Preliminary characterization, antioxidant and α-glucosidase inhibitory activities of polysaccharides from Mallotus furetianus

Structural characterization of a α-d-glucan from Ginkgo biloba seeds and its protective effects on non-alcoholic fatty liver disease in mice

Nonalcoholic fatty liver disease (NAFLD) poses a great global challenge to public health, yet it holds promise for amelioration through plant-derived polysaccharide. Ginkgo biloba seeds have long been used as medicine and food, which has potential benefits for various chronic diseases. However, the protective role of Ginkgo biloba seed polysaccharide against NAFLD remains unclear. In this study, we isolated and purified polysaccharide (GBSP-2) from Ginkgo biloba seeds. GBSP-2 is composed of α-d-glucopyranose residues, which are interconnected with α-d-glucopyranose units linked by (1→4) bonds, (1→4,6) bonds and (1→3,4) bonds, the ratio distribution is 15:1:1. By studying a mouse model, we investigated the effect of GBSP-2 (100 or 200 mg/kg) on high-fat-diet-induced NAFLD. We demonstrated that GBSP-2 significantly alleviated NAFLD, as evidenced by reduced hepatic steatosis, decreased inflammation, improved oxidative stress and ameliorative glucolipid metabolic disorders. Furthermore, GBSP-2 mitigated gut microbiota disturbance of NAFLD mice and markedly increased the abundance of Akkermansia, Romboutsia, Lactobacillus and Bacteroides. Mechanistically, GBSP-2 could activate AMPK/ACC signaling pathway to inhibit lipid synthesis by generating 3,4-dihydroxyphenylpropionic acid (DHPPA). Overall, these findings suggest that GBSP-2 plays a multi-channel and multi-target role in improving NAFLD through the gut-liver axis.

Deep eutectic solvent extraction and biological activity of polysaccharides from Tenebrio molitor

This study aimed to extract polysaccharides from Tenebrio molitor using ultrasound-assisted deep eutectic solvent (DESs) and to evaluate their structural features, as well as their antimicrobial, antioxidant, and α-amylase inhibitory activities. Various DESs were tested for polysaccharides extraction, and the process was optimized using response surface methodology (RSM). A preliminary structural analysis of the polysaccharides was conducted using infrared spectrum. The DESs were characterized by measuring their pH, viscosity, conductivity, refractive index, and density. The optimal extraction agent and parameters were determined. Significant differences in pH, viscosity, and conductivity were observed among DESs, whereas differences in refractive index and density were not significant. Choline chloride-lactic acid was identified as the optimal extraction agent. The optimal extraction parameters were a DES molar ratio of 1:2.1, a water content of 27 %, an extraction temperature of 70 °C, and an extraction time of 44 min, resulting in polysaccharides yield of 18.62 %. The extracted polysaccharides exhibited strong inhibitory effects against Salmonella, along with antioxidant activity and α-amylase inhibitory activities. The study demonstrated that polysaccharides from Tenebrio molitor can be efficiently extracted using DESs, showcasing significant biological activities, including antibacterial, antioxidant, and α-amylase inhibitory properties. These findings highlight the potential applications of Tenebrio molitor polysaccharides as valuable biological resources.

Immunomodulatory activity of red algal galactans and their partially depolymerized derivatives in RAW264.7 macrophages

Funoran and furcellaran were isolated through a successive cascade extraction process, followed by the depolymerization of extracted polymers via an auto-hydrolysis process. The molecular weight and structural peculiarities of both native and partially depolymerized polysaccharides were investigated using size-exclusion chromatography (SEC), FTIR, and NMR spectroscopy. Immunotropic effects of the native and partially depolymerized polysaccharides were explored through various in vitro assays. Although both higher and lower molecular weight funoran exhibited anti-inflammatory activity on LPS-stimulated RAW264.7 cells by significantly downregulating iNOS and COX-2 gene expression, as well as the secretion of pro-inflammatory cytokines, native funoran performed slightly better. Conversely, higher molecular weight furcellaran remarkably activated RAW264.7 cells compared to the non-treated control by inducing inflammatory mediators and pro-inflammatory cytokines, including the anti-inflammatory cytokine IL-10. Lower molecular weight furcellaran was unable to activate the macrophages, showing a similar behavior pattern to funoran samples in LPS-treated cells. Furthermore, the TLR4/NF-κB signaling pathway appears to be modulated by sulfated polysaccharides, leading to both anti-inflammatory and immunostimulatory responses in RAW264.7 cells through blocking and activating mechanisms. These findings indicate that sulfated polysaccharides could be promising therapeutic agents, and indeed, the molecular weight of polysaccharides plays a crucial role in the immune response of RAW264.7 macrophages.

Structural characteristics and antioxidant activity of a low-molecular-weight jujube polysaccharide by ultrasound assisted metal-free Fenton reaction

This study used an ultrasonically accelerated metal-free Fenton (H2O2-Vc system) reaction to promote water-extracted degrading polysaccharides from Ziziphus Jujuba cv. Muzao (DZMP). A novel jujube polysaccharide (DPZMP3) was obtained by degradation using DEAE-Sepharose Fast Flow and Sephacryl S-100 column chromatography. Methylation analysis, HPGPC, ion chromatography, FT-IR, and NMR spectroscopies were used to clarify the chemical structures of DPZMP3. Monosaccharide compositional analysis of DPZMP3 revealed the presence of Rha, Ara, Gal, and GalA at a molar ratio of 1.00:1.49:1.60:7.68, and the HPGPC data demonstrated the average Mw of 34.3 kDa. Based on the structural and linkage research using NMR spectroscopy and GC-MS, it was determined that DPZMP3 was a homogalacturonan pectic polysaccharide with a (1 → 4)-Galp branch at C-6 and a small amount of Araf and Rhap residues. The ultrasonic-aided Fenton treatment did not significantly alter the structure of DPZMP3. It may also be useful for DZMP and enhancing their antioxidant activity in vitro. The current study's findings could pave the way for the food sector to use jujube polysaccharides obtained by degradation as a functional food component.

A review of in vitro antioxidant and antidiabetic polysaccharides: Extraction methods, physicochemical and structure-activity relationships

Nowadays, various plant polysaccharides have been successfully extracted which exhibited strong biological activities and might be useful for diabetes management. However, the effect of extraction methods, physicochemical and the structural-activity relationships of polysaccharides to exhibit antioxidants and antidiabetics were inadequate to explain their mechanism in action. The uses of advance extraction methods might be preferred to obtain higher antioxidants and antidiabetic activities of polysaccharides compared to conventional methods, but the determination of optimal extraction conditions might be crucial to preserve their structure and biological functions. Other than that, the physicochemical and structural properties of polysaccharides were closely related to their biological activities such as antioxidant and antidiabetic activities. Therefore, this review addressed the research gap of the influence of extraction methods, physicochemical and structural relationships of polysaccharides to biological activities, pointing out the challenges and limitations as well as future prospects to the current findings.

Ultrasound-assisted extraction and antioxidant activity of polysaccharides from Tenebrio molitor

Tenebrio molitor, which is rich in various nutrients, and its polysaccharides, as significant bioactive substances, exhibit strong antioxidant effects. This study utilized defatted T. molitor as raw material and employed an ultrasound-assisted extraction method. The factors considered include extraction temperature, time, ultrasound power, and liquid-to-feed ratio, with the yield of T. molitor polysaccharides as the response value. Based on single-factor experiments and response surface methodology, the optimal extraction parameters for T. molitor polysaccharides were determined. Following purification, protein removal, and dialysis to eliminate impurities, the structure of the extracted polysaccharides was preliminarily investigated using infrared spectroscopy. Their antioxidant activities were explored by measuring their DPPH·, OH·, and ABTS+· radical scavenging abilities and Fe3+ reducing power. The results indicated that the optimal conditions for ultrasound-assisted extraction were an extraction temperature of 75 °C, an extraction time of 150 min, an ultrasound power of 270 W, and a liquid-to-feed ratio of 15:1 mL/g, yielding a polysaccharide extraction rate of 9.513%. Infrared spectroscopy analysis revealed the presence of pyranose sugars with main functional groups including C-O, C=O, and O-H. Antioxidant activity tests showed that within a certain concentration range, the higher the polysaccharide concentration, the stronger its radical scavenging abilities. Compared with Vitamin C(Vc), the polysaccharides had stronger scavenging abilities for DPPH· and OH·, some scavenging ability for ABTS+·, and Fe3+ reduction ability, and corresponding to IC50 values of 0.9625, 9.1909, and 235.69 mg/mL respectively. The Fe3+ reducing power reached a maximum absorbance of 0.38899 at a concentration of 1.6 mg/mL. T. molitor polysaccharides demonstrate promising antioxidant activity and potential as functional ingredients in food, health products, and pharmaceuticals, providing new technical references for the development and utilization of T. molitor resources.

Physicochemical and processing properties and in vitro fecal fermentation characteristics of Prunus cerasifera Ehrhart polysaccharide

Prunus cerasifera Ehrhart fruit polysaccharide (PCP) was obtained after determining the optimal extraction conditions for complex enzyme-assisted hot buffer extraction based on single-factor experiments and response surface methodology, followed by characterization of its physicochemical, processing, rheological, and biological properties. PCP was a thermally stable carbohydrate with acidic functional groups and a molecular weight of 1398.69 kDa, exhibiting smooth, dense flake and honeycomb network microstructures. PCP had favorable hygroscopicity, moisturizing properties, water and oil-holding capacity, proemulsification capability, and in vitro antioxidant activity. The apparent viscosity of PCP in an aqueous system was dependent on concentration and temperature and was altered by the variety and amount of metal ions added; its aqueous solutions exhibited strong viscosity and hydrogel-forming tendencies at suitable concentrations, along with excellent hydrogel properties after gelation. Furthermore, PCP favored the growth of beneficial gut microbiota and associated microbes responsible for producing essential short-chain fatty acids. Overall, PCP displayed high potential as a multifunctional additive for applications in the food, pharmaceutical, and cosmetic industries.

A Neutral Polysaccharide from Medicago Sativa L.: Structural Properties and Hypoglycemic Activity In Vitro and In Vivo

Medicago sativa polysaccharides (MSPs) are beneficial compounds extracted from Medicago sativa L. that exhibit multiple medicinal activities. However, little is known about their hypoglycemic effects. In this study, MSP-II-a, a neutral polysaccharide with an Mw of 4.3×104 Da, was isolated and purified from M. sativa L. Monosaccharide composition analysis determined that MSP-II-a was composed of arabinose, glucose, galactose, mannose, rhamnose, and xylose in a molar ratio of 2.1 : 4.0 : 1.1:0.4 : 1.4 : 1.1. Structural characterization of MSP-II was performed using a combination of methylation analysis, Fourier transform infrared spectroscopy, and scanning electron microscopy. The results showed that MSP-II-a was mainly comprised of 1,4-p-Glc, 1,3,4-Rha, and 1,3-p-Gal glycosidic linkages, revealing a mesh-like texture with irregular blade shapes. In vitro assays demonstrated that MSP-II-a, at concentrations of 200 and 400 μg/mL, promoted glucose uptake in insulin-resistant 3T3-L1 adipocytes. In vivo studies have shown that MSP-II-a significantly alleviates insulin resistance by reducing fasting blood glucose levels and increasing hepatic glycogen synthesis in HFD/STZ-induced diabetic mice. These findings revealed that MSP-II-a is a promising source of bioactive polysaccharides with potential hypoglycemic activity.

Purification, characterization, and hypoglycemic activity of exopolysaccharides from Lactiplantibacillus plantarum MY04

As natural polymers, Lactiplantibacillus plantarum exopolysaccharides (EPS) possess a wide range of bioactivities but suffer from low yields and unclear relationships between functional activity and structure. To this end, the chemical structure and bioactive properties of EPS from Lactiplantibacillus plantarum MY04 were investigated. As a result, three polysaccharide fractions (EPS-1, EPS-2, EPS-3) were separated and purified, of which EPS-2 had better antioxidant activity and α-glucosidase inhibitory ability. More importantly, EPS-2 can significantly enhance insulin sensitivity in HepG2 cells by upregulating enzyme activities in the glycolytic pathway and mitigating oxidative stress-induced damage. In addition, the structural characterization of EPS-2 was also comprehensively elucidated. It was found that EPS-2 was mainly composed of mannose with a molecular weight of 2.3 × 106 Da, and its main chain structure is →3)-Manp-(1 → 2)-Manp-(1 → 2,6)-Manp-(1 → 2,6)-Manp-(1→, providing a theoretical basis for understanding the relationship between structure and function of polysaccharides.

Integrated transcriptomics and lipidomics reveals protective effect in vascular endothelial barrier of a polysaccharide from Typhae Pollen

Endothelial cell dysfunction caused by inflammation and even vascular leakage are important manifestations of blood stasis syndrome (BSS). Reversible regulation of vascular integrity to cure BSS has attracted considerable interest. Herein, a novel acidic polysaccharide (TPP-4) was purified and characterized from Typhae Pollen, a typical traditional Chinese medicine for treating BSS, especially for bleeding caused by blood stasis. A series of structural characterization methods, including spectroscopic methods (FT-IR and UV), chromatographic methods (HPGPC, HPAEC-PDA and GC-MS) and NMR, have been used to reveal the fine structure of TPP-4. TPP-4 was a homogeneous heteropolysaccharide comprised with RG-I backbone. TPP-4 showed fantastic activities in vascular integrity regulation both in vitro (HUVECs) and in vivo (zebrafish). Transcriptomics revealed that SOX7 and lipid metabolism were the potential targets. Lipidomics showed that TPP-4 could regulate lipid metabolism disorders caused by vascular inflammation, particularly affecting LPE levels. The above regulatory effects were furtherly demonstrated to be related with VEGFA/PI3K/mTOR signaling pathway through various molecular biological experiments.

A review: Polysaccharides targeting mitochondria to improve obesity

Polysaccharides are one of the most important and widely used bioactive components of natural products, which can be used to treat metabolic diseases. Natural polysaccharides (NPs) have been the subject of much study and research in the field of treating obesity in recent years. Studies in the past have demonstrated that mitochondria are important for the initiation, progression, and management of obesity. Additionally, NPs have the ability to improve mitochondrial dysfunction via a variety of mechanisms. This review summarized the relationship between the structure of NPs and their anti-obesity activity, focusing on the anti-obesity effects of these compounds at the mitochondrial level. We discussed the association between the structure and anti-obesity action of NPs, including molecular weight, monosaccharide composition, glycosidic linkage, conformation and extraction methods. Furthermore, NPs can demonstrate a range of functions in adipose tissue, including but not limited to improving the mitochondrial oxidative respiratory chain, inhibiting oxidative stress, and maintaining mitochondrial mass homeostasis. The purpose of this work is to acquire a thorough understanding of the function that mitochondria play in the anti-obesity effects of NPs and to offer fresh insights for the investigation of how NPs prevent obesity and the creation of natural anti-obesity medications.

Novel glucomannan-like polysaccharide from Lycium barbarum L. ameliorates renal fibrosis via blocking macrophage-to-myofibroblasts transition

The macrophage to myofibroblasts transition (MMT) has been reported as a newly key target in renal fibrosis. Lycium barbarum L. is a traditional Chinese medicine for improving renal function, in which its polysaccharides (LBPs) are the mainly active components. However, whether the role of LBPs in treating renal fibrosis is related to MMT process remain unclear. The purpose of this study was to explore the relationship between the regulating effect on MMT process and the anti-fibrotic effect of LBPs. Initially, small molecular weight LBPs fractions (LBP-S) were firstly isolated via Sephadex G-100 column. Then, the potent inhibitory effect of LBP-S on MMT process was revealed on bone marrow-derived macrophages (BMDM) model induced by TGF-β. Subsequently, the chemical structure of LBP-S was elucidated through monosaccharide, methylation and NMR spectrum analysis. In vivo biodistribution characteristics studies demonstrated that LBP-S exhibited effectively accumulation in kidney via intraperitoneal administration. Finally, LBP-S showed a satisfactory anti-renal fibrotic effect on unilateral ureteral obstruction operation (UUO) mice, which was significantly reduced following macrophage depletion. Overall, our findings indicated that LPB-S could alleviate renal fibrosis through regulating MMT process and providing new candidate agents for chronic kidney disease (CKD) related fibrosis treatment.

Preparation and characterization of carboxymethylated Anemarrhena asphodeloides polysaccharide and its effect on the gelatinization of wheat starch

In this study, a carboxymethylated Anemarrhena asphodeloides polysaccharide (CM-AARP) with an molecular weight (Mw) of 7.8 × 104 Da was obtained. CM-AARP was composed of four monosaccharides including d-mannose, d-glucose, d-galactose, and l-arabinose. Nuclear magnetic resonance (NMR) spectra revealed that the skeleton of CM-AARP was identical to that of AARP. Compared with AARP, CM-AARP had a superior inhibition effect on the gelatinization of wheat starch (WS) under the same condition. The addition of CM-AARP and AARP at 12 % enhanced the gelatinization temperature (60.47 ± 1.30 °C) of WS to 73.88 ± 0.49 °C and 69.75 ± 0.52 °C, respectively. CM-AARP could maintain the crystal structure of WS during gelatinization, the relative crystallinity with the 12 % CM-AARP addition was determined as 29.18 % ± 1.49 %, exceeding that of pure WS at 21.96 % ± 0.66 %. Moreover, CM-AARP influenced the rheological behavior of the gelatinized WS by reducing the viscosity and improving the fluidity. The results suggested that CM-AARP played an essential role in starch gelatinization and was a potential stabilizer in the starch-based food industry.

Ultrasonic-assisted extraction, analysis and properties of purple mangosteen scarfskin polysaccharide and its acetylated derivative

Purple mangosteen scarfskin polysaccharide has many important physiological functions, but its preparation method, structure, and function need further exploration. A polysaccharide was obtained from mangosteen scarfskin by ultrasonic-assisted extraction and purified. On this basis, its structure and physicochemical properties were investigated. The Congo red experiment was used to determine whether it has a triple helix conformation. The structure of purple mangosteen scarfskin polysaccharide was further analyzed by infrared spectroscopy and nuclear magnetic analysis. The antioxidant activities of the above three polysaccharides were studied by related experiments. It was found that the monosaccharide composition of purple mangosteen scarfskin polysaccharide mainly contained a large amount of arabinose, a small amount of rhamnoose and a very small amount of galacturonic acid, and its core main chain was composed of 1,4-α-arabinose. It did not have this spatial configuration. After the acetylation of purple mangosteen scarfskin polysaccharide, the acetylated derivative with a degree of substitution of 0.33 was obtained. It was found that they had certain scavenging and inhibiting effects on hydroxyl radicals and lipid peroxidation, and their activities were related to the concentration of polysaccharides. Meanwhile, the antioxidant activity of the polysaccharide was significantly enhanced after the modified treatment of acetylation, which indicated that chemical modification could effectively improve some activities of polysaccharide. The above studies provided some reference value for the further research and development of purple mangosteen scarfskin polysaccharide.

Hypoglycemic and hypolipidemic bioactive compounds from edible traditional Chinese medicines and their action of mechanisms explored by multitarget affinity ultrafiltration with liquid chromatography–mass spectrometry

Edible traditional Chinese medicines (TCMs) have a long‐standing history in tackling obesity, diabetes, and metabolic diseases, which, in turn, significantly promotes the exploration of functional food products derived from edible TCMs with lower toxicity and reduced side effects. However, most of bioactive components from TCMs and their mechanisms in regulating blood glucose and lipids remain elusive, which poses a challenge for the development of safer and more effective TCM products. In this context, the development of high‐throughput screening methods has become even more important for the identification of active components and the in‐depth evaluation of hypoglycemic and hypolipidemic activity in vitro and in vivo. Therefore, this work provides an overview of edible TCMs for managing glucose and lipid metabolism disorders and summarizes the most recent progresses in identifying hypoglycemic and hypolipidemic bioactive compounds in edible TCMs through various screening methods. One significant approach involves the utilization of multitarget‐based ultrafiltration liquid chromatography coupled with mass spectrometry. This technique enables the concurrent screening and identification of potential pharmacodynamically active components in TCMs, as well as the investigation of their mechanisms of action. The bioactive compounds identified may serve as crucial active agents in reducing blood glucose and lipids, exhibiting promising potential for incorporation into functional foods or natural health products.

Natural hypoglycaemic bioactives: Newer avenues and newer possibilities

The incidences of endocrine and metabolic disorders like diabetes have increased worldwide. Several proposed molecular pathways mechanisms for the management of diabetes have been identified, but glycaemic control is still a challenging task in the drug discovery process. Most of the drug discovery processes lead to numerous scaffolds that are prominent in natural products. The review deals with the natural bioactives as an α-amylase inhibitors, α-glucosidase inhibitors, protein tyrosine phosphatase-1B inhibitors, dipeptidyl peptidase-IV inhibitors, G-protein coupled receptors-40 agonists, PPAR-γ agonists and the activators of 5'-adenosine monophosphate-activated protein kinase and glucokinase. So, in this review, we focused on the hypoglycaemic bioactives, which will assist scientific developers, traditional medicinal practitioners, and readers to discover some potent antidiabetic molecules. Strategies like chemometric approaches, scaffold hopping, and total synthesis of natural products by group modification or ring opening/closing mechanism could be useful for the development of novel hit/lead antidiabetic molecules. The study concludes that each phyto molecule inherits a potential to get explored by repurposing techniques for various antidiabetic targets and offer an alternative antidiabetic therapeutic medicinal potential.

Pichia pastoris Mediated Digestion of Water-Soluble Polysaccharides from Cress Seed Mucilage Produces Potent Antidiabetic Oligosaccharides

Diabetes mellitus is a heterogeneous metabolic disorder that poses significant health and economic challenges across the globe. Polysaccharides, found abundantly in edible plants, hold promise for managing diabetes by reducing blood glucose levels (BGL) and insulin resistance. However, most of these polysaccharides cannot be digested or absorbed directly by the human body. Here we report the production of antidiabetic oligosaccharides from cress seed mucilage polysaccharides using yeast fermentation. The water-soluble polysaccharides extracted from cress seed mucilage were precipitated using 75% ethanol and fermented with Pichia pastoris for different time intervals. The digested saccharides were fractionated through gel permeation chromatography using a Bio Gel P-10 column. Structural analysis of the oligosaccharide fractions revealed the presence of galacturonic acid, rhamnose, glucuronic acid, glucose and arabinose. Oligosaccharide fractions exhibited the potential to inhibit α-amylase and α-glucosidase enzymes in a dose-dependent manner in vitro. The fraction DF73 exhibited strong inhibitory activity against α-amylase with IC50 values of 38.2 ± 1.12 µg/mL, compared to the positive control, acarbose, having an IC50 value of 29.18 ± 1.76 µg/mL. Similarly, DF72 and DF73 showed the highest inhibition of α-glucosidase, with IC50 values of 9.26 ± 2.68 and 50.47 ± 5.18 µg/mL, respectively. In in vivo assays in streptozotocin (STZ)-induced diabetic mice, these oligosaccharides significantly reduced BGL and improved lipid profiles compared to the reference drug metformin. Histopathological observations of mouse livers indicated the cytoprotective effects of these sugars. Taken together, our results suggest that oligosaccharides produced through microbial digestion of polysaccharides extracted from cress seed mucilage have the potential to reduce blood glucose levels, possibly through inhibition of carbohydrate-digesting enzymes and regulation of the various signaling pathways.

Breaking barriers: How modified citrus pectin inhibits galectin-8

Inhibition of galectin-3-mediated interactions by modified citrus pectin (MCP) could affect several rate-limiting steps in cancer metastasis, but the ability of MCP to antagonize galectin-8 function remains unknown. We hypothesized that MCP could bind to galectin-8 in addition to galectin-3. In this study, a combination of gradual ethanol precipitation and DEAE-Sepharose Fast Flow chromatography was used to isolate several fractions from MCP. The ability of these fractions to antagonize galectin-8 function was studied as well as the primary structure and initial structure-function relationship of the major active component MCP-30-3. The results showed that MCP-30-3 (168 kDa) was composed of Gal (13.8%), GalA (63.1%), GlcA (13.0%), and Glc (10.1%). MCP-30-3 could specifically bind to galectin-8, with an MIC value of 0.04 mg mL-1. After MCP-30-3 was hydrolyzed by β-galactosidase or pectinase, its binding activity was significantly reduced. These results provide new insights into the interaction between MCP structure and galectin function, as well as the potential utility in the development of functional foods.

Physicochemical Characterization, Antioxidant and Anticancer Activity Evaluation of an Acidic Polysaccharide from Alpinia officinarum Hance

AHP-3a, a triple-helix acidic polysaccharide isolated from Alpinia officinarum Hance, was evaluated for its anticancer and antioxidant activities. The physicochemical properties and structure of AHP-3a were investigated through gel permeation chromatography, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy. The weight-average molecular weight of AHP-3a was 484 kDa, with the molar percentages of GalA, Gal, Ara, Xyl, Rha, Glc, GlcA, and Fuc being 35.4%, 21.4%, 16.9%, 11.8%, 8.9%, 3.1%, 2.0%, and 0.5%, respectively. Based on the results of the monosaccharide composition analysis, methylation analysis, and NMR spectroscopy, the main chain of AHP-3a was presumed to consist of (1→4)-α-D-GalpA and (1→2)-α-L-Rhap residues, which is a pectic polysaccharide with homogalacturonan (HG) and rhamnogalacturonan-I (RG-I) structural domains containing side chains. In addition, the results of the antioxidant activity assay revealed that the ability of AHP-3a to scavenge DPPH, ABTS, and OH free radicals increased with an increase in its concentration. Moreover, according to the results from the EdU, wound healing, and Transwell assays, AHP-3a can control the proliferation, migration, and invasion of HepG2 and Huh7 hepatocellular carcinoma cells without causing any damage to healthy cells. Thus, AHP-3a may be a natural antioxidant and anticancer component.

Cassia Seed Gum Films Incorporated with Partridge Tea Extract as an Edible Antioxidant Food Packaging Film for Preservation of Chicken Jerky

The use of edible packaging films to delay food spoilage has attracted widespread attention. In this study, partridge tea extract (PTE) was added to cassia gum (CG) to prepare CG/PTE films. The microstructure, optical, mechanical, barrier, and antioxidant properties of CG/PTE films were investigated, and the effect of PTE on CG films was shown. The films had high transparency and smooth surface structure. Additionally, PTE significantly improved the elongation at break and antioxidant activity of films. At 2.5% of PTE, the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging rate of the film was 46.88% after diluting 50 times, indicating excellent antioxidant property, which could be applied to food preservation. After 9 days of storage, the thiobarbituric acid reactive substances values (TBARS) of chicken jerk packaged with films containing 0% and 2.5% PTE increased from 0.12% to 1.04% and 0.11% to 0.40%, respectively. This study suggests that CG/PTE films can be used to preserve cooked meat.

Lichen pectin-containing polysaccharide from Xanthoria elegans and its ability to effectively protect LX-2 cells from H2O2-induced oxidative damage

Xanthoria elegans, a drought-tolerant lichen, is the original plant of the traditional Chinese medicine "Shihua" and effectively treats a variety of liver diseases. However, thus far, the hepatoprotective effects of polysaccharides, the most important chemical constituents of X. elegans, have not been determined. The aim of this study was to screen the polysaccharide fraction for hepatoprotective activity by using free radical scavenging assays and a H2O2-induced Lieming Xu-2 cell (LX-2) oxidative damage model and to elucidate the chemical composition of the bioactive polysaccharide fraction. In the present study, three polysaccharide fractions (XEP-50, XEP-70 and XEP-90) were obtained from X. elegans by hot-water extraction, DEAE-cellulose anion exchange chromatography separation and ethanol gradient precipitation. Among the three polysaccharide fractions, XEP-70 exhibited the best antioxidant activity in free radical scavenging capacity and reducing power assays. Structural studies showed that XEP-70 was a pectin-containing heteropolysaccharide fraction that was composed mainly of (1 → 4)-linked and (1 → 4,6)-linked α-D-Glcp, (1 → 4)-linked α-D-GalpA, (1 → 2)-linked, (1 → 6)-linked and (1 → 2,6)-linked α-D-Manp, and (1 → 6)-linked and (1 → 2,6)-linked β-D-Galf. Furthermore, XEP-70 exhibited effectively protect LX-2 cells against H2O2-induced oxidative damage by enhancing cellular antioxidant capacity by activating the Nrf2/Keap1/ARE signaling pathway. Thus, XEP-70 has good potential to protect hepatic stellate cells against oxidative damage.

Microwave-assisted aqueous two-phase extraction of polysaccharides from Hippophae rhamnoide L.: Modeling, characterization and hypoglycemic activity

Natural polysaccharides are concerned for their high biological activity and low toxicity. Two kinds of polysaccharides were extracted from Hippophae rhamnoide L. by microwave-assisted aqueous two-phase system. Under the optimal conditions predicted by RSM model (K2HPO4/ethanol (18.93 %/28.29 %), liquid to material ratio 77 mL/g, power 625 W and temperature 61 °C), the yield of total polysaccharides reached 35.91 ± 0.76 %. Moreover, the polysaccharides extraction was well fitted to the Weibull model. After purification by Sepharose-6B, the polysaccharides from top phase (PHTP, purity of 81.44 ± 1.25 %) and bottom phase (PHBP, purity of 88.85 ± 1.40 %) were obtained. GC, FT-IR, methylation and NMR analyses confirmed the backbone of PHTP was composed of a repeated unit →4)-β-D-Glcp-(1 → 2)-α-L-Rhap-(1 → 4)-β-D-Galp-(1 → 4)-α-D-GalAp-(1 → 3)-α-L-Araf-(1 → 3)-α-D-Manp-(1→, while the repeated unit in PHBP was →3)-α-L-Araf-(1 → 2)-α-L-Rhap-(1 → 4)-β-D-Glcp-(1 → 3)-α-D-Manp-(1 → 4)-β-D-Galp-(1 → 4)-α-D-GalAp-(1→. Compared with PHTP (6.46 × 106 g/mol), PHBP with relatively low molecular weight (8.2 × 105 g/mol) exhibited the smaller particle size, better water-solubility, thermal and rheological property, stronger anti-glycosylation and α-amylase inhibitory effects. Moreover, PHTP and PHBP displayed a reversible inhibition on α-amylase in a competitive manner. This study provides a high-efficient and eco-friendly method for polysaccharides extraction, and lays a foundation for sea buckthorn polysaccharides as potential therapeutic agents in preventing and ameliorating diabetes.

Immune regulation and inflammation inhibition of Arctium lappa L. polysaccharides by TLR4/NF-κB signaling pathway in cells

Arctium lappa L. polysaccharides (ALP) are important active ingredients of burdocks with various bioactivities. In the present study, a crude polysaccharide was extracted from A. lappa L. roots and purified using DEAE-52 and Sephacryl™ S-400 columns to reach 99 % purity. This neutral polysaccharide contained fructose, glucose, galactose and arabinose in a ratio of 0.675:0.265:0.023:0.016 and had a Mw of 4256 Da. The immunomodulatory activity and intestinal inflammation inhibitory effects of ALP were investigated in in vitro models, including lipopolysaccharide-induced macrophage RAW264.7 and interleukin (IL)-1β-induced colon Caco-2 cells. The results revealed that ALP possessed both antioxidant and anti-inflammatory effects by decreasing nuclear factor-E2-related factor 2 mRNA expression and reactive oxygen species. Furthermore, ALP was found to have inhibitory effects on pro-inflammatory cytokines, including IL-8, IL-6, IL-1β, and tumor necrosis factor-α, as well as inflammatory cytokines, such as intercellular adhesion molecule-1, vascular cell adhesion molecule-1, and monocyte chemoattractant protein-1 by down-regulating the Toll-like receptor 4 (TLR4)/NF-κB (nuclear factor-kappa B signaling) pathway. It indicated that A. lappa L. was an ideal source of bioactive polysaccharides having potential to be developed as functional foods or nutraceuticals to improve immune system and prevent/treat intestinal inflammation.

A review on the hypoglycemic effect, mechanism and application development of natural dietary polysaccharides

Diabetes mellitus (DM) as one chronic metabolic disease was greatly increased over recent decades. The major agents treating diabetes have noticeable side effects as well as the tolerability problems. The bioactive dietary polysaccharides from abundant natural resources exhibit good hypoglycemic effect with rare adverse effects, which might serve as a candidate to prevent and treat diabetes. However, the correlations between the hypoglycemic mechanism of polysaccharides and their structure were not mentioned in several studies, what's more, most of the current hypoglycemic studies on polysaccharides were based on in vitro and in vivo experiments, and there was a lack of knowledge about the effects in human clinical trials. The aim of this review is to discuss recent literature about the variety of dietary polysaccharides with hypoglycemic activity, as well the mechanism of action and the structure-function relationship are highlighted. Meanwhile, the application of dietary polysaccharides in functional foods and clinical medicine are realized with an in-depth understanding. So as to promote the exploration of dietary polysaccharides in low glycemic healthy foods or clinical medicine to prevent and treat diabetes.

Optimization and Physicochemical Characterization of Polysaccharide Purified from Sonneratia caseolaris Mangrove Leaves: a Potential Antioxidant and Antibiofilm Agent

The Box-Behnken design was applied to determine the optimal parameters of the extraction condition by using the response surface methodology (RSM) from the leaves of Sonneratia caseolaris L. The result indicates the best-optimized conditions used for the extraction of polysaccharides at 84.02 °C temperature, 3.12 h time, and 27.31 mL/g for the water-to-material ratio. The maximum experimental yield of 8.81 ± 0.09% was obtained which is in agreement with the predicted value of 8.79%. Thereafter, low molecular weight polysaccharide (SCLP) was separated after sequentially being purified through column chromatography with a relative molecular weight of 3.74 kDa. The physicochemical properties were evaluated by characterization techniques such as FT-IR spectra, NMR spectrum, and SEM analysis. RP-HPLC analysis confirmed that SCLP was a heteropolysaccharide, majorly comprising rhamnose (28.25%), and xylose (27.17%) residues, followed by mannose (18.90%), and galactose (17.17%), respectively. Thermal analysis (TGA-DSC) results showed that SCLP is a highly thermostable polymer with a degradation temperature of 361.63 °C. X-ray diffraction patterns and tertiary structure analyses indicate that SCLP had a semi-crystalline polymer having a triple-helical configuration. Moreover, SCLP displayed potential antibiofilm ability for all the tested pathogens while stronger activity against Klebsiella pneumoniae and Pseudomonas aeruginosa. In addition, SCLP has potential in vitro antioxidant activity on DPPH, ABTS radical, superoxide, and Fe2+ chelating. These findings indicate that the polysaccharide has potentially been used in functional food, cosmetics, and pharmacological industries.

Chemical characterization, antioxidant and immunomodulatory activities of acetylated polysaccharides from Cyperus esculentus

This research was designed to characterize the structure of Cyperus esculentus polysaccharide (CEP) and its acetylated one (ACEP), and then investigated the effects of acetylation on the changes in physicochemical properties, thermal stability, antioxidant and immunomodulatory activities. Results showed that CEP and ACEP were heteropolysaccharides consisting of glucose, mannose, arabinose and xylose. The main chain of CEP included α-1,4-Glcp residues with the branching points at the O-6 position of the α-1,6-Manp residues. Acetyl groups were substituted at the O-2 and O-6 positions of some glucose residues. Meanwhile, the acetylation remarkably improved the polysaccharides thermal stability, and the ACEP exhibited a greater antioxidant activity. Furthermore, CEP and ACEP were proved to protect RAW 264.7 cells against LPS-induced inflammation by improving cellular morphology and decreasing reactive oxygen species secretion. This study may highlight a new approach for developing a high value-added ingredient from C. esculentus for functional food industry.

Structure characterization of novel heteropolysaccharides from Pteridium revolutum with antioxidant and antiglycated activities

This study aims to analysis the structures of polysaccharides isolated from Pteridium revolutum and their antioxidant and antiglycated activities. Three novel water-soluble heteropolysaccharides, named PRP0, PRP1, and PRP2, were isolated from P. revolutum. The average molecular weight was determined by high performance gel permeation chromatography analysis as 1.04 × 106, 8.39 × 105, and 7.37 × 105 Da, respectively. Their structures were characterized using physicochemical and spectroscopic methods. The antioxidant and antiglycated activities were assayed in vitro. PRP0, PRP1, and PRP2 consist of l-Ara, l-Rha, d-Man, d-Xyl, d-Fuc, d-Gal, and d-Glc in different proportions. PRP1 mainly has a backbone of (1 → 3,6)-linked d-Man and (1 → 3)-linked d-Gal on main chain. PRP2 is mainly composed of (1 → 2,4)-linked d-Man and (1 → 3)-linked d-Gal on main chain. All polysaccharides have strong scavenging power on 2,2-difenil-1-picril-hidrazil and hydroxyl radicals and significantly antiglycated activity in Bovine serum albumin-Glucose model, which showing that the polysaccharides have potential application value on the functional food.

UV/H2O2-Degraded Polysaccharides from Sargassum fusiforme: Purification, Structural Properties, and Anti-Inflammatory Activity

The main purpose of this study was to analyze the structural properties and anti-inflammatory activity of the purified fractions derived from UV/H2O2-degraded polysaccharides from Sargassum fusiforme. Results indicated that twofractions with different monosaccharide compositions and morphological characteristics, PT-0.25 (yield 39.5%) and PT-0.5 (yield 23.9%), were obtained. The average molecular weights of PT-0.25 and PT-0.5 were 14.52 kDa and 22.89 kDa, respectively. In addition, PT-0.5 exhibited better anti-inflammatory activity with a clear dose dependence. The mechanism was associated with the inhibition of LPS-activated Toll-like receptor 4-mediated inflammatory pathways in RAW264.7 cells. The results showed that PT-0.5 was a complex polysaccharide mainly composed of 4-Fucp, t-Manp, 6-Galp, t-Fucp, and 3,4-GlcAp. These results would provide theoretical support for studying the structural properties and biological activities of UV/H2O2-degraded polysaccharides.

Aroma Difference Analysis of Partridge Tea (Mallotus oblongifolius) with Different Drying Treatments Based on HS-SPME-GC-MS Technique

Partridge tea has high medicinal value due to its rich content of terpenoids, phenols, flavonoids, and other related bioactive components. In order to study the best drying method for partridge tea, four treatments, including outdoor sun drying (OD), indoor shade drying (ID), hot-air drying (HAD), and low-temperature freeze-drying (LTD), were performed. The results showed that the OD and HAD treatments favored the retention of the red color of their products, while the ID and LTD treatments were more favorable for the retention of the green color. The HS-SPME-GC-MS results showed that a total of 82 compounds were identified in the four drying treatments of partridge tea, and the most abundant compounds were terpenoids (88.34-89.92%). The HAD-treated tea had the highest terpenoid content (89.92%) and high levels of flavor compounds typical of partridge tea (52.28%). OPLS-DA and PCA showed that α-copaene, β-bourbonene, caryophyllene, α-guaiene, and δ-cadinene could be considered candidate marker compounds for judging the aroma quality of partridge tea with different drying treatments. This study will not only provide a basis for processing and flavor quality control but also for spice and seasoning product development in partridge tea.

Comparison in structural, physicochemical and functional properties of sweet potato stems and leaves polysaccharide conjugates from different technologies

In order to better understand the influences of extraction techniques on the yield, characteristics, and bioactivities of polysaccharide conjugates, hot reflux extraction (HRE), ultrasonic-assisted extraction (UAE), microwave-assisted extraction (MAE), complex enzymolysis extraction (CEE), ultra-high pressure extraction (UPE), ultrasonic complex enzymes extraction (UEE) were used to extract sweet potato stems leaves polysaccharide conjugates (SPSPCs), and their physicochemical characteristics, functional properties, antioxidant and hypoglycemic activities were compared. Results showed that compared with HRE conjugate (HR-SPSPC), the yield, content of uronic acid (UAC), total phenol (TPC), total flavonoid (TFC) and sulfate group (SGC), water solubility (WS), percentage of glucuronic acid (GlcA), galacuronic acid (GalA) and galactose (Gal), antioxidant and hypoglycemia activities of UEE polysaccharide conjugates (UE-SPSPC) significant increased, while its molecular weight (Mw), degree of esterification (DE), content of protein (PC) and percentage of glucose (Glc) declined, but monosaccharides and amino acid types, and glycosyl linkages were not much different. Indeed, UE-SPSPC possessed the highest antioxidant activities and hypolipidemic activities among six SPSPCs, which might be due to the high UAC, TPC, TFC, SGC, GlcA, GalA and WS, low Mw, DE and Glc of UE-SPSPC. The results reveal that UEE is an effective extraction and modification technology of polysaccharide conjugates.

Enhanced In Vitro Anti-Photoaging Effect of Degraded Seaweed Polysaccharides by UV/H2O2 Treatment

The high molecular weight and poor solubility of seaweed polysaccharides have limited their function and application. In this study, ultraviolet/hydrogen peroxide (UV/H2O2) treatment was used to prepare low-molecular-weight seaweed polysaccharides from Sargassum fusiforme. The effects of UV/H2O2 treatment on the physicochemical properties and anti-photoaging activity of S. fusiforme polysaccharides were studied. UV/H2O2 treatment effectively degraded polysaccharides from S. fusiforme (DSFPs), reducing their molecular weight from 271 kDa to 26 kDa after 2 h treatment. The treatment did not affect the functional groups in DSFPs but changed their molar percentage of monosaccharide composition and morphology. The effects of the treatment on the anti-photoaging function of S. fusiforme polysaccharides were investigated using human epidermal HaCaT cells in vitro. DFSPs significantly improved the cell viability and hydroxyproline secretion of UVB-irradiated HaCaT cells. In particular, DSFP-45 obtained from UV/H2O2 treatment for 45 min showed the best anti-photoaging effect. Moreover, DSFP-45 significantly increased the content and expression of collagen I and decreased those of pro-inflammatory cytokines, including interleukin-1β, interleukin-6, and tumor necrosis factor-α. Thus, UV/H2O2 treatment could effectively improve the anti-photoaging activity of S. fusiforme polysaccharides. These results provide some insights for developing novel and efficient anti-photoaging drugs or functional foods from seaweed polysaccharides.

Determining the potent immunostimulation potential arising from the heteropolysaccharide structure of a novel fucoidan, derived from Sargassum Zhangii

A preliminary study was conducted of the chemical, structural properties and immunomodulatory activities of fucoidan isolated from Sargassum Zhangii (SZ). Sargassum Zhangii fucoidan (SZF) was determined to have a sulfate content of 19.74 ± 0.01% (w/w) and an average molecular weight of 111.28 kDa. SZF possessed a backbone structure of (1,4)-α-d-linked-galactose, (3,4)-α-l-fucose, (1,3)-α-d-linked-xylose, β-d-linked-mannose and a terminal (1,4)-α-d-linked-glucose. The main monosaccharide composition was determined as (w/w) 36.10% galactose, 20.13% fucose, 8.86% xylose, 7.36% glucose, 5.62% mannose, and 18.07% uronic acids, respectively. An immunostimulatory assay showed that SZF, compared to commercial fucoidans (Undaria pitnnaifida and Fucus vesiculosus sources), significantly elevated nitric oxide production via up-regulation of cyclooxygenase-2 and inducible nitric oxide synthase at both gene and protein levels. These results suggest that SZ has the potential to be a source of fucoidan with enhanced properties that may act as a useful ingredient for functional foods, nutritional supplements, and immune enhancers.

Supramolecular structure of banana peel pectin and its transformations during extraction by acidic methods

In this study, the approaches to describe the mesh structure in the homogalacturonate domains of pectin and the effect of the native structure violations on the stabilization effectiveness of the oil-in-water emulsion were demonstrated. Pectin with a native structure was isolated from banana peel by enzymolysis of insoluble dietary fibres. This pectin was compared with pectins, which were isolated using hydrochloric and citric acids. The properties of pectins were analyzed taking into account the ratio of galacturonate units in nonsubstituted, methoxylated and calcium-pectate forms. The content of calcium-pectate units determines the density of inter-molecular crosslinking formation. The simulation results reflect the structure of rigid "egg-box" crosslinking blocks and flexible segments formed in native pectin mainly by methoxylated links. Hydrochloric acid extraction is accompanied by the destruction of the crosslinking blocks and depolymerization of pectin. Citric acid partially demineralizes the crosslinking blocks contributing to the release of macromolecular chains that do not have calcium-pectate units. The granulometric data indicates that the individual macromolecules take the thermodynamically stable form of a statistical tangle. Such conformation is an ideal basis for the formation of "host-guest" microcontainers having a hydrophilic shell and a hydrophobic core with an oil-soluble functional substance.

Structural characterization of Euglena gracilis polysaccharide and its in vitro hypoglycemic effects by alleviating insulin resistance

Diabetes mellitus, characterized by hyperglycemia and insulin resistance, is a disorder of the endocrine metabolic system which has emerged as a common chronic disease worldwide. Euglena gracilis polysaccharides have ideal development potential in the treatment of diabetes. However, their structure and bioactivity are largely unclear. A novel purified water-soluble polysaccharide (EGP-2A-2A) from E. gracilis with a molecular weight of 130.8 kDa consisted of xylose, rhamnose, galactose, fucose, glucose, arabinose, and glucosamine hydrochloride. The SEM image for EGP-2A-2A suggested a rough surface with the presence of globule-like protrusions. Methylation and NMR spectral analyses revealed that EGP-2A-2A was mainly composed of →6)-β-D-Galp-(1 → 2)-α-D-Glcp-(1 → 2)-α-L-Rhap-(1 → 3)-α-L-Araf-(1 → 6)-β-D-Galp-(1 → 3)-α-D-Araf-(1 → 3)-α-L-Rhap-(1 → 4)-β-D-Xylp-(1 → 6)-β-D-Galp-(1 → with complex branching structure. EGP-2A-2A significantly increased glucose consumption and glycogen content in IR-HeoG2 cells and modulates glucose metabolism disorders by regulating PI3K, AKT, and GLUT4 signaling pathways. EGP-2A-2A significantly suppressed TC, TG, and LDL-c levels, and enhanced that of HDL-c. EGP-2A-2A ameliorated abnormalities caused by disorders of glucose metabolism and the hypoglycemic activity of EGP-2A-2A may be mainly positively related to its high glucose content and the β-configuration in the main chain. These results suggested that EGP-2A-2A played an important role in alleviating disorders of glucose metabolism through insulin resistance and has the potential for development as a novel functional food with nutritional and health benefits.

The mechanism leading to color differences between purple-red and green partridge tea leaves

BACKGROUND

Partridge tea (Mallotus oblongifolius) is used as an important beverage and medical plant in Hainan province of China. Although some information about the morphology, cytology, and genetics of partridge tea has been reported in the literature, knowledge about this plant is still very limited. The leaves are the most important part for every tea plant, with a major role in nutrition and other functions. The leaves of different cultivars of partridge tea are different in colors and functions. The molecular mechanism of color formation of partridge tea leaf is still unclear. We reveal the molecular mechanism of the color difference between purple-red and green partridge tea leaves through metabolome and transcriptome analysis.

RESULTS

We identified 665 compounds in the two partridge tea cultivars through metabolome analysis. Among these compounds, the content of 324 differed between the two cultivars. We also annotated 50 042 unigenes in the two cultivars by transcriptome analysis; 9665 unigenes were expressed differently between the two cultivars. Using an integrated analysis of the metabolome and transcriptome data, we found that the compounds and genes involved in anthocyanin biosynthesis were up-regulated in the purple-red leaves, compared with the green leaves.

CONCLUSION

Our results showed that the anthocyanin biosynthesis pathway genes were up-regulated, which resulted in the up-regulation of the anthocyanin, making the leaf color purple-red. Our study reveals the molecular mechanism of the color difference between purple-red and green partridge tea, and lays a foundation for the genetic breeding of partridge tea genetic and the utilization of its volatile components. © 2022 Society of Chemical Industry.

Microwave-assisted enzymatic extraction brings a notably high yield of polysaccharides from mountain Zizania latifolia

Mountain Zizania latifolia is produced at scale in China, and the edible swollen culm is exported to many countries, but little attention has been paid to its functional components. In this work, microwave-assisted enzymatic extraction (MAEE) is used for the first time to extract polysaccharides from mountain Z. latifolia swollen culm (PMZL). MAEE conditions optimized by Box-Behnken design-response surface methodology were as follows: 2.4% cellulase, microwaving for 6.0 min at 607 W, with a liquid-to-solid ratio of 63:1 ml g^-1 . Under these conditions, a notably high yield of 60.43% ± 1.12% for PMZL was achieved, which was significantly higher (p < 0.01) than from plain-grown varieties. PMZL are naturally occurring sulfated polysaccharide-protein complexes containing 8.46% ± 0.18% proteins and 7.86% ± 0.73% sulfates. PMZL comprises mannose, glucosamine, rhamnose, glucose, galactose, and arabinose at molar ratios of 3.80:2.68:1.00:17.41:5.12:2.91, with a weight-average molecular weight of 1569,219 Da and a number-average molecular weight of 364,088 Da. The surface morphology of PMZL is composed of tightly packed oval particles, and this kind of promising polysaccharides preferentially scavenges reactive nitrogen species. PRACTICAL APPLICATION: Due to global warming, the land available for planting vegetables is likely to expand to higher areas, so greater attention should now be paid to mountain-grown vegetables. This study provides an efficient way to obtain novel polysaccharides from mountain Zizania latifolia using microwave-assisted enzymatic extraction with a remarkably high yield of 60.4%. This promising source of natural carbohydrates has potential uses in pharmaceutical, nutraceutical, functional foods, cosmetics, and functional materials industries.

Extraction optimization, structure features, and bioactivities of two polysaccharides from Corydalis decumbens

Two polysaccharides (CPS1 and CPW2) from Corydalis decumbens were obtained to develop insights into natural medical resources. Optimal extraction conditions of total sugars were researched using the method of response surface methodology, polysaccharides were purified using a combination of ethanol precipitation and anion-exchange chromatography, and structure features were analyzed by scanning electron microscopy, transmission electron microscopy, and Congo-red assay. The bioactivities were estimated in terms of antioxidant and anti-inflammatory effects. Total sugars were extracted with an experimental yield of 32.74% under optimum conditions. CPS1 and CPW2 were purified with yields of 12.01% and 8.23%, respectively. CPS1 was a unique polysaccharide with a molecular weight (Mw) of 360 kDa and consisted of glucose, galactose, mannose, and arabinose in a ratio of 4.9:2.0:1:1.9, and CPW2 was composed of glucose with the Mw of 550 kDa. CPS1 possessed a four-helix conformation, and CPW2 was identified as a linear molecule without branched and entangled chains. The mRNA expressions of TNF-α (71.80%), IL-1β (56.55%), IL-6 (43.98%), and COX-2 (91.88%) in LPS-stimulated RAW 264.7 cells were significantly inhibited by 75 μg/mL CPS1 (P < 0.0001), while CPW2 showed lower inhibitory effects than CPS1. Compared with CPW2, CPS1 showed stronger scavenging abilities for hydroxyl (EC50 = 520.46 μg/mL), ABTS (EC50 = 533.99 μg/mL), and superoxide (EC50 = 1512.06 μg/mL) radicals. CPS1 with four-helix conformation exhibited more outstanding bioactivities than CPW2 without entangled chains.

Anticancer and Antioxidant Activity of Water-Soluble Polysaccharides from Ganoderma aff. australe against Human Osteosarcoma Cells

Wild mushrooms have gained great importance for being a source of biologically active compounds. In this work, we evaluate the anticancer and antioxidant activity of a water-soluble crude polysaccharide extract isolated from the fruiting bodies of the Ganoderma aff. australe (GACP). This mushroom was collected in San Mateo (Boyacá, Colombia) and identified based on macroscopic and microscopic characterization. GACP was characterized by UV-Vis spectroscopy, Fourier-transform infrared spectroscopy, high-performance liquid chromatography-diode array detector, and nuclear magnetic resonance. The antiradical and antioxidant activity were evaluated by different methods and its anticancer activity was verified in the osteosarcoma MG-63 human cell line. Chemical and spectroscopic analysis indicated that GACP consisted of β-D-Glcp-(1→, →3)-β-D-Glcp-(1→ and α-D-Glcp-(1→ residues. The results of the biological activity showed that GACP exhibited high antioxidant activity in the different methods and models studied. Moreover, the results showed that GACP impaired cell viability (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay) and cell proliferation (clonogenic assay) in a dose-response manner on MG-63 cells. The findings of this work promote the use of mushroom-derived compounds as anticancer and antioxidant agents for potential use in the pharmaceutical and food industries.

Optimization of Extraction Process of Polysaccharides MAP-2 from Opuntia Milpa Alta by Response Surface Methodology and Evaluation of Its Potential as α-Glucosidase Inhibitor

The α-glucosidase inhibitors play an important role in blood glucose control in patients with type 2 diabetes. At present, the development of new α-glucosidase inhibitors is an urgent clinical need. Our previous studies have found that the polysaccharide MAP-2 in the cactus Opuntia Milpa Alta has significantly better activity than acarbose (one of the most widely used first-line α-glucosidase inhibitors in clinical practice), but its optimal extraction process parameters and inhibition kinetic characteristics are not clear, and whether it has the potential to become a new α-glucosidase inhibitors is also unclear. In this study, based on previous research, we used the combination of single factor experiments and the response surface method (RSM) to identify the optimal extraction conditions for MAP-2 as follows: solid-liquid ratio 1:4, extraction temperature 90 °C, extraction time 1 h. Under these conditions, the extraction yield of MAP-2 was 3.47 ± 0.062%. When the concentration of MAP-2 was 16 mg/mL, the inhibition rate of α-glucosidase was 91.13 ± 0.62%. In addition, the results of inhibition kinetics showed that the inhibition rate of MAP-2 on α-glucosidase was the highest at pH 7.4 for 30 min, and showed a good dose-effect relationship, which was a reversible competitive inhibition. Meanwhile, we also compared the activities of MAP-2 and acarbose on the side effects of acarbose related enzymes. Compared with acarbose, MAP-2 not only had a better activation effect on lactase, but also inhibited the activity of hyaluronidase, and the activation and inhibition rate were positively correlated with the concentration. However, under the same conditions, the effect of acarbose on hyaluronidase was opposite to that of MAP-2. At low concentration, acarbose had a certain activation effect on lactase, but gradually attained an inhibitory effect with the increase in concentration. In contrast, MAP-2 not only activates lactase activity, improves diarrhea, abdominal distension, and abdominal pain, but also inhibits hyaluronidase activity, to solve the side effects of allergic reactions, suggesting that MAP-2 has the potential to become a novel and effective inhibitor of α-glucosidase with fewer side effects.

Recent Updates on Phytoconstituent Alpha-Glucosidase Inhibitors: An Approach towards the Treatment of Type Two Diabetes

Diabetes is a common metabolic disorder marked by unusually high plasma glucose levels, which can lead to serious consequences such as retinopathy, diabetic neuropathy and cardiovascular disease. One of the most efficient ways to reduce postprandial hyperglycemia (PPHG) in diabetes mellitus, especially insulin-independent diabetes mellitus, is to lower the amount of glucose that is absorbed by inhibiting carbohydrate hydrolyzing enzymes in the digestive system, such as α-glucosidase and α-amylase. α-Glucosidase is a crucial enzyme that catalyzes the final stage of carbohydrate digestion. As a result, α-glucosidase inhibitors can slow D-glucose release from complex carbohydrates and delay glucose absorption, resulting in lower postprandial plasma glucose levels and control of PPHG. Many attempts have been made in recent years to uncover efficient α-glucosidase inhibitors from natural sources to build a physiologic functional diet or lead compound for diabetes treatment. Many phytoconstituent α-glucosidase inhibitors have been identified from plants, including alkaloids, flavonoids, anthocyanins, terpenoids, phenolic compounds, glycosides and others. The current review focuses on the most recent updates on different traditional/medicinal plant extracts and isolated compounds' biological activity that can help in the development of potent therapeutic medications with greater efficacy and safety for the treatment of type 2 diabetes or to avoid PPHG. For this purpose, we provide a summary of the latest scientific literature findings on plant extracts as well as plant-derived bioactive compounds as potential α-glucosidase inhibitors with hypoglycemic effects. Moreover, the review elucidates structural insights of the key drug target, α-glucosidase enzymes, and its interaction with different inhibitors.

Drying Kinetic Modeling and Assessment of Mineral Content, Antimicrobial Activity, and Potential α-Glucosidase Activity Inhibition of a Green Seaweed (Ulva spp.) Subjected to Different Drying Methods

The green algal genus Ulva grows widely on all continents and is used for several applications such as functional foods, cosmeceuticals, nutraceuticals, and pharmaceuticals due to its nutritional characteristics. However, to increase its shelf-life and retain its bioactive components, it is necessary to apply some conservation technology, such as drying. The aim of this work is to describe the drying kinetic behavior of the green seaweed Ulva spp. by applying three dehydration methods: convective drying (CD), vacuum drying (VD), and solar drying (SD) by mathematical modeling and determining the retention of mineral content by atomic absorption spectroscopy and the antimicrobial potential against four strains such as Staphylococcus aureus, Escherichia coli, Saccharomyces cerevisiae, and Penicillium sp. by measurement of inhibition zones and α-glucosidase activity inhibition, as reported by IC50 determination. A freeze-dried sample was used as the control. The equilibrium moisture values calculated using the Guggenheim-Anderson-de Boer model were 0.0108, 0.0108, and 0.0290 g water/g d.m., for CD, VD and SD, respectively. The Midilli and Kucuk model showed robustness to fit all the experimental data of drying kinetic modeling. Ulva spp. is an important source of potassium with a ratio of Na/K < 0.29. Inhibition halos were observed in all samples against S. cerevisiae and Penicillium sp. with higher values than fluconazole action. An inhibitory effect on α-glucosidase activity was observed in all samples, mainly in the freeze-dried sample. Finally, dried Ulva spp. is a rich source of macro- and microminerals with antimicrobial activity and is a potential α-glucosidase inhibitor. Thus, it can be considered as a potential functional ingredient for food manufacturing.