to form a gel or viscous solution that is insoluble in water. Tragacanth may also contain some karaya, India gum, or acacia, other natural gums used for similar purposes.
When added to water, tragacanth swells to form a viscous jelly that is mixed with other ingredients to create the desired consistency in the final product. This action is probably attributable to the bassorin content; high-quality gums contain less tragacanthin. The herb also exerts a mild laxative effect.
Tragacanth appears to be a relatively innocuous substance. In one study, large doses (10 g) of tragacanth reduced intestinal transit time and increased fecal fat levels . Plasma biochemistry, hematologic indexes, urinalysis parameters, glucose tolerance, breath hydrogen, methane concentrations, and serum cholesterol, triglyceride, and phospholipid were not significantly changed. The quantity of tragacanth used in this study far exceeds the normal annual dietary intake. Other claims are that tragacanth stimulates phagocytosis, increases plasma cell counts of T lymphocytes, and acts against some experimental tumors . Confirmatory data are lacking.
Tragacanth is not allergenic, mutagenic, or teratogenic. No adverse toxicologic effects have been observed in nonallergic people .
FDA guidelines state that tragacanth may be used in concentrations of 0.2% to 1.30/0 to thicken, emulsify, stabilize, or flavor foods . The concentration in medicinal products ranges from 4.8% to 6% in oral liquids and from 0.42 to 100 mg in tablets . Because of its action with water, tragacanth is used for preparing adhesives, emulsions, protective or lubricating barriers, and suspensions. It may be used in oral and topical products with glycerin to create emulsions and suspensions.
Tragacanth is more resistant to acid hydrolysis than other hydrocolloids and is preferred in the preparation of acidic compounds. It has also been used as a binder and stabilizer in preparing cosmetics and hand lotions, to stiffen cloth, as a glue in bookbinding, and in making candy and other products . The herb is used as well in denture adhesives and toothpastes and as a bulk-forming laxative . In African folk medicine, tragacanth is used as a mild laxative; the leaves are used to prepare a first aid lotion .
FDA dietary guidelines allow concentrations of 0.2% and 1.3% as a thickener, stabilizer, and flavoring agent in foods. Little consensus exists, but the usual recommended dose ranges from 0.42 to 100 mg in tablet form P.O. b.i.d. or t.i.d.
EENT: rhinitis, sneezing.
GI: abdominal pain.
Respiratory: asthma, dyspnea.
Skin: contact dermatitis pruritus, rash, urticaria.
Other: angioedema, fever, hypersensitivity reactions .
Fat, fat-soluble nutrients: May decrease absorption of these agents if taken in excess. Avoid excessive use.
Contraindications and Precautions
Tragacanth is contraindicated in patients who are hypersensitive to natural gums used in food or pharmaceutical products. Avoid its use in pregnant or breast-feeding patients; effects are unknown.
Alert The gum may contain microbial contaminants, such as coliform and Salmonella bacteria. Monitor the patient closely for signs of infection.
Monitor for hypersensitivity reactions.
Advise women to avoid using tragacanth during pregnancy or when breast-feeding.
Points of Interest
Tragacanth’s use in foods, cosmetics, and pharmaceutical products has declined in favor of synthetic substances with similar physical properties.
The FDA lists tragacanth as a generally safe food additive.
Tragacanth gets its name from the Greek words tragas (goat) and akantha (horn), probably in reference to the curved or twisted appearance of the dried exudate.
Because other natural and synthetic suspending and emulsifying agents are available, tragacanth is no longer widely used in U.S. pharmaceuticals, except in extemporaneous compounding and some commercial suspensions or tablets. The herb is regarded as safe for use in foods and other products, and no known reports exist of adverse reactions in nonallergic people. Although it may be used as a mild bulk-forming laxative, safer and more effective products are readily available.