Isolation of polysaccharide and non-polysaccharide fractions from STW 42, Althea officinalis L. root extract and characterization of their anti-oxidative and wound-healing properties on human fibroblasts in vitro

Whether the effect of locally acting products for treating irritative cough is a pharmacological effect or just a physical effect has been an open discussion. The root extract of marshmallow ( Althaea officinalis L., REAo) is used in this field and in mild stomach/gut discomfort. The medicinal product STW 42 has been shown to have pharmacological effects fostering mucosal regeneration [ 1 ] [ 2 ] [ 3 ] [ 4 ]. Mucosal wound repair depends on the recruitment of fibroblasts. The anti-oxidative, anti-inflammatory, and wound-healing properties of STW 42 and its active ingredient REAo have recently been demonstrated in MΦ and confirmed in endothelial cells [ 2 ] [ 3 ]. Anti-oxidative activity regulation may facilitate the healing process. Investigating the effect of its two main components would help to understand the action mechanism. The objective was to isolate the polysaccharide and non-polysaccharide fractions from REAo to study their anti-oxidative and pro-migratory properties on human fibroblasts. To investigate the migratory capacity by scratch assay, normal human dermal fibroblast (NHDF) were treated with STW 42, REAo, or its polysaccharide and non-polysaccharide fractions or pre-treated and co-incubated with H2O2 to quantify the effect on intracellular reactive oxygen species (ROS) production and mitochondrial membrane potential (MMP) stability. STW 42, REAo, or its non-polysaccharide fraction inhibited the production of H2O2-induced intracellular ROS and protected against MMP destabilization. STW 42, REAo, and its polysaccharide fraction improved the migratory capacity and stimulated wound closure in the scratch assay. These properties may support the benefit of STW 42 [5] in patients who are burdened with irritated laryngopharyngeal or gastrointestinal mucosa. These applications could have significant implications for the cough and gastrointestinal therapy field. Publication History Article published online: 05 March 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany