Structural Characterization and In-Vitro Antioxidant and Immunomodulatory Activities of Polysaccharide Fractions Isolated from Artemisia annua L.

Abstract

Arimisia annua L. is an important anticancer herb used in traditional Chinese medicine. The molecular basis underpinning the anticancer activity is complex and not fully understood, but the herbal polysaccharides, broadly recognised as having immunomodulatory, antioxidant and anticancer activities, are potential key active agents. To examine the functions of polysaccharides from A. annua, their immunomodulatory and antioxidant potentials were evaluated, as well as their structural characterization. The water-soluble polysaccharides (AAPs) were fractionated using size-exclusion chromatography to obtain three dominant fractions, AAP-1, AAP-2 and AAP-3, having molecular masses centered around 1684, 455 and 5.8kDa, respectively. The antioxidant potentials of the isolated polysaccharides were evaluated by measuring radical scavenging activities against DPPH● (2,2-diphenyl-1-picrylhydrazyl radical), ABTS●+ (2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid radical ion), and the OH● (hydroxyl radical). AAP-1 displayed high antioxidant activities against these radicals, which were 68%, 73% and 78%, respectively. AAP-2 displayed lower scavenging activities than the other two fractions. Immunostimulatory activities of AAPs were measured using mouse macrophages. The three polysaccharide fractions displayed significant antioxidant activities and stimulated the production of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). AAP-1 showed significant immunostimulatory activity (16-fold increase in the production of IL-6 compared to the control and 13-fold increase in the production of TNF-α) with low toxicity (>60% cell viability at 125 μg/mL concentration). Preliminary structural characterization of the AAPs was carried out using gas chromatography (GC) and FTIR techniques. The results indicate that AAP-1 and AAP-2 are pyranose-containing polysaccharides with β-linkages, and AAP-3 is a β-fructofuranoside. The results suggest that these polysaccharides are potential candidates for immunotherapy and cancer treatment.

Future antimalarials fromArtemisia? A rationale for natural product mining against drug-refractoryPlasmodiumstages

“…2), 115 in addition to neutral or acidic branched hetero-polysaccharides. [160][161][162] In the former category, (E)-melilotoside possesses very weak growth inhibitory activity against P. falciparum asexual blood stages in vitro. 163 The existence of related compounds in A. afra remains speculative.…”

LC-ESI-MS/MS-Based Comparative Metabolomic Study, Antioxidant and Antidiabetic Activities of Three Lobelia Species: Molecular Modeling and ADMET Study

“…However, polysaccharides isolated from L. chinensis reported antioxidant and anticancer activities L.…”

“…22 However, polysaccharides isolated from L. chinensis reported antioxidant and anticancer activities. 23 L. nicotianifolia methanol extract of the leaves reported higher antioxidant activity than roots methanol extract. 24 Cui et al examined the antioxidant activity of two L. chinensis extracts, stating that the antioxidant activity of both extracts was associated with the type and polarity of the extraction solvent.…”

Artemisia annua L. polysaccharide improves the growth performance and intestinal barrier function of broilers challenged with Escherichia coli

“…AAP was consisted of rhamnose, arabinose, galactose, glucose, mannose, galacturonic acid, and glucuronic acid, with a molar ratio of 2.93:3.75:7.44:58.47:20.87:5.49:1.07. According to the previous study, the appropriate dosage of AAP is 750 mg/kg ( Zhang, 2023 ).…”

“…Addition of A. annua extract to Nile tilapia diets modulated the intestinal microbiota and altered the abundance of specific bacteria ( Fusobacteriaceae , Stenotrophomonas , and Clostridium ), thereby improving growth performance ( Soares et al, 2022 ). Notably, the polysaccharide, being a bioactive substance in A. annua , has been found to possess antitumor activity ( Yan et al, 2019 ), along with antioxidant and immunomodulatory properties, as confirmed by in vitro experiments ( Zhang et al, 2022a ). The stable structures and properties of polysaccharides, as macromolecular compounds, contribute to their notably high safety profile.…”