Effects of multi-frequency ultrasonic on the physicochemical properties and bioactivities of polysaccharides from different parts of ginseng

Extraction of Pithecellobium clypearia Benth polysaccharides by dual-frequency ultrasound-assisted extraction: Structural characterization, antioxidant, hypoglycemic and anti-hyperlipidemic activities

In this research, the extraction process of polysaccharides from Pithecellobium clypearia Benth (PCBPs) was optimized using dual-frequency ultrasound-assisted extraction (DUAE). The biological activities of PCBPs were investigated by in vitro antioxidant, hypoglycemic, and anti-hyperlipidemic assay. High-performance anion-exchange chromatography, high-performance gel permeation chromatography, SEM, UV-Vis spectroscopy, and FT-IR spectra were used to analyze the monosaccharide composition, molecular weight, microscopic morphology, and characteristic structure of PCBPs. The results showed that the maximum extraction rate of PCBPs was 9.90 ± 0.16% when the ultrasonic time was 8 min, the liquid-to-material ratio was 32 mL/g, and the ultrasonic power was 510 W. The PCBPs also possessed excellent in vitro antioxidant, hypoglycemic, and anti-hyperlipidemic activities. In addition, the average molecular weight of PCBPs was 15.07 kDa. PCBPs consisted of rhamnose, arabinose, galactose, glucose, xylose, mannose, and glucuronic acid, with the molar ratios of 11.07%, 18.54%, 48.17%, 10.44%, 4.62%, 4.96%, and 2.20%, respectively. Moreover, the results of SEM showed that PCBPs mainly showed a fine spherical mesh structure. The above studies provided a valuable theoretical basis for the subsequent in-depth study of PCBPs.

Plant polysaccharides extracted by high pressure: A review on yields, physicochemical, structure properties, and bioactivities

Polysaccharides are biologically essential macromolecules, widely exist in plants, which are used in food, medicine, bioactives' encapsulation, targeted delivery and other fields. Suitable extraction technology can not only improve the yield, but also regulate the physicochemical, improve the functional property, and is the basis for the research and application of polysaccharide. High pressure (HP) extraction (HPE) induces the breakage of raw material cells and tissues through rapid changes in pressure, increases extraction yield, reduces extraction time, and modifies structure of polysaccharides. However, thus far, literature review on the mechanism of extraction, improved yield and modified structure of HPE polysaccharide is lacking. Therefore, the present work reviews the mechanism of HPE polysaccharide, increasing extraction yield, regulating physicochemical and functional properties, modifying structure and improving activity. This review contributes to a full understanding of the HPE or development of polysaccharide production and modification methods and promotes the application of HP technology in polysaccharide production.

Ginseng polysaccharides ameliorate ulcerative colitis via regulating gut microbiota and tryptophan metabolism

Ulcerative colitis (UC) is regarded as a recurring inflammatory disorder of the gastrointestinal tract, for which treatment approaches remain notably limited. In this study, we demonstrated that ginseng polysaccharides (GPs) could alleviate the development of dextran sulfate sodium (DSS)-induced UC as reflected by the ameliorated pathological lesions in the colon. GPs strikingly suppressed the expression levels of multiple inflammatory cytokines, as well as significantly inhibited the infiltration of inflammatory cells. Microbiota-dependent investigations by virtue of 16S rRNA gene sequencing, antibiotic treatment and fecal microbiota transplantation illustrated that GPs treatment prominently restored intestinal microbial balance predominantly through modulating the relative abundance of Lactobacillus. Additionally, GPs remarkably influenced the levels of microbial tryptophan metabolites, diminished the intestinal permeability and strengthened intestinal barrier integrity via inhibiting the 5-HT/HTR3A signaling pathway. Taken together, the promising therapeutic potential of GPs on the development of UC predominantly hinges on the capacity to suppress the expression of inflammatory cytokines as well as to influence Lactobacillus and microbial tryptophan metabolites.

The effect of sequential extraction on the physicochemical and rheological properties of Naematelia aurantialba polysaccharides

To overcome the difficulty of separation and low rate of extraction caused by highly viscous polysaccharides from Naematelia aurantialba (NA), four N. aurantialba polysaccharides (NAPs) were sequentially extracted using water (enzyme-/ultrasound-assisted extraction), alkali (0.1 mol/L NaOH), and acid (0.1 mol/L HCl), and named E-NAP, U-NAP, Al-NAP, and Ac-NAP. The properties of four NAPs were different. The yields of NAPs were 26.05 % (Ac-NAP) > 20.33 % (Al-NAP) > 17.99 % (U-NAP) > 12.77 % (E-NAP), respectively. The monosaccharide composition of NAPs was composed primarily of mannose, xylose, glucose, glucuronic acid, and galactose. Sequential extraction improved the purity and solubility of NAPs, but decreased the particle size, thermal stability, water retention, and crystallinity. Two polysaccharides, U-NAP and Al-NAP, had a triple helix structure. All the NAPs were pseudoplastic fluids with concentration/frequency-dependent entangled structure. Al-NAP with the highest viscosity exhibited an elastic gel, while Ac-NAP with the lowest viscosity was a viscous gel. The behavior of NAPs differed from that predicted using the Cox-Merz rule, and in particular, E-NAP and U-NAP more significantly deviated from the rule. In this study, four NAPs with different properties were extracted sequentially, which provided a theoretical basis for the down-stream processing with high added-value and utilization of NA and NAP.

Structural, chemical and technofunctional properties pectin modification by green and novel intermediate frequency ultrasound procedure

The impact of intermediate frequency ultrasound (IFUS, 582, 864 and 1144 kHz), mode of operation (continue and pulsed) and ascorbic acid (Aa) addition on the structural, chemical and technofunctional properties of commercial citrus high methoxyl-grade pectin (HMP) was investigated. The chemical dosimetry of IFUS, monitored by the triiodide formation rate (I3-), demonstrated that the pulsed ratio (1900 ms on/100 ms off) at the three frequencies was similar to that of continue mode but IFUS1144 kHz produced more acoustic streaming demonstrated by the height liquid measured using image analysis. In presence of Aa, HMP presented higher fragmentation than in its absence. IFUS did not give rise any changes in the main functional groups of the HMP. In general, a reduction in molecular weight was observed, being the presence of Aa the most influencing factor. Regarding monosaccharides, IFUS modified the structure of homogalacturonan and rhamnogalacturonan-I and increased of GalA contents of the HMP in presence of Aa at the above three frequencies. A reducing of the consistency index (k) and increasing of the flow index (n) of HMP were showed by IFUS frequency and Aa addition. The emulsifying activity and stability index were increased for HMP treated by IFUS in continue mode at all frequencies and in presence of Aa. The results presented in this research shown the effectiveness of IFUS as tool to modify pectin into different structures with different functionalities.

Structural Characterization and Anti-Inflammatory Activity of Polysaccharides from Tremella fuciformis on Monosodium Urate-Stimulated RAW264.7 Macrophages

The structural characteristics and anti-inflammatory activity of Tremella fuciformis polysaccharides (TFPs) were investigated. The study showed that TFPs were mainly composed of mannose, rhamnose, glucuronic acid, glucose, galactose, xylose, and fucose. TFPs significantly inhibited monosodium urate (MSU)-induced inflammation of RAW264.7 cells, as well as the secretion levels of TNF-α, IL-1β, and IL-18 cytokines. The concentrations of malondialdehyde and reactive oxygen species in RAW264.7 macrophages were reduced, but superoxide dismutase activity was increased. RNA-Seq technology was applied to explore the mechanisms of TFPs ameliorating MSU-induced inflammation of RAW264.7 macrophages. Results revealed that TFPs significantly reduce MSU-stimulated inflammatory damage in RAW 264.7 cells by inhibiting signaling pathways like the hypoxia inducible factor-1 (HIF-1) signaling pathway and erythroblastic oncogene B (ErbB) signaling pathway. This study provides a foundation for TFPs to be developed as novel anti-inflammatory drugs.

Comparative Evaluation of the Physiochemical Properties, and Antioxidant and Hypoglycemic Activities of Dendrobium officinale Leaves Processed Using Different Drying Techniques

Dendrobium officinale leaves have the potential to be processed into natural antioxidants, functional foods, and food additives. To maximally maintain their quality, fresh D. officinale leaves were dehydrated using different drying methods, i.e., hot air drying (HD), microwave drying (MD), infrared drying (IRD), and freeze drying (FD), and then the physicochemical properties, microstructure, and biological activities of the dried samples were compared. The results showed that, with the FD method, the samples had a porous microstructure, maintained the highest phenolic content, and demonstrated the highest antioxidant and hypoglycemic activities. Among the three thermal drying methods, with the IRD method, the samples retained higher phenolic contents, showed stronger DPPH free-radical scavenging, ferric ion reducing, ferrous ion chelating, and α-glucosidase inhibitory abilities, and more strongly promoted glucose metabolism in insulin-resistant HL-7702 cells than the samples with the MD and HD methods. These results suggested that FD was the most suitable method. However, IRD might be a promising alternative, owing to the high cost and long time needed for FD for the large-scale drying of D. officinale leaves.

Effect of Ultrasonic Treatment on Structure, Antibacterial Activity of Sugarcane Leaf Polysaccharides

This study investigated the impact of ultrasonic extraction (UE) on the structure and in vitro antibacterial activity of polysaccharides from sugarcane leaves (SLW). Native sugarcane leaf polysaccharides were treated with ultrasound (480 W) for 3 h to yield sugarcane leaf polysaccharides (SLU). Compared to SLW (33.59 kDa), the molecular weight of SLU (13.08 kDa) was significantly decreased, while the monosaccharide composition of SLU was unchanged. The results of SEM and XRD indicated that UE significantly changed the surface morphology of SLW and destroyed its inner crystalline structure. In vitro experiments showed that SLU had stronger antibacterial activity. These findings revealed that UE treatment could alter the tertiary structure of SLW but had no impact on its primary structure. Furthermore, the antibacterial activity of SLW could be greatly enhanced after UE treatment. As a bioactive additive, SLU has great application potential in functional foods, cosmetics, and pharmaceuticals.

Research Progress on Extraction, Isolation, Structural Analysis and Biological Activity of Polysaccharides from Panax Genus

The panax genus is a widely used medicinal plant with good biological activity. As one of the main active components of the Panax genus, polysaccharides have various pharmacological effects. This review summarizes the latest research reports on ginseng, American ginseng, and Panax notoginseng polysaccharides and compares the differences in extraction, isolation and purification, structural characteristics, and biological activities. The current research mainly focuses on ginseng polysaccharides, and the process of extraction, isolation, and structure analysis of each polysaccharide is roughly the same. Modern pharmacological studies have shown that these polysaccharides have antioxidants, antitumor, immunomodulatory, antidiabetic, intestinal protection, skin repair, and other biological activities. This review provides new insights into the differences between the three kinds of ginseng polysaccharides which will help to further study the medicinal value of ginseng in traditional Chinese medicine.

Efficient decolorization of oligosaccharides in ginseng (Panax ginseng) residue using ultrasound-assisted macroporous resin

An efficient decolorization method for ginseng residue oligosaccharides (GROs) using ultrasound-assisted D392 macroporous resin was developed. The decolorization effects and color differences of activated carbon adsorption, hydrogen peroxide oxidation, and resin adsorption were evaluated. The optimal conditions of the three decolorization methods for static, dynamic, ultrasound-assisted resin adsorption were compared. The results showed that ultrasound-assisted decolorization had the best decolorization effect of greatly decreasing the decolorization time to 80 min. Color difference analysis revealed the process of pigment removal during GRO decolorization. The UV-visible full-wavelength scan showed that most pigments were removed after decolorization. The characterizations by the Fourier-transform infrared spectroscopy and X-ray diffraction analysis showed that the chemical structure and crystallinity of the GROs did not change upon decolorization. In addition, the molecular weight distribution did not change significantly. This research contributes to further exploration of the structures and functions of GROs.

The protective effect and antitumor activity of Aconiti Lateralis Radix Praeparata (Fuzi) polysaccharide on cyclophosphamide-induced immunosuppression in H22 tumor-bearing mice

Background: Aconiti Lateralis Radix Praeparata, also known as Fuzi in Chinese, has been used in Traditional Chinese Medicine for more than 2,000 years. In recent years, some traditional herbal compounds containing Fuzi have achieved positive clinical results in tumor treatment. And the polysaccharide isolated from Fuzi has attracted much attention as a potential immunomodulator. However, its immunomodulatory mechanism remains to be further studied. Aim of the study. Fuzi neutral polysaccharide (FNPS) and cyclophosphamide (CTX) were combined to treat Hepatoma 22 (H22) tumor-bearing mice, and its mechanism of ameliorating immunosuppression caused by CTX was studied. Methods: FNPS was isolated and purified. The molecular weight, functional groups, monosaccharide composition, and apparent morphology were characterized by gel permeation chromatography, Fourier transform infrared spectrometer, ion chromatography and scanning electron microscope, respectively. Through the analysis of tumor, immune organs, and serum cytokine levels of H22 tumor-bearing mice, the immunomodulatory effect and the protective effect on immunosuppressive mice induced by CTX was evaluated. And the immunomodulatory activity of FNPS was further verified by macrophage functional experiments. Results: FNPS was composed of rhamnose, arabinose, galactose, glucose, and mannose in a molar ratio of 0.008:0.017:0.018:0.908:0.048. Its molecular weight was 94 kDa. In vivo experiments showed that 200 mg mL^-1 FNPS could alleviate the suppression of immune organs and immune cells caused by CTX treatment, enhance the antitumor effect of CTX, increase the serum levels of Th1 immune-related pro-inflammatory cytokines (IL-1β and IL-6), and decrease Th2 immune-related anti-inflammatory cytokine (IL-10) and tumor-related pro-inflammatory cytokine (TNF-α) in the chemotherapy mice. Functional experiments revealed that 25 μg mL^-1 FNPS could promote phagocytosis and proliferation of macrophages. When the concentration reached 50 μg mL^-1, it enhanced the migration activity. Conclusion: FNPS has the potential to alleviate the immunosuppressive effect of CTX by activating immune cells and promoting inflammation. It could be used as a potential auxiliary medication for liver cancer treatment.