Extraction, purification and structural characterization of polysaccharides from Apocynum venetum L. roots with anti-inflammatory activity

Structural characterization and hypoglycemic effect of polysaccharides of Polygonatum sibiricum

Polygonatum sibiricum polysaccharide (PSP) was extracted and purified from raw material obtained from P. sibiricum. The structural features of PSP were investigated by Congo red, circular dichroism spectrum, high-performance gel permeation chromatography, scanning electron microscope, atomic force microscope, ultraviolet spectroscopy, and Fourier transform infrared spectroscopy analysis. In vitro simulations were conducted to investigate the kinetics of PSP enzyme inhibition. Moreover, a type II diabetes mouse model (T2DM) with streptozotocin-induced insulin resistance was established, and the indexes of lipid quadruple, insulin resistance index, oral glucose tolerance (OGTT), organ index, and pancreatic morphology of model mice were measured. The results showed that PSP mainly consists of monosaccharides, such as mannose, glucose, galactose, xylose, and arabinose. It also has a β-glycosidic bond of a pyranose ring and an irregular reticulated aggregated structure with a triple helix. In vitro enzyme inhibition assays revealed that PSP acts as a reversible competitive inhibitor of α-glucosidase and α-amylase. Furthermore, PSP was found to reduce insulin resistance index, increase OGTT and serum insulin levels, decrease free fatty acid content to improve lipid metabolism, and lower glycated serum protein content to enhance glucose metabolism in T2DM mice, thereby leading to a reduction in blood glucose concentration. Additionally, PSP exhibited reparative effects on the damaged liver tissue cells and pancreatic tissue in T2DM mice. The experiment results provide a preliminary basis for the therapeutic mechanism of PSP about type II diabetes and a theoretical reference for application in food and pharmaceutical development.

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.

Research progress in the preparation, structural characterization, and biological activities of polysaccharides from traditional Chinese medicine

Traditional Chinese medicines are tremendous sources of polysaccharides, which are of great interest in the human welfare system as natural medicines, food, and cosmetics. This review aims to highlight the recent trends in extraction (conventional and non-conventional), purification and analytic techniques of traditional Chinese medicine polysaccharides (TCMPs), and the chemical structure, biological activities (anti-tumor, hypoglycemic, antioxidant, intestinal flora regulation, immunomodulatory, anti-inflammatory, anti-aging, hypolipidemic, hepatoprotective, and other activities), and the underlying mechanisms of polysaccharides extracted from 76 diverse traditional Chinese medicines were compared and discussed. With this wide coverage, a total of 164 scientific articles were searched from the database including Google Scholar, PubMed, Web of Science, and China Knowledge Network. This comprehensive survey from previous reports indicates that TCMPs are non-toxic, highly biocompatible, and good biodegradability. Besides, this review highlights that TCMPs may be excellent functional factors and effective therapeutic drugs. Finally, the current problems and future research advances of TCMPs are also introduced. New valuable insights for the future researches regarding TCMPs are also proposed in the fields of therapeutic agents and functional foods.

Skin healthcare protection with antioxidant and anti-melanogenesis activity of polysaccharide purification from Bletilla striata

In this study, we investigated the structural characterization and biological activities of Bletilla striata polysaccharides (BSPs) for their role as antioxidants and anti-melanogenesis agents in skin healthcare protection. Three neutral polysaccharides (BSP-1, BSP-2, and BSP-3) with molecular weights of 269.121 kDa, 57.389 kDa, and 28.153 kDa were extracted and purified. Their structural characteristics were analyzed by ion chromatography, GC-MS, and 1D/2D NMR. The results showed that BSP-1, which constitutes the major part of BSPs, was composed of α-D-Glcp, β-D-Glcp, β-D-Manp, and 2-O-acetyl-β-D-Manp, with the branched-chain accompanied by β-D-Galp and α-D-Glcp. BSP-1, BSP-2, and BSP-3 can enhance the total antioxidant capacity of skin fibroblasts with non-toxicity. Meanwhile, BSP-1, BSP-2, and BSP-3 could significantly inhibit the proliferative activity of melanoma cells. Among them, BSP-1 and BSP-2 showed more significance in anti-melanogenesis, tyrosinase inhibition activity, and cell migration inhibition. BSPs have effective antioxidant capacity and anti-melanogenesis effects, which should be further emphasized and developed as skin protection components.

Apocynum venetum, a medicinal, economical and ecological plant: a review update

Apocynum venetum L. is an important medicinal perennial rhizome plant with good ecological and economic value. Its leaves have many pharmacological effects such as anti-inflammatory, anti-depression, anti-anxiolytic, etc., while its fibers have the title of "king of wild fibers". Furthermore, it was suitable for the restoration of degraded saline soil in arid areas. An increasing studies have been published in the past years. A scientometric analysis was used to analyze the publications of Apocynum venetum L. to clearly review the pharmacology, fiber application of Apocynum venetum L. and the potential value with its similar species (Apocynum pictum Schrenk) to the environment.

Effects of Sparassis latifolia neutral polysaccharide on immune activity via TLR4-mediated MyD88-dependent and independent signaling pathways in RAW264.7 macrophages

Background

Sparassis latifolia (S. latifolia) is a precious edible fungus with multiple biological activities. To date, no study has been investigated the underlying molecular mechanism of immunoregulation caused by the neutral polysaccharide of S. latifolia.

Materials and methods

To investigate immunomodulatory mechanism of S. latifolia neutral polysaccharide (SLNP), SLNP was obtained from S. latifolia and its structure, immune receptors and regulation mechanism were studied.

Results

S. latifolia neutral polysaccharide consisted of arabinose, galactose, glucose, xylose, and mannose with a molar ratio of 6:12:63:10:5. SLNP was a pyran polysaccharide with a relative molecular weight of 3.2 × 105 Da. SLNP promoted the proliferation of RAW264.7, which further induced the secretions of nitric oxide, TNF-α, IL-6, and IFN-β, and upregulated the immune receptor TLR4 expression. Moreover, SLNP increased remarkably the levels of TRAF6, IRF3, JNK, ERK, p38, and p38 mRNA and protein mediated by TLR4.

Conclusion

S. latifolia neutral polysaccharide regulated the immune function of RAW264.7 through MyD88-dependent and -independent signaling pathways mediated by TLR4 receptor, which suggests that SLNP is a new immunomodulator.