Structure-activity relationship of antioxidant polysaccharides from Huangshui based on the HPLC fingerprint combined with chemometrics methods

Research Progress on Saccharide Molecule Detection Based on Nanopores

Saccharides, being one of the fundamental molecules of life, play essential roles in the physiological and pathological functions of cells. However, their intricate structures pose challenges for detection. Nanopore technology, with its high sensitivity and capability for single-molecule-level analysis, has revolutionized the identification and structural analysis of saccharide molecules. This review focuses on recent advancements in nanopore technology for carbohydrate detection, presenting an array of methods that leverage the molecular complexity of saccharides. Biological nanopore techniques utilize specific protein binding or pore modifications to trigger typical resistive pulses, enabling the high-sensitivity detection of monosaccharides and oligosaccharides. In solid-state nanopore sensing, boronic acid modification and pH gating mechanisms are employed for the specific recognition and quantitative analysis of polysaccharides. The integration of artificial intelligence algorithms can further enhance the accuracy and reliability of analyses. Serving as a crucial tool in carbohydrate detection, we foresee significant potential in the application of nanopore technology for the detection of carbohydrate molecules in disease diagnosis, drug screening, and biosensing, fostering innovative progress in related research domains.

Preparation, antibacterial activity, and structure-activity relationship of low molecular weight κ-carrageenan

κ-Carrageenan (KC) is a polysaccharide widely used in food industry. It has been widely studied for its excellent physicochemical and beneficial properties. However, the high molecular weight and high viscosity of KC make it difficult to be absorbed and to exert its' biological activities, thus limit its extensive industrial application. In order to solve this problem, five low molecular weight κ-carrageenans (DCPs) were prepared by the degradation of KC using hydrogen peroxide (H2O2) and ascorbic acid (AH2). The chemical compositions and structure characteristics of the DCPs were then determined. The results showed that H2O2 and AH2 could effectively degrade KC to DCPs, and DCPs remained the basic skeletal structure of KC. DCPs showed good antibacterial activities against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Bacillus subtilis. The Minimum Inhibitory Concentration (MIC) of DCPs with the highest antibacterial effects were 5.25, 4.5, 5.25, and 4.5 mg/mL, respectively. This is due to the underlying mechanism of DCPs that bind to the bacterial membrane proteins and change the membrane permeability, thus exerting antibacterial activity. In addition, Spearman's rank correlation and Ridge regression analysis revealed that the molecular weight and the contents of 3,6-anhydro-D-galactose, aldehyde group, carboxyl, and sulfate were the main structural characteristics affecting the antibacterial activity. Our findings reveal that the H2O2-AH2 degradation treatment could significantly improve the antibacterial activity of KC and provide insights into the quantitative structure-activity relationships of the antibacterial activity of DCPs.

Preparation of reusable hydrogel spheres based on sodium alginate/Fe3O4 modified with carboxymethyl Huangshui polysaccharide and the efficient adsorption performance for methylene blue

This study successfully constructed a novel multifunctional bio-adsorbent using sodium alginate (SA), ferroferric oxide (FFO), and carboxymethyl Huangshui polysaccharide (CMHSP) with rapid separation, pH sensitivity, efficient adsorption, and reusability for enhancing the removal of methylene blue (MB) in wastewater. FTIR, XRD, SEM, and VSM results indicated CMHSP improved the porosity of the hydrogel spheres, thus significantly enhancing the MB adsorption capacity with the rate-limiting controlled by chemical adsorption, intraparticle diffusion, and film diffusion. The maximum adsorption capacity obtained from Langmuir model of SA-FFO-CMHSP (186.57 mg/g) was obviously higher than that of SA-FFO (178.82 mg/g). Thermodynamic results showed that the MB adsorption process was endothermic, spontaneous, and favorable, and physical adsorption was dominant. Remarkably, MB adsorption maintained 87% ∼ 95% of the initial after four adsorption-desorption cycles, and proper carboxymethylation was conducive to MB adsorption over a broader range pH. These findings provided reference for designing new efficient bio-adsorbents and the recyclable utilization of Huangshui by-products, which was of great value.

The Regulatory Effect of Huangshui Polysaccharides on Intestinal Microbiota and Metabolites during In Vitro Fermentation

Huangshui polysaccharides (HSPs) have attracted extensive attention recently for their biological activity and physicochemical property. This research investigated the extraction, structural characterization, and prebiotic activity of three different HSPs (HSP40-0, HSP60-0, and HSP80-0) in vitro to reveal the scientific support for the high-value utilization of Huangshui. HSPs were heteropolysaccharide with diverse structures and surface morphologies. Comprehensive analysis was conducted through 16S rRNA gene sequencing and metabolite profiling techniques, and results showed that HSPs had different potentials to regulate the gut microbiota due to their different structures; for instance, both HSP40-0 and HSP80-0 could notably increase the relative abundance of Bacteroidota, whereas HSP60-0 could increase the relative abundance of Phascolarctobacterium. In addition, HSPs upregulated beneficial differential metabolites, especially short-chain fatty acids (SCFAs). Fermentation products containing these metabolites exhibited anti-inflammatory effects on LPS-treated Caco-2 cells. This study will provide reference for exploring the relationship between the natural polysaccharide structure and the prebiotic activity and widen the application of Huangshui.

Effects of extraction methods on the physicochemical properties and functionalities of pectic polysaccharides from burdock (Arctium lappa L.)

In this work, the effects of four different extraction methods, acid (HCl), alkali (NaOH), enzymes (cellulase/pectinase), and buffer (pH 7.0) on the physicochemical properties and functionalities of burdock pectin were systematically investigated and compared. Buffer extraction gave a low yield (2.8 %) and is therefore limited in its application. The acid treatment hydrolyzed the neutral sidechains and gave a homogalacturonan content of 72.6 %. By contrast, alkali and enzymes preserved the sidechains while degrading the polygalacturonan backbone, creating a rhamnogalacturonan-I dominant structure. The branched structure, low molecular weight, and high degree of methylation (42.3 %) contributed to the interfacial adsorption, emulsifying capacity, and cellular antioxidant activity of the enzyme-extracted product. For the acid-extracted product, the strong intramolecular electrostatic repulsion restricted the formation of a contact interface to prevent coalescence of the emulsion. In addition, they did not have sufficient reducing ends to scavenge free radicals. Although a high branching size (5.0) was adopted, the low degree of methylation (19.5 %) affected the emulsifying capacity of the alkali-extracted products. These results provide useful information for pectic polysaccharides production with tailored properties.

Preparation, Structural Analysis, and Intestinal Probiotic Properties of a Novel Oligosaccharide from Enzymatic Degradation of Huangshui Polysaccharide

Huangshui polysaccharide (HSP) has attracted more and more interest due to its potential health benefits. Despite being an excellent source for the preparation of oligosaccharides, there are currently no relevant research reports on HSP. In the present study, a novel oligosaccharide (HSO) with a molecular weight of 1791 Da and a degree of polymerization of 11 was prepared through enzymatic degradation of crude HSP (cHSP). Methylation and NMR analyses revealed that the main chain of HSO was (1 → 4)-α-d-glucose with two O-6-linked branched chains. Morphological observations indicated that HSO exhibited smooth surface with lamellar and filamentary structure, and the glycan size ranged from 0.03 to 0.20 μm. Notably, HSO significantly promoted the proliferation of Bifidobacterium, Bacteroides, and Phascolarctobacterium, thereby making positive alterations in intestinal microbiota composition. Moreover, HSO markedly increased the content of short-chain fatty acids during in vitro fermentation. Metabolomics analysis illustrated the important metabolic pathways primarily involving glucose metabolism, amino acid metabolism, and fatty acid metabolism.

Cold Alkali-Extractable Antioxidative Polysaccharide from Russula pseudocyanoxantha (Agaricomycetes), a Novel Mushroom, Stimulates Immune Responses in RAW264.7 Cells by Regulating the TLR/NF-κB Pathway

In our previous study, we have established Russula pseudocyanoxantha as a unique species, playing a crucial role in indigenous diets through ages. The research also brought attention to bioactive potential of polysaccharide fraction extracted from the unexplored food using hot water. However, residue of the conventional process still contains therapeutic biopolymers that could further be utilized for pharmacological purposes instead of being discarded. Therefore, the current study aims to valorize the solid remnants, contributing to a deeper understanding of the novel taxon. Subsequently, the leftover was treated with cold alkali, leading to the preparation of a high-yield fraction (RP-CAP). Chemical characterization through FT-IR, GC-MS, HPTLC, and spectroscopy demonstrated presence of several monomers in the carbohydrate backbone, predominantly composed of β-glucan. Furthermore, GPC chromatogram indicated presence of a homogeneous polymer with molecular weight of ~ 129.28 kDa. Subsequently, potent antioxidant activity was noted in terms of radical scavenging (O2·-, OH·, DPPH· and ABTS·+), chelating ability, reducing power and total antioxidant activity where EC50 values ranged from 472-3600 μg/mL. Strong immune-boosting effect was also evident, as the biopolymers stimulated murine macrophage cell proliferation, phagocytic activity, pseudopod formation, and NO as well as ROS synthesis particularly at the concentration of 100 μg/mL. In-depth analysis through RT-PCR revealed that the fraction stimulated synthesis of several inflammatory mediators, elucidating the mode of action through TLR/ NF-κB pathway. Therefore, the findings collectively suggest that RP-CAP possesses great potential to serve as a healthimproving component in functional food and pharmaceutical sectors.

The Prebiotic Activity of a Novel Polysaccharide Extracted from Huangshui by Fecal Fermentation In Vitro

A novel polysaccharide, HSP80-2, with an average molecular weight of 13.8 kDa, was successfully isolated by the gradient ethanol precipitation (GEP) method from Huangshui (HS), the by-product of Chinese Baijiu. It was mainly composed of arabinose, xylose, and glucose with a molar ratio of 4.0:3.1:2.4, which was completely different from the previous reported HS polysaccharides (HSPs). Morphological observations indicated that HSP80-2 exhibited a smooth but uneven fragmented structure. Moreover, HSP80-2 exerted prebiotic activity evaluated by in vitro fermentation. Specifically, HSP80-2 was utilized by gut microbiota, and significantly regulated the composition and abundance of beneficial microbiota such as Phascolarctobacterium, Parabacteroides, and Bacteroides. Notably, KEGG pathway enrichment analysis illustrated that HSP80-2 enriched the pathways of amino sugar and nucleotide sugar metabolism (Ko00520), galactose metabolism (ko00052), and the citrate cycle (TCA cycle) (ko00020). Meanwhile, the contents of short-chain fatty acids (SCFAs) mainly including acetic acid, propionic acid, and butyric acid in the HSP80-2 group were remarkably increased, which was closely associated with the growth of Lachnoclostridium and Parabacteroides. These results showed that HSP80-2 might be used as a potential functional factor to promote human gut health, which further extended the high value utilization of HS.

Effects including photobiomodulation of galactomannan gel from Cassia grandis seeds in the healing process of second-degree burns

The epithelium recovery of skin-burned wounds has been currently achieved by several therapies, for example, hydrogel-based dressings and photobiomodulation therapy (PBMT). Thus, this work aimed to evaluate the healing activity of Cassia grandis seeds' galactomannan gel, associated or not with PBMT, in second-degree burns. Sixty male Wistar rats were assigned to four groups: Control (CG), Gel (GG), Laser/PBMT (LG), and Laser+Gel (GLG). Burns were made with an aluminum bar (90 °C), and submitted to clinical observations diary and area measurements at specific days. Microscopic analysis was based on histological criteria. The results showed that GG, LG, and GLG had a higher contraction rate (p < 0.05) than CG on the 14th experimental day, not differing from each other (∼95 %). At 21 days, all groups showed complete contraction (p > 0.05). Considering the histological results, LG and GLG showed excellent pro-wound healing properties after 14 days; at 21 days, all groups showed wound recovery compared to previous days. In view of the macroscopic and microscopic observations, the isolated treatments (Gel or Laser) effectively accelerated healing; however, the association (Laser+Gel) promoted re-epithelialization and stromal remodeling with better evolution of epithelium recovery due to the positive synergistic effect, thus emerging as a promising therapeutic alternative in the repair of burns.

Anti-inflammation activity of Zhizi Jinhua Pills and overall quality consistency evaluation based on integrated HPLC, DSC and electrochemistry fingerprints

ETHNOPHARMACOLOGICAL RELEVANCE

Zhizi Jinhua Pills (ZZJHP), a compound preparation composed of 8 traditional Chinese medicines (TCM), is widely used clinically to clearing heat, purging fire, cooling blood and detoxifying. However, the studies on its pharmacological activity and the determination of active compounds are relatively few. There is a lack of quality control methods that can reflect the effectiveness of the drug.

AIM OF THE STUDY

The objective was to construct fingerprint profiles, conduct a spectrum-effect relationship study and establish an overall quality control method for ZZJHP through anti-inflammatory and redox activity studies.

MATERIALS AND METHODS

Firstly, anti-inflammatory activity was tested using the xylene-induced ear edema model in mice. Then, Five-wavelength fusion HPLC fingerprint, electrochemical fingerprint, and Differential scanning calorimetry (DSC) profiling were established to evaluate ZZJHP more comprehensively, where Euclidean quantified fingerprint method (EQFM) was proposed for the similarity assessment of these three fingerprints. Moreover, the spectrum-activity relationship of HPLC-FP and DSC-FP with electrochemical activity helped explore the active components or ranges in the fingerprint. Finally, integrated analysis of HPLC, DSC and electrochemistry were used for the quality screen of samples from different manufacturers.

RESULTS

ZZJHP was found to significantly decrease the levels of both TNF-α and IL-6 in the mice. Qualitatively, the integrated similarity S_m of 21 samples were all greater than 0.9, indicating the great consistency in chemical composition. Quantitatively, 9 batches of samples were classified as Grade1∼4; 6 batches of samples were classified as Grade5∼7 due to higher P_INT; 6 batches of samples were classified as Grade4∼5 due to lower P_INT. EQFM can qualitatively and quantitatively characterize the fingerprint profile information from an overall perspective.

CONCLUSIONS

This strategy will contribute to the quantitative characterization of TCM and promote the application of fingerprint technology in the phytopharmacy field.

Extraction, Isolation, Screening, and Preliminary Characterization of Polysaccharides with Anti-Oxidant Activities from Oudemansiella raphanipies

Response surface methodology (RSM) was used to find the optimal extraction process of Oudemansiella raphanipies polysaccharides (ORPs). The results showed that the optimal extraction parameters were an alkali concentration of 0.02 mol/L, a ratio of material to liquid of 1:112.7 g/mL, an extraction temperature of 66.0 °C, and an extraction time of 4.0 h. Under the optimal conditions, the yield of ORPs was raised to 16.2 ± 0.1%. The antioxidant activities of ORPs-I~V were determined and compared, and ORPs-V was further purified by chromatography, with an average molecular weight (Mw) of 18.86 kDa. The structure of ORPs-V was determined by Fourier transform-infrared spectroscopy (FT-IR), monosaccharide analysis, and nuclear magnetic resonance (NMR) spectroscopy. The ORPs-V comprised fucose, rhamnose, arabinose, glucose, galactose, mannose, xylose, fructose, galacturonic acid, and glucuronic acid at a ratio of 1.73:1.20:1.13:2.87:8.71:2.89:1.42:0.81. Compared to other ORPs, ORPs-V showed the strongest antioxidant activities (ABTS radical cation, hydroxyl radical and DPPH scavenging activities, and reducing power), and were able to significantly increase the activities of superoxide dismutase, catalase, lactate dehydrogenase, and glutathione peroxidase. However, they reduced the malondialdehyde content in mice fed a high-fat diet. These results indicate that ORPs-V may be good anti-oxidant agents to be applied in functional foods.

Huangshui Polysaccharide Exerts Intestinal Barrier Protective Effects through the TLR4/MyD88/NF-κB and MAPK Signaling Pathways in Caco-2 Cells

Several reports have demonstrated that natural polysaccharides exert protective effects on intestinal barrier function. In our previous study, we isolated a polysaccharide named HSP-W from Huangshui (HS). In the present study, the protective role of HSP-W in LPS-induced intestinal barrier dysfunction was determined by several molecular biological techniques. The results showed that HSP-W treatment alleviated the deduced TEER and increased the permeability of intestinal epithelial cells induced by LPS through inhibiting the release of inflammatory cytokines and enhancing the expression of tight junction (TJ) proteins. The underlying molecular mechanisms were elucidated by RNA-seq technique, which indicated that the differentially expressed genes (DEGs) between the LPS-treated and LPS+HSP-W-treated groups were enriched in the "MAPK" signaling pathway. Notably, the overlapping DEGs reversed by HSP-W intervention highlighted the pathways of the "Toll-like receptor" and "NF-κB" signaling pathways. The suppression of p38 and NF-κB were mediated by the inhibition of MyD88. Furthermore, HSP-W treatment prevented the translocation of NF-κB to nucleus, thus inhibiting the release of TNF-α, IL-6, and IL-1β. Overall, HSP-W has beneficial effects on LPS-induced inflammation; it protects the intestinal barrier from injury in Caco-2 cells through inhibiting the TLR4/MyD88/NF-κB and p38 MAPK signaling pathways.

Structure elucidation and intestinal barrier protection of an α-D-glucan in Huangshui

WLY-0, as an α-D-glucan with a molecular weight (Mw) of 11.12 kDa, was successfully isolated and purified from Huangshui (HS). The results of methylation and NMR indicated that the mainchain of WLY-0 was (1 → 4)-α-D-glucan, with side chains linking at O-6. Meanwhile, the surface morphology characterization showed that WLY-0 had an irregular flake-like morphology with a rough and uneven surface and varies in sizes from nanometers to microns. Furthermore, WLY-0 relieved the increased paracellular permeability of FD4 and decreased TEER challenged by LPS, meanwhile inhibited the production of pro-inflammatory cytokines (TNF-α, IL-6, and IL-1β) and up-regulated the expression of TJ protein (Occludin, Claudin-1, ZO-1, and JAM-A) in Caco-2 cells, so to improve the intestinal barrier function. Our findings about the structural characteristics and biological activities of WLY-0 provided a scientific foundation for the utilization of HS as a potent source of an effective adjuvant in intestinal barrier injury treatment.

Hawthorn Juice Simulation System for Pectin and Polyphenol Adsorption Behavior: Kinetic Modeling Properties and Identification of the Interaction Mechanism

The interaction between polyphenols and polysaccharides plays an important role in increasing the turbidity stability of fruit juice and improving unpleasant sensory experiences. The binding adsorption behavior between hawthorn pectin (HP) and polyphenols (epicatechin and chlorogenic acid) accorded with the monolayer adsorption behavior driven by chemical action and were better fitted by pseudo-second order dynamic equation and Langmuir model. The HP binding sites (Qm) and adsorption capacity (Qe) to epicatechin were estimated at 75.188 and 293.627 μg/mg HP, respectively, which was about nine and twelve times higher than that of chlorogenic acid. The interaction between HP and polyphenols exhibited higher turbidity characteristics, particle size and lower zeta potential than epicatechin and chlorogenic acid alone. Meanwhile, according to Fourier Transform Infrared Spectroscopy (FT-IR) analysis, it could be speculated that the interaction between HP and polyphenols resulted in chemical combination. Moreover, ΔH < 0 and TΔS < 0, which indicated that the interaction between HP and polyphenols was mainly driven by hydrogen bonds and van der Waals forces.