Characterization of a novel alkali-soluble heteropolysaccharide from tetraploid Gynostemma pentaphyllum Makino and its potential anti-inflammatory and antioxidant properties

Structural characterization, molecular dynamic simulation, and conformational visualization of a water-soluble glucan with high molecular weight from Gastrodia elata Blume

Polysaccharides have been widely used in the development of natural drugs and health food. However, polysaccharide characterization lags due to inherently complicated features and the limitations of existing detection approaches. We aimed to provide new insight into the fine structure and conformational visualization of polysaccharides from Gastrodia elata Blume, a medicinal and edible plant. A water-soluble polysaccharide (GEP2-6) with the high molecular weight of 2.7 × 106 Da was first obtained, and its purity reached 99.2 %. Chemical and spectroscopic analyses jointly revealed that GEP2-6 was a glucan linked by α-(1 → 4) and α-(1 → 6) glycosidic bonds. After enzymolysis, the local structure of GEP2-6 included α-1,4-Glcp, α-1,6-Glcp, α-1,4,6-Glcp, and α-1-Glcp at a molar ratio of 31.27∶1.32∶1.08∶0.93. The glycosidic linkage pattern of repeating units was further simulated by a glycan database and spatial examination software. The good dissolution performance was interpreted by dynamics simulation and practical molecular characteristics. Spherical flexible chains and the porous stable conformation were corroborated using atomic force microscopy. In addition, GEP2-6 could effectively scavenge DPPH and hydroxyl radicals as a promising natural antioxidant. These efforts will contribute to the expansion of clinical applications of this G. elata polysaccharide and the structural elucidation for macromolecular polysaccharides combined with traditional and modern analysis techniques.

Structural characterization of chia seed polysaccharides and evaluation of its immunomodulatory and antioxidant activities

This study aims to extract an active heteropolysaccharide Chia seed polysaccharide (CSP-A) and further purified by DEAE Sepharose Fast Flow and Sepharose CL-6B chromatographic column, characterize its structure, and evaluate its antioxidant and immunomodulatory activities. Structural analysis revealed that CSP-A was composed of d-mannose, d-glucuronic acid and d-xylose in a molar ratio of 1:3:4 with molecular weight of 1.688 × 105 Da, owning 4 sugar residues of β-d-Manp-(1→, →4)-α-d-GlcpA-(1→, →2,4)-β-d-Xylp-(1→, and → 4)-β-d-Manp-(1 →. Congo red assay and microscopic characteristics showed that CSP-A in its solution may possess a helical conformation. In vitro experiments showed that CSP-A had moderate DPPH· and OH· scavenging activities. CSP-A also enhanced the phagocytosis ability of RAW 264.7 cells and prompted the release of NO, TNF-α, IL-6 and IL-1β from RAW 264.7 cells, which indicated CSP-A had immune regulation effect. This experiment provides scientific basis for further utilization and development of chia seeds, a kind of functional food.

Structural Characterization of Polysaccharides in Waste Liquor Produced by Wet Decortication of Sesame Seeds

The wet decortication of sesame seeds produces wastewater containing diverse minerals and organic pollutants that could be valuable resources for the food industry. This investigation aimed to reclaim, purify, and characterize the polysaccharides contained in the waste liquor from the sesame decortication industry. The purified polysaccharide fractions were characterized using monosaccharide analysis, GPC (high-performance gel permeation chromatography), FT-IR (Fourier-transform infrared) spectroscopy, methylation analysis, 1D and 2D Nucleai Magnetic Resonance (NMR) analysis, and thermal analysis. Four fractions were found (SSP-1,-2,-3, -4), of which SSP-2 was proportionately the largest and most interesting. The backbone of SSP-2 is mainly composed of (1→2,4)-β-_D-Xylp residues with side chains connected to the O-4 position, with many T-β-_D-Galp and (1→5)-α-_L-Araf residues, and fewer (1→4)-α-_D-Glcp, (1→2)-α-_L-Rhap, T-α-_L-Araf, and (1→2)-β-_D-GlcpA residues. An efficient method for removing the polysaccharides would simplify wastewater treatment while finding a use for them would benefit the sesame, food, and pharmaceutical industries.

Preparation, chemical structure, and immunostimulatory activity of a water-soluble heteropolysaccharide from Suillus granulatus fruiting bodies

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A water-soluble heteropolysaccharide (SGP2-1) was purified from Suillus granulatus.

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SGP2-1with Mw of 150.75 kDa had the (1 → 4)-α-Glcp backbone structure.

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SGP2-1 could be recognized by toll-like receptor 2 in RAW 264.7 macrophages.

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SGP2-1 enhanced pinocytic capacity and promoted ROS, NO, and cytokine production.

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SGP2-1 exerted immunoregulatory activity through MAPKs, PI3K/Akt and NF-κB pathways.

A water-soluble heteropolysaccharide (SGP2-1) was purified from Suillus granulatus fruiting bodies by anion-exchange chromatography and gel permeation chromatography. The structural characteristics were analyzed by high-performance gel permeation chromatography, high-performance liquid chromatography, Fourier transform infrared spectroscopy, gas chromatography-mass spectrometry, and nuclear magnetic resonance spectroscopy. The immunostimulatory activity was investigated using RAW 264.7 macrophages. Results showed that SGP2-1 with weight average molecular weight of 150.75 kDa was composed of mannose, glucose, and xylose. The backbone of SGP2-1 was mainly composed of → 4)-α-Glcp-(1→, and the terminal group α-d-Glcp → was linked to the main chain by O-6 position. SGP2-1 could significantly enhance pinocytic capacity, reactive oxygen species production, and cytokines secretion. SGP2-1 exerted immunomodulatory effects through interacting with toll-like receptor 2, and activating mitogen-activated protein kinase, phosphatidylinositol-3-kinase/protein kinase B, and nuclear factor-kappa B signaling pathways. These findings indicated that SGP2-1 could be explored as a potential immunomodulatory agent for application in functional foods.

Purification, Physicochemical Properties, and Antioxidant Activities of Two Low-Molecular-Weight Polysaccharides from Ganoderma leucocontextum Fruiting Bodies

Two low-molecular-weight polysaccharides (GLP-1 and GLP-2) were purified from Ganoderma leucocontextum fruiting bodies, and their physicochemical properties and antioxidant activities were investigated and compared in this study. The results showed that GLP-1 and GLP-2 were mainly composed of mannose, glucose, galactose, xylose, and arabinose, with weight-average molecular weights of 6.31 and 14.07 kDa, respectively. Additionally, GLP-1 and GLP-2 had a similar chain conformation, crystal structure, and molecular surface morphology. Moreover, GLP-1 exhibited stronger antioxidant activities than GLP-2 in five different assays: 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), hydroxyl radical, superoxide anion radical, ferric reducing antioxidant power (FRAP), and oxygen radical antioxidant capacity (ORAC). The main linkage types of GLP-1 were found to be →4)-α-D-Glcp-(1→, →4)-β-D-Glcp-(1→, →3)-β-D-Glcp-(1→, →6)-β-D-Galp-(1→, →6)-α-D-Glcp-(1→, →4,6)-α-D-Glcp-(1→, and Glcp-(1→ by methylation analysis and nuclear magnetic resonance (NMR) spectroscopy. In addition, GLP-1 could protect NIH3T3 cells against tert-butyl hydroperoxide (tBHP)-induced oxidative damage by increasing catalase (CAT) and glutathione peroxidase (GSH-Px) activities, elevating the glutathione/oxidized glutathione (GSH/GSSG) ratio, and decreasing the malondialdehyde (MDA) level. These findings indicated that GLP-1 could be explored as a potential antioxidant agent for application in functional foods.

Advances in Research on the Bioactivity of Alginate Oligosaccharides

Alginate is a natural polysaccharide present in various marine brown seaweeds. Alginate oligosaccharide (AOS) is a degradation product of alginate, which has received increasing attention due to its low molecular weight and promising biological activity. The wide-ranging biological activity of AOS is closely related to the diversity of their structures. AOS with a specific structure and distinct applications can be obtained by different methods of alginate degradation. This review focuses on recent advances in the biological activity of alginate and its derivatives, including their anti-tumor, anti-oxidative, immunoregulatory, anti-inflammatory, neuroprotective, antibacterial, hypolipidemic, antihypertensive, and hypoglycemic properties, as well as the ability to suppress obesity and promote cell proliferation and regulate plant growth. We hope that this review will provide theoretical basis and inspiration for the high-value research developments and utilization of AOS-related products.

Purification, antitumor and anti-inflammation activities of an alkali-soluble and carboxymethyl polysaccharide CMP33 from Poria cocos

A carboxymethyl polysaccharide CMP33 (15.23 × 10⁴ Da) was isolated from edible and pharmaceutical mushroom Poria cocos using alkaline extraction followed by DEAE-52 and Saphadex-G200 + Saphadex-G150 column chromatographies. The structure analysis showed that CMP33 was composed of glucosyl residues containing a backbone chain of (1 → 3)-linked glucose residues and side chains of (1 → 6) and (1 → 2)-linked glucose residues, and possessed triple-helix structure. Bioassay results revealed that CMP33 displayed a dose-dependent inhibition on 5 cancer cells (HepG-2, MCF-7, SGC-7901, A549) in the range of 31.25-1000 μg/mL, but low cytotoxicity on normal liver cells L-O2. Moreover, CMP33 stimulated NO release and cytokine secretion (IL-1β, IL-6 and TNF-α), and also inhibited LPS-stimulated overproduction of NO, IL-6, TNF-α and IL-1β, in RAW264.7 cells. These results suggested that CMP33 possessed anticancer, anti-inflammation and immune-stimulation activities, and potential for developing as a bioactive ingredient in functional foods.

Amelioration of hepatic steatosis is associated with modulation of gut microbiota and suppression of hepatic miR-34a in Gynostemma pentaphylla (Thunb.) Makino treated mice

Background

Non-alcoholic fatty liver disease (NAFLD) is a chronic and progressive liver disease with an increased risk of morbidity and mortality. However, so far no specific pharmacotherapy has been approved. Gynostemma pentaphylla (Thunb.) Makino (GP) is a traditional Chinese medicine that is widely used against hyperlipemia as well as hyperglycemia. This study aims to evaluate the effect of GP on NAFLD and explore the possible mechanism.

Methods

High-fat-diet induced NAFLD mice model were orally administrated with GP at dose of 11.7 g/kg or equivalent volume of distilled water once a day for 16 weeks. Body weight, food intake and energy expenditure were assessed to evaluate the general condition of mice. The triglycerides, total cholesterol content in the liver and liver histopathology, serum lipid profile and serum insulin level, fecal microbiome, hepatic microRNAs and relative target genes were analyzed.

Results

Mice in GP treatment group displayed improved hepatic triglycerides content with lower lipid droplet in hepatocyte and NAFLD activity score. Besides, GP treatment altered the composition of gut microbiota and the relative abundance of some of the key components that are implicated in metabolic disorders, especially phylum Firmicutes (Eubacterium, Blautia, Clostridium and Lactobacillus). Several hepatic microRNAs were downregulated by GP treatment such as miR-130a, miR-34a, miR-29a, miR-199a, among which the expression miR-34a was altered by more than four-fold compared to that of HFD group (3:14). The correlation analysis showed that miR-34a was strongly related to the change of gut microbiota especially phylum Firmicutes (R = 0.796). Additionally, the target genes of miR-34a (HNF4α, PPARα and PPARα) were restored by GP both in mRNA and protein levels.

Conclusion

Our results suggested that GP modulated the gut microbiota and suppressed hepatic miR-34a, which was associated with the amelioration of hepatic steatosis.

Anti-inflammatory lignans and phenylethanoid glycosides from the root of Isodon ternifolius (D.Don) Kudô

Five undescribed lignans, three undescribed phenylethanoid glycosides and eight known compounds were isolated from the root of Isodon ternifolius (D.Don) Kudô (Lamiaceae). The structures of all of the isolated constituents were characterized by physical data analyses including NMR, MS and ECD. The anti-inflammatory activities of the isolates were evaluated based on their ability to inhibit NO, PGE2 and TNF-α production in LPS-induced RAW 264.7 macrophage cells. Six phenyl-naphthalene lignans, ternifoliuslignan A, ternifoliuslignan B, ternifoliuslignan C, ternifoliuslignan D, ternifoliuslignan E and 3-carboxy-6,7-dihydroxy-1-(3',4'-dihydroxyphenyl) -naphthalene, can substantially inhibit the release of NO with IC₅₀ values in the range of 9.98-29.14 μM, which are better than the positive reference. These phenyl-naphthalene lignans could markedly decrease the secretions of PGE2 and TNF-α in LPS-induced RAW264.7 cells. Ternifoliuslignan C and ternifoliuslignan D decreased iNOS, COX-2 and NF-κB/p65 protein expression. A preliminary structure-activity relationship among the phenyl-naphthalene lignans for the anti-inflammatory activity was discussed.

A new heteropolysaccharide from the seed husks of Plantago asiatica L. with its thermal and antioxidant properties

A new heteropolysaccharide (PMH) with a molecular weight of 1.4 × 10³ kDa was isolated from the seed husks of Plantago asiatica L. The monosaccharide composition of PMH was determined as glucose, xylose, arabinose, rhamnose, galactose and galacturonic acid with a molar ratio of 1.0 : 1.8 : 2.4 : 3.8 : 4.9 : 8.5. The backbone of PMH consisted of 1,4-β-d-GalpA with the side chains mainly composed of 1,3-α-d-Galp and 1,2-α-d-Galp which were attached to the O-3 of GlapA. The thermal analysis using the Flynn-Wall-Ozawa (FWO) method revealed that PMH had an apparent activation energy (E_a) of 173.1 kJ mol^-1. PMH experienced a major decomposition during the heating process at a temperature of 91.1 °C with a dry weight loss of 31.1%. Moreover, PMH exhibited stronger antioxidant ability than commercial psyllium, partially due to its higher content of uronic acid. The results suggested that PMH could be used in functional foods due to its structural, thermal and antioxidant characteristics.

Structural characterization and immunomodulating activities of a novel polysaccharide from Nervilia fordii

Nervilia fordii (Hance) Schltr. has been widely used as a medicinal and edible herb in Southwest China and Southeast Asia. In this study, NFP-1, a new water-soluble polysaccharidewith a purity of 97.8%, was purified from water extract of Nervilia fordii by DEAE-cellulose and Sephadex G-100 chromatography. NFP-1 has a relative molecular weight of 950 kDa determined by high performance gel-permeation chromatography (HPGPC). Its monosaccharide compositions were analyzed by high performance liquid chromatography (HPLC) after pre-column derivatizing its hydrolysate with 1-phenyl-3-methyl-5-pyrazolone (PMP). NFP-1 mainly consists of galactose, arabinose, rhamnose, and galacturonic acid. Based on FT-IR, methylation and GC–MS analysis, and NMR, the structure unit of NFP-1 was established as →4)-α-Rhap-(2→ 4)-α-GalpA-(1→2)-α-Rhap-(1→2)-α-Rhap-(4→1)-β-Galp-T containing two branch chains of →2,4)-α-Rhap-(1→5)-α-Araf-(1→3)-α-Araf-(1→, and →2,4)-α-Rhap-(1→4)-β-Galp-(1→. The immunomodulatory assays revealed the dual-functionalities of NFP-1. NFP-1 could significantly induce the secretion of nitric oxide (NO), and promote the secretions of TNF-α, IL-6, and IL-1β in RAW264.7 macrophages. NFP-1 could also significantly inhibit the production of NO, depress the secretions of TNF-α, IL-6 and IL-1β in RAW264.7 macrophages activated by lipopolysaccharide (LPS), and promote the production of IL-10 meanwhile. Our study suggested that Nervilia fordii could be an ideal medicinal or functional food due to its dual immunomodulatory activities.

Structural characterization and immunomodulatory activity of a novel polysaccharide from Ficus carica

A novel polysaccharide (FCPW80-2) with a molecular weight of 1.21 × 10⁵ Da was first isolated from Ficus carica through hot water extraction and several chromatographic methods.

Preliminary characterization and antioxidant and hypoglycemic activities in vivo of polysaccharides from Huidouba

Here, the antioxidant and hypoglycemic activities of polysaccharides from Huidouba were preliminarily characterized.

Comparison of structural features and antioxidant activity of polysaccharides from natural and cultured Cordyceps sinensis

Four polysaccharides (named as P1, P2, and P3 from three natural Cordyceps sinensis and P4 from cultured C. sinensis) were obtained by hot-water extraction and ethanol precipitation and their structural characteristics as well as antioxidant potentials were compared. Results revealed that the backbone of P1, P2, and P3 comprised α-1,4-glucose, with a branching point mainly at position 6 and terminating at glucose. On the other hand, the structure of P4 was highly complex, mainly comprising glucose, galactose, and mannose, with 1,4-glucose and 1,4-galactose as the main chain. For in vitro antioxidant assays, all the four polysaccharides showed similar scavenging capacity against DPPH and hydroxyl radicals, whereas P1 had a relatively low ferric reducing ability, possibly related to a combination of factors such as the phenolic compounds and amino acids that conjugated in polysaccharides.

Structural Characterization of a Novel Polysaccharide from Lepidium meyenii (Maca) and Analysis of Its Regulatory Function in Macrophage Polarization in Vitro

In our previous study, three novel polysaccharides, named MC-1, MC-2, and MC-3, were separated from the roots of maca (Lepidium meyenii), which is a food source from the Andes region. The structural information and immunomodulatory activity of MC-1 were then investigated. The structure and activity of MC-2 are still unknown. In this study, structural characterization revealed that MC-2 has an average molecular weight of 9.83 kDa and is composed of arabinose (20.9%), mannose (4.5%), glucose (71.9%), and galactose (2.7%). The main linkage types of MC-2 were proven to be (1→5)-α-l-Ara, (1→3)-α-l-Man, (1→)-α-d-Glc, (1→4)-α-d-Glc, (1→6)-α-d-Glc, and (1→6)-β-d-Gal by methylation and NMR analyses. Congo red assay showed that MC-2 possesses a triple-helix conformation. Immunostimulating assays indicated that MC-2 could induce M1 polarization of original macrophages and convert M2 macrophages into M1 phenotype. Although MC-2 could not shift M1 macrophages into M2, it could still inhibit inflammatory reactions induced by lipopolysaccharide. Furthermore, Toll-like receptor 2, tTll-like receptor 4, complement receptor 3, and mannose receptor were confirmed as the membrane receptors for MC-2 on macrophages. These results indicate that MC-2 could potentially be used toward hypoimmunity and tumor therapies.

Immunomodulatory and Antioxidant Effects of Polysaccharides from Gynostemma pentaphyllum Makino in Immunosuppressed Mice

The immunomodulatory and antioxidant activities of crude polysaccharides extracted from Gynostemma pentaphyllum Makino (GPMPP) were investigated. GPMPP was composed of rhamnose, arabinose, xylose, mannose, glucose and galactose in the molar ratio of 1.39:3.76:1.00:1.64:4.98:5.88. In vivo studies showed GPMPP significantly increased the spleen and thymus indices, activated the macrophage phagocytosis and NK cells, and exhibited activity on none or Con A/LPS-stimulated splenocytes in a dose-dependent manner in C57BL/6 mice. Moreover, GPMPP elevated CD4⁺ T lymphocyte counts as well as the CD4⁺/CD8⁺ ratio dose-dependently, and it increased IL-2 level in the sera and spleen of Cy-immunosuppressed mice. Furthermore, GPMPP significantly increased the SOD, GSH-Px, T-AOC, GSH and CAT level, and decreased the MDA level. The results showed that GPMPP might play an important role in prevention of oxidative damage in immunological system. These findings indicate GPMPP has immunomodulatory activity in vivo and seems to be an effective natural immunomodulatory agent.

Physicochemical Characterization of a Polysaccharide Fraction from Platycladus orientalis (L.) Franco and Its Macrophage Immunomodulatory and Anti-Hepatitis B Virus Activities

A polysaccharide fraction, here called POP1, was purified from the leaves of Platycladus orientalis (L.) Franco by water extraction and alcohol precipitation. Physicochemical characterization indicated that POP1 had a relative molecular weight of 8.10 × 10(3) Da and consisted of rhamnose (5.74%), arabinose (12.58%), mannose (10.97%), glucose (64.96%), and galactose (6.55%). The main linkage types of POP1 consisted of (1→5)-linked α-l-Ara, (1→3)-linked α-l-Man, (1→6)-linked β-l-Rha, (1→4)-linked α-d-Glc, (1→6)-linked α-d-Glc, (1→6)-linked β-d-Gal, (1→3,6)-linked β-d-Gal, and termination with α-l-Man and α-d-Glc residues based on periodate oxidation, Smith degradation, methylation, and NMR analysis. POP1 exhibited excellent immunostimulating activity by enhancing macrophage NO, TNF-α, IL-6, and IL-12 secretion and activating related mRNA expression. Besides, POP1 showed significant anti-HBV activity through inhibiting the expression of HBsAg (IC50 = 1.33 ± 0.12 mg/mL) and HBeAg (IC50 = 1.67 ± 0.13 mg/mL) and interfering with the HBV DNA replication (IC50 = 0.80 ± 0.03 mg/mL). The present study suggested that POP1 could be used as immunoregulatory agent in functional foods for the prevention of HBV infection.

Structure elucidation of a major fucopyranose-rich heteropolysaccharide (STP-II) from Sargassum thunbergii

A crude polysaccharide was extracted from the edible algae S. thunbergii. DEAE-Sepharose CL-6B column chromatography was used to separate and purify a major polysaccharide STP-II (63.75%) from the crude polysaccharide. STP-II was found to be a homogeneous polysaccharide with a single peak by high-performance size-exclusion chromatography with a Sugar KS-804 column, have a molecular weight of 550 kD, and consist mainly of fucose, xylose, galactose, glucose and glucuronic acid. The structural assignment of STP-II was carried out using Fourier transform infrared spectroscopy analysis, periodate oxidation-smith degradation, partial hydrolysis with acid, methylation analysis and nuclear magnetic resonance studies, and the repeating unit of STP-II was thus determined. The result indicated that (1→3)-linked-fucose, (1→3)-linked-xylose and (1→3)-linked-galactose formed the major components of the main-chain structure, and the branch ratios were 17.5%. The branching and terminal residues were (1→2)-linked-glucuronic acid, (1→4)-linked-glucose, (1→)-linked-xylose and (1→)-linked-4-O-acetyl-glucose, respectively.

Structural Characterization and Immunomodulatory Activity of a Novel Polysaccharide from Lepidium meyenii

A novel polysaccharide named as MC-1 was isolated from the roots of Lepidium meyenii using a water extraction method. Structural characterization revealed that MC-1 had an average molecular weight of 11.3 kDa and consisted of arabinose (26.21%), mannose (11.81%), glucose (53.66%), and galactose (8.32%). The main linkage types of MC-1 were proven to be (1 → 5)-α-L-Ara, (1 → 3)-α-L-Man, (1 → 2,6)-α-L-Man, (1 → )-α-D-Glc, (1 → 4)-α-D-Glc, (1 → 6)-α-D-Glc and (1 → 6)-β-D-Gal by methylation analysis, periodate oxidation-Smith degradation and NMR analysis. The immunostimulating assay indicated that MC-1 could significantly enhance the pinocytic and phagocytic capacity and promote the NO, TNF-α, and IL-6 secretion of RAW 264.7 cells, involving toll-like receptor 2, complement receptor 3, and mannose receptor mainly. These results suggested the potential utilization of MC-1 as an attractive functional food supplement candidate for hypoimmunity population.

Polysaccharides of Trametes versicolor Improve Bone Properties in Diabetic Rats

This study investigates the effects of Trametes versicolor (L.:Fr.) Pilát (TVP, also known as Yunzhi) on bone properties in diabetic rats. Forty-five male Wistar rats (8 weeks old) were fed either a chow diet (control) or a high-fat diet throughout the study period of 28 days. Animals in the high-fat-diet group were injected with nicotinamide and streptozotocin to induce diabetes mellitus (DM). The DM rats were divided into a group receiving distilled water (vehicle) and another group receiving TVP at 0.1 g/kg weight by gavage. Relative to the vehicle group, TVP gavage lowered postprandial blood sugar (225 ± 18 mg/dL for TVP vs 292 ± 15 mg/dL for vehicle, p < 0.001) on day 26. Compared to the vehicle group, TVP mitigated DM-induced bone deterioration as determined by increasing bone volume of proximal tibia (22.8 ± 1.4% for TVP vs 16.8 ± 1.3% for vehicle, p = 0.003), trabecular number (p = 0.011), and femoral bone strength (11% in maximal load, 22% in stiffness, 14% in modulus, p < 0.001), and by reducing loss of femoral cortical porosity by 25% (p < 0.001). Our study demonstrates the protective effect of TVP on bone properties was mediated through, in part, the improvement of hyperglycemic control in DM animals.

Anti-inflammatory activity of guluronate oligosaccharides obtained by oxidative degradation from alginate in lipopolysaccharide-activated murine macrophage RAW 264.7 cells

Alginate has notably diverse pharmacological activities. The present study investigated the anti-inflammatory activity of the guluronate oligosaccharides prepared by oxidative degradation (GOS-OD) from alginate. GOS-OD significantly attenuated the production of nitric oxide (NO), prostaglandin E2 (PGE2), and reactive oxygen species (ROS), the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2, and the secretion of pro-inflammatory cytokines in lipopolysaccharide (LPS)-activated murine macrophage RAW 264.7 cells. Moreover, GOS-OD potently decreased the binding of LPS to the cell surface and LPS-induced Toll-like receptor 4 (TLR4) and cluster of differentiation (CD) 14 expression. Additionally, GOS-OD could remarkably inhibit the LPS-induced activation of nuclear factor (NF)-κB and mitogen-activated protein (MAP) kinase pathways in RAW 264.7 cells. These results indicate that GOS-OD may reduce the LPS-stimulated inflammatory responses through blocking the activation of NF-κB and MAP kinases, suggesting that GOS-OD may be considered as a potential nutraceutical for inflammation.

Novel dammarane saponins from Gynostemma pentaphyllum and their cytotoxic activities against HepG2 cells

Two new dammarane saponins, 2α,3β,12β-trihydroxydammar-20(22),24-diene-3-O-[β-D-glucopyranoxyl(1→2)-β-D-6″-O-acetylglucopyranoside (1, namely damulin C) and 2α,3β,12β-trihydroxydammar-20(21),24-diene-3-O-[β-D-glucopyranoxyl(1→2)-β-D-6″-O-acetylglucopyranoside (2, namely damulin D), were isolated from the ethanol extract of Gynostemma pentaphyllum, which had been heat processed by steaming at 125 °C. The NMR spectroscopic data of the novel saponins were completely assigned by using a combination of 2D NMR experiments including (1)H-(1)H COSY, HSQC, and HMBC. Their cytotoxic activities of human liver adenocarcinoma HepG2 cells were evaluated in vitro. They showed cytotoxicities against HepG2 cell line with IC50 of 40±0.7 and 38±0.5 μg/ml, respectively.