Tea Polysaccharide Prevents Colitis-Associated Carcinogenesis in Mice by Inhibiting the Proliferation and Invasion of Tumor Cells.

The imbalance between cell proliferation and apoptosis can lead to tumor progression, causing oncogenic transformation, abnormal cell proliferation and cell apoptosis suppression. Tea polysaccharide (TPS) is the major bioactive component in green tea, it has showed antioxidant, antitumor and anti-inflammatory bioactivities. In this study, the chemoprophylaxis effects of TPS on colitis-associated colon carcinogenesis, especially the cell apoptosis activation and inhibition effects on cell proliferation and invasion were analyzed. The azoxymethane/dextran sulfate sodium (AOM/DSS) was used to induce the colorectal carcinogenesis in mice. Results showed that the tumor incidence was reduced in TPS-treated AOM/DSS mice compared to AOM/DSS mice. TUNEL staining and Ki-67 immunohistochemistry staining showed that the TPS treatment increased significantly the cell apoptosis and decreased cell proliferation among AOM/DSS mice. Furthermore, TPS reduced the expression levels of the cell cycle protein cyclin D1, matrix metalloproteinase (MMP)-2, and MMP-9. In addition, in vitro studies showed that TPS, suppressed the proliferation and invasion of the mouse colon cancer cells. Overall, our findings demonstrated that TPS could be a potential agent in the treatment and/or prevention of colon tumor, which promoted the apoptosis and suppressed the proliferation and invasion of the mouse colon cancer cells via arresting cell cycle progression.

Modulation of cytokine gene expression by selected Lactobacillus isolates in the ileum, caecal tonsils and spleen of Salmonella-challenged broilers.

Probiotics have been used to control Salmonella colonization in the chicken intestine. Recently, we demonstrated that certain selected Lactobacillus isolates were able to reduce Salmonella infection in the chicken spleen and liver as well as down-regulated Salmonella pathogenicity island 1 virulence gene expression in the chicken caecum. To further understand the mechanisms through which Lactobacillus protected chickens from Salmonella infection, the present study has investigated the Lactobacillus isolate(s)-induced host immune response of chickens to Salmonella enterica serovar Typhimurium infection. A thorough examination of cytokine gene expression in the ileum, caecal tonsils, and spleen on days 1 and 3 post-Salmonella infection showed a dynamic spatial and temporal response to Salmonella infection and Lactobacillus treatments. In most instances, it was evident that treatment of chickens with Lactobacillus isolates could significantly attenuate Salmonella-induced changes in the gene expression profile. These included the genes encoding pro-inflammatory cytokines [lipopolysaccharide-induced TNF factor, interleukin (IL)-6, and IL-8], T helper 1 cytokines [IL-12 and interferon (IFN)-γ], and T helper 2 cytokines (IL-4 and IL-10). Another important observation from the present investigation was that the response induced by a combination of Lactobacillus isolates was generally more effective than that induced by a single Lactobacillus isolate. Our results show that administration of certain selected Lactobacillus isolates can effectively modulate Salmonella-induced cytokine gene expression, and thus help reduce Salmonella infection in chickens.

Tea polyphenol and epigallocatechin gallate ameliorate hyperlipidemia via regulating liver metabolism and remodeling gut microbiota.

Hyperlipidemia can directly cause metabolic diseases that seriously endanger disorder and metabolism and gut health. Tea polyphenol (TP) and epigallocatechin gallate (EGCG) was found to improve blood lipid levels and gut microbiota. This study aimed to investigate the effects of TP and EGCG on alleviating hyperlipidemia and liver fat accumulation with physiology, genomics, and metabolomics. Results showed that both TP and EGCG reduced body weight, and TP showed advantages in the decrease of serum cholesterol and triglycerides in hyperlipidemic rats induced by the high-fat diet. Moreover, EGCG may protect liver function via reducing the glycerophospholipids increased by high-fat diet intervention. TP remodeled the gut microbiota composition and enriched the abundance of beneficial bacteria (Bacteroides, Faecalibacterium, Parabacteroides, Akkermansia), and EGCG may improve gut health via promoting the acid-producing bacteria (such as Butyricimonas, Desulfovibrio). The above results provided new insights into the hypolipidemic mechanism of TP and EGCG.

Antimicrobial activity of saponin-rich fraction from Camellia oleifera cake and its effect on cell viability of mouse macrophage RAW 264.7.

BACKGROUND: As a by-product of oil production, several million tons of Camellia oleifera cake is discarded every year in China. The aim of this study was to evaluate the antimicrobial activity of a saponin-rich fraction isolated from C. oleifera cake and investigate its effect on the cell viability of RAW 264.7, a macrophage-like cell line present in almost all mouse tissues. RESULTS: The saponin-rich fraction was isolated from C. oleifera cake in several steps and had a saponin content of 95.42 ± 0.10% (w/w). It showed significant inhibitory activity against the bacteria Staphylococcus aureus, Escherichia coli and Bacillus subtilis and the fungi Mucor racemosus, Aspergillus oryzae, Rhizopus stolonifer, Saccharomyces cerevisiae and Penicillium glaucum, with minimum inhibitory concentrations of 31.3, 31.3, 62.5, 250, 250, 250, 31.3 and 125 µg ml(-1) respectively. In addition, mouse macrophage RAW 264.7 pretreated with the saponin-rich fraction (80-200 µg mL(-1) ) exhibited a significant loss of cell viability in a dose-dependent manner. CONCLUSION: These results may be useful for the future application of saponins from C. oleifera cake. However, the potential use of the saponin-rich fraction as an antimicrobial agent should be decided according to the target micro-organisms in order to avoid causing harm in humans.

Resistant starches and gut microbiota.

Resistant starches (RS), which are considered as one of the dietary fibers, could exert widely beneficial impacts, reduce fat accumulation, show significant effects on regulating blood glucose metabolism and insulin levels, and have protective effects on the gut. Five types of RS have different responses to chronic disease by modulating gut microbiota. Short-chain fatty acids are the linkage between gut microbiota and RS, and RS could improve the metabolism of gut microbiota as well as increase the abundance of beneficial microbes in the gut. The composition of gut microbiota is associated with RS properties, which is reflected by the changes of butyrate-producing bacteria primarily influenced by consumption of RS with various fine structures and types of crystallinities. RS with different fine structures and properties is consumed to varying degrees by gut microbiota, which can be applied to produce functional foods for gut health in future.

Revealing the architecture and solution properties of polysaccharide fractions from Macrolepiota albuminosa (Berk.) Pegler.

Macrolepiota albuminosa (Berk.) Pegler is abundant in active polysaccharides, but little is known about their structures and solution properties. In this study, water-extracted polysaccharides from M. albuminosa (MAWP) were purified into three fractions with structural heterogeneity, which was attributed to the diversity in molecular weight, monosaccharide composition and linkage patterns, further affecting their solution properties. Methylation and NMR analysis revealed MAWP-60p and MAWP-70 were a 3-O-methylated glucomannogalactan and a previously unreported glucomannogalactan, whereas MAWP-80 was elucidated as a branched galactoglucan. Besides, three fractions exhibited random coil conformation in aqueous solution, while MAWP-60p had the highest viscosity due to its highest molecular weight, mean square radius of gyration (Rg) and O-methyl group attached to the backbone. The molecular weight, monosaccharide composition and glycosidic linkages might be the major contributors to the flexibility, molecular size and stereochemistry of mushroom polysaccharide chains.

Structural characteristic of pectin-glucuronoxylan complex from Dolichos lablab L. hull.

Polysaccharides are important constituents in Dolichos lablab hull. Herein, pectin-glucuronoxylan complex from D. lablab hull designated as DLHP-3 (D. lablab hull polysaccharide,) was prepared by ion exchange and gel permeation chromatography, and further characterized by acid degradation and enzymatic hydrolysis, methylation combined with GC-MS, NMR and MALDI-TOF-MS analysis. Both of pectin and glucuronoxylan regions were found in DLHP-3. The glucuronoxylan region consisted of a →4)-ß-Xylp-(1→ backbone with branches of α-GlcpA-(1→ substituted at O-2 site, and the ratio of xylose to glucuronic acid was about 5:1. Acetyl groups were mainly attached to O-3 site of →2,4)-ß-Xylp-(1→ residues. The main chain of pectin region could be represented by →4)-α-GalpA-(1→4)-α-GalpA-(1→ and →2)-α-Rhap-(1→4)-α-GalpA-(1→ with partial methyl-esterification. The side chains were deduced to embrace arabinan and arabinogalactan linked to rhamnogalacturonan-I region. Pectin was probably covalently bound to glucuronoxylan. Our findings uncovered the molecular structure of pectin-glucuronoxylan complex from D. lablab hull.

Isolation and structure characterization of glucuronoxylans from Dolichos lablab L. hull.

Polysaccharides were extracted by hot water and alkali in sequence from Dolichos lablab L. hull, and further purified by ion-exchange and gel columns. Hot water extracted D. lablab hull polysaccharide (DLHP) was rich in glucuronoxylan and pectin, and alkali extracted polysaccharide (DLHAP) mostly embraced glucuronoxylan. The structures of purified glucuronoxylans from DLHP and DLHAP were mainly analyzed by HPAEC-PAD, methylation combined with GC-MS, NMR and SEC-MALLS. DLHP-1 was identified as acetylated glucuronoxylan containing →4)-ß-Xylp-(1→ backbone with substitution at O-2 site by α-GlcpA/4-O-methyl-α-GlcpA. The molar ratio of ß-Xylp to α-GlcpA was 6.9:1, and acetylation was mainly at O-3 site of ß-Xylp with acetylation degree of 21.5%. DLHP-1 and DLHP-2 had similar physicochemical properties, except for molecular weight (Mw). DLHAP-1 was the non-methylated glucuronoxylan almost without acetylation, and it had the molar ratio of ß-Xylp to α-GlcpA of 5.6:1. Besides, DLHP-1 (Mw of 20.0 × 103 g mol-1) adopted semi-flexible chain, while DLHAP-1 (Mw of 15.4 × 103 g mol-1) showed flexible chain. These results provided a structural basis for study on polysaccharides from D. lablab hull, which was benefit for understanding biological activities and developing functional food or pharmaceuticals of D. lablab.

Polysaccharides from fermented Momordica charantia L. with Lactobacillus plantarum NCU116 ameliorate metabolic disorders and gut microbiota change in obese rats.

Obesity is a chronic disease characterized by overweight resulting from fat accumulation, along with disturbance of metabolism and gut microbiota. Fermentation, as a green processing method, is beneficial for improving the nutrition capacity of food components. Polysaccharides are considered as one of the important components in food and are also potential supplements for anti-obesity treatment. This study aimed to investigate the anti-obesity effects of polysaccharides from fermented and non-fermented Momordica charantia L. with Lactobacillus plantarum NCU116 (FP and NFP) on obese rats by serum metabolomics and gut microbiota analysis. Metabolomics results revealed that abnormal lipid metabolism was formed due to obesity. The supplement of FP and NFP improved the glycerophospholipids, glycosphingolipids, and amino acid metabolism of the obese rats, which alleviated the hypercholesterolemia and overweight in rats. Furthermore, the disorder of gut microbiota was ameliorated by FP and NFP. FP promoted the growth of beneficial bacteria, such as phylum Firmicutes, Actinobacteria, and genera Anaerostipes, Coprococcus, Lactobacillus, and Bifidobacterium. FP also reduced several harmful bacteria belonging to the phylum Proteobacteria and genera Helicobacter. The positive correlation of the weight loss and lowering of serum lipids with the increased beneficial bacteria further elucidated that the anti-obesity effect of FP in obese rats is associated with the regulation of gut microbiota and serum metabolites. The results of this study could provide information for developing probiotic products in the future that may have beneficial effects on the prevention or treatment of obesity.

[Determination of inorganic elements in oleum camelliae by ICP-AES].

In the present study, the contents of eighteen inorganic elements such as Ca, K, Mg, Cu, Cr, Zn and Sr in oleum camelliae during different stages of refining process were determined using ICP-AES technique. The recoveries obtained by the standard addition method ranged between 82.7% and 112.5%, and RSDs were lower than 6.66%. The detection limits of the method for the eighteen elements were in the range of 0.4-10 microg x L(-1). The experimental results proved that oleum camelliae is rich in inorganic elements. The results also showed that depending on the intensity of refining, the contents of elements will decrease accordingly. After the degumming process, the contents of elements P, Ca and Mg in oleum camelliae declined remarkably. Besides, the contents of some trace elements such as Fe, Cu, Mn and Ni that cause oxidation to occur decreased significantly after refining. In addition, Pb was not detected after the degumming and deacidification process while Co and Cd were not detected both in the crude oil and the refined oil. In conclusion, through refining many excessive metal elements in oleum camelliae were removed effectively and the levels of these elements were able to meet the national standards set by the government. Meanwhile, the experimental results indicated that the ICP-AES technique, which can be used to determine the inorganic elements in oleum camelliae, is easy to operate, rapid, accurate, and highly sensitive, and can also determine many elements simultaneously.

Fermented Momordica charantia L. juice modulates hyperglycemia, lipid profile, and gut microbiota in type 2 diabetic rats.

The effect of Lactobacillus plantarum-fermentation on the anti-diabetic functionality of Momordica charantia was examined using a high-fat-diet and low-dose streptozocin-induced type 2 diabetic rat model. Fermented Momordica charantia juice (FMCJ) administration mitigated the hyperglycemia, hyperinsulinemia, hyperlipidemia, and oxidative stress in diabetic rats more favorably than the non-fermented counterpart. Treatments with FMCJ improved ergosterols and lysomonomethyl-phosphatidylethanolamines metabolisms more effectively. Supplement of FMCJ regulated the composition of the gut microbiota, such as increased the abundance of Bacteroides caecigallinarum, Oscillibacter ruminantium, Bacteroides thetaiotaomicron, Prevotella loescheii, Prevotella oralis, and Prevotella melaninogenica, in diabetic rats compared with untreated diabetic rats. Moreover, FMCJ-treated diabetic rats exhibited higher concentrations of acetic acid, propionic acid, butyric acid, total short-chain fatty acids and lower pH values in colonic contents than that in non-fermented juice-treated rats. These results demonstrated that Lactobacillus plantarum-fermentation enhanced the anti-diabetic property of MC juice by favoring the regulation of gut microbiota and the production of SCFAs.

Polysaccharides from fermented Momordica charantia ameliorate obesity in high-fat induced obese rats.

Momordica charantia (M. charantia) has been widely used to treat obesity due to its bioactive ingredients. This research aimed to investigate the anti-obesity effect of polysaccharides (FP) from fermented M. charantia with Lactobacillus plantarum NCU116 on high-fat induced obese rats. We found that FP could effectively lower the body weight gain, Lee's index, insulin resistance and cell sizes of epididymal adipose tissues in obese rats compared with polysaccharides from non-fermented M. charantia (NFP). FP treatments decreased the total cholesterol, triacylglycerols, and low-density lipoprotein cholesterol, leptin, whereas they elevated the high-density lipoprotein cholesterol, adiponectin, significantly in the serum of obese rats. Furthermore, administrations of FP notably improved oxidative balance in obese rats. Lipidomics results indicated that 24 potential biomarkers have been identified in serum. Additionally, 21 lipids were considerably altered by FP and NFP intakes, such as fatty acyls, glycerolipids, sphingolipids, sterol lipids and glycerophospholipids. The anti-obesity properties of FP were revealed via relieving insulin resistance and fat accumulation of obese rats, which was associated with the regulation of lipid metabolism. Overall, FP exerted more favourable impacts on the anti-obesity effect than NFP, which may be attributed to fermentation.

Antidiabetic Mechanism of Dietary Polysaccharides Based on Their Gastrointestinal Functions.

Diabetes mellitus is a worldwide concern and obviously influences the quality of life of humans. Dietary polysaccharides were mainly from natural sources, namely, plants, fungi, algae, etc. They were resistant to human digestion and absorption, with complete or partial fermentation in the large bowel, and have shown antidiabetic ability. In this perspective, a literature search was conducted to provide information on the antidiabetic mechanism of dietary polysaccharides based on the whole gastrointestinal process, which was a new angle of view for understanding their antidiabetic mechanism. Further studies could take efforts on the mechanisms of the polysaccharide action through host-microbiota interactions targeting diabetes.

Tea Polysaccharides Inhibit Colitis-Associated Colorectal Cancer via Interleukin-6/STAT3 Pathway.

The interleukin-6 (IL-6)/signal transducer and activator of transcription (STAT)-3 signaling pathway regulates proliferation and survival of intestinal epithelial cells and has profound impact on the tumorigenesis of colitis-associated cancer (CAC). Tea polysaccharides (TPS) are the major nutraceutical component isolated from tea-leaves and are known to possess antioxidant, anti-inflammatory, and antitumor bioactivities. Here, we investigated the antitumor activities of TPS on CAC using the azoxymethane/dextran sulfate sodium (AOM/DSS) mouse model and IL-6-induced colorectal cancer cell line (CT26) and determined whether TPS exerted its antitumor effects through the IL-6/STAT3 pathway. Results demonstrated that TPS significantly decreased the tumor incidence, tumor size, and markedly inhibited the infiltration of pro-inflammatory cells and the secretion of pro-inflammatory cytokines via balancing cellular microenvironment. Furthermore, we found that TPS suppressed the activation of STAT3 and transcriptionally regulated the expressions of downstream genes including MMP2, cyclin Dl, survivin, and VEGF both in vivo and in vitro. Thus, it was concluded that TPS attenuated the progress of CAC via suppressing IL-6/STAT3 pathway and downstream genes' expressions, which indicated that TPS may be a hopeful antitumor agent for the prevention and treatment of colon cancer.

Protective properties of combined fungal polysaccharides from Cordyceps sinensis and Ganoderma atrum on colon immune dysfunction.

In vivo an ecological network of polysaccharides utilization by gut microbiota is not only an intense competition but also an impressive cooperation pattern. The present study evaluated the in vivo protective effect of combined fungal polysaccharides (CFP) from Cordyceps sinensis and Ganoderma atrum on colon immune dysfunction, induced by 150mg/kg cyclophosphamide (CP). The results showed that C. sinensis polysaccharides (CSP) significantly promoted microbial-derived butyrate to improve histone h3 acetylation mediating regulatory T (Treg) cell specific Foxp3, as well as significantly restored CP-induced elevation of interleukin (IL)-17 and IL-21. Additionally, G. atrum polysaccharides (PSG) significantly down-regulated MyD88, as well as significantly increased IL-10 and TGF-ß3. Furthermore, CFP balanced the disequilibrium of cytokines secretion and Foxp3/RORγt ratio related Treg/T helper 17 (Th17) balance, as well as down-regulated the TLR-mediated inflammatory signaling pathway and promoted secretory immunoglobulin A (sIgA) secretion to suppress colonic inflammation. Therefore, our results typically contribute to understand the in vivo immunoregulatory function of fungal polysaccharides compounds, involving microbial-associated inflammatory signals and specific metabolic products.

Polysaccharide from fermented Momordica charantia L. with Lactobacillus plantarum NCU116 ameliorates type 2 diabetes in rats.

The influence of Lactobacillus plantarum-fermentation on the structure and anti-diabetic effects of Momordica charantia polysaccharides were evaluated. High-fat diet and streptozotocin-induced type 2 diabetic rats were administrated with polysaccharides from fermented and non-fermented Momordica charantia (FP and NFP) for 4 weeks. Fermentation affected the physicochemical characterization, monosaccharide composition, molecular weight, and viscosity of Momordica charantia polysaccharides. Treatment with FP significantly ameliorated hyperglycemia, hyperinsulinemia, hyperlipidemia, and oxidative stress in diabetic rats compared with NFP. Moreover, the diversity and abundance of gut microbiota (Lactococcus laudensis and Prevotella loescheii) in diabetic rats were notably increased by treatment with FP in comparison to NFP. Meanwhile, FP-treated diabetic rats exhibited more colonic short-chain fatty acids (SCFAs) and lower pH values than that in NFP-treated rats. Overall, Lactobacillus plantarum-fermentation could enhance the anti-diabetes effects of Momordica charantia polysaccharides in rats by modifying the structure of polysaccharides to optimize gut microbiota and heighten the production of SCFAs.

Study on Dendrobium officinale O-Acetyl-glucomannan (Dendronan). 7. Improving Effects on Colonic Health of Mice.

This research was aimed to study the effect of Dendrobium officinale polysaccharide (Dendronan) on colonic health. Mice were fed Dendronan at doses of 40, 80, and 160 mg/kg body weight for 0, 10, 20, and 30 days, respectively. Results showed that Dendronan, which has a special structure formed by mannose and glucose, rich in O-acetyl groups, exhibited improving effects on colonic and fecal parameters of Balb/c mice. After Dendronan feeding, the content of short-chain fatty acids (SCFAs), colon length and index, and fecal moisture were increased, whereas colonic pH was decreased and defecation time was shortened. All of these changes were significantly different between polysaccharide-treated groups and the control group (p < 0.05). These findings suggested that an adequate intake of Dendronan is beneficial to the process of fermentation and regulation of colonic microenvironment, thus playing a role in the maintenance of colonic health.

In vitro fermentation of the polysaccharides from Cyclocarya paliurus leaves by human fecal inoculums.

In vitro fermentation of polysaccharide from Cyclocarya paliurus leaves by human fecal inoculums was investigated by determining the changes in contents of neutral and reducing sugar and pH value, consumption of monosaccharide and production of short-chain fatty acids (SCFAs). During fermentation, the content of neutral sugar and reducing sugar decreased as fermentation time increased except that the content of reducing sugar increased within the fermentation time 0.5h. The pH value significantly dropped from 7.2 to 6.04. Remarkably, the greatest yields and the fastest consumption of galacturonic acid were found and the yield of glucose and arabinose were relatively high. The dominant SCFAs, which were acetic acid, propionic acid and n-butyric acid, significantly increased. These results showed that polysaccharide was partly fermented, glycosidic bonds with galacturonic acid being more susceptible to be attacked by gut bacteria and galacturonic acid might be deemed as the main producer of acetic acid.

Polysaccharide from seeds of Plantago asiatica L. affects lipid metabolism and colon microbiota of mouse.

Polysaccharide from the seeds of Plantago asiatica L. was given via oral administration to mice (0.4 g/kg body weight, 30 days) to observe its effects on mouse nutrient metabolism and colon microbiota. It was found the polysaccharide intake could lower the apparent absorption of lipid. Total triglyceride, cholesterol, and atherogenic index in blood serum with total lipid and cholesterol levels in liver of polysaccharide group mice were all significantly lower than those of the control group (p < 0.05). Furthermore, the effect of the polysaccharide intake on mouse colon bacterial communities was investigated. Mice from the polysaccharide group showed a higher colon bacterial diversity than the control group. Bacteroides sp., Eubacterium sp., butyrate-producing bacteria Butyrivibrio sp., and probiotics Bifidobacterium bifidum , Lactobacillus fermentum , and Lactobacillus reuteri in mouse colon were all increased after polysaccharide intake. These indicated that the intake of polysaccharide from P. asiatica L. could be beneficial for lipid metabolism and colon microbiota.

Effect of gum arabic on glucose levels and microbial short-chain fatty acid production in white rice porridge model and mixed grain porridge model.

White rice porridge and mixed grain porridge, which are often consumed in many countries, were used as two models to evaluate the effects of gum arabic on glucose levels and microbial short-chain fatty acids (SCFA). Gum arabic was incorporated into the two porridges individually. Apparent viscosity of the two porridges was significantly increased, and their glucose productions during gastrointestinal digestion were notably lowered (p < 0.05). Diffused glucose amount was significantly decreased after gum arabic addition (p < 0.05). Furthermore, blood glucose rise after oral administration of porridges in mice was considerably lowered after fortified with gum arabic (p < 0.05). Microbial SCFA production during in vitro fermentation of porridges was significantly increased after gum arabic addition, which may also have beneficial effects on reducing postprandial glycemic response. Therefore, gum arabic may be a helpful ingredient, which could be added in porridges to have benefits for the reduction of postprandial glycemic response.