Isolation and Assessment of a Highly-Active Anti-Inflammatory Exopolysaccharide from Mycelial Fermentation of a Medicinal Fungus Cs-HK1

Abstract

The purpose of this work was to fractionate the complex exopolysaccharide (EPS) from a medicinal fungus Ophiocordyceps sinensis Cs-HK1 based on the molecular weight (MW) range and to assess the in vitro anti-inflammatory activity of different EPS fractions in THP-1 cell culture. The lower MW fraction (EPS-LM-1) showed a much higher anti-inflammatory activity. EPS-LM-1 was identified as a heteropolysaccharide consisting of mannose, glucose, and galactose residues with an average MW of 360 kDa. EPS-LM-1 significantly inhibited the lipopolysaccharide-induced inflammatory responses with the effective concentrations for 50% inhibition below 5 µg/mL on a few major proinflammatory markers. With such a notable in vitro anti-inflammatory activity, EPS-LM-1 is a promising candidate for the development of a new anti-inflammation therapy.

Modification and enhanced anti-inflammatory activity by Bifidobacterial fermentation of an exopolysaccharide from a medicinal fungus Cs-HK1

“…The aqueous solution was then collected and dialyzed against distilled water through a 3500 MW-cut off membrane for 48 h, and then freeze-dried as the final EPS-LM fraction for the following experiments. The deproteinized EPS-LM fraction was mainly composed of a heteroglycan with three monosaccharide residues, Man, Glc and Gal at 7.31: 12.95:1 mole ratio, which were similar to those reported previously [20].…”

“…The fermentation liquid was then centrifuged and the supernatant was collected for the isolation of exopolysaccharide (EPS). As reported previously [20], a two-step ethanol precipitation was performed, firstly adding 40% (v/v) ethanol to the fermentation liquid to precipitate the high-MW EPS (EPS-HM) and 80% (v/v) to the remaining liquid to precipitate the lower-MW EPS (EPS-LM). The precipitate was recovered from the liquid by centrifugation (12,000 rpm, 15 min) and freeze dried as the crude EPS fractions.…”

“…The chemical composition and molecular weight (MW) of digesta with or without the EPS-LM as well as the liquid medium before the Bifidobacterial fermentation were determined by the methods as reported previously [20]. The MW distribution was analyzed by high-pressure gel permeation chromatography (HPGPC).…”

“…The crude and partially purified EPS fractions isolated from the Cs-HK1 fermentation liquid have shown notable prebiotic [17,18] and anti-inflammatory activities [19]. Very recently, a lower molecular weight (MW) fraction with an average MW of 360 kDa, designated EPS-LM, was separated from the complex EPS, which was mainly composed of three monosaccharide residues including glucose, mannose and galactose [20]. This EPS-LM has been found more active than the whole EPS and the higher MW EPS fraction to inhibit the LPS-induced proinflammatory responses in THP-1 cell culture.…”

Separation, Purification, Structural Characterization, and Anticancer Activity of a Novel Exopolysaccharide from Mucor sp.

“…These studies indicate the immense potential of fungal polysaccharides. Additionally, numerous studies have shown that the diversity in the relative molecular weight, monosaccharide composition and content, glycosidic bond type, and sugar-ring configuration in fungal polysaccharides contributes to their structural diversity and functional novelty [ 18 , 19 , 20 , 21 , 22 ]. To date, only a few studies on the isolation, purification, structural characterization, and activity of Mucor fungus polysaccharides have been reported.…”