A novel polysaccharide from Hericium erinaceus: Preparation, structural characteristics, thermal stabilities, and antioxidant activities in vitro

Comprehensive review on recent trends and perspectives of natural exo-polysaccharides: Pioneering nano-biotechnological tools

Exopolysaccharides (EPSs), originating from various microbes, and mushrooms, excel in their conventional role in bioremediation to showcase diverse applications emphasizing nanobiotechnology including nano-drug carriers, nano-excipients, medication and/or cell encapsulation, gene delivery, tissue engineering, diagnostics, and associated treatments. Acknowledged for contributions to adsorption, nutrition, and biomedicine, EPSs are emerging as appealing alternatives to traditional polymers, for biodegradability and biocompatibility. This article shifts away from the conventional utility to delve deeply into the expansive landscape of EPS applications, particularly highlighting their integration into cutting-edge nanobiotechnological methods. Exploring EPS synthesis, extraction, composition, and properties, the discussion emphasizes their structural diversity with molecular weight and heteropolymer compositions. Their role as raw materials for value-added products takes center stage, with critical insights into recent applications in nanobiotechnology. The multifaceted potential, biological relevance, and commercial applicability of EPSs in contemporary research and industry align with the nanotechnological advancements coupled with biotechnological nano-cleansing agents are highlighted. EPS-based nanostructures for biological applications have a bright future ahead of them. Providing crucial information for present and future practices, this review sheds light on how eco-friendly EPSs derived from microbial biomass of terrestrial and aquatic environments can be used to better understand contemporary nanobiotechnology for the benefit of society.

A neutral polysaccharide from Persicaria hydropiper (L.) Spach ameliorates lipopolysaccharide-induced intestinal barrier injury via regulating the gut microbiota and modulating AKT/PI3K/mTOR and MAPK signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Persicaria hydropiper (L.) Spach, a herb that is prevalent across Asia and Europe, finds utility as both a culinary ingredient and medicinal herb. In China, P. hydropiper decoction is commonly employed to alleviate dysentery, gastroenteritis, and diarrhea symptoms.

AIM OF THE STUDY

To assess the effects of a neutral polysaccharide from P. hydropiper (PHP) on the intestinal barrier (IB) injury induced by lipopolysaccharide (LPS) in mice, and elucidate the molecular mechanisms involved.

MATERIALS AND METHODS

PHP was extracted from dried P. hydropiper herb using hot water extraction, followed by ethanol precipitation. The extract underwent successive isolation and purification steps involving anion-exchange and gel filtration chromatography. The primary structure of PHP was determined using Fourier-transformed infrared spectroscopy, ion chromatography, gas chromatography-mass spectrometry (GC-MS), and nuclear magnetic resonance (NMR) spectroscopy. Male BALB/c mice were randomly assigned to control (CON), model (MOD), berberine hydrochloride (BBR), and PHP (20, 40 and 80 mg/kg) groups. Histopathological changes in jejunal tissues were assessed through hematoxylin and eosin (HE) staining. The expression levels of proteins and genes involved in AKT/PI3K/mTOR and MAPK signaling pathways were evaluated using qRT-PCR and Western blotting, respectively. The composition and abundance of the gut microbiota in mice were analyzed using high-throughput 16S rRNA gene sequencing. Additionally, the concentrations of short-chain fatty acids (SCFAs) were determined using GC-MS.

RESULTS

The main components of PHP included arabinose, galactose, and glucose (molar ratio = 1.00:5.52:11.39). The backbone of PHP consisted of →4)-Glcp-(1→, →4,6)-Glcp-(1→, →4)-Galp-(1→, →4,6)-Galp-(1→. The branched chains primarily consisted of 5)-Araf-(1→ residues, which were attached to the backbone through →6)-Glcp-(1→ and →6)-Galp-(1→ at the 6-position. Histological analysis demonstrated that PHP exhibited a mitigating effect on intestinal damage induced by LPS. PHP could markedly reduce the mRNA levels of PI3K, AKT, mTOR, p70 S6K, Ras, Raf1, MEK1/2, p38, ERK1/2, and JNK, while downregulating the protein levels of p-mTOR, p-PI3K, p-AKT, p-p38, p-ERK, and p-JNK. PHP also modulated the diversities and abundances of the gut microbiota, resulting in an increase in the abundances of Lactobacillaceae, Anaerovoracaceae, Lachnospiraceae, Eggerthellaceae, and Desulfovibrionaceae and a decrease in the abundances of Muribaculaceae, Prevotellaceae, and Rikenellaceae. Additionally, PHP significantly increased the content of various SCFAs.

CONCLUSION

PHP emerges as a pivotal factor in the repair of IB injury by virtue of its ability to regulate the gut microbiota, elevate SCFA levels, and inhibit the MAPK and AKT/PI3K/mTOR pathways. It is worth noting that the therapeutic effect of high-dose PHP was remarkably significant, surpassing even the positive control of berberine hydrochloride.

Evaluation of the "Relative Ordered Structure of Hericium erinaceus Polysaccharide" from Different Origins: Based on Similarity and Dissimilarity

Polysaccharides are organic compounds widely distributed in nature, but structural order and disorder remain a formidable problem. In this study, based on the theoretical framework of the "relative ordered structure of polysaccharide" proposed in our previous work, the structural order of Hericium erinaceus polysaccharides from different regions was evaluated by FT-IR, methylation analysis, and 1H NMR spectroscopy combined with chemometric methods. The results of principal component analysis and heatmap cluster analysis revealed that 18-subfractions exhibit four different structural types with representative glycoside linkage types: fucogalactoglucan, glucofucogalactan, fucoglucan, and glucan. The main chain of heteroglucans often consists of β-(1 → 6)-Glcp, β-(1 → 4)-Glcp, and β-(1 → 3)-Glcp residues, which are predominantly substituted at the O-3 and O-6 positions. The main chain structure of heterogalactans is α-(1 → 6)-Galp residues, which may be replaced by Fucp and Galp residues at O-2. Overall, our findings demonstrate the validity of the "relative ordered structure of polysaccharide" in Hericium erectus polysaccharides and simplify the complexity of polysaccharide structures.

Structural Characterization and Anti-Nonalcoholic Fatty Liver Effect of High-Sulfated Ulva pertusa Polysaccharide

The high-sulfated derivative of Ulva pertusa polysaccharide (HU), with unclear structure, has better anti-hyperlipidmia activity than U pertusa polysaccharide ulvan (U). In this study, we explore the main structure of HU and its therapeutic effect against nonalcoholic fatty liver disease (NAFLD). The main structure of HU was elucidated using FT-IR and NMR (13C, 1H, COSY, HSQC, HMBC). The anti-NAFLD activity of HU was explored using the high-fat diet mouse model to detect indicators of blood lipid and liver function and observe the pathologic changes in epididymal fat and the liver. Results showed that HU had these main structural fragments: →4)-β-D-Glcp(1→4)-α-L-Rhap2,3S(1→; →4)-α-L-Rhap3S(1→4)-β-D-Xylp2,3S(1→; →4)-α-L-Rhap3S(1→4)-β-D-Xylp(1→; →4)-α-L-IdopA3S(1→4)-α-L-Rhap3S(1→; →4)-β-D-GlcpA(1→3)-α-L-Rhap(1→; →4)-α-L-IdopA3S(1→4)-β-D-Glcp3Me(1→; →4)-β-D-Xylp2,3S(1→4)-α-L-IdopA3S(1→; and →4)-β-D-Xylp(1→4)-α-L-IdopA3S(1→. Treatment results indicated that HU markedly decreased levels of TC, LDL-C, TG, and AST. Furthermore, lipid droplets in the liver were reduced, and the abnormal enlargement of epididymal fat cells was suppressed. Thus, HU appears to have a protective effect on the development of NAFLD.

Structure characterization and antioxidant activity analysis of polysaccharides from Lanzhou Lily

Lanzhou Lily (Lilium davidii var. unicolor) is a traditional medicinal plant and popular edible vegetable bulb in China. In this study, the polysaccharides of Lanzhou Lily (LLPs) were extracted by polyethylene glycol-based ultrasonic-assisted enzymatic extraction method (PEG-UAEE). The optimum process conditions were obtained by single-factor experiments and response surface methodology (RSM). Then, the preliminarily structure of LLPs was characterized by HPLC, FT-IR, and SEM, and its antioxidant activities were evaluated. The results showed that LLPs yield reached 14.75% under the optimized conditions: E/S ratio 1,400 U/g; pH 5.0, ultrasonic time 30 min; and ultrasonic temperature 50 °C. The LLPs has pyranoid ring, uronic acid, and the characteristic absorption peaks of -OH, C = O, and C-H. The results of scanning electron microscope indicated that the LLPs had irregular distribution, dispersed structure, and many holes. The HPLC analysis showed that the LLPs were heteropolysaccharide containing galactose (6.36%), glucose (76.03%), rhamnose (2.02%), and arabinose (7.09%). Moreover, the LLPs showed obvious antioxidant effect in vitro.

Structure Characterization, Antioxidant and Immunomodulatory Activities of Polysaccharide from Pteridium aquilinum (L.) Kuhn

Pteridium aquilinum (L.) Kuhn (Pteridaceae family) has been widely used as a food and medicine in China and Korea. Previous studies indicate that P. aquilinum contains a variety of bioactive chemical components such as flavonoids, phenols, terpenoids, saponins, polysaccharides, and so on. In the present study, a novel polysaccharide (named as PAP-3) with average molecular weight of 2.14 × 10⁵ Da was obtained from P. aquilinum. The structure was studied through physicochemical and spectroscopic analysis. The results indicated that PAP-3 consists of arabinose, rhamnose, fucose, galactose, mannose, and xylose in a molar ratio of 1.58:1.00:3.26:4.57:4.81:3.33. The polysaccharide is mainly composed of (1→2)-linked xylose and (1→3,6)-linked mannose on the main chain, with (1→2)-linked xylose, (1→6)-linked mannose, and (1→6)- and (1→3,6)-linked galactose as side chains. Galactose, fucose, and xylose are located at the end of the side chains. The in vitro immunomodulatory and antioxidant activities were assayed. PAP-3 has strong free-radical scavenging activity on DPPH and ABTS radicals and significant immunomodulatory activity on RAW264.7 cells. These data provide useful information for further study on the polysaccharides of P. aquilinum and their applications in the food and medical industries.