Carboxymethylation of a polysaccharide extracted from Ganoderma lucidum enhances its antioxidant activities in vitro

Polysaccharides from Artemisia argyi leaves: Environmentally friendly ultrasound-assisted extraction and antifatigue activities

Artemisia argyi leaf polysaccharide (AALPs) were prepared through ultrasound-assisted extraction (UAE), and their antifatigue activities were evaluated. Extraction was optimized using response surface methodology (RSM), which yielded the following optimal UAE conditions: ultrasonication power of 300 W, extraction temperature of 51 °C, liquid:solid ratio of 20 mL/g, and ultrasonication time of 47 mins. The above optimal conditions resulted in the maximum extraction rate of 10.49 %. Compared with hot water extraction (HWE), UAE supported higher yields and total sugar, uronic acid, and sulfate contents of AALPs. Meanwhile, AALP prepared through UAE (AALP-U) exhibited higher stability due to its smaller particle size and higher absolute value of zeta potential than AALP prepared through HWE (AALP-H). In addition, AALP-U demonstrated stronger antioxidant activity than AALP-H. In forced swimming tests on mice, AALP-U could significantly prolong swimming time with a dose-dependent effect, increase liver and muscle glycogen levels, and improve other biochemical indices, thus showing great potential for application in functional food.

Structural relationship of regioselectively-sulfonated botryosphaeran derivatives on activity against herpes simplex virus type 1

The bioactivities of sulfonated polysaccharides are frequently related to their substitution pattern. In this study, the regioselective sulfonation of an exocellular fungal (1→3)(1→6)-β-D-glucan (botryosphaeran) was performed by two different methods: mild sulfonation (MS) and via pivaloyl ester (PS), in order to study the influence of the sulfonation pattern on the antiviral activity of the respective derivatives. Two sulfonated derivatives with substitution degrees of 0.82 (MS) and 0.49 (PS) were obtained, with substitution patterns at positions C-6, and C-2/C-4 of the glucose units, respectively. All derivatives were chemically characterized and evaluated for antiviral activity against Herpes simplex virus type 1 (HSV-1) KOS strain, and dengue type 2 (DENV-2). The sample sulfonated at positions C-6 (MS) showed a remarkable antiviral effect on HSV-1 (IC50 of 5.38 μg mL1), while PS remained inactive. The investigation of the mode of action of sample MS pointed to the inhibition of HSV-1 adsorption to the host cells. Both samples were inactive towards the dengue virus strain. This study demonstrated that the presence of sulfate groups at the C-6 positions of botryosphaeran is the preferred substitution pattern that enables the antiviral activity towards HSV-1.

Ganoderma lucidum Polysaccharide Supplementation Significantly Activates T-Cell-Mediated Antitumor Immunity and Enhances Anti-PD-1 Immunotherapy Efficacy in Colorectal Cancer

Ganoderma lucidum polysaccharide (GLP) is a prebiotic with immunomodulatory effects. However, the therapeutic potential of GLP in tumor immunotherapy has not been fully explored, especially in T cell-mediated antitumor immunity. In this study, we found that GLP significantly inhibited tumor growth and activated antitumor immunity in colorectal cancer (CRC). In the spleens and tumor tissues, the proportion of cytotoxic CD8+T cells and Th1 helper cells increased, while immunosuppressive Tregs decreased. Additionally, microbiota dysbiosis was alleviated by GLP, and short-chain fatty acid production was increased. Meanwhile, GLP decreased the ratio of kynurenine and tryptophan (Kyn/Trp) in the serum, which contributed to antitumor immunity of T cells. More importantly, the combination of GLP and the immune checkpoint inhibitor anti-PD-1 monoclonal antibody further enhanced the efficacy of anti-PD-1 immunotherapy. Thus, GLP as a prebiotic has the potential to be used in tumor immunotherapy.

Study on fermentation preparation, physicochemical properties and biological activity of carboxymethylpachymaran with different degrees of substitution

BACKGROUND

Carboxymethylpachymaran (CMP) is created by carboxymethylating pachyman (PM), which increases its water solubility and enhances a number of biological activities. Traditional polysaccharides modified by carboxymethylation employ strong chemical techniques. Carboxymethylcellulose (CMC) has been used previously for liquid fermentation to carboxymethyl modify bacterial polysaccharides. This theory can be applied to fungal polysaccharides because Poria cocos has the ability to naturally utilize cellulose.

RESULTS

CMC with different degrees of substitution (DS) (0.7, 0.9 and 1.2) were added to P. cocos fermentation medium, and CMPs with different DS (0.38, 0.56 and 0.78, respectively) were prepared by liquid fermentation. The physical and chemical properties and biological activities of the CMPs were determined. Their structures were confirmed by Fourier transform infrared (FTIR) spectroscopy and monosaccharide composition. With the increase of DS, the viscosity and viscosity-average molecular weight of CMPs decreased, whereas polysaccharide content and water solubility increased, although the triple helix structure was not affected. The results of bioactivity assay showed that the higher the DS of CMPs, the higher the 2,2-diphenyl-1-picrylhydrazyl radical scavenging ability, and the stronger the bacterial inhibition ability.

CONCLUSION

The present study has developed a method for producing CMPs by P. cocos liquid fermentation. The results of the study confirm that enhancing the DS of CMP could effectively enhance its potential biological activity. The findings provide safe and reliable raw materials for creating CMP-related foods and encourage CMP application in the functional food industry. © 2024 Society of Chemical Industry.

Carboxymethylated Rhizoma alismatis polysaccharides reduces the risk of calcium oxalate stone formation by reducing cellular inflammation and oxidative stress

This study aims to elucidate the mechanism and potential of Rhizoma alismatis polysaccharides (RAPs) in preventing oxidative damage to human renal proximal tubule epithelial cells. The experimental approach involved incubating HK-2 cells with 100 nm calcium oxalate monohydrate for 24 h to establish a cellular injury model. Protection was provided by RAPs with varying carboxyl group contents: 3.57%, 7.79%, 10.84%, and 15.33%. The safeguarding effect of RAPs was evaluated by analyzing relevant cellular biochemical indicators. Findings demonstrate that RAPs exhibit notable antioxidative properties. They effectively diminish the release of reactive oxygen species, lactate dehydrogenase, and malondialdehyde, a lipid oxidation byproduct. Moreover, RAPs enhance superoxide dismutase activity and mitochondrial membrane potential while attenuating the permeability of the mitochondrial permeability transition pore. Additionally, RAPs significantly reduce levels of inflammatory factors, including NLRP3, TNF-α, IL-6, and NO. This reduction corresponds to the inhibition of overproduced pro-inflammatory mediator nitric oxide and the caspase 3 enzyme, leading to a reduction in cellular apoptosis. RAPs also display the ability to suppress the expression of the HK-2 cell surface adhesion molecule CD44. The observed results collectively underscore the substantial anti-inflammatory and anti-apoptotic potential of all four RAPs. Moreover, their capacity to modulate the expression of cell surface adhesion molecules highlights their potential in inhibiting the formation of kidney stones. Notably, RAP3, boasting the highest carboxyl group content, emerges as the most potent agent in this regard.

Therapeutic potential of the medicinal mushroom Ganoderma lucidum against Alzheimer's disease

Alzheimer's disease (AD) is a high-incidence neurodegenerative disorder, characterized by cognitive impairment, memory loss, and psychiatric abnormalities. Ganoderma lucidum is a famous medicinal fungus with a long history of dietary intake, containing various bioactive components, and have been documented to exhibit antioxidant, anti-inflammatory, anti-tumor, anti-aging, and immunomodulatory effects, among others. Recent studies have shown that G. lucidum and its components have promising therapeutic potential against AD from various aspects, which can delay the progression of AD, improve cognitive function and quality of life. The underlying mechanisms mainly include inhibiting tau hyperphosphorylation, inhibiting Aβ formation, affecting activated microglia, regulating NF-κB/MAPK signalling pathway, inhibiting neuronal apoptosis, modulating immune system, and inhibiting acetylcholinesterase, etc. This paper systematically reviewed the relevant studies on the therapeutic potential of G. lucidum and its active components for treatment of AD, key points related with the mechanism studies and clinical trials have been discussed, and further perspectives have been proposed. Totally, as a natural medicinal mushroom, G. lucidum has the potential to be developed as effective adjuvant for AD treatment owing to its therapeutic efficacy against multiple pathogenesis of AD. Further mechanical investigation and clinical trials can help unlock the complete potential of G. lucidum as a therapeutic option for AD.

Some new insights into the biological activities of carboxymethylated polysaccharides from Lasiodiplodia theobromae

BACKGROUND

Carboxymethylated Lasiodiplodan (LaEPS-C), Lasiodiplodia theobromae β-glucan exopolysaccharide derivative, has a well-known range of biological activities. Compared to LaEPS-C, its fractions, Linear (LLaEPS-C) and Branched (BLaEPS-C), have biological potentialities scarcely described in the literature. So, in this study, we investigate the immunomodulatory, antiviral, antiproliferative, and anticoagulant activities of LLaEPS-C and BLaEPS-C and compare them to the LaEPS-C.

METHODS

LaEPS was obtained from L. theobromae MMBJ. After carboxymethylation, LaEPS-C structural characteristics were confirmed by Elementary Composition Analysis by Energy Dispersive X-Ray Detector (EDS), Fourier Transform Infrared (FTIR), and Nuclear Magnetic Resonance (NMR). The immunomodulatory activity on cytokine secretion was evaluated in human monocyte-derived macrophage cultures. The antiviral activity was evaluated by Hep-2 cell viability in the presence or absence of hRSV (human respiratory syncytial virus). In vitro antiproliferative activity was tested by sulforhodamine B assay. The anticoagulant activity was determined by APTT (Activated Partial Thromboplastin Time) and PT (Prothrombin Time).

RESULTS

LaEPS-C showed low macrophage cell viability only at 100 µg/mL (52.84 ± 24.06, 48 h), and LLaEPS-C presented no effect. Conversely, BLaEPS-C showed cytotoxicity from 25 to 100 µg/mL (44.36 ± 20.16, 40.64 ± 25.55, 33.87 ± 25.16; 48 h). LaEPS-C and LLaEPS-C showed anti-inflammatory activity. LaEPS-C presented this at 100 µg/mL (36.75 ± 5.53, 48 h) for IL-10, and LLaEPS-C reduces TNF-α cytokine productions at 100 µg/mL (18.27 ± 5.80, 48 h). LLaEPS-C showed an anti-hRSV activity (0.7 µg/ml) plus a low cytotoxic activity for Hep-2 cells (1.4 µg/ml). LaEPS-C presented an antiproliferative activity for NCI-ADR/RES (GI50 65.3 µg/mL). A better PT was achieved for LLaEPS-C at 5.0 µg/mL (11.85 ± 0.87s).

CONCLUSIONS

These findings demonstrated that carboxymethylation effectively improves the biological potential of the LaEPS-C and their fractions. From those polysaccharides tested, LLaEPS provided the best results with low toxicity for anti-inflammatory, antiviral, and anticoagulant activities.

The Separation, Purification, Structure Identification, and Antioxidant Activity of Elaeagnus umbellata Polysaccharides

In order to investigate the antioxidant activity of Elaeagnus umbellata polysaccharides, the physicochemical characteristics of purified Elaeagnus umbellata polysaccharides (EUP, consisting of two fractions, EUP1 and EUP2) were investigated using UV spectrophotometry, high-performance liquid chromatography (HPLC), high-performance gel permeation chromatography (HPGPC), and Fourier transform infrared spectroscopy (FT-IR). This revealed that EUP1 and EUP2 were acidic polysaccharides with an average molecular weight (MW) of 63 and 38 kDa, respectively. EUP1 mainly consisted of L-rhamnose and D-galactose in a molar ratio of 2.05:1, and EUP2 consisted of D-mannose, L-rhamnose, D-galactose, and D-arabinose in a molar ratio of 2.06:1:2.78:1. Furthermore, EUP exhibited considerable antioxidant potential for scavenging hydroxyl, superoxide anion, DPPH, and ABTS radicals. Therefore, EUP can be developed as a potential antioxidant for the functional food or pharmaceutical field.

Carboxymethylated Rhizoma alismatis Polysaccharides Regulate Calcium Oxalate Crystals Growth and Reduce the Regulated Crystals' Cytotoxicity

OBJECTIVE

This study explored the effects of polysaccharides (RAPD) extracted from the traditional anti-stone Chinese medicine Rhizoma alismatis and their carboxymethylated derivatives (RAPs) on the crystal phase, morphology, and size of calcium oxalate (CaOx). It also determined the damaging ability of the regulated crystals on human renal tubular epithelial cells (HK-2).

METHODS

RAPD carboxymethylation with a carboxyl group (-COOH) content of 3.57% was carried out by the chloroacetic acid solvent method. The effects of -COOH content in RAPs and RAP concentration on the regulation of CaOx crystal growth were studied by controlling the variables. Cell experiments were conducted to explore the differences in the cytotoxicity of RAP-regulated crystals.

RESULTS

The -COOH contents of RAPD, RAP1, RAP2, and RAP3 were 3.57%, 7.79%, 10.84%, and 15.33%, respectively. RAPs can inhibit the growth of calcium oxalate monohydrate (COM) and induce the formation of calcium oxalate dihydrate (COD). When the -COOH content in RAPs was high, their ability to induce COD formation was enhanced. In the crystals induced by RAPs, a high COD content can lower the damage to cells. In particular, the cytotoxicity of the crystals induced by RAP3 was the lowest. When the concentration of RAP3 increased, the cytotoxicity gradually increased due to the reduced size of the formed COD crystals. An interaction was observed between RAPs and crystals, and the number of RAPs adsorbed in the crystals was positively correlated with the -COOH content in RAPs.

CONCLUSIONS

RAPs can reduce the damage of CaOx to HK-2 cells by regulating the crystallization of CaOx crystals and effectively reducing the risk of kidney stone formation. RAPs, especially RAP3 with a high carboxyl group content, has the potential to be developed as a novel green anti-stone drug.

Effects of degradation on the physicochemical and antioxidant properties of carboxymethyl pachymaran

Poria cocos (Schw.) Wolf is a well-known edible and medicinal fungus. The polysaccharide in the sclerotium of P. cocos was extracted and prepared into carboxymethyl pachymaran (CMP). Three different degradation treatments including high temperature (HT), high pressure (HP) and gamma irradiation (GI) were used to process CMP. The changes in physicochemical properties and antioxidant activities of CMP were then comparatively investigated. We found that the molecular weights of HT-CMP, HP-CMP, and GI-CMP decreased from 787.9 kDa to 429.8, 569.5 and 6.0 kDa, respectively. Degradation treatments had no effect on the main chains of →3-β-D-Glcp-(1 → while changed the branched sugar residues. The polysaccharide chains of CMP were depolymerized after high pressure and gamma irradiation treatments. The three degradation methods improved the stability of CMP solution while decreased the thermal stability of CMP. In addition, we found that the GI-CMP with lowest molecular weight had the best antioxidant activity. Our results suggest that gamma irradiation treatment could degrade CMP as functional foods with strong antioxidant activity.

Carboxymethylation modification, characterization of dandelion root polysaccharide and its effects on gel properties and microstructure of whey protein isolate

In the present study, a native polysaccharide (DP) with sugar content of 87.54 ± 2.01 % was isolated from dandelion roots. DP was chemically modified to obtain a carboxymethylated polysaccharide (CMDP) with DS of 0.42 ± 0.07. DP and CMDP were composed of the same six monosaccharides including mannose, rhamnose, galacturonic acid, glucose, galactose, and arabinose. The molecular weights of DP and CMDP were 108,200 and 69,800 Da, respectively. CMDP exhibited more stable thermal performance and better gelling properties than DP. The effects of DP and CMDP on the strength, water holding capacity (WHC), microstructure, and rheological properties of whey protein isolate (WPI) gels were investigated. Results showed that CMDP-WPI gels had higher strength and WHC than DP-WPI gels. With the addition of 1.5 % CMDP, WPI gel had a good three-dimensional network structure. The apparent viscosities, loss modulus (G"), and storage modulus (G') of WPI gels were increased with the polysaccharide addition, the influence of CMDP was remarkable compared to DP at the same concentration. These findings suggest that CMDP may be used as a functional ingredient in protein-containing food products.

Advances in Plant Polysaccharides as Antiaging Agents: Effects and Signaling Mechanisms

Aging refers to the gradual physiological changes that occur in an organism after reaching adulthood, resulting in senescence and a decline in biological functions, ultimately leading to death. Epidemiological evidence shows that aging is a driving factor in the developing of various diseases, including cardiovascular diseases, neurodegenerative diseases, immune system disorders, cancer, and chronic low-grade inflammation. Natural plant polysaccharides have emerged as crucial food components in delaying the aging process. Therefore, it is essential to continuously investigate plant polysaccharides as potential sources of new pharmaceuticals for aging. Modern pharmacological research indicates that plant polysaccharides can exert antiaging effects by scavenging free radicals, increasing telomerase activity, regulating apoptosis, enhancing immunity, inhibiting glycosylation, improving mitochondrial dysfunction regulating gene expression, activating autophagy, and modulating gut microbiota. Moreover, the antiaging activity of plant polysaccharides is mediated by one or more signaling pathways, including IIS, mTOR, Nrf2, NF-κB, Sirtuin, p53, MAPK, and UPR signaling pathways. This review summarizes the antiaging properties of plant polysaccharides and signaling pathways participating in the polysaccharide-regulating aging process. Finally, we discuss the structure-activity relationships of antiaging polysaccharides.

Ultrasound-assisted extraction and properties of polysaccharide from Ginkgo biloba leaves

Response surface methodology (RSM) was used to optimize the ultrasound-assisted extraction conditions of Ginkgo biloba leaves polysaccharide (GBLP). The optimum extraction conditions for the ultrasound-assisted extraction of GBLP were obtained as liquid to material ratio of 30 mL/g, ultrasonic power of 340 W, and extraction time of 50 min. Under these conditions, the yield of GBLP was 5.37 %. Two chemically modified polysaccharides, CM-GBLP and Ac-GBLP, were obtained by carboxymethylation and acetylation of GBLP. The physicochemical properties of these three polysaccharides were comparatively studied and their in vitro antioxidant activities were evaluated comprehensively. The results showed that the solubility of the chemically modified polysaccharides was significantly enhanced and the in vitro antioxidant activity was somewhat improved. This suggests that carboxymethylation and acetylation are effective methods to enhance polysaccharide properties, but the results exhibited some uncontrollability. At the same time, GBLP has also shown high potential for research and application.

Effects of Carboxymethyl Modification on the Acidic Polysaccharides from Calocybe indica: Physicochemical Properties, Antioxidant, Antitumor and Anticoagulant Activities

An acidic polysaccharide fraction was obtained from Calocybe indica (CIP3a) after subjecting it to hot water extraction followed by purification through DEAE-cellulose 52 and Sepaharose 6B column chromatography. The CIP3a was further modified using chloroacetic acid to yield carboxymethylated derivatives (CMCIP3a). The modified polysaccharide was characterized using various spectroscopic methods. In addition, further antioxidant, antitumor and anticoagulant activities were also investigated. The polysaccharides CIP3a and CMCIP3a were heterogeneous in nature and composed of various molar percentages of glucose, arabinose and mannose with molecular weights of 1.456 × 10³ and 4.023 × 10³ Da, respectively. The NMR and FT-IR data demonstrated that the carboxymethylation on the polysaccharide was successful. In comparison to CIP3a polysaccharides, the modified derivatives had lower sugar and protein contents, and higher levels of uronic acid. The in vitro antioxidant activity showed that CMCIP3a with higher molecular weight displayed an elevated ability in scavenging the DPPH radical, ABTS, superoxide, hydroxyl radical, ferric reducing power, cupric reducing power and erythrocyte hemolysis inhibition with an EC₅₀ value of 2.49, 2.66, 4.10, 1.60, 3.48, 1.41 and 2.30 mg/mL, respectively. The MTT assay results revealed that CMCIP3a displayed a dose-dependent inhibition on five cancer cells (HT29, PC3, HeLa, Jurkat and HepG-2) in the range of 10-320 μg/mL. The APTT, PT and TT were significantly extended by CMCIP3a in relation to dosage, indicating that the anticoagulant effect of CIP was both extrinsic and intrinsic, along with a common coagulation pathway. These findings demonstrated that carboxymethylation might effectively improve the biological potential of the derivatives and offer a theoretical framework for the creation of novel natural antioxidants, low-toxicity antitumor and antithrombotic drugs.

Effects of Wet Processing on Physicochemical and Functional Characteristics of Millet Flour

In recent times, millet emerged as a gluten-free alternative cereal with a rich nutritional profile. However, the nutritional value is hindered by antinutritional factors, like tannin and phytic acid, present in the grain. In the current work, wet pre-processing methods, namely steeping, fermentation, germination, and a combination of germination-fermentation were studied for their effect on these antinutritional factors along with other functional and chemical properties of millet flour. Starch hydrolysation due to these wet pre-treatments was found to improve various aspects of the functional properties of millet flour. Steeping and fermentation resulted in increased protein and fat fraction in the treated flour with better water absorption capacity and hygroscopicity. At the same time, germination improved the protein and fibre content with better water solubility and oil absorption capacity. The aqueous environment during these pre-treatments was also found to reduce gelatinisation temperature and content of antinutritional factors in the treated flour samples. The present study indicated that wet pre-processing could be a good value addition to millet flour preparation with better functional and nutritional properties.

Carboxymethylation of Desmodium styracifolium Polysaccharide and Its Repair Effect on Damaged HK-2 Cells

Objective

Desmodium styracifolium is the best traditional medicine for treating kidney calculi in China. This study is aimed at increasing the carboxyl (-COOH) content of D. styracifolium polysaccharide (DSP0) and further increasing its antistone activity.

Methods

DSP0 was carboxymethylated with chloroacetic acid at varying degrees. Then, oxalate-damaged HK-2 cells were repaired with modified polysaccharide, and the changes in biochemical indices before and after repair were detected.

Results

Three modified polysaccharides with 7.45% (CDSP1), 12.2% (CDSP2), and 17.7% (CDSP3) -COOH are obtained. Compared with DSP0 (-COOH content = 1.17%), CDSPs have stronger antioxidant activity in vitro and can improve the vitality of damaged HK-2 cells. CDSPs repair the cell morphology and cytoskeleton, increase the cell healing ability, reduce reactive oxygen species and nitric oxide levels, increase mitochondrial membrane potential, limit autophagy level to a low level, reduce the eversion of phosphatidylserine in the cell membrane, weaken the inhibition of oxalate on DNA synthesis, restore cell cycle to normal state, promote cell proliferation, and reduce apoptosis/necrosis.

Conclusion

The carboxymethylation modification of DSP0 can improve its antioxidant activity and enhance its ability to repair damaged HK-2 cells. Among them, CDSP2 with medium -COOH content has the highest activity of repairing cells, whereas CDSP3 with the highest -COOH content has the highest antioxidant activity. This difference may be related to the active environment of polysaccharide and conformation of the polysaccharide and cell signal pathway. This result suggests that Desmodium styracifolium polysaccharide with increased -COOH content may have improved potential treatment and prevention of kidney calculi.

Anticancer effects of carboxymethylated (1→3)(1→6)-β-D-glucan (botryosphaeran) on multicellular tumor spheroids of MCF-7 cells as a model of breast cancer

Breast cancer is the most common cancer worldwide among the female population. The fungal exopolysaccharide botryosphaeran is a (1→3)(1→6)-β-D-glucan with limited solubility in water that can be promoted through carboxymethylation. Thus, the aim of this study was to examine in-vitro anticancer effects of carboxymethylated-botryosphaeran (CM-BOT) on breast cancer MCF-7 cells cultivated in multicellular tumor spheroids (MCTS). CM-BOT (≥ 600 µ/ml) decreased the viability (resazurin assay) of MCF-7 grown in monolayers after 24 hr incubation. Although CM-BOT did not markedly alter viability of MCTS in the resazurin assay after 24, 48 or 72 hr, CM-BOT ≥ 600 µg/ml produced cell-death by apoptosis after 72 hr utilizing the triple staining assay and labeling dead cells with propidium iodide, which can also be visualized on the architecture of MCTS. CM-BOT (1000 µg/ml) inhibited cell proliferation, which resulted in MCTSs with smaller diameters than controls. CM-BOT at all concentrations examined decreased the ability of MCF-7 to form colonies and to migrate in the extracellular matrix. This is the first report using MCTS-architecture to study anti-tumor effects of β-glucans. Our findings are important in the search for compounds for use in breast cancer therapy, or as adjuvants in reducing the adverse effects of mammary tumor chemotherapy.

Preparation, characterization and immunoregulatory activity of derivatives of polysaccharide from Atractylodes lancea (Thunb.) DC

A polysaccharide (ALP-1) extracted from Atractylodes lancea (Thunb.) DC. was carboxymethylated (C-ALP-1), phosphorylated (P-ALP-1) and acetylated (A-ALP-1) to improve its physicochemical properties and bioactivities. The solubility of all derivatives was increased, and the solubility of A-ALP-1 increased to 137.5 mg/mL, which was much higher than the solubility of ALP-1 (15.0 mg/mL). The results of HPSEC-MALLS-RID showed that the molecular weight of polysaccharides was slightly increased after the modification, and the root mean square radius of rotation (Rz) and morphology of polysaccharides in solution were also changed. The scanning electron microscopy (SEM) and X-ray diffraction (XRD) results confirmed that the surface morphology of ALP-1 changed dramatically and the crystallinity decreased after structural modification. From thermal analysis results, the T₅₀ of ALP-1, C-ALP-1, P-ALP-1 and A-ALP-1 were 281.34, 292.14, 333.75 and 298.70 °C, which showed that derivatives had stronger thermal stability than ALP-1. The immunomodulatory activity studies displayed that P-ALP-1 showed the best ability to stimulate RAW264.7 macrophages to release NO, and A-ALP-1 showed the best capacity to stimulate TNF-α and IL-6 releasing. These results indicated that chemical modification could enhance the solubility, the thermal stability and immunomodulatory activity of polysaccharides, which is beneficial for the development and utilization of natural polysaccharides.

Purification, characterization, and determination of biological activities of water-soluble polysaccharides from Mahonia bealei

Mahonia bealei is one of the important members of the genus Mahonia and Traditional Chinese Medicine (TCM). Several compounds isolated from this plant have exhibited useful biological activities. Polysaccharides, an important biomacromolecule have been underexplored in case of M. bealei. In this study, hot water extraction and ethanol precipitation were used for the extraction of polysaccharides from the stem of M. bealei, and then extract was purified using ultrafiltration membrane at 50,000 Da cut off value. Characterization of the purified M. bealei polysaccharide (MBP) was performed using Fourier Transform Infrared Spectroscopy (FT-IR), along with Scanning Electron Microscopy (SEM), X-ray crystallography XRD analysis and Thermal gravimetric analysis (TGA). The purified polysaccharide MBP was tested for antioxidant potential by determining its reducing power, besides determining the DPPH, ABTS, superoxide radical, and hydroxyl radical scavenging along with ferrous ion chelating activities. An increased antioxidant activity of the polysaccharide was reported with increase in concentration (0.5 to 5 mg/ml) for all the parameters. Antimicrobial potential was determined against gram positive and gram-negative bacteria. 20 µg/ml MBP was found appropriate with 12 h incubation period against Escherichia coli and Bacillus subtilis bacteria. We conclude that polysaccharides from M. bealei possess potential ability of biological importance; however, more studies are required for elucidation of their structure and useful activities.

β-Glucan-Functionalized Mesoporous Silica Nanoparticles for Smart Control of Fungicide Release and Translocation in Plants

In this work, an enzyme-responsive nanovehicle for improving captan (CAP) contact fungicide bioactivity and translocation in plant tissues was synthesized (CAP-MSNs-β-glucan) by attaching β-glucan to the outer surface of mesoporous silica nanoparticles. CAP-MSNs-β-glucan properties were tested by FTIR, ζ-potential, DLS, XRD, TGA, FE-SEM, and HR-TEM. Cargo protection ability of CAP-MSNs-β-glucan from photolysis and hydrolysis was examined in comparison to CAP commercial formulation (CAP-CF). CAP-MSNs-β-glucan distribution in plant tissues, bioactivity against Fusarium graminearum, and biotoxicity toward zebrafish (Danio rerio) were tested and compared with that of CAP-CF. CAP-MSNs-β-glucan results showed good loading efficacy reaching 18.39% and enzymatic-release dependency up to 83.8% of the total cargo after 20 days of β-glucan unsealing. CAP-MSNs-β-glucan showed significant release protection under pH changes. MSNs-β-glucan showed excellent CAP protection from UV. CAP-MSNs-β-glucan showed better distribution in corn tissues and 1.28 more inhibiting potency to Fusarium graminearum than CAP-CF. CAP-MSNs-β-glucan showed 1.88 times lower toxicity than CAP-CF to zebrafish after 96 h of treatment. We recommend using such formulations to overcome shortcomings of contact fungicides and achieve better and sustainable farming.

The effect of carboxymethylation on the macromolecular conformation of the (1 → 3)-β -D-glucan of curdlan in water

The chain conformational change in curdlan during carboxymethylation was investigated using nuclear magnetic resonance (NMR), circular dichroism (CD) spectroscopy, and atomic force microscopy (AFM). The distributions of carboxymethyl substituents within anhydroglucose unit (AGU) of CMCD were found to follow the order of OH (6) > OH (4) > OH (2) for CMCD with a low DS and OH (6) > OH (2) > OH (4) for CMCD with relatively high DS. The increased carboxymethylation level induced the chain conformation transition of curdlan from triple helix to random coil in water. The DS of 0.25 was the critical value of chain conformation transition, below which CMCD chains were triple helices. For DS larger than 0.25, CMCD existed in the state of random coils. The intermolecular hydrogen bonding between C2 hydroxyls in AGU sustained the triple helical conformation and stiffness of the polymer chain, which weakened with the increase in DS.

Sulfonated and Carboxymethylated β-Glucan Derivatives with Inhibitory Activity against Herpes and Dengue Viruses

The infection of mammalian cells by enveloped viruses is triggered by the interaction of viral envelope glycoproteins with the glycosaminoglycan, heparan sulfate. By mimicking this carbohydrate, some anionic polysaccharides can block this interaction and inhibit viral entry and infection. As heparan sulfate carries both carboxyl and sulfate groups, this work focused on the derivatization of a (1→3)(1→6)-β-D-glucan, botryosphaeran, with these negatively-charged groups in an attempt to improve its antiviral activity. Carboxyl and sulfonate groups were introduced by carboxymethylation and sulfonylation reactions, respectively. Three derivatives with the same degree of carboxymethylation (0.9) and different degrees of sulfonation (0.1; 0.2; 0.4) were obtained. All derivatives were chemically characterized and evaluated for their antiviral activity against herpes (HSV-1, strains KOS and AR) and dengue (DENV-2) viruses. Carboxymethylated botryosphaeran did not inhibit the viruses, while all sulfonated-carboxymethylated derivatives were able to inhibit HSV-1. DENV-2 was inhibited only by one of these derivatives with an intermediate degree of sulfonation (0.2), demonstrating that the dengue virus is more resistant to anionic β-D-glucans than the Herpes simplex virus. By comparison with a previous study on the antiviral activity of sulfonated botryosphaerans, we conclude that the presence of carboxymethyl groups might have a detrimental effect on antiviral activity.

Preparation and antioxidant activity of phosphorylated polysaccharide from purple sweet potato

Purple sweet potato polysaccharide was extracted via hot water, and it was chemically modified by phosphorus oxychloride-pyridine to obtain phosphorylated polysaccharide from purple sweet potato (P-PPSP) with certain degrees of substitution. Furthermore, the structure and antioxidant activity in vitro of PPSP and phosphorylated derivative were compared. The result indicated that the phosphorylation modification product of polysaccharide from purple sweet potato could improve the scavenging effect on hydroxyl radical and superoxide anion of PPSP, significantly. It also could improve the anti-lipid peroxidation ability while fail to improve the reducing ability of PPSP.

Health-Promoting of Polysaccharides Extracted from Ganoderma lucidum

Medicinal mushrooms are rich sources of pharmacologically active compounds. One of the mushrooms commonly used in traditional Chinese medicine is Ganoderma lucidum (Leyss. Ex Fr.) Karst. In Asian countries it is treated as a nutraceutical, whose regular consumption provides vitality and improves health. Ganoderma lucidum is an important source of biologically active compounds. The pharmacologically active fraction of polysaccharides has antioxidant, immunomodulatory, antineurodegenerative and antidiabetic activities. In this review, we summarize the activity of Ganoderma lucidum polysaccharides (GLP).

Preparation Optimization, Characterization, and Antioxidant and Prebiotic Activities of Carboxymethylated Polysaccharides from Jujube

In this study, jujube polysaccharides (JP) were extracted from Jinsixiaozao, and carboxymethylated jujube polysaccharides (CMJP) were prepared. The optimum carboxymethylation conditions optimized by Response Surface Methodology (RSM) were as follows: the reaction temperature was 60°C, the concentration of sodium hydroxide (NaOH) solution was 2.8 mol/L, and the content of chloroacetic acid was 2.12% with a degree of substitution (DS) of 0.2275 ± 0.0108. Physicochemical characterizations and in vitro antioxidant and prebiotic activities of JP and CMJP were evaluated. Compared with unmodified JP, water solubility and viscosity were improved in CMJP. Chemical analysis revealed that CMJP was composed of Rha: Ara: Xyl: Glc: Gal = 0.18 : 9.09 : 0.45 : 0.36 : 0.98 with a molecular weight of 3.04 × 105 Da. The signals of carboxymethyl were observed at 1600, 1420, and 1328 cm−1 in FT-IR. In addition, CMJP showed obviously strong hydroxyl radical scavenging ability compared with JP and also exhibited stronger abilities than JP on the proliferation growth of Lactobacillus acidophilus, Lactobacillus plantarum, and Lactobacillus rhamnosus strains. These results indicated that CMJP could be explored as a promising resource for the development of functional foods.

Carboxymethylation of Corn Silk Polysaccharide and Its Inhibition on Adhesion of Nanocalcium Oxalate Crystals to Damaged Renal Epithelial Cells

The purpose of this study was to explore the repair effect of carboxymethyl-modified corn silk polysaccharide (CSP) on oxidatively damaged renal epithelial cells and the difference in adhesion between cells and calcium oxalate crystals. The CSP was degraded and modified through carboxymethylation. An oxidatively damaged cell model was constructed by oxalate damage to human kidney proximal tubular epithelial (HK-2) cells. Then, the damaged cells were repaired by modified polysaccharides, and the changes in biochemical indexes and adhesion ability between cells and crystals before and after repair were detected. Four modified polysaccharides with carboxyl group (-COOH) contents of 3.92% (CSP0), 7.75% (CCSP1), 12.90% (CCSP2), and 16.38% (CCSP3) were obtained. Compared with CSP0, CCSPs had stronger antioxidant activity, could repair damaged HK-2 cells, and could reduce phosphorylated serine eversion on the cell membrane, the expression of osteopontin (OPN) and Annexin A1, and crystal adhesion. However, its effect on the expression of hyaluronic acid synthase was not substantial. The carboxymethyl modification of the CSP can improve its ability to repair cells and inhibit crystal adhesion and aggregation. A high carboxymethylation degree results in strong polysaccharide activity. CCSPs are expected to reduce the risk of kidney stone formation and recurrence.

Biological activity of aqueous extracts of Southern Brazilian mushrooms

This study aims to perform a bioactive analysis of five mushrooms collected in south of Brazil. The total phenol content of the extracts was equivalent to the antioxidant activity by ACAP assay. All extracts were able to inhibit the growth of Acinetobacter baumanni, and Auricularia auricula and Lactarius deliciosus extract showed the best antibacterial activity. In addition, no extract showed cytotoxic activity against VERO cells at the highest concentration evaluated (2500 µg/mL). Our results showed better antioxidant activity through the inhibition of the oxidation via peroxyl radical. It can be observed that all extracts were active against A. baumanni, and even moderately, all extracts could be inhibited of at least one of the bacteria used in the study. Added for these, the aqueous extracts showed no toxicity in VERO cells, highlighting the importance of research about the active compounds of mushrooms of the region.

Inhibition of Calcium Oxalate Formation and Antioxidant Activity of Carboxymethylated Poria cocos Polysaccharides

Three carboxymethylated Poria cocos polysaccharides (PCP-C1, PCP-C2, and PCP-C3) with -COOH contents of 6.13%, 10.24%, and 16.22%, respectively, were obtained by carboxymethylation of the original polysaccharide (PCP-C0), which has a molecular weight of 4 kDa and a carboxyl (-COOH) content of 2.54%. The structure of the PCP-Cs was characterized by FT-IR, ¹H NMR, and ¹³C NMR spectra. The four PCP-Cs exhibited antioxidant activity, and their ability to scavenge radicals (hydroxyl and DPPH) and chelate ferrous ions was positively correlated with the degree of carboxymethylation. As the content of -COOH groups in the PCP-Cs increases, their ability to regulate the growth of calcium oxalate (CaOx) crystals was enhanced, thus inhibiting the growth of calcium oxalate monohydrate (COM) crystals and inducing the formation of more calcium oxalate dihydrate (COD) crystals. The formed CaOx crystal was more round and blunt, the absolute value of the Zeta potential on the crystal surface increased, and the aggregation between crystals was inhibited. Thermogravimetric analysis curves showed that the proportions of PCP-C0, PCP-C1, PCP-C2, and PCP-C3 incorporated into the crystal were 20.52%, 15.60%, 10.65%, and 9.78%, respectively, in the presence of 0.4 g/L PCP-Cs. PCP-C protection resisted oxidative damages of human kidney proximal tubular epithelial cells (HK-2) caused by oxalate, resulting in increased cell viability and superoxide dismutase activity and decreased reactive oxygen species levels, malondialdehyde content, and 8-hydroxy-deoxyguanosine expression. Hence, PCP-Cs, especially PCP-C3, can inhibit the formation of CaOx crystals and may have the potential to be an alternative antistone drug.

Research Note: Effects of polysaccharide-enriched Acanthopanax senticosus extract on growth performance, immune function, antioxidation, and ileal microbial populations in broiler chickens

Acanthopanax senticosus (AS) is a well-known, highly effective traditional Chinese herbal medicine. Polysaccharides extracted from AS (ASPS) have multiple pharmacologic and biological activities with potential use as additives in broiler chicken feed. This trial evaluated the effects of dietary ASPS on growth performance, immune function, antioxidation, and ileal microbial populations in broiler chickens. A total of 240 1-day-old Arbor Acres male broiler chicks were randomly divided into 4 groups, with 10 replicates of 6 chicks and fed a corn- and soybean-based diet supplemented with 0, 1, 2, or 4 g/kg ASPS. Compared with the control group, supplementation with 1 g/kg ASPS increased ADG and ADFI in the finisher and overall periods and decreased the feed conversion ratio in the finisher period (both P < 0.05). Serum IgA and IgM were significantly increased by supplementation with 1 and 2 g/kg of ASPS (P < 0.05). Superoxide dismutase and glutathione peroxidase activities were increased and malondialdehyde concentration was decreased in birds fed ASPS-supplemented diets compared with those in the control group (P < 0.05). Polysaccharides extracted from AS supplementation increased Lactobacillus and decreased Escherichia coli and Salmonella counts in the ileal contents compared with the control diet (both P < 0.05). The results show that dietary ASPS improved growth performance, immune status, and antioxidant capacity and stimulated the growth of beneficial gut bacteria in broiler chickens. In conclusion, ASPS was effective as a natural additive in broiler chicken feed; 1 g/kg can be considered as the optimum dosage.

Insight into anti-oxidative carbohydrate polymers from medicinal plants: Structure-activity relationships, mechanism of actions and interactions with bovine serum albumin

Recently, research associated with natural anti-oxidants leads to the chemical characterization of many compounds possessing strong anti-oxidant activity. Among these anti-oxidants, naturally occurring carbohydrate polymers containing pectic arabinogalactans esterified with phenolic acids in monomeric and dimeric forms are noteworthy. The presence of highly branched arabinogalactan type II side chains and sugar linked phenolic acid residues have been resolved as important parameters. The anti-oxidant activity of these compounds depend on their ability to convert free radicals into stable by-products and themselves oxidized to more stable and less reactive resonance stabilized radicals. Moreover, these carbohydrate polymers form water soluble stable complexes with protein. Such findings support their applications in a diversity of fields including food industry and pharmacy. This review highlights experimental evidences supporting that the carbohydrate polymers containing phenolic polysaccharides may become promising drug candidate for the prevention of aging and age related diseases.

Carboxymethylation of polysaccharides: Synthesis and bioactivities

Polysaccharides are a structurally diverse class of biomolecules with a wide variety of bioactivities. Natural polysaccharides isolated from plants and fungi are used as raw materials in food and pharmaceutical industries due to their therapeutic properties, non-toxicity, and negligible side effects, but many natural polysaccharides possess low bioactivities when compared to synthetic medicines due to their structure and physicochemical properties. Literature studies revealed that carboxymethylation of polysaccharides enhances the bioactivities and water solubility of native polysaccharides significantly, and provide structural diversity and even the addition of new bioactivities. This review article mainly focuses on the recent research on carboxymethylation of polysaccharides including preparation, characterization, and bioactivities. This article also throws light on future directions and scope to develop new carboxymethylated polysaccharide derivatives for many industries such as food processing, cosmetics, nutraceuticals, and pharmaceutical industry.

Molecular α-relaxation process of exopolysaccharides extracted from Nostoc commune cyanobacteria

Broadband dielectric spectroscopy was used to investigate the molecular α-relaxation of the exopolysaccharides (EPS) extracted from Nostoc commune cyanobacteria. The EPS were modified in different ways. EPS were carboxymethylated to obtain carboxymethyl-exopolysaccharides (CEPS). EPS and CEPS were doped with ammonium iodide and 1-butyl-3-methylimidazolium chloride. An α relaxation process was observed for all specimens. The temperature dependence of the relaxation times for pure and doped, EPS and CEPS polymers exhibited non-Arrhenius behavior. This relaxation process was associated with the glass transition of the complex heteropolysaccharides produced by the cyanobacteria. The molecular mobility at the glass transition, T_g, was affected by both the carboxymethylation treatment and the doping. The fragility index also decreased for the doped specimens, which may be attributed to an increase in the mobility of the polymer chains due to the plasticizing effect of the doping agents.

Covalent attachment of laccase to carboxymethyl-botryosphaeran in aqueous solution for the construction of a voltammetric biosensor to quantify quercetin

Laccase from Botryosphaeria rhodina MAMB-05 was covalently immobilized on carboxymethyl-botryosphaeran by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide (EDC/NHS) in aqueous solution. This approach was employed to fabricate a novel laccase-based biosensor to electrochemically quantify quercetin (QCT), using a simple carbon black paste electrode as a transducer. The proposed biosensor was characterized by electrochemical impedance spectroscopy and Nyquist plots were used to evaluate the immobilization of the enzyme. For determining QCT, variables were optimized, that included experimental conditions for laccase immobilization, pH of the supporting electrolyte, and instrumental parameters of the electroanalytical technique. From square-wave-voltammograms, a linear dependence between the cathodic current peak and QCT concentration was observed within the range 4.98-50.0 × 10^-8 mol L^-1, with a theoretical detection limit of 2.6 × 10^-8 mol L^-1. The proposed method was successfully applied to determine QCT in beverages, pharmaceuticals, and biological samples. The proposed biosensor device presented good selectivity in the presence of uric acid, various inorganic ions, as well as other phenolic compounds, demonstrating the potential application of this biosensing platform in chemically complex solutions. Operational and analytical stability of the laccase-biosensor were evaluated, and good intra-day (SD = 1.23%) and inter-day (SD = 2.32%) repeatability, and long storage stability (SD = 3.47%) are presented.