Mucoadhesion, Rheology, Swelling Behavior, and Immunomodulatory Properties of Polysaccharides of Gum Exudates Obtained from Astracantha echidnaeformis (Sirj.) Podlech as a Formulary Excipient Candidate

Abstract

The physicochemical, rheological, and mucoadhesive characteristics of gum derived from Astracantha echidnaeformis are investigated. It's polysaccharides are isolated using chromatography techniques, and their immunomodulatory characteristics are evaluated by subjecting Jurkat cells to the WST‐1 assay. The composition of these polysaccharides is analyzed using gas chromatography‐mass spectrometry (GC‐MS). The viscosity and shear‐thinning behavior of gum are directly influenced by its concentration and the presence of NaCl, whereas they are inversely affected by temperature. The gum has strong potential as a thickening agent for dispersed systems. The mucoadhesion strength of the gum insoluble fraction is 109 ± 4.58 g cm−2, indicating excellent adhesiveness for application to mucoadhesive formulations. Cells’ proliferation enhancement is found for the isolated manno‐arabinoglucan (MW: ≤1.27 kDa) and galacto‐arabinan (MW: ≥667.8 kDa) at concentrations lower than 400 µ mL−1, but at higher concentrations they inhibited the proliferation. The isolated pectic galacto‐arabinan (MW: 669.58 kDa) exhibited a proliferative effect at 250 µg mL−1, but the isolated manno‐galactoglucan (MW: 80.90 kDa) showed cytotoxicity at higher doses. The isolated proteoglycans has mostly galacto‐arabinan backbones with immunomodulatory properties. The gum can be used as a thickening agent for the physical stabilization of suspensions and gels, specifically those needing to be stored at cold temperatures.