(1 → 3),(1 → 6) and (1 → 3)-ß-D-glucan physico-chemical features drive their fermentation profile by the human gut microbiota.

Mushroom polysaccharides consist of a unique set of polymers that arrive intact in the human large intestine becoming available for fermentation by resident gut bacteria with potential benefits to the host. Here we have obtained four glucans from two mushrooms (Pholiota nameko and Pleurotus pulmonarius) under different extraction conditions and their fermentation profile by human gut bacteria in vitro was evaluated. These glucans were isolated and characterized as (1 â†’ 3),(1 â†’ 6)-ß-D-glucans varying in branching pattern and water-solubility. An aliquot of each (1 â†’ 3),(1 â†’ 6)-ß-D-glucan was subjected to controlled smith degradation process in order to obtain a linear (1 â†’ 3)-ß-D-glucan from each fraction. The four ß-D-glucans demonstrated different water solubilities and molar mass ranging from 2.2 × 105 g.mol-1 to 1.9 × 106 g.mol-1. In vitro fermentation of the glucans by human gut microbiota showed they induced different short chain fatty acid production (52.0-97.0 mM/50 mg carbohydrates), but an overall consistent high propionate amount (28.5-30.3 % of total short chain fatty acids produced). All glucans promoted Bacteroides uniformis, whereas Anaerostipes sp. and Bacteroides ovatus promotion was strongly driven by the ß-D-glucans solubility and/or branching pattern, highlighting the importance of ß-D-glucan discrete structures to their fermentation by the human gut microbiota.

Arabinan-rich pectic polysaccharide fraction from Malpighia emarginata fruits alleviates inflammatory pain in mice.

Malpighia emarginata (Malpighiaceae), popularly known as "acerola", is a tropical and subtropical fruit native to the Americas. Despite its high vitamin C content, which gives it a high antioxidant property, soluble dietary fibers, such as polysaccharides, are also abundant constituents of acerola (10% of the dried fruit). The acerola cold-water soluble (ACWS) fraction presented anti-fatigue and antioxidant effects in vivo and in vitro. To infer further systemic effects of ACWS, this study aimed to investigate the antinociceptive, anti-inflammatory, and antioxidant effects of ACWS in murine models of pain. In formalin-induced nociception, ACWS (0.1, 1, and 10 mg/kg) reduced only the inflammatory phase, and also (10 and 30 mg/kg) attenuated the acetic acid-induced writhing and leukocyte migration in the peritoneal cavity. The mechanical allodynia and paw edema induced by intraplantar injection of carrageenan were greatly reduced by ACWS (10 mg/kg). At the inflammatory pick induced by carrageenan (4 h), ACWS significantly reduced myeloperoxidase activity, TNF-α, IL-1ß, and PGE2 levels, and restored IL-10 levels. ACWS also exhibited antioxidant properties by decreasing lipid hydroperoxides content, increasing GSH levels, and restoring superoxide dismutase and catalase activities in the carrageenan model and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging assay. Collectively, these results support the antinociceptive, anti-inflammatory, and antioxidant effects of ACWS and reveal a promising candidate for the treatment of inflammatory pain conditions.

Chemical Evaluation of Liquidambar styraciflua L. Fruits Extracts and Their Potential as Anticancer Drugs.

Liquidambar styraciflua L. is an aromatic species, popularly used in traditional Chinese medicine to treat diarrhea, dysentery, coughs, and skin sores. The present study was designed to investigate the chemical composition and biological potential of extracts obtained from the fruits of this plant. For the chemical evaluation, it was used mainly liquid and gas chromatography, plus NMR, and colorimetric methods. The aqueous extract (EA) originated two other fractions: an aqueous (P-EA) and an ethanolic (S-EA). The three extracts were composed of proteins, phenolic compounds, and carbohydrates in different proportions. The analyses showed that the polysaccharide extract (P-EA) contained pectic polysaccharides, such as acetylated and methyl esterified homogalacturonans together with arabinogalactan, while the fraction S-EA presented phenolic acids and terpenes such as gallic acid, protocathecuic acid, liquidambaric acid, combretastatin, and atractyloside A. EA, P-EA, and S-EA showed antioxidant activity, with IC50 values of 4.64 µg/mL, 16.45 µg/mL, and 3.67 µg/mL, respectively. The cytotoxicity followed the sequence S-EA > EA > P-EA, demonstrating that the toxic compounds were separated from the non-toxic ones by ethanol precipitation. While the fraction S-EA is very toxic to any cell line, the fraction P-EA is a promising candidate for studies against cancer due to its high toxicity to tumoral cells and low toxicity to normal cells.

Synergistic Effect of Polysaccharides from Chamomile Tea with Nitazoxanide Increases Treatment Efficacy against Giardia intestinalis.

Giardia intestinalis (syn. G. lamblia, G. duodenalis) is a protozoa parasite that produces one of the most frequent waterborne causes of diarrhea worldwide. This protozoan infects most mammals, including humans, and colonizes the small intestine, adhering to intestinal cells. The mechanism by which G. intestinalis causes diarrhea is multifactorial, causing intestinal malabsorption. The treatment of giardiasis uses chemotherapeutic drugs such as nitroimidazoles, furazolidone, paromomycin, and benzimidazole compounds. However, they are toxic, refractory, and may generate resistance. To increase efficacy, a current treatment strategy is to combine these drugs with other compounds, such as polysaccharides. Several studies have shown that polysaccharides have gastroprotective effects. Polysaccharides are high-molecular weight polymers, and they differ in structure and functions, being widely extracted from vegetables and fruits. In the present study, we show that polysaccharides found in chamomile tea (called MRW), in contact with antiparasitic agents, potentially inhibit the adhesion of parasites to intestinal cells. Moreover, at 500 µg/mL, they act synergistically with nitazoxanide (NTZ), increasing its effectiveness and decreasing the drug dose needed for giardiasis treatment.

An α-D-galactan and a ß-D-glucan from the mushroom Amanita muscaria: Structural characterization and antitumor activity against melanoma.

Polysaccharides α-D-galactan (GAL-Am) and ß-D-glucan (GLC-Am) were obtained from Amanita muscaria fruiting bodies. They were purified using different methodologies, such as Fehling precipitation (for both fractions), freeze-thawing process and ultrafiltration (for GLC-Am). Results showed that the GAL-Am has (1 â†’ 6)-linked Galp main chain branched at O-2 by terminal Galp units and has not been previously reported. Besides, GLC-Am has (1 â†’ 3)-linked Glcp in the main chain, substituted at O-6 by (1 â†’ 6)-linked ß-Glcp units. Both are water-soluble, with 9.0 × 103 g/moL and 1.3 × 105 g/moL, respectively. GAL-Am and GLC-Am presented a selective proliferation reduction against B16-F10 melanoma cell line, not affecting non tumoral BALB/3T3 fibroblast cell line. Furthermore, both fractions reduced clonogenic capacity of melanoma cell line over an extended period of time. These results were obtained without modulations in B16-F10 cell adhesion, reinforcing the biological activities towards cell proliferation impairment and eliciting these polysaccharides as promising compounds to further exploration of their antimelanoma properties.

Hypoglycemic and Vasorelaxant Effect of Passiflora edulis Fruit Peel By-Product.

Passiflora edulis fo. flavicarpa (Passifloraceae) is popularly known as yellow passion fruit and its fruit peels are considered a rich by-product in bioactive compounds which has greatly beneficial health properties. The objective of this study was to evaluate the effects of P. edulis fruit peel extracts in a type 1 diabetes model and the potential vasorelaxant effect. The aqueous and hydroethanolic extracts were obtained from P. edulis fruit peels and orientin and isorientin flavonoids were identified in both extracts through ultra-high performance liquid chromatography. Pectin was only identified in the aqueous extract by high-performance steric exclusion chromatography and nuclear magnetic resonance. Regarding the vascular system, the hydroethanolic extract showed better vasorelaxant effects in the mesenteric artery rings when compared to the aqueous extract. These effects mainly occur by opening the potassium channels. In the type 1 diabetes model, extracts at doses of 400 and 600 mg/kg were able to restore the effect of insulin in diabetic rats which were not responding to its action. The antidiabetic effect was more significant for the aqueous extract. Thus, the results suggest that the hydroethanolic and aqueous extracts have greater potential to be used to treat cardiovascular diseases such as hypertension and as a hypoglycemic agent, respectively. Taken together, P. edulis fruit peel extracts proved to be a source of valuable bioactive raw material to produce nutraceuticals or pharmaceutical products.

Microwave treatment enhances human gut microbiota fermentability of isolated insoluble dietary fibers.

Most insoluble dietary fibers are known to be relatively poorly fermented by the human gut microbiota. Here, the potential of microwave (MW) treatment to enhance the susceptibility of insoluble fruit polysaccharides to fermentation by the human gut microbiota was evaluated. Insoluble fruits dietary fibers before (xylan A, xylan T, and arabinan) and after MW (xylan A-MW, xylan T-MW, and arabinan-MW) treatment were fermented using an in vitro fermentation model. Gas production, shifts in pH, and short chain fatty acids (SCFAs) production showed an increase in fermentability of all tested dietary fibers, with an average 4-fold increase in SCFAs production after microwaving with total SCFAs ranging from 17.1 mM in the arabinan-MW to 40.4 mM in the xylan T-MW. While arabinan-MW and xylan T-MW promoted all three SCFAs proportionally (acetate:propionate:butyrate), xylan A-MW led to a marked and slow increase in butyrate reaching 28.1% of total SCFAs at 24 h. Rearrangements in three-dimensional structure that potentially facilitate bacterial accessibility to the dietary fiber were observed by scanning electron microscopy in xylan A-MW, forming coin-like particles with ~1.1 µm diameter. 16S rRNA gene sequencing indicated that microbiota shifts were related to both treatment (native versus MW) and dietary fiber type with many butyrogenic species being promoted by xylan A-MW. Overall, MW treatment enhanced insoluble dietary fiber fermentability promoting increased SCFAs production and bacterial shifts which are related to health benefits.

Prebiotic potential of mushroom d-glucans: implications of physicochemical properties and structural features.

Mushroom d-glucans are recognized as dietary fibers and as biologically active natural polysaccharides, with the advantages of being quite inexpensive for production, tolerable, and having a range of possible structures and physicochemical properties. The prebiotic potential of mushroom d-glucans has been explored in recent years, but the relationship between their various structural features and activity is poorly understood. This review focuses on comprehensively evaluating the prebiotic potential of mushroom d-glucans in face of their structural variations. Overall, mushroom d-glucans provide a unique set of different structures and physicochemical properties with prebiotic potential, where linkage type and solubility degree seem to be associated with prebiotic activity outcomes. The understanding of the effects of distinct structures and physicochemical properties in mushroom d-glucans on the gut microbiota contributes to the design and selection of new prebiotics in a more predictable way.

Polysaccharides from Pleurotus eryngii: Selective extraction methodologies and their modulatory effects on THP-1 macrophages.

Polysaccharides from P. eryngii mushroom were selectively extracted using low-cost technologies (water at different conditions of temperature and pressure). Mannogalactan was the main polysaccharide in cold-water extracted fraction (CWEF), while a linear (1→6)-ß-d-glucan was the main polymer in hot-water extracted fraction (HWEF). Autoclave-extracted fraction (AEF) contained a mixture of at least four different α- and ß-glucans. The report of linear (1→6)-ß-glucan and linear (1→3)-ß-glucan is a new finding for P. eryngii fruiting bodies. The immunostimulatory properties of the fractions on THP-1 macrophages were studied. All fractions at 50, 250 and 500 µg/mL were not cytotoxic and produced different stimulus on NO, IL-1ß and IL-10 secretion by the cells. Thus, our results showed that it is possible to concentrate different P. eryngii polysaccharides in selected fractions using a simple and low-cost procedure. Since biological effects depends on the polysaccharide structure, this technique allows the obtainment of fractions with distinct immunomodulatory activities.

Chamomile tea: Source of a glucuronoxylan with antinociceptive, sedative and anxiolytic-like effects.

Chamomile is one of the most ancient medicinal herbs known to mankind and among its traditional uses are the calming effects. However, few studies explored its effects on the central nervous system (CNS). In this study we further proceed with structural elucidation of polysaccharides from chamomile tea. A highly substituted 4-O-methyl-glucuronoxylan (fraction SN-50R) was purified and chemically characterized, presenting Xyl:GlcA ratio of 1.7:1, Mw of 500 kDa and total sugar content of 98%. Its bioactivity on pain and on CNS was explored. Animals treated with SN-50R presented antinociceptive effect and a dose-dependent decrease in the number of crossings in the activity chamber and in the open field test, as well as a significant reduction in the number of marbles buried when compared to control. These results suggest that SN-50R presented sedative and anxiolytic-like effects and may be contributing for the calming effects obtained by chamomile tea ingestion.

High methoxyl pectin from the soluble dietary fiber of passion fruit peel forms weak gel without the requirement of sugar addition.

Passion fruit peel (PFP) is a by-product from the fruit processing industry, accounting for approximately 50 % of the fruit weight. It is well known for its health properties, although few studies evaluated its rheological properties. PFP polysaccharides (PFPP) contain a high methoxyl pectin (HMP), specifically a 70 % methyl-esterified homogalacturonan. Flow behaviour analysis of PFPP (with or without sucrose) revealed a shear-thinning non-Newtonian behaviour. Dynamic oscillatory tests showed a weak gel-like behaviour, even without sucrose addition. Moreover, under simulated pasteurization process PFPP maintained its gel structure. Taken together we demonstrated that PFPP has divergent behaviour from commercial HMP, since it does not require sucrose or low pH to form gel. The present work reinforces the use of PFP as a source of soluble dietary fibres and pectins, providing its alternative application as a rheological modifier in a wide range of products, including those with low sugar.

Polysaccharides from green sweet pepper increase the antineoplastic effect of methotrexate on mammary tumor cells.

This study investigated the antineoplastic effects and toxicity of long-term treatment with polysaccharides from sweet green pepper (Capsicum annuum [CAP]), and concomitant treatment with CAP + methotrexate (MTX) on mammary tumor cells in vivo and in vitro. Ehrlich tumor cells were subcutaneously inoculated in female Swiss mice. The long-term treatment (31 days) with CAP (100 mg kg-1, p.o.) reduced the tumor growth and did not induce toxicity. The combined treatment protocol of 100 mg kg-1 CAP (p.o.) + 1 mg kg-1 MTX (i.p.) for 21 days inhibited the tumor growth in 95%, higher than the inhibition induced by MTX alone (1.0 or 2.5 mg kg-1, i.p.). In tumors, both CAP and CAP + MTX decreased the gene expression of Vegf, vessel area, and IL-4 and IL-10 levels, and increased IL-6 levels and the degree of necrosis. Treatment with CAP + MTX also increased TNF-α levels in tumors. Additionally, CAP + MTX treatment reduced the viability of human MDA-MB-231 and MDA-MB-436 mammary tumor cells in culture. In fact, CAP exerted antineoplastic effects in vivo and in vitro against mammary tumor cells, possibly by modulating inflammation and angiogenesis. CAP may be a promising adjunct chemotherapy with lower toxicity.

Dietary fibres from guavira pomace, a co-product from fruit pulp industry: Characterization and cellular antioxidant activity.

Exotic fruits and their co-products may be valuable sources of antioxidant dietary fibres (DF) which are useful for food industry and human health. In this study, we aimed to characterize DF obtained from guavira fruit pomace and investigate its antioxidant potential employing TEAC assay as well as a cell model. The DF were chemically characterized as containing arabinan, highly-methoxylated homogalacturonan and arabinogalactan. The DF-containing fraction (CPW) presented ABTS free radical scavenger activity. MTT and DCFH-DA assay were performed to assess, respectively, changes in cell viability and the potential intracellular antioxidant activity against H2O2-induced oxidative stress in murine NIH 3T3 fibroblast. CPW exhibited no effects on cell viability, moreover, when administered 48 h prior the induction of H2O2 toxic effects, it protected the cells, significantly increasing the cell viability compared to control. This protection may be related to the observed reduction of reactive oxygen species levels. Thus, the pre-treatment of cells with guavira DF for 48 h remarkably induced a cytoprotection against pro-oxidant conditions, and may be a valuable functional compound recovered from an unexploited agroindutrial waste.

Pectins from cashew apple fruit (Anacardium occidentale): Extraction and chemical characterization.

The cashew tree (Anacardium occidentale) is a tropical evergreen tree largely cultivated in Brazil, which produces the cashew apple, a peduncle rich in carbohydrates and considered an industrial waste of the nut production. Until now, there were no data available about the chemical structure of cell wall polysaccharides found in cashew apple. In this work, its pectic polysaccharides have been characterized through monosaccharide composition, HPSEC, methylation and 13C and 1H/13C HSQC-DEPT-NMR analyses. Highly methyl esterified homogalacturonan with a DE of 76% mixed with arabinogalactan were found. This latter was purified and presented a highly branched type II arabinogalactan (AG II) and small amounts of a type I rhamnogalacturonan in which the AG II could be anchored. These findings about the chemical structure of cashew apple pectins could contribute to develop future nutritional, biotechnological and pharmacological uses for this industrial waste from the cashew nut production.

ß-L-Araf-containing arabinan and glucuronoxylan from guavira fruit pomace.

Guavira is a plant that belongs to Myrtaceae family, being widespread in the Brazilian Cerrado. In this study, pectic and hemicellulosic polysaccharides from guavira pomace, an agroindustry residue from pulp production, were structurally characterized using GPC, monosaccharide composition, methylation and NMR experiments. The absolute configurations of monosaccharides and the nature of uronic acids were attributed according to numerous data on the composition of related plant arabinogalactans and hemicelluloses present in the literature. An arabinan was purified, presenting Ara (85.0%), Rha (3.3%), Gal (7.7%) and GalA (4.0%). Mono and bidimensional NMR analyses of this arabinan demonstrated the presence of terminal ß-L-Araf units, whose occurrence has been scarcely reported in the literature. Hemicellulosic fraction contained a glucuronoxylan, with α-D-GlcpA/4-O-methyl-α-D-GlcpA group linked to O-2 of a (1 → 4)-ß-D-xylan, presenting one uronic acid residue for every six xylose units. These findings about guavira pomace polysaccharides could contribute to develop future nutraceutical and technological uses for this industrial waste.

Chemical characterization of fructooligosaccharides, inulin and structurally diverse polysaccharides from chamomile tea.

Chamomile is one of most known species of medicinal plants. It has valuable pharmacological properties that produce positive effects in many therapeutical uses. Some of these properties are attributed to the presence of secondary metabolites but is already known that primary metabolites can also produce positive effects. In this study we elucidate the fine chemical structure of polysaccharides present in the infusion of chamomile flower chapters. After ethanolic precipitation, polysaccharides were obtained from the tea (fraction MRW, 3.2% yield), purified and characterized as an inulin type fructan, a highly methyl esterified and acetylated homogalacturonan (DE = 87% and DA = 19%), and a type II arabinogalactan. From ethanolic supernatant (20.2% yield), fructooligosaccharides (FOS) ranging from GF2 (m/z 543) to GF10 (m/z 1839) were detected. Inulin and FOS are well-established prebiotics, as well as the pectic polysaccharides. Thus, chamomile could be a source of structurally diverse dietary fibers with potential prebiotic, gastrointestinal and immunological functions.

Gelling functional property, anti-inflammatory and antinociceptive bioactivities of ß-D-glucan from the edible mushroom Pholiota nameko.

A ß-D-glucan was obtained from the edible mushroom Pholiota nameko by hot aqueous extraction and purification. NMR and methylation analyses of the purified fraction (GHW-PN, 1.46% yield) indicated the presence of a (1 → 3)-linked ß-D-glucan, highly substituted (~27%) at O-6 by single units of ß-D-Glcp or by (1 → 6)-ß-D-Glcp fragments. The ß-glucan (at 0.5, 1, and 2%) showed shear thinning behavior and when the concentration of the solution increased, there was an increase in apparent viscosity. The ß-D-glucan presented gel-like behavior and thermal stability under a simulated pasteurization process, suggesting its potential as a thickening and gelling agent in products submitted to temperature variations. The ß-D-glucan at 0.3, 1.0 and 3.0 mg kg-1 significantly inhibited the inflammatory pain in 24.8, 56.9 and 82.3%, respectively, in the formalin-induced nociception in mice. The results pointed out that the ß-D-glucan (GHW-PN) isolated from P. nameko presents potential application for the food industry or for medical purposes.

Soluble xyloglucan generates bigger bacterial community shifts than pectic polymers during in vitro fecal fermentation.

Xyloglucans and pectic polymers can be obtained from a variety of plants ubiquitous in the human diet, however, their fermentability in the colon and consequent nutritional benefits are poorly understood. Here, we evaluated metabolite profiles and bacterial shifts during in vitro fecal fermentations of two isolated pectic polymers and a xyloglucan. Depending on their chemical structure, pectic polymers were more acetogenic or propiogenic. Xyloglucan fermentation also resulted in elevated propionate if compared to FOS. Bacteroides plebeius, B. uniformis, Parabacteroides distasonis and bacterial groups such as Blautia, Lachnospira, Clostridiales and Lachnospiraceae, presented distinct abundances on each dietary fiber ferment. PCA and heat map analysis showed that major microbiota shifts occurred during xyloglucan fermentation, but not pectin fermentation. These data suggest that uncommon carbohydrate structures (i.e. isolated, soluble xyloglucan) in the diet hold the potential to generate larger shifts in microbiota communities than commonly consumed fibers (i.e. pectins).

Antineoplastic effect of pectic polysaccharides from green sweet pepper (Capsicum annuum) on mammary tumor cells in vivo and in vitro.

The present study investigated the antineoplastic effects of pectic polysaccharides that were extracted from green sweet pepper (Capsicum annuum [CAP]) in the Ehrlich carcinoma in mice and in human mammary tumor lineages. After the subcutaneous inoculation of 2 × 106 Ehrlich tumor cells, Female Swiss mice received 50, 100, or 150 mg/kg CAP or vehicle orally once daily or methotrexate (2.5 mg/kg, i.p., every 5 days) for 21 days. CAP dose-dependently reduced Ehrlich tumor growth. It also reduced the viability of MCF-7, MDA-MB-231, and MDA-MB-436 human mammary cell lineages. Treatment with CAP reduced the gene expression of vascular endothelial growth factor in vivo and in vitro, reduced vessel areas of the tumors, and induced necrosis in Ehrlich solid tumors. CAP treatment significantly increased Interleukin-6 in tumors. The antineoplastic effect of CAP appears to depend on the regulation of inflammation and angiogenesis. Further studies are encouraged to better understand the CAP potential for the treatment of breast tumors.

Simple and effective purification approach to dissociate mixed water-insoluble α- and ß-D-glucans and its application on the medicinal mushroom Fomitopsis betulina.

Differences in anomericity and in the branching degree of glucans lead to characteristic intermolecular association that influences their solubility in water or other solvents. A simple purification approach, based on the glucan solubility in aq. 0.1 M NaOH solution, was applied for the separation of mixed water-insoluble α-D-glucans from ß-D-glucans extracted from fruiting bodies of Fomitopsis betulina, which is an underexploited medicinal mushroom. The results indicated that the ß-D-glucan is constituted by (1→3)-linked ß-D-Glcp units substituted at O-6 by non-reducing ß-D-Glcp and (1→6)-linked ß-D-Glcp units, while the α-D-glucan has a linear (1→3)-linked glucan structure. Thus, the 0.1 M NaOH treatment proved to be a simple, efficient and low-cost purification method for separation of water-insoluble glucans with different anomeric configurations and degree of branching that were interacting by intermolecular forces.