Dextran: Influence of Molecular Weight in Antioxidant Properties and Immunomodulatory Potential

Abstract

Dextrans (α-d-glucans) extracted from Leuconostoc mesenteroides, with molecular weights (MW) of 10 (D10), 40 (D40) and 147 (D147) kDa, were evaluated as antioxidant, anticoagulant and immunomodulatory drugs for the first time. None presented anticoagulant activity. As for the antioxidant and immunomodulatory tests, a specific test showed an increase in the dextran activity that was proportional to the increase in molecular weight. In a different assay, however, activity decreased or showed no correlation to the MW. As an example, the reducing power assay showed that D147 was twice as potent as other dextrans. On the other hand, all three samples showed similar activity (50%) when it came to scavenging the OH radical, whereas only the D10 sample showed sharp activity (50%) when it came to scavenging the superoxide ion. D40 was the single dextran that presented with immunomodulatory features since it stimulated the proliferation (~50%) of murine macrophages (RAW 264.7) and decreased the release of nitric oxide (~40%) by the cells, both in the absence and presence of lipopolysaccharides (LPS). In addition, D40 showed a greater scavenging activity (50%) for the hydrogen peroxide, which caused it to also be the more potent dextran when it came to inhibiting lipid peroxidation (70%). These points toward dextrans with a 40 kDa weight as being ideal for antioxidant and immunomodulatory use. However, future studies with the D40 and other similarly 40 kDa dextrans are underway to confirm this hypothesis.

Gallic Acid-Dextran Conjugate: Green Synthesis of a Novel Antioxidant Molecule

“…Both dextran and Dex–Gal failed to exhibit ferric chelating activity under all tested conditions (from 0.1 to 2 mg/mL). This data corroborates previous data that show dextrans are not good iron chelators [10]. Although GA has iron chelation activity [38], the conjugation of dextran to GA acid did not affect the chelating activity of this polysaccharide.…”

“…Dextran failed to exhibit any positive activity under the conditions evaluated. A previous study also evaluated the scavenging capacity of L. mesenteroides dextran superoxide ions with molecular masses of 10, 40, and 147 kDa and found that only 10 kDa dextran showed high activity (~50%); the activity did not exceed 9% for the other two types [10]. Dextrans from Leuconostoc pseudomesenteroides also showed low activity (about 15%) [11].…”

“…The use of dextran to produce nanomaterials with antioxidant activities, such as colloidal complexes [6], nanoparticles [7], hydrogels [8], submicron particles [9], has also gained momentum. However, dextran only serves as a vehicle for the antioxidant compound in such molecules, owing to its low antioxidant capacity [10,11,12]. Hence, it may not contribute to the antioxidant effect of the resulting material.…”

Characterization and Antioxidant Activity of the Exopolysaccharide Produced by Bacillus amyloliquefaciens GSBa-1

“…In addition, negatively charged acidic polysaccharides containing higher uronic acid showed higher metal chelating activity [59,60]. Soeiro et al [61] showed some dextrans with 5% of iron chelating activity at a concentration of 2 mg/ml. Only about 10% of iron chelating activity was found for α-glucans isolated from Aconitumm Kusnezoffii [62].…”

Production, partial characterization and antioxidant properties of exopolysaccharide α-d-glucan produced by Leuconostoc lactis KC117496 isolated from an idli batter

“…EPS produced by Bacillus tequilensis FR9 showed potential strong antioxidant effects through scavenging reactive oxygen species (ROS) (Rani et al 2017). The commercial glucan with different molecular weight (1, 4, and 14.7 9 10 4 Da) synthesized by L. mesenteroides exhibited strong antioxidant, anticoagulant and immunomodulatory activities (Soeiro et al 2016). The in vitro antioxidant properties of the EPS showed remarkable scavenging effects on superoxide anion radical and hydroxyl radical (Adesulu-Dahunsi et al 2018).…”